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Cryptocurrency News: This Week on Bitfinex, Tether, Coinbase, & More

Cryptocurrency News
On the whole, cryptocurrency prices are down from our previous report on cryptos, with the market slipping on news of an exchange being hacked and a report about Bitcoin manipulation.

However, there have been two bright spots: 1) an official from the U.S. Securities and Exchange Commission (SEC) said that Ethereum is not a security, and 2) Coinbase is expanding its selection of tokens.

Let’s start with the good news.
SEC Says ETH Is Not a Security
Investors have some reason to cheer this week. A high-ranking SEC official told attendees of the Yahoo! All Markets Summit: Crypto that Ethereum and Bitcoin are not.

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Ripple Price Forecast: XRP vs SWIFT, SEC Updates, and More

Ripple vs SWIFT: The War Begins
While most criticisms of XRP do nothing to curb my bullish Ripple price forecast, there is one obstacle that nags at my conscience. Its name is SWIFT.

The Society for Worldwide Interbank Financial Telecommunication (SWIFT) is the king of international payments.

It coordinates wire transfers across 11,000 banks in more than 200 countries and territories, meaning that in order for XRP prices to ascend to $10.00, Ripple needs to launch a successful coup. That is, and always has been, an unwritten part of Ripple’s story.

We’ve seen a lot of progress on that score. In the last three years, Ripple wooed more than 100 financial firms onto its.

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Cryptocurrency Price Forecast: Trust Is Growing, But Prices Are Falling

Trust Is Growing…
Before we get to this week’s cryptocurrency news, analysis, and our cryptocurrency price forecast, I want to share an experience from this past week. I was at home watching the NBA playoffs, trying to ignore the commercials, when a strange advertisement caught my eye.

It followed a tomato from its birth on the vine to its end on the dinner table (where it was served as a bolognese sauce), and a diamond from its dusty beginnings to when it sparkled atop an engagement ring.

The voiceover said: “This is a shipment passed 200 times, transparently tracked from port to port. This is the IBM blockchain.”

Let that sink in—IBM.

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Cryptocurrency Price Forecast: Trust Is Growing, But Prices Are Falling

Cryptocurrency News: Vitalik Buterin Doesn’t Care About Bitcoin ETFs

Cryptocurrency News
While headline numbers look devastating this week, investors might take some solace in knowing that cryptocurrencies found their bottom at roughly $189.8 billion in market cap—that was the low point. Since then, investors put more than $20.0 billion back into the market.

During the rout, Ethereum broke below $300.00 and XRP fell below $0.30, marking yearly lows for both tokens. The same was true down the list of the top 100 biggest cryptos.

Altcoins took the brunt of the hit. BTC Dominance, which reveals how tightly investment is concentrated in Bitcoin, rose from 42.62% to 53.27% in just one month, showing that investors either fled altcoins at higher.

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Cryptocurrency News: Vitalik Buterin Doesn’t Care About Bitcoin ETFs

Cryptocurrency News: New Exchanges Could Boost Crypto Liquidity

Cryptocurrency News
Even though the cryptocurrency news was upbeat in recent days, the market tumbled after the U.S. Securities and Exchange Commission (SEC) rejected calls for a Bitcoin (BTC) exchange-traded fund (ETF).

That news came as a blow to investors, many of whom believe the ETF would open the cryptocurrency industry up to pension funds and other institutional investors. This would create a massive tailwind for cryptos, they say.

So it only follows that a rejection of the Bitcoin ETF should send cryptos tumbling, correct? Well, maybe you can follow that logic. To me, it seems like a dramatic overreaction.

I understand that legitimizing cryptos is important. But.

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Cryptocurrency News: Bitcoin ETF Rejection, AMD Microchip Sales, and Hedge Funds

Cryptocurrency News
Although cryptocurrency prices were heating up last week (Bitcoin, especially), regulators poured cold water on the rally by rejecting calls for a Bitcoin exchange-traded fund (ETF). This is the second time that the proposal fell on deaf ears. (More on that below.)

Crypto mining ran into similar trouble, as you can see from Advanced Micro Devices, Inc.‘s (NASDAQ:AMD) most recent quarterly earnings. However, it wasn’t all bad news. Investors should, for instance, be cheering the fact that hedge funds are ramping up their involvement in cryptocurrency markets.

Without further ado, here are those stories in greater detail.
ETF Rejection.

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Cryptocurrency News: What You Need to Know This Week

Cryptocurrency News
Cryptocurrencies traded sideways since our last report on cryptos. However, I noticed something interesting when playing around with Yahoo! Finance’s cryptocurrency screener: There are profitable pockets in this market.

Incidentally, Yahoo’s screener is far superior to the one on CoinMarketCap, so if you’re looking to compare digital assets, I highly recommend it.

But let’s get back to my epiphany.

In the last month, at one point or another, most crypto assets on our favorites list saw double-digit increases. It’s true that each upswing was followed by a hard crash, but investors who rode the trend would have made a.

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Cryptocurrency News: XRP Validators, Malta, and Practical Tokens

Cryptocurrency News & Market Summary
Investors finally saw some light at the end of the tunnel last week, with cryptos soaring across the board. No one quite knows what kicked off the rally—as it could have been any of the stories we discuss below—but the net result was positive.

Of course, prices won’t stay on this rocket ride forever. I expect to see a resurgence of volatility in short order, because the market is moving as a single unit. Everything is rising in tandem.

This tells me that investors are simply “buying the dip” rather than identifying which cryptos have enough real-world value to outlive the crash.

So if you want to know when.

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Cryptocurrency News: XRP Validators, Malta, and Practical Tokens

Gene therapy – Wikipedia

In the medicine field, gene therapy (also called human gene transfer) is the therapeutic delivery of nucleic acid into a patient’s cells as a drug to treat disease.[1][2] The first attempt at modifying human DNA was performed in 1980 by Martin Cline, but the first successful nuclear gene transfer in humans, approved by the National Institutes of Health, was performed in May 1989.[3] The first therapeutic use of gene transfer as well as the first direct insertion of human DNA into the nuclear genome was performed by French Anderson in a trial starting in September 1990.

Between 1989 and February 2016, over 2,300 clinical trials had been conducted, more than half of them in phase I.[4]

Not all medical procedures that introduce alterations to a patient’s genetic makeup can be considered gene therapy. Bone marrow transplantation and organ transplants in general have been found to introduce foreign DNA into patients.[5] Gene therapy is defined by the precision of the procedure and the intention of direct therapeutic effect.

Gene therapy was conceptualized in 1972, by authors who urged caution before commencing human gene therapy studies.

The first attempt, an unsuccessful one, at gene therapy (as well as the first case of medical transfer of foreign genes into humans not counting organ transplantation) was performed by Martin Cline on 10 July 1980.[6][7] Cline claimed that one of the genes in his patients was active six months later, though he never published this data or had it verified[8] and even if he is correct, it’s unlikely it produced any significant beneficial effects treating beta-thalassemia.

After extensive research on animals throughout the 1980s and a 1989 bacterial gene tagging trial on humans, the first gene therapy widely accepted as a success was demonstrated in a trial that started on 14 September 1990, when Ashi DeSilva was treated for ADA-SCID.[9]

The first somatic treatment that produced a permanent genetic change was performed in 1993.[citation needed]

Gene therapy is a way to fix a genetic problem at its source. The polymers are either translated into proteins, interfere with target gene expression, or possibly correct genetic mutations.

The most common form uses DNA that encodes a functional, therapeutic gene to replace a mutated gene. The polymer molecule is packaged within a “vector”, which carries the molecule inside cells.

Early clinical failures led to dismissals of gene therapy. Clinical successes since 2006 regained researchers’ attention, although as of 2014[update], it was still largely an experimental technique.[10] These include treatment of retinal diseases Leber’s congenital amaurosis[11][12][13][14] and choroideremia,[15] X-linked SCID,[16] ADA-SCID,[17][18] adrenoleukodystrophy,[19] chronic lymphocytic leukemia (CLL),[20] acute lymphocytic leukemia (ALL),[21] multiple myeloma,[22] haemophilia,[18] and Parkinson’s disease.[23] Between 2013 and April 2014, US companies invested over $600 million in the field.[24]

The first commercial gene therapy, Gendicine, was approved in China in 2003 for the treatment of certain cancers.[25] In 2011 Neovasculgen was registered in Russia as the first-in-class gene-therapy drug for treatment of peripheral artery disease, including critical limb ischemia.[26]In 2012 Glybera, a treatment for a rare inherited disorder, became the first treatment to be approved for clinical use in either Europe or the United States after its endorsement by the European Commission.[10][27]

Following early advances in genetic engineering of bacteria, cells, and small animals, scientists started considering how to apply it to medicine. Two main approaches were considered replacing or disrupting defective genes.[28] Scientists focused on diseases caused by single-gene defects, such as cystic fibrosis, haemophilia, muscular dystrophy, thalassemia, and sickle cell anemia. Glybera treats one such disease, caused by a defect in lipoprotein lipase.[27]

DNA must be administered, reach the damaged cells, enter the cell and either express or disrupt a protein.[29] Multiple delivery techniques have been explored. The initial approach incorporated DNA into an engineered virus to deliver the DNA into a chromosome.[30][31] Naked DNA approaches have also been explored, especially in the context of vaccine development.[32]

Generally, efforts focused on administering a gene that causes a needed protein to be expressed. More recently, increased understanding of nuclease function has led to more direct DNA editing, using techniques such as zinc finger nucleases and CRISPR. The vector incorporates genes into chromosomes. The expressed nucleases then knock out and replace genes in the chromosome. As of 2014[update] these approaches involve removing cells from patients, editing a chromosome and returning the transformed cells to patients.[33]

Gene editing is a potential approach to alter the human genome to treat genetic diseases,[34] viral diseases,[35] and cancer.[36] As of 2016[update] these approaches were still years from being medicine.[37][38]

Gene therapy may be classified into two types:

In somatic cell gene therapy (SCGT), the therapeutic genes are transferred into any cell other than a gamete, germ cell, gametocyte, or undifferentiated stem cell. Any such modifications affect the individual patient only, and are not inherited by offspring. Somatic gene therapy represents mainstream basic and clinical research, in which therapeutic DNA (either integrated in the genome or as an external episome or plasmid) is used to treat disease.

Over 600 clinical trials utilizing SCGT are underway[when?] in the US. Most focus on severe genetic disorders, including immunodeficiencies, haemophilia, thalassaemia, and cystic fibrosis. Such single gene disorders are good candidates for somatic cell therapy. The complete correction of a genetic disorder or the replacement of multiple genes is not yet possible. Only a few of the trials are in the advanced stages.[39]

In germline gene therapy (GGT), germ cells (sperm or egg cells) are modified by the introduction of functional genes into their genomes. Modifying a germ cell causes all the organism’s cells to contain the modified gene. The change is therefore heritable and passed on to later generations. Australia, Canada, Germany, Israel, Switzerland, and the Netherlands[40] prohibit GGT for application in human beings, for technical and ethical reasons, including insufficient knowledge about possible risks to future generations[40] and higher risks versus SCGT.[41] The US has no federal controls specifically addressing human genetic modification (beyond FDA regulations for therapies in general).[40][42][43][44]

The delivery of DNA into cells can be accomplished by multiple methods. The two major classes are recombinant viruses (sometimes called biological nanoparticles or viral vectors) and naked DNA or DNA complexes (non-viral methods).

In order to replicate, viruses introduce their genetic material into the host cell, tricking the host’s cellular machinery into using it as blueprints for viral proteins. Retroviruses go a stage further by having their genetic material copied into the genome of the host cell. Scientists exploit this by substituting a virus’s genetic material with therapeutic DNA. (The term ‘DNA’ may be an oversimplification, as some viruses contain RNA, and gene therapy could take this form as well.) A number of viruses have been used for human gene therapy, including retroviruses, adenoviruses, herpes simplex, vaccinia, and adeno-associated virus.[4] Like the genetic material (DNA or RNA) in viruses, therapeutic DNA can be designed to simply serve as a temporary blueprint that is degraded naturally or (at least theoretically) to enter the host’s genome, becoming a permanent part of the host’s DNA in infected cells.

Non-viral methods present certain advantages over viral methods, such as large scale production and low host immunogenicity. However, non-viral methods initially produced lower levels of transfection and gene expression, and thus lower therapeutic efficacy. Later technology remedied this deficiency.[citation needed]

Methods for non-viral gene therapy include the injection of naked DNA, electroporation, the gene gun, sonoporation, magnetofection, the use of oligonucleotides, lipoplexes, dendrimers, and inorganic nanoparticles.

Some of the unsolved problems include:

Three patients’ deaths have been reported in gene therapy trials, putting the field under close scrutiny. The first was that of Jesse Gelsinger, who died in 1999 because of immune rejection response.[51] One X-SCID patient died of leukemia in 2003.[9] In 2007, a rheumatoid arthritis patient died from an infection; the subsequent investigation concluded that the death was not related to gene therapy.[52]

In 1972 Friedmann and Roblin authored a paper in Science titled “Gene therapy for human genetic disease?”[53] Rogers (1970) was cited for proposing that exogenous good DNA be used to replace the defective DNA in those who suffer from genetic defects.[54]

In 1984 a retrovirus vector system was designed that could efficiently insert foreign genes into mammalian chromosomes.[55]

The first approved gene therapy clinical research in the US took place on 14 September 1990, at the National Institutes of Health (NIH), under the direction of William French Anderson.[56] Four-year-old Ashanti DeSilva received treatment for a genetic defect that left her with ADA-SCID, a severe immune system deficiency. The defective gene of the patient’s blood cells was replaced by the functional variant. Ashantis immune system was partially restored by the therapy. Production of the missing enzyme was temporarily stimulated, but the new cells with functional genes were not generated. She led a normal life only with the regular injections performed every two months. The effects were successful, but temporary.[57]

Cancer gene therapy was introduced in 1992/93 (Trojan et al. 1993).[58] The treatment of glioblastoma multiforme, the malignant brain tumor whose outcome is always fatal, was done using a vector expressing antisense IGF-I RNA (clinical trial approved by NIH protocolno.1602 November 24, 1993,[59] and by the FDA in 1994). This therapy also represents the beginning of cancer immunogene therapy, a treatment which proves to be effective due to the anti-tumor mechanism of IGF-I antisense, which is related to strong immune and apoptotic phenomena.

In 1992 Claudio Bordignon, working at the Vita-Salute San Raffaele University, performed the first gene therapy procedure using hematopoietic stem cells as vectors to deliver genes intended to correct hereditary diseases.[60] In 2002 this work led to the publication of the first successful gene therapy treatment for adenosine deaminase deficiency (ADA-SCID). The success of a multi-center trial for treating children with SCID (severe combined immune deficiency or “bubble boy” disease) from 2000 and 2002, was questioned when two of the ten children treated at the trial’s Paris center developed a leukemia-like condition. Clinical trials were halted temporarily in 2002, but resumed after regulatory review of the protocol in the US, the United Kingdom, France, Italy, and Germany.[61]

In 1993 Andrew Gobea was born with SCID following prenatal genetic screening. Blood was removed from his mother’s placenta and umbilical cord immediately after birth, to acquire stem cells. The allele that codes for adenosine deaminase (ADA) was obtained and inserted into a retrovirus. Retroviruses and stem cells were mixed, after which the viruses inserted the gene into the stem cell chromosomes. Stem cells containing the working ADA gene were injected into Andrew’s blood. Injections of the ADA enzyme were also given weekly. For four years T cells (white blood cells), produced by stem cells, made ADA enzymes using the ADA gene. After four years more treatment was needed.[62]

Jesse Gelsinger’s death in 1999 impeded gene therapy research in the US.[63][64] As a result, the FDA suspended several clinical trials pending the reevaluation of ethical and procedural practices.[65]

The modified cancer gene therapy strategy of antisense IGF-I RNA (NIH n 1602)[59] using antisense / triple helix anti-IGF-I approach was registered in 2002 by Wiley gene therapy clinical trial – n 635 and 636. The approach has shown promising results in the treatment of six different malignant tumors: glioblastoma, cancers of liver, colon, prostate, uterus, and ovary (Collaborative NATO Science Programme on Gene Therapy USA, France, Poland n LST 980517 conducted by J. Trojan) (Trojan et al., 2012). This anti-gene antisense/triple helix therapy has proven to be efficient, due to the mechanism stopping simultaneously IGF-I expression on translation and transcription levels, strengthening anti-tumor immune and apoptotic phenomena.

Sickle-cell disease can be treated in mice.[66] The mice which have essentially the same defect that causes human cases used a viral vector to induce production of fetal hemoglobin (HbF), which normally ceases to be produced shortly after birth. In humans, the use of hydroxyurea to stimulate the production of HbF temporarily alleviates sickle cell symptoms. The researchers demonstrated this treatment to be a more permanent means to increase therapeutic HbF production.[67]

A new gene therapy approach repaired errors in messenger RNA derived from defective genes. This technique has the potential to treat thalassaemia, cystic fibrosis and some cancers.[68]

Researchers created liposomes 25 nanometers across that can carry therapeutic DNA through pores in the nuclear membrane.[69]

In 2003 a research team inserted genes into the brain for the first time. They used liposomes coated in a polymer called polyethylene glycol, which unlike viral vectors, are small enough to cross the bloodbrain barrier.[70]

Short pieces of double-stranded RNA (short, interfering RNAs or siRNAs) are used by cells to degrade RNA of a particular sequence. If a siRNA is designed to match the RNA copied from a faulty gene, then the abnormal protein product of that gene will not be produced.[71]

Gendicine is a cancer gene therapy that delivers the tumor suppressor gene p53 using an engineered adenovirus. In 2003, it was approved in China for the treatment of head and neck squamous cell carcinoma.[25]

In March researchers announced the successful use of gene therapy to treat two adult patients for X-linked chronic granulomatous disease, a disease which affects myeloid cells and damages the immune system. The study is the first to show that gene therapy can treat the myeloid system.[72]

In May a team reported a way to prevent the immune system from rejecting a newly delivered gene.[73] Similar to organ transplantation, gene therapy has been plagued by this problem. The immune system normally recognizes the new gene as foreign and rejects the cells carrying it. The research utilized a newly uncovered network of genes regulated by molecules known as microRNAs. This natural function selectively obscured their therapeutic gene in immune system cells and protected it from discovery. Mice infected with the gene containing an immune-cell microRNA target sequence did not reject the gene.

In August scientists successfully treated metastatic melanoma in two patients using killer T cells genetically retargeted to attack the cancer cells.[74]

In November researchers reported on the use of VRX496, a gene-based immunotherapy for the treatment of HIV that uses a lentiviral vector to deliver an antisense gene against the HIV envelope. In a phase I clinical trial, five subjects with chronic HIV infection who had failed to respond to at least two antiretroviral regimens were treated. A single intravenous infusion of autologous CD4 T cells genetically modified with VRX496 was well tolerated. All patients had stable or decreased viral load; four of the five patients had stable or increased CD4 T cell counts. All five patients had stable or increased immune response to HIV antigens and other pathogens. This was the first evaluation of a lentiviral vector administered in a US human clinical trial.[75][76]

In May researchers announced the first gene therapy trial for inherited retinal disease. The first operation was carried out on a 23-year-old British male, Robert Johnson, in early 2007.[77]

Leber’s congenital amaurosis is an inherited blinding disease caused by mutations in the RPE65 gene. The results of a small clinical trial in children were published in April.[11] Delivery of recombinant adeno-associated virus (AAV) carrying RPE65 yielded positive results. In May two more groups reported positive results in independent clinical trials using gene therapy to treat the condition. In all three clinical trials, patients recovered functional vision without apparent side-effects.[11][12][13][14]

In September researchers were able to give trichromatic vision to squirrel monkeys.[78] In November 2009, researchers halted a fatal genetic disorder called adrenoleukodystrophy in two children using a lentivirus vector to deliver a functioning version of ABCD1, the gene that is mutated in the disorder.[79]

An April paper reported that gene therapy addressed achromatopsia (color blindness) in dogs by targeting cone photoreceptors. Cone function and day vision were restored for at least 33 months in two young specimens. The therapy was less efficient for older dogs.[80]

In September it was announced that an 18-year-old male patient in France with beta-thalassemia major had been successfully treated.[81] Beta-thalassemia major is an inherited blood disease in which beta haemoglobin is missing and patients are dependent on regular lifelong blood transfusions.[82] The technique used a lentiviral vector to transduce the human -globin gene into purified blood and marrow cells obtained from the patient in June 2007.[83] The patient’s haemoglobin levels were stable at 9 to 10 g/dL. About a third of the hemoglobin contained the form introduced by the viral vector and blood transfusions were not needed.[83][84] Further clinical trials were planned.[85] Bone marrow transplants are the only cure for thalassemia, but 75% of patients do not find a matching donor.[84]

Cancer immunogene therapy using modified antigene, antisense/triple helix approach was introduced in South America in 2010/11 in La Sabana University, Bogota (Ethical Committee 14 December 2010, no P-004-10). Considering the ethical aspect of gene diagnostic and gene therapy targeting IGF-I, the IGF-I expressing tumors i.e. lung and epidermis cancers were treated (Trojan et al. 2016).[86][87]

In 2007 and 2008, a man (Timothy Ray Brown) was cured of HIV by repeated hematopoietic stem cell transplantation (see also allogeneic stem cell transplantation, allogeneic bone marrow transplantation, allotransplantation) with double-delta-32 mutation which disables the CCR5 receptor. This cure was accepted by the medical community in 2011.[88] It required complete ablation of existing bone marrow, which is very debilitating.

In August two of three subjects of a pilot study were confirmed to have been cured from chronic lymphocytic leukemia (CLL). The therapy used genetically modified T cells to attack cells that expressed the CD19 protein to fight the disease.[20] In 2013, the researchers announced that 26 of 59 patients had achieved complete remission and the original patient had remained tumor-free.[89]

Human HGF plasmid DNA therapy of cardiomyocytes is being examined as a potential treatment for coronary artery disease as well as treatment for the damage that occurs to the heart after myocardial infarction.[90][91]

In 2011 Neovasculgen was registered in Russia as the first-in-class gene-therapy drug for treatment of peripheral artery disease, including critical limb ischemia; it delivers the gene encoding for VEGF.[92][26] Neovasculogen is a plasmid encoding the CMV promoter and the 165 amino acid form of VEGF.[93][94]

The FDA approved Phase 1 clinical trials on thalassemia major patients in the US for 10 participants in July.[95] The study was expected to continue until 2015.[85]

In July 2012, the European Medicines Agency recommended approval of a gene therapy treatment for the first time in either Europe or the United States. The treatment used Alipogene tiparvovec (Glybera) to compensate for lipoprotein lipase deficiency, which can cause severe pancreatitis.[96] The recommendation was endorsed by the European Commission in November 2012[10][27][97][98] and commercial rollout began in late 2014.[99] Alipogene tiparvovec was expected to cost around $1.6 million per treatment in 2012,[100] revised to $1 million in 2015,[101] making it the most expensive medicine in the world at the time.[102] As of 2016[update], only one person had been treated with drug.[103]

In December 2012, it was reported that 10 of 13 patients with multiple myeloma were in remission “or very close to it” three months after being injected with a treatment involving genetically engineered T cells to target proteins NY-ESO-1 and LAGE-1, which exist only on cancerous myeloma cells.[22]

In March researchers reported that three of five adult subjects who had acute lymphocytic leukemia (ALL) had been in remission for five months to two years after being treated with genetically modified T cells which attacked cells with CD19 genes on their surface, i.e. all B-cells, cancerous or not. The researchers believed that the patients’ immune systems would make normal T-cells and B-cells after a couple of months. They were also given bone marrow. One patient relapsed and died and one died of a blood clot unrelated to the disease.[21]

Following encouraging Phase 1 trials, in April, researchers announced they were starting Phase 2 clinical trials (called CUPID2 and SERCA-LVAD) on 250 patients[104] at several hospitals to combat heart disease. The therapy was designed to increase the levels of SERCA2, a protein in heart muscles, improving muscle function.[105] The FDA granted this a Breakthrough Therapy Designation to accelerate the trial and approval process.[106] In 2016 it was reported that no improvement was found from the CUPID 2 trial.[107]

In July researchers reported promising results for six children with two severe hereditary diseases had been treated with a partially deactivated lentivirus to replace a faulty gene and after 732 months. Three of the children had metachromatic leukodystrophy, which causes children to lose cognitive and motor skills.[108] The other children had Wiskott-Aldrich syndrome, which leaves them to open to infection, autoimmune diseases, and cancer.[109] Follow up trials with gene therapy on another six children with Wiskott-Aldrich syndrome were also reported as promising.[110][111]

In October researchers reported that two children born with adenosine deaminase severe combined immunodeficiency disease (ADA-SCID) had been treated with genetically engineered stem cells 18 months previously and that their immune systems were showing signs of full recovery. Another three children were making progress.[18] In 2014 a further 18 children with ADA-SCID were cured by gene therapy.[112] ADA-SCID children have no functioning immune system and are sometimes known as “bubble children.”[18]

Also in October researchers reported that they had treated six hemophilia sufferers in early 2011 using an adeno-associated virus. Over two years later all six were producing clotting factor.[18][113]

In January researchers reported that six choroideremia patients had been treated with adeno-associated virus with a copy of REP1. Over a six-month to two-year period all had improved their sight.[114][115] By 2016, 32 patients had been treated with positive results and researchers were hopeful the treatment would be long-lasting.[15] Choroideremia is an inherited genetic eye disease with no approved treatment, leading to loss of sight.

In March researchers reported that 12 HIV patients had been treated since 2009 in a trial with a genetically engineered virus with a rare mutation (CCR5 deficiency) known to protect against HIV with promising results.[116][117]

Clinical trials of gene therapy for sickle cell disease were started in 2014.[118][119] There is a need for high quality randomised controlled trials assessing the risks and benefits involved with gene therapy for people with sickle cell disease.[120]

In February LentiGlobin BB305, a gene therapy treatment undergoing clinical trials for treatment of beta thalassemia gained FDA “breakthrough” status after several patients were able to forgo the frequent blood transfusions usually required to treat the disease.[121]

In March researchers delivered a recombinant gene encoding a broadly neutralizing antibody into monkeys infected with simian HIV; the monkeys’ cells produced the antibody, which cleared them of HIV. The technique is named immunoprophylaxis by gene transfer (IGT). Animal tests for antibodies to ebola, malaria, influenza, and hepatitis were underway.[122][123]

In March, scientists, including an inventor of CRISPR, Jennifer Doudna, urged a worldwide moratorium on germline gene therapy, writing “scientists should avoid even attempting, in lax jurisdictions, germline genome modification for clinical application in humans” until the full implications “are discussed among scientific and governmental organizations”.[124][125][126][127]

In October, researchers announced that they had treated a baby girl, Layla Richards, with an experimental treatment using donor T-cells genetically engineered using TALEN to attack cancer cells. One year after the treatment she was still free of her cancer (a highly aggressive form of acute lymphoblastic leukaemia [ALL]).[128] Children with highly aggressive ALL normally have a very poor prognosis and Layla’s disease had been regarded as terminal before the treatment.[129]

In December, scientists of major world academies called for a moratorium on inheritable human genome edits, including those related to CRISPR-Cas9 technologies[130] but that basic research including embryo gene editing should continue.[131]

In April the Committee for Medicinal Products for Human Use of the European Medicines Agency endorsed a gene therapy treatment called Strimvelis[132][133] and the European Commission approved it in June.[134] This treats children born with adenosine deaminase deficiency and who have no functioning immune system. This was the second gene therapy treatment to be approved in Europe.[135]

In October, Chinese scientists reported they had started a trial to genetically modify T-cells from 10 adult patients with lung cancer and reinject the modified T-cells back into their bodies to attack the cancer cells. The T-cells had the PD-1 protein (which stops or slows the immune response) removed using CRISPR-Cas9.[136][137]

A 2016 Cochrane systematic review looking at data from four trials on topical cystic fibrosis transmembrane conductance regulator (CFTR) gene therapy does not support its clinical use as a mist inhaled into the lungs to treat cystic fibrosis patients with lung infections. One of the four trials did find weak evidence that liposome-based CFTR gene transfer therapy may lead to a small respiratory improvement for people with CF. This weak evidence is not enough to make a clinical recommendation for routine CFTR gene therapy.[138]

In February Kite Pharma announced results from a clinical trial of CAR-T cells in around a hundred people with advanced Non-Hodgkin lymphoma.[139]

In March, French scientists reported on clinical research of gene therapy to treat sickle-cell disease.[140]

In August, the FDA approved tisagenlecleucel for acute lymphoblastic leukemia.[141] Tisagenlecleucel is an adoptive cell transfer therapy for B-cell acute lymphoblastic leukemia; T cells from a person with cancer are removed, genetically engineered to make a specific T-cell receptor (a chimeric T cell receptor, or “CAR-T”) that reacts to the cancer, and are administered back to the person. The T cells are engineered to target a protein called CD19 that is common on B cells. This is the first form of gene therapy to be approved in the United States. In October, a similar therapy called axicabtagene ciloleucel was approved for non-Hodgkin lymphoma.[142]

In December the results of using an adeno-associated virus with blood clotting factor VIII to treat nine haemophilia A patients were published. Six of the seven patients on the high dose regime increased the level of the blood clotting VIII to normal levels. The low and medium dose regimes had no effect on the patient’s blood clotting levels.[143][144]

In December, the FDA approved Luxturna, the first in vivo gene therapy, for the treatment of blindness due to Leber’s congenital amaurosis.[145] The price of this treatment was 850,000 US dollars for both eyes.[146][147]

Speculated uses for gene therapy include:

Gene therapy techniques have the potential to provide alternative treatments for those with infertility. Recently, successful experimentation on mice has proven that fertility can be restored by using the gene therapy method, CRISPR.[148] Spermatogenical stem cells from another organism were transplanted into the testes of an infertile male mouse. The stem cells re-established spermatogenesis and fertility.[149]

Athletes might adopt gene therapy technologies to improve their performance.[150] Gene doping is not known to occur, but multiple gene therapies may have such effects. Kayser et al. argue that gene doping could level the playing field if all athletes receive equal access. Critics claim that any therapeutic intervention for non-therapeutic/enhancement purposes compromises the ethical foundations of medicine and sports.[151]

Genetic engineering could be used to cure diseases, but also to change physical appearance, metabolism, and even improve physical capabilities and mental faculties such as memory and intelligence. Ethical claims about germline engineering include beliefs that every fetus has a right to remain genetically unmodified, that parents hold the right to genetically modify their offspring, and that every child has the right to be born free of preventable diseases.[152][153][154] For parents, genetic engineering could be seen as another child enhancement technique to add to diet, exercise, education, training, cosmetics, and plastic surgery.[155][156] Another theorist claims that moral concerns limit but do not prohibit germline engineering.[157]

Possible regulatory schemes include a complete ban, provision to everyone, or professional self-regulation. The American Medical Associations Council on Ethical and Judicial Affairs stated that “genetic interventions to enhance traits should be considered permissible only in severely restricted situations: (1) clear and meaningful benefits to the fetus or child; (2) no trade-off with other characteristics or traits; and (3) equal access to the genetic technology, irrespective of income or other socioeconomic characteristics.”[158]

As early in the history of biotechnology as 1990, there have been scientists opposed to attempts to modify the human germline using these new tools,[159] and such concerns have continued as technology progressed.[160][161] With the advent of new techniques like CRISPR, in March 2015 a group of scientists urged a worldwide moratorium on clinical use of gene editing technologies to edit the human genome in a way that can be inherited.[124][125][126][127] In April 2015, researchers sparked controversy when they reported results of basic research to edit the DNA of non-viable human embryos using CRISPR.[148][162] A committee of the American National Academy of Sciences and National Academy of Medicine gave qualified support to human genome editing in 2017[163][164] once answers have been found to safety and efficiency problems “but only for serious conditions under stringent oversight.”[165]

Regulations covering genetic modification are part of general guidelines about human-involved biomedical research. There are no international treaties which are legally binding in this area, but there are recommendations for national laws from various bodies.

The Helsinki Declaration (Ethical Principles for Medical Research Involving Human Subjects) was amended by the World Medical Association’s General Assembly in 2008. This document provides principles physicians and researchers must consider when involving humans as research subjects. The Statement on Gene Therapy Research initiated by the Human Genome Organization (HUGO) in 2001 provides a legal baseline for all countries. HUGOs document emphasizes human freedom and adherence to human rights, and offers recommendations for somatic gene therapy, including the importance of recognizing public concerns about such research.[166]

No federal legislation lays out protocols or restrictions about human genetic engineering. This subject is governed by overlapping regulations from local and federal agencies, including the Department of Health and Human Services, the FDA and NIH’s Recombinant DNA Advisory Committee. Researchers seeking federal funds for an investigational new drug application, (commonly the case for somatic human genetic engineering,) must obey international and federal guidelines for the protection of human subjects.[167]

NIH serves as the main gene therapy regulator for federally funded research. Privately funded research is advised to follow these regulations. NIH provides funding for research that develops or enhances genetic engineering techniques and to evaluate the ethics and quality in current research. The NIH maintains a mandatory registry of human genetic engineering research protocols that includes all federally funded projects.

An NIH advisory committee published a set of guidelines on gene manipulation.[168] The guidelines discuss lab safety as well as human test subjects and various experimental types that involve genetic changes. Several sections specifically pertain to human genetic engineering, including Section III-C-1. This section describes required review processes and other aspects when seeking approval to begin clinical research involving genetic transfer into a human patient.[169] The protocol for a gene therapy clinical trial must be approved by the NIH’s Recombinant DNA Advisory Committee prior to any clinical trial beginning; this is different from any other kind of clinical trial.[168]

As with other kinds of drugs, the FDA regulates the quality and safety of gene therapy products and supervises how these products are used clinically. Therapeutic alteration of the human genome falls under the same regulatory requirements as any other medical treatment. Research involving human subjects, such as clinical trials, must be reviewed and approved by the FDA and an Institutional Review Board.[170][171]

Gene therapy is the basis for the plotline of the film I Am Legend[172] and the TV show Will Gene Therapy Change the Human Race?.[173] In 1994, gene therapy was a plot element in The Erlenmeyer Flask, The X-Files’ first-season finale. It is also used in Stargate as a means of allowing humans to use Ancient technology.[174]

Original post:

Gene therapy – Wikipedia

Gene therapy – Wikipedia

In the medicine field, gene therapy (also called human gene transfer) is the therapeutic delivery of nucleic acid into a patient’s cells as a drug to treat disease.[1][2] The first attempt at modifying human DNA was performed in 1980 by Martin Cline, but the first successful nuclear gene transfer in humans, approved by the National Institutes of Health, was performed in May 1989.[3] The first therapeutic use of gene transfer as well as the first direct insertion of human DNA into the nuclear genome was performed by French Anderson in a trial starting in September 1990.

Between 1989 and February 2016, over 2,300 clinical trials had been conducted, more than half of them in phase I.[4]

Not all medical procedures that introduce alterations to a patient’s genetic makeup can be considered gene therapy. Bone marrow transplantation and organ transplants in general have been found to introduce foreign DNA into patients.[5] Gene therapy is defined by the precision of the procedure and the intention of direct therapeutic effect.

Gene therapy was conceptualized in 1972, by authors who urged caution before commencing human gene therapy studies.

The first attempt, an unsuccessful one, at gene therapy (as well as the first case of medical transfer of foreign genes into humans not counting organ transplantation) was performed by Martin Cline on 10 July 1980.[6][7] Cline claimed that one of the genes in his patients was active six months later, though he never published this data or had it verified[8] and even if he is correct, it’s unlikely it produced any significant beneficial effects treating beta-thalassemia.

After extensive research on animals throughout the 1980s and a 1989 bacterial gene tagging trial on humans, the first gene therapy widely accepted as a success was demonstrated in a trial that started on 14 September 1990, when Ashi DeSilva was treated for ADA-SCID.[9]

The first somatic treatment that produced a permanent genetic change was performed in 1993.[citation needed]

Gene therapy is a way to fix a genetic problem at its source. The polymers are either translated into proteins, interfere with target gene expression, or possibly correct genetic mutations.

The most common form uses DNA that encodes a functional, therapeutic gene to replace a mutated gene. The polymer molecule is packaged within a “vector”, which carries the molecule inside cells.

Early clinical failures led to dismissals of gene therapy. Clinical successes since 2006 regained researchers’ attention, although as of 2014[update], it was still largely an experimental technique.[10] These include treatment of retinal diseases Leber’s congenital amaurosis[11][12][13][14] and choroideremia,[15] X-linked SCID,[16] ADA-SCID,[17][18] adrenoleukodystrophy,[19] chronic lymphocytic leukemia (CLL),[20] acute lymphocytic leukemia (ALL),[21] multiple myeloma,[22] haemophilia,[18] and Parkinson’s disease.[23] Between 2013 and April 2014, US companies invested over $600 million in the field.[24]

The first commercial gene therapy, Gendicine, was approved in China in 2003 for the treatment of certain cancers.[25] In 2011 Neovasculgen was registered in Russia as the first-in-class gene-therapy drug for treatment of peripheral artery disease, including critical limb ischemia.[26]In 2012 Glybera, a treatment for a rare inherited disorder, became the first treatment to be approved for clinical use in either Europe or the United States after its endorsement by the European Commission.[10][27]

Following early advances in genetic engineering of bacteria, cells, and small animals, scientists started considering how to apply it to medicine. Two main approaches were considered replacing or disrupting defective genes.[28] Scientists focused on diseases caused by single-gene defects, such as cystic fibrosis, haemophilia, muscular dystrophy, thalassemia, and sickle cell anemia. Glybera treats one such disease, caused by a defect in lipoprotein lipase.[27]

DNA must be administered, reach the damaged cells, enter the cell and either express or disrupt a protein.[29] Multiple delivery techniques have been explored. The initial approach incorporated DNA into an engineered virus to deliver the DNA into a chromosome.[30][31] Naked DNA approaches have also been explored, especially in the context of vaccine development.[32]

Generally, efforts focused on administering a gene that causes a needed protein to be expressed. More recently, increased understanding of nuclease function has led to more direct DNA editing, using techniques such as zinc finger nucleases and CRISPR. The vector incorporates genes into chromosomes. The expressed nucleases then knock out and replace genes in the chromosome. As of 2014[update] these approaches involve removing cells from patients, editing a chromosome and returning the transformed cells to patients.[33]

Gene editing is a potential approach to alter the human genome to treat genetic diseases,[34] viral diseases,[35] and cancer.[36] As of 2016[update] these approaches were still years from being medicine.[37][38]

Gene therapy may be classified into two types:

In somatic cell gene therapy (SCGT), the therapeutic genes are transferred into any cell other than a gamete, germ cell, gametocyte, or undifferentiated stem cell. Any such modifications affect the individual patient only, and are not inherited by offspring. Somatic gene therapy represents mainstream basic and clinical research, in which therapeutic DNA (either integrated in the genome or as an external episome or plasmid) is used to treat disease.

Over 600 clinical trials utilizing SCGT are underway[when?] in the US. Most focus on severe genetic disorders, including immunodeficiencies, haemophilia, thalassaemia, and cystic fibrosis. Such single gene disorders are good candidates for somatic cell therapy. The complete correction of a genetic disorder or the replacement of multiple genes is not yet possible. Only a few of the trials are in the advanced stages.[39]

In germline gene therapy (GGT), germ cells (sperm or egg cells) are modified by the introduction of functional genes into their genomes. Modifying a germ cell causes all the organism’s cells to contain the modified gene. The change is therefore heritable and passed on to later generations. Australia, Canada, Germany, Israel, Switzerland, and the Netherlands[40] prohibit GGT for application in human beings, for technical and ethical reasons, including insufficient knowledge about possible risks to future generations[40] and higher risks versus SCGT.[41] The US has no federal controls specifically addressing human genetic modification (beyond FDA regulations for therapies in general).[40][42][43][44]

The delivery of DNA into cells can be accomplished by multiple methods. The two major classes are recombinant viruses (sometimes called biological nanoparticles or viral vectors) and naked DNA or DNA complexes (non-viral methods).

In order to replicate, viruses introduce their genetic material into the host cell, tricking the host’s cellular machinery into using it as blueprints for viral proteins. Retroviruses go a stage further by having their genetic material copied into the genome of the host cell. Scientists exploit this by substituting a virus’s genetic material with therapeutic DNA. (The term ‘DNA’ may be an oversimplification, as some viruses contain RNA, and gene therapy could take this form as well.) A number of viruses have been used for human gene therapy, including retroviruses, adenoviruses, herpes simplex, vaccinia, and adeno-associated virus.[4] Like the genetic material (DNA or RNA) in viruses, therapeutic DNA can be designed to simply serve as a temporary blueprint that is degraded naturally or (at least theoretically) to enter the host’s genome, becoming a permanent part of the host’s DNA in infected cells.

Non-viral methods present certain advantages over viral methods, such as large scale production and low host immunogenicity. However, non-viral methods initially produced lower levels of transfection and gene expression, and thus lower therapeutic efficacy. Later technology remedied this deficiency.[citation needed]

Methods for non-viral gene therapy include the injection of naked DNA, electroporation, the gene gun, sonoporation, magnetofection, the use of oligonucleotides, lipoplexes, dendrimers, and inorganic nanoparticles.

Some of the unsolved problems include:

Three patients’ deaths have been reported in gene therapy trials, putting the field under close scrutiny. The first was that of Jesse Gelsinger, who died in 1999 because of immune rejection response.[51] One X-SCID patient died of leukemia in 2003.[9] In 2007, a rheumatoid arthritis patient died from an infection; the subsequent investigation concluded that the death was not related to gene therapy.[52]

In 1972 Friedmann and Roblin authored a paper in Science titled “Gene therapy for human genetic disease?”[53] Rogers (1970) was cited for proposing that exogenous good DNA be used to replace the defective DNA in those who suffer from genetic defects.[54]

In 1984 a retrovirus vector system was designed that could efficiently insert foreign genes into mammalian chromosomes.[55]

The first approved gene therapy clinical research in the US took place on 14 September 1990, at the National Institutes of Health (NIH), under the direction of William French Anderson.[56] Four-year-old Ashanti DeSilva received treatment for a genetic defect that left her with ADA-SCID, a severe immune system deficiency. The defective gene of the patient’s blood cells was replaced by the functional variant. Ashantis immune system was partially restored by the therapy. Production of the missing enzyme was temporarily stimulated, but the new cells with functional genes were not generated. She led a normal life only with the regular injections performed every two months. The effects were successful, but temporary.[57]

Cancer gene therapy was introduced in 1992/93 (Trojan et al. 1993).[58] The treatment of glioblastoma multiforme, the malignant brain tumor whose outcome is always fatal, was done using a vector expressing antisense IGF-I RNA (clinical trial approved by NIH protocolno.1602 November 24, 1993,[59] and by the FDA in 1994). This therapy also represents the beginning of cancer immunogene therapy, a treatment which proves to be effective due to the anti-tumor mechanism of IGF-I antisense, which is related to strong immune and apoptotic phenomena.

In 1992 Claudio Bordignon, working at the Vita-Salute San Raffaele University, performed the first gene therapy procedure using hematopoietic stem cells as vectors to deliver genes intended to correct hereditary diseases.[60] In 2002 this work led to the publication of the first successful gene therapy treatment for adenosine deaminase deficiency (ADA-SCID). The success of a multi-center trial for treating children with SCID (severe combined immune deficiency or “bubble boy” disease) from 2000 and 2002, was questioned when two of the ten children treated at the trial’s Paris center developed a leukemia-like condition. Clinical trials were halted temporarily in 2002, but resumed after regulatory review of the protocol in the US, the United Kingdom, France, Italy, and Germany.[61]

In 1993 Andrew Gobea was born with SCID following prenatal genetic screening. Blood was removed from his mother’s placenta and umbilical cord immediately after birth, to acquire stem cells. The allele that codes for adenosine deaminase (ADA) was obtained and inserted into a retrovirus. Retroviruses and stem cells were mixed, after which the viruses inserted the gene into the stem cell chromosomes. Stem cells containing the working ADA gene were injected into Andrew’s blood. Injections of the ADA enzyme were also given weekly. For four years T cells (white blood cells), produced by stem cells, made ADA enzymes using the ADA gene. After four years more treatment was needed.[62]

Jesse Gelsinger’s death in 1999 impeded gene therapy research in the US.[63][64] As a result, the FDA suspended several clinical trials pending the reevaluation of ethical and procedural practices.[65]

The modified cancer gene therapy strategy of antisense IGF-I RNA (NIH n 1602)[59] using antisense / triple helix anti-IGF-I approach was registered in 2002 by Wiley gene therapy clinical trial – n 635 and 636. The approach has shown promising results in the treatment of six different malignant tumors: glioblastoma, cancers of liver, colon, prostate, uterus, and ovary (Collaborative NATO Science Programme on Gene Therapy USA, France, Poland n LST 980517 conducted by J. Trojan) (Trojan et al., 2012). This anti-gene antisense/triple helix therapy has proven to be efficient, due to the mechanism stopping simultaneously IGF-I expression on translation and transcription levels, strengthening anti-tumor immune and apoptotic phenomena.

Sickle-cell disease can be treated in mice.[66] The mice which have essentially the same defect that causes human cases used a viral vector to induce production of fetal hemoglobin (HbF), which normally ceases to be produced shortly after birth. In humans, the use of hydroxyurea to stimulate the production of HbF temporarily alleviates sickle cell symptoms. The researchers demonstrated this treatment to be a more permanent means to increase therapeutic HbF production.[67]

A new gene therapy approach repaired errors in messenger RNA derived from defective genes. This technique has the potential to treat thalassaemia, cystic fibrosis and some cancers.[68]

Researchers created liposomes 25 nanometers across that can carry therapeutic DNA through pores in the nuclear membrane.[69]

In 2003 a research team inserted genes into the brain for the first time. They used liposomes coated in a polymer called polyethylene glycol, which unlike viral vectors, are small enough to cross the bloodbrain barrier.[70]

Short pieces of double-stranded RNA (short, interfering RNAs or siRNAs) are used by cells to degrade RNA of a particular sequence. If a siRNA is designed to match the RNA copied from a faulty gene, then the abnormal protein product of that gene will not be produced.[71]

Gendicine is a cancer gene therapy that delivers the tumor suppressor gene p53 using an engineered adenovirus. In 2003, it was approved in China for the treatment of head and neck squamous cell carcinoma.[25]

In March researchers announced the successful use of gene therapy to treat two adult patients for X-linked chronic granulomatous disease, a disease which affects myeloid cells and damages the immune system. The study is the first to show that gene therapy can treat the myeloid system.[72]

In May a team reported a way to prevent the immune system from rejecting a newly delivered gene.[73] Similar to organ transplantation, gene therapy has been plagued by this problem. The immune system normally recognizes the new gene as foreign and rejects the cells carrying it. The research utilized a newly uncovered network of genes regulated by molecules known as microRNAs. This natural function selectively obscured their therapeutic gene in immune system cells and protected it from discovery. Mice infected with the gene containing an immune-cell microRNA target sequence did not reject the gene.

In August scientists successfully treated metastatic melanoma in two patients using killer T cells genetically retargeted to attack the cancer cells.[74]

In November researchers reported on the use of VRX496, a gene-based immunotherapy for the treatment of HIV that uses a lentiviral vector to deliver an antisense gene against the HIV envelope. In a phase I clinical trial, five subjects with chronic HIV infection who had failed to respond to at least two antiretroviral regimens were treated. A single intravenous infusion of autologous CD4 T cells genetically modified with VRX496 was well tolerated. All patients had stable or decreased viral load; four of the five patients had stable or increased CD4 T cell counts. All five patients had stable or increased immune response to HIV antigens and other pathogens. This was the first evaluation of a lentiviral vector administered in a US human clinical trial.[75][76]

In May researchers announced the first gene therapy trial for inherited retinal disease. The first operation was carried out on a 23-year-old British male, Robert Johnson, in early 2007.[77]

Leber’s congenital amaurosis is an inherited blinding disease caused by mutations in the RPE65 gene. The results of a small clinical trial in children were published in April.[11] Delivery of recombinant adeno-associated virus (AAV) carrying RPE65 yielded positive results. In May two more groups reported positive results in independent clinical trials using gene therapy to treat the condition. In all three clinical trials, patients recovered functional vision without apparent side-effects.[11][12][13][14]

In September researchers were able to give trichromatic vision to squirrel monkeys.[78] In November 2009, researchers halted a fatal genetic disorder called adrenoleukodystrophy in two children using a lentivirus vector to deliver a functioning version of ABCD1, the gene that is mutated in the disorder.[79]

An April paper reported that gene therapy addressed achromatopsia (color blindness) in dogs by targeting cone photoreceptors. Cone function and day vision were restored for at least 33 months in two young specimens. The therapy was less efficient for older dogs.[80]

In September it was announced that an 18-year-old male patient in France with beta-thalassemia major had been successfully treated.[81] Beta-thalassemia major is an inherited blood disease in which beta haemoglobin is missing and patients are dependent on regular lifelong blood transfusions.[82] The technique used a lentiviral vector to transduce the human -globin gene into purified blood and marrow cells obtained from the patient in June 2007.[83] The patient’s haemoglobin levels were stable at 9 to 10 g/dL. About a third of the hemoglobin contained the form introduced by the viral vector and blood transfusions were not needed.[83][84] Further clinical trials were planned.[85] Bone marrow transplants are the only cure for thalassemia, but 75% of patients do not find a matching donor.[84]

Cancer immunogene therapy using modified antigene, antisense/triple helix approach was introduced in South America in 2010/11 in La Sabana University, Bogota (Ethical Committee 14 December 2010, no P-004-10). Considering the ethical aspect of gene diagnostic and gene therapy targeting IGF-I, the IGF-I expressing tumors i.e. lung and epidermis cancers were treated (Trojan et al. 2016).[86][87]

In 2007 and 2008, a man (Timothy Ray Brown) was cured of HIV by repeated hematopoietic stem cell transplantation (see also allogeneic stem cell transplantation, allogeneic bone marrow transplantation, allotransplantation) with double-delta-32 mutation which disables the CCR5 receptor. This cure was accepted by the medical community in 2011.[88] It required complete ablation of existing bone marrow, which is very debilitating.

In August two of three subjects of a pilot study were confirmed to have been cured from chronic lymphocytic leukemia (CLL). The therapy used genetically modified T cells to attack cells that expressed the CD19 protein to fight the disease.[20] In 2013, the researchers announced that 26 of 59 patients had achieved complete remission and the original patient had remained tumor-free.[89]

Human HGF plasmid DNA therapy of cardiomyocytes is being examined as a potential treatment for coronary artery disease as well as treatment for the damage that occurs to the heart after myocardial infarction.[90][91]

In 2011 Neovasculgen was registered in Russia as the first-in-class gene-therapy drug for treatment of peripheral artery disease, including critical limb ischemia; it delivers the gene encoding for VEGF.[92][26] Neovasculogen is a plasmid encoding the CMV promoter and the 165 amino acid form of VEGF.[93][94]

The FDA approved Phase 1 clinical trials on thalassemia major patients in the US for 10 participants in July.[95] The study was expected to continue until 2015.[85]

In July 2012, the European Medicines Agency recommended approval of a gene therapy treatment for the first time in either Europe or the United States. The treatment used Alipogene tiparvovec (Glybera) to compensate for lipoprotein lipase deficiency, which can cause severe pancreatitis.[96] The recommendation was endorsed by the European Commission in November 2012[10][27][97][98] and commercial rollout began in late 2014.[99] Alipogene tiparvovec was expected to cost around $1.6 million per treatment in 2012,[100] revised to $1 million in 2015,[101] making it the most expensive medicine in the world at the time.[102] As of 2016[update], only one person had been treated with drug.[103]

In December 2012, it was reported that 10 of 13 patients with multiple myeloma were in remission “or very close to it” three months after being injected with a treatment involving genetically engineered T cells to target proteins NY-ESO-1 and LAGE-1, which exist only on cancerous myeloma cells.[22]

In March researchers reported that three of five adult subjects who had acute lymphocytic leukemia (ALL) had been in remission for five months to two years after being treated with genetically modified T cells which attacked cells with CD19 genes on their surface, i.e. all B-cells, cancerous or not. The researchers believed that the patients’ immune systems would make normal T-cells and B-cells after a couple of months. They were also given bone marrow. One patient relapsed and died and one died of a blood clot unrelated to the disease.[21]

Following encouraging Phase 1 trials, in April, researchers announced they were starting Phase 2 clinical trials (called CUPID2 and SERCA-LVAD) on 250 patients[104] at several hospitals to combat heart disease. The therapy was designed to increase the levels of SERCA2, a protein in heart muscles, improving muscle function.[105] The FDA granted this a Breakthrough Therapy Designation to accelerate the trial and approval process.[106] In 2016 it was reported that no improvement was found from the CUPID 2 trial.[107]

In July researchers reported promising results for six children with two severe hereditary diseases had been treated with a partially deactivated lentivirus to replace a faulty gene and after 732 months. Three of the children had metachromatic leukodystrophy, which causes children to lose cognitive and motor skills.[108] The other children had Wiskott-Aldrich syndrome, which leaves them to open to infection, autoimmune diseases, and cancer.[109] Follow up trials with gene therapy on another six children with Wiskott-Aldrich syndrome were also reported as promising.[110][111]

In October researchers reported that two children born with adenosine deaminase severe combined immunodeficiency disease (ADA-SCID) had been treated with genetically engineered stem cells 18 months previously and that their immune systems were showing signs of full recovery. Another three children were making progress.[18] In 2014 a further 18 children with ADA-SCID were cured by gene therapy.[112] ADA-SCID children have no functioning immune system and are sometimes known as “bubble children.”[18]

Also in October researchers reported that they had treated six hemophilia sufferers in early 2011 using an adeno-associated virus. Over two years later all six were producing clotting factor.[18][113]

In January researchers reported that six choroideremia patients had been treated with adeno-associated virus with a copy of REP1. Over a six-month to two-year period all had improved their sight.[114][115] By 2016, 32 patients had been treated with positive results and researchers were hopeful the treatment would be long-lasting.[15] Choroideremia is an inherited genetic eye disease with no approved treatment, leading to loss of sight.

In March researchers reported that 12 HIV patients had been treated since 2009 in a trial with a genetically engineered virus with a rare mutation (CCR5 deficiency) known to protect against HIV with promising results.[116][117]

Clinical trials of gene therapy for sickle cell disease were started in 2014.[118][119] There is a need for high quality randomised controlled trials assessing the risks and benefits involved with gene therapy for people with sickle cell disease.[120]

In February LentiGlobin BB305, a gene therapy treatment undergoing clinical trials for treatment of beta thalassemia gained FDA “breakthrough” status after several patients were able to forgo the frequent blood transfusions usually required to treat the disease.[121]

In March researchers delivered a recombinant gene encoding a broadly neutralizing antibody into monkeys infected with simian HIV; the monkeys’ cells produced the antibody, which cleared them of HIV. The technique is named immunoprophylaxis by gene transfer (IGT). Animal tests for antibodies to ebola, malaria, influenza, and hepatitis were underway.[122][123]

In March, scientists, including an inventor of CRISPR, Jennifer Doudna, urged a worldwide moratorium on germline gene therapy, writing “scientists should avoid even attempting, in lax jurisdictions, germline genome modification for clinical application in humans” until the full implications “are discussed among scientific and governmental organizations”.[124][125][126][127]

In October, researchers announced that they had treated a baby girl, Layla Richards, with an experimental treatment using donor T-cells genetically engineered using TALEN to attack cancer cells. One year after the treatment she was still free of her cancer (a highly aggressive form of acute lymphoblastic leukaemia [ALL]).[128] Children with highly aggressive ALL normally have a very poor prognosis and Layla’s disease had been regarded as terminal before the treatment.[129]

In December, scientists of major world academies called for a moratorium on inheritable human genome edits, including those related to CRISPR-Cas9 technologies[130] but that basic research including embryo gene editing should continue.[131]

In April the Committee for Medicinal Products for Human Use of the European Medicines Agency endorsed a gene therapy treatment called Strimvelis[132][133] and the European Commission approved it in June.[134] This treats children born with adenosine deaminase deficiency and who have no functioning immune system. This was the second gene therapy treatment to be approved in Europe.[135]

In October, Chinese scientists reported they had started a trial to genetically modify T-cells from 10 adult patients with lung cancer and reinject the modified T-cells back into their bodies to attack the cancer cells. The T-cells had the PD-1 protein (which stops or slows the immune response) removed using CRISPR-Cas9.[136][137]

A 2016 Cochrane systematic review looking at data from four trials on topical cystic fibrosis transmembrane conductance regulator (CFTR) gene therapy does not support its clinical use as a mist inhaled into the lungs to treat cystic fibrosis patients with lung infections. One of the four trials did find weak evidence that liposome-based CFTR gene transfer therapy may lead to a small respiratory improvement for people with CF. This weak evidence is not enough to make a clinical recommendation for routine CFTR gene therapy.[138]

In February Kite Pharma announced results from a clinical trial of CAR-T cells in around a hundred people with advanced Non-Hodgkin lymphoma.[139]

In March, French scientists reported on clinical research of gene therapy to treat sickle-cell disease.[140]

In August, the FDA approved tisagenlecleucel for acute lymphoblastic leukemia.[141] Tisagenlecleucel is an adoptive cell transfer therapy for B-cell acute lymphoblastic leukemia; T cells from a person with cancer are removed, genetically engineered to make a specific T-cell receptor (a chimeric T cell receptor, or “CAR-T”) that reacts to the cancer, and are administered back to the person. The T cells are engineered to target a protein called CD19 that is common on B cells. This is the first form of gene therapy to be approved in the United States. In October, a similar therapy called axicabtagene ciloleucel was approved for non-Hodgkin lymphoma.[142]

In December the results of using an adeno-associated virus with blood clotting factor VIII to treat nine haemophilia A patients were published. Six of the seven patients on the high dose regime increased the level of the blood clotting VIII to normal levels. The low and medium dose regimes had no effect on the patient’s blood clotting levels.[143][144]

In December, the FDA approved Luxturna, the first in vivo gene therapy, for the treatment of blindness due to Leber’s congenital amaurosis.[145] The price of this treatment was 850,000 US dollars for both eyes.[146][147]

Speculated uses for gene therapy include:

Gene therapy techniques have the potential to provide alternative treatments for those with infertility. Recently, successful experimentation on mice has proven that fertility can be restored by using the gene therapy method, CRISPR.[148] Spermatogenical stem cells from another organism were transplanted into the testes of an infertile male mouse. The stem cells re-established spermatogenesis and fertility.[149]

Athletes might adopt gene therapy technologies to improve their performance.[150] Gene doping is not known to occur, but multiple gene therapies may have such effects. Kayser et al. argue that gene doping could level the playing field if all athletes receive equal access. Critics claim that any therapeutic intervention for non-therapeutic/enhancement purposes compromises the ethical foundations of medicine and sports.[151]

Genetic engineering could be used to cure diseases, but also to change physical appearance, metabolism, and even improve physical capabilities and mental faculties such as memory and intelligence. Ethical claims about germline engineering include beliefs that every fetus has a right to remain genetically unmodified, that parents hold the right to genetically modify their offspring, and that every child has the right to be born free of preventable diseases.[152][153][154] For parents, genetic engineering could be seen as another child enhancement technique to add to diet, exercise, education, training, cosmetics, and plastic surgery.[155][156] Another theorist claims that moral concerns limit but do not prohibit germline engineering.[157]

Possible regulatory schemes include a complete ban, provision to everyone, or professional self-regulation. The American Medical Associations Council on Ethical and Judicial Affairs stated that “genetic interventions to enhance traits should be considered permissible only in severely restricted situations: (1) clear and meaningful benefits to the fetus or child; (2) no trade-off with other characteristics or traits; and (3) equal access to the genetic technology, irrespective of income or other socioeconomic characteristics.”[158]

As early in the history of biotechnology as 1990, there have been scientists opposed to attempts to modify the human germline using these new tools,[159] and such concerns have continued as technology progressed.[160][161] With the advent of new techniques like CRISPR, in March 2015 a group of scientists urged a worldwide moratorium on clinical use of gene editing technologies to edit the human genome in a way that can be inherited.[124][125][126][127] In April 2015, researchers sparked controversy when they reported results of basic research to edit the DNA of non-viable human embryos using CRISPR.[148][162] A committee of the American National Academy of Sciences and National Academy of Medicine gave qualified support to human genome editing in 2017[163][164] once answers have been found to safety and efficiency problems “but only for serious conditions under stringent oversight.”[165]

Regulations covering genetic modification are part of general guidelines about human-involved biomedical research. There are no international treaties which are legally binding in this area, but there are recommendations for national laws from various bodies.

The Helsinki Declaration (Ethical Principles for Medical Research Involving Human Subjects) was amended by the World Medical Association’s General Assembly in 2008. This document provides principles physicians and researchers must consider when involving humans as research subjects. The Statement on Gene Therapy Research initiated by the Human Genome Organization (HUGO) in 2001 provides a legal baseline for all countries. HUGOs document emphasizes human freedom and adherence to human rights, and offers recommendations for somatic gene therapy, including the importance of recognizing public concerns about such research.[166]

No federal legislation lays out protocols or restrictions about human genetic engineering. This subject is governed by overlapping regulations from local and federal agencies, including the Department of Health and Human Services, the FDA and NIH’s Recombinant DNA Advisory Committee. Researchers seeking federal funds for an investigational new drug application, (commonly the case for somatic human genetic engineering,) must obey international and federal guidelines for the protection of human subjects.[167]

NIH serves as the main gene therapy regulator for federally funded research. Privately funded research is advised to follow these regulations. NIH provides funding for research that develops or enhances genetic engineering techniques and to evaluate the ethics and quality in current research. The NIH maintains a mandatory registry of human genetic engineering research protocols that includes all federally funded projects.

An NIH advisory committee published a set of guidelines on gene manipulation.[168] The guidelines discuss lab safety as well as human test subjects and various experimental types that involve genetic changes. Several sections specifically pertain to human genetic engineering, including Section III-C-1. This section describes required review processes and other aspects when seeking approval to begin clinical research involving genetic transfer into a human patient.[169] The protocol for a gene therapy clinical trial must be approved by the NIH’s Recombinant DNA Advisory Committee prior to any clinical trial beginning; this is different from any other kind of clinical trial.[168]

As with other kinds of drugs, the FDA regulates the quality and safety of gene therapy products and supervises how these products are used clinically. Therapeutic alteration of the human genome falls under the same regulatory requirements as any other medical treatment. Research involving human subjects, such as clinical trials, must be reviewed and approved by the FDA and an Institutional Review Board.[170][171]

Gene therapy is the basis for the plotline of the film I Am Legend[172] and the TV show Will Gene Therapy Change the Human Race?.[173] In 1994, gene therapy was a plot element in The Erlenmeyer Flask, The X-Files’ first-season finale. It is also used in Stargate as a means of allowing humans to use Ancient technology.[174]

Excerpt from:

Gene therapy – Wikipedia

Genetic engineering – Wikipedia

Genetic engineering, also called genetic modification or genetic manipulation, is the direct manipulation of an organism’s genes using biotechnology. It is a set of technologies used to change the genetic makeup of cells, including the transfer of genes within and across species boundaries to produce improved or novel organisms. New DNA is obtained by either isolating and copying the genetic material of interest using recombinant DNA methods or by artificially synthesising the DNA. A construct is usually created and used to insert this DNA into the host organism. The first recombinant DNA molecule was made by Paul Berg in 1972 by combining DNA from the monkey virus SV40 with the lambda virus. As well as inserting genes, the process can be used to remove, or “knock out”, genes. The new DNA can be inserted randomly, or targeted to a specific part of the genome.

An organism that is generated through genetic engineering is considered to be genetically modified (GM) and the resulting entity is a genetically modified organism (GMO). The first GMO was a bacterium generated by Herbert Boyer and Stanley Cohen in 1973. Rudolf Jaenisch created the first GM animal when he inserted foreign DNA into a mouse in 1974. The first company to focus on genetic engineering, Genentech, was founded in 1976 and started the production of human proteins. Genetically engineered human insulin was produced in 1978 and insulin-producing bacteria were commercialised in 1982. Genetically modified food has been sold since 1994, with the release of the Flavr Savr tomato. The Flavr Savr was engineered to have a longer shelf life, but most current GM crops are modified to increase resistance to insects and herbicides. GloFish, the first GMO designed as a pet, was sold in the United States in December 2003. In 2016 salmon modified with a growth hormone were sold.

Genetic engineering has been applied in numerous fields including research, medicine, industrial biotechnology and agriculture. In research GMOs are used to study gene function and expression through loss of function, gain of function, tracking and expression experiments. By knocking out genes responsible for certain conditions it is possible to create animal model organisms of human diseases. As well as producing hormones, vaccines and other drugs genetic engineering has the potential to cure genetic diseases through gene therapy. The same techniques that are used to produce drugs can also have industrial applications such as producing enzymes for laundry detergent, cheeses and other products.

The rise of commercialised genetically modified crops has provided economic benefit to farmers in many different countries, but has also been the source of most of the controversy surrounding the technology. This has been present since its early use, the first field trials were destroyed by anti-GM activists. Although there is a scientific consensus that currently available food derived from GM crops poses no greater risk to human health than conventional food, GM food safety is a leading concern with critics. Gene flow, impact on non-target organisms, control of the food supply and intellectual property rights have also been raised as potential issues. These concerns have led to the development of a regulatory framework, which started in 1975. It has led to an international treaty, the Cartagena Protocol on Biosafety, that was adopted in 2000. Individual countries have developed their own regulatory systems regarding GMOs, with the most marked differences occurring between the USA and Europe.

Genetic engineering is a process that alters the genetic structure of an organism by either removing or introducing DNA. Unlike traditionally animal and plant breeding, which involves doing multiple crosses and then selecting for the organism with the desired phenotype, genetic engineering takes the gene directly from one organism and inserts it in the other. This is much faster, can be used to insert any genes from any organism (even ones from different domains) and prevents other undesirable genes from also being added.[3]

Genetic engineering could potentially fix severe genetic disorders in humans by replacing the defective gene with a functioning one.[4] It is an important tool in research that allows the function of specific genes to be studied.[5] Drugs, vaccines and other products have been harvested from organisms engineered to produce them.[6] Crops have been developed that aid food security by increasing yield, nutritional value and tolerance to environmental stresses.[7]

The DNA can be introduced directly into the host organism or into a cell that is then fused or hybridised with the host.[8] This relies on recombinant nucleic acid techniques to form new combinations of heritable genetic material followed by the incorporation of that material either indirectly through a vector system or directly through micro-injection, macro-injection or micro-encapsulation.[9]

Genetic engineering does not normally include traditional breeding, in vitro fertilisation, induction of polyploidy, mutagenesis and cell fusion techniques that do not use recombinant nucleic acids or a genetically modified organism in the process.[8] However, some broad definitions of genetic engineering include selective breeding.[9] Cloning and stem cell research, although not considered genetic engineering,[10] are closely related and genetic engineering can be used within them.[11] Synthetic biology is an emerging discipline that takes genetic engineering a step further by introducing artificially synthesised material into an organism.[12]

Plants, animals or micro organisms that have been changed through genetic engineering are termed genetically modified organisms or GMOs.[13] If genetic material from another species is added to the host, the resulting organism is called transgenic. If genetic material from the same species or a species that can naturally breed with the host is used the resulting organism is called cisgenic.[14] If genetic engineering is used to remove genetic material from the target organism the resulting organism is termed a knockout organism.[15] In Europe genetic modification is synonymous with genetic engineering while within the United States of America and Canada genetic modification can also be used to refer to more conventional breeding methods.[16][17][18]

Humans have altered the genomes of species for thousands of years through selective breeding, or artificial selection[19]:1[20]:1 as contrasted with natural selection, and more recently through mutagenesis. Genetic engineering as the direct manipulation of DNA by humans outside breeding and mutations has only existed since the 1970s. The term “genetic engineering” was first coined by Jack Williamson in his science fiction novel Dragon’s Island, published in 1951[21] one year before DNA’s role in heredity was confirmed by Alfred Hershey and Martha Chase,[22] and two years before James Watson and Francis Crick showed that the DNA molecule has a double-helix structure though the general concept of direct genetic manipulation was explored in rudimentary form in Stanley G. Weinbaum’s 1936 science fiction story Proteus Island.[23][24]

In 1972, Paul Berg created the first recombinant DNA molecules by combining DNA from the monkey virus SV40 with that of the lambda virus.[25] In 1973 Herbert Boyer and Stanley Cohen created the first transgenic organism by inserting antibiotic resistance genes into the plasmid of an Escherichia coli bacterium.[26][27] A year later Rudolf Jaenisch created a transgenic mouse by introducing foreign DNA into its embryo, making it the worlds first transgenic animal.[28] These achievements led to concerns in the scientific community about potential risks from genetic engineering, which were first discussed in depth at the Asilomar Conference in 1975. One of the main recommendations from this meeting was that government oversight of recombinant DNA research should be established until the technology was deemed safe.[29][30]

In 1976 Genentech, the first genetic engineering company, was founded by Herbert Boyer and Robert Swanson and a year later the company produced a human protein (somatostatin) in E.coli. Genentech announced the production of genetically engineered human insulin in 1978.[31] In 1980, the U.S. Supreme Court in the Diamond v. Chakrabarty case ruled that genetically altered life could be patented.[32] The insulin produced by bacteria was approved for release by the Food and Drug Administration (FDA) in 1982.[33]

In 1983, a biotech company, Advanced Genetic Sciences (AGS) applied for U.S. government authorisation to perform field tests with the ice-minus strain of Pseudomonas syringae to protect crops from frost, but environmental groups and protestors delayed the field tests for four years with legal challenges.[34] In 1987, the ice-minus strain of P. syringae became the first genetically modified organism (GMO) to be released into the environment[35] when a strawberry field and a potato field in California were sprayed with it.[36] Both test fields were attacked by activist groups the night before the tests occurred: “The world’s first trial site attracted the world’s first field trasher”.[35]

The first field trials of genetically engineered plants occurred in France and the USA in 1986, tobacco plants were engineered to be resistant to herbicides.[37] The Peoples Republic of China was the first country to commercialise transgenic plants, introducing a virus-resistant tobacco in 1992.[38] In 1994 Calgene attained approval to commercially release the first genetically modified food, the Flavr Savr, a tomato engineered to have a longer shelf life.[39] In 1994, the European Union approved tobacco engineered to be resistant to the herbicide bromoxynil, making it the first genetically engineered crop commercialised in Europe.[40] In 1995, Bt Potato was approved safe by the Environmental Protection Agency, after having been approved by the FDA, making it the first pesticide producing crop to be approved in the USA.[41] In 2009 11 transgenic crops were grown commercially in 25 countries, the largest of which by area grown were the USA, Brazil, Argentina, India, Canada, China, Paraguay and South Africa.[42]

In 2010, scientists at the J. Craig Venter Institute created the first synthetic genome and inserted it into an empty bacterial cell. The resulting bacterium, named Mycoplasma laboratorium, could replicate and produce proteins.[43][44] Four years later this was taken a step further when a bacterium was developed that replicated a plasmid containing a unique base pair, creating the first organism engineered to use an expanded genetic alphabet.[45][46] In 2012, Jennifer Doudna and Emmanuelle Charpentier collaborated to develop the CRISPR/Cas9 system,[47][48] a technique which can be used to easily and specifically alter the genome of almost any organism.[49]

Creating a GMO is a multi-step process. Genetic engineers must first choose what gene they wish to insert into the organism. This is driven by what the aim is for the resultant organism and is built on earlier research. Genetic screens can be carried out to determine potential genes and further tests then used to identify the best candidates. The development of microarrays, transcriptomics and genome sequencing has made it much easier to find suitable genes.[50] Luck also plays its part; the round-up ready gene was discovered after scientists noticed a bacterium thriving in the presence of the herbicide.[51]

The next step is to isolate the candidate gene. The cell containing the gene is opened and the DNA is purified.[52] The gene is separated by using restriction enzymes to cut the DNA into fragments[53] or polymerase chain reaction (PCR) to amplify up the gene segment.[54] These segments can then be extracted through gel electrophoresis. If the chosen gene or the donor organism’s genome has been well studied it may already be accessible from a genetic library. If the DNA sequence is known, but no copies of the gene are available, it can also be artificially synthesised.[55] Once isolated the gene is ligated into a plasmid that is then inserted into a bacterium. The plasmid is replicated when the bacteria divide, ensuring unlimited copies of the gene are available.[56]

Before the gene is inserted into the target organism it must be combined with other genetic elements. These include a promoter and terminator region, which initiate and end transcription. A selectable marker gene is added, which in most cases confers antibiotic resistance, so researchers can easily determine which cells have been successfully transformed. The gene can also be modified at this stage for better expression or effectiveness. These manipulations are carried out using recombinant DNA techniques, such as restriction digests, ligations and molecular cloning.[57]

There are a number of techniques available for inserting the gene into the host genome. Some bacteria can naturally take up foreign DNA. This ability can be induced in other bacteria via stress (e.g. thermal or electric shock), which increases the cell membrane’s permeability to DNA; up-taken DNA can either integrate with the genome or exist as extrachromosomal DNA. DNA is generally inserted into animal cells using microinjection, where it can be injected through the cell’s nuclear envelope directly into the nucleus, or through the use of viral vectors.[58]

In plants the DNA is often inserted using Agrobacterium-mediated recombination,[59] taking advantage of the Agrobacteriums T-DNA sequence that allows natural insertion of genetic material into plant cells.[60] Other methods include biolistics, where particles of gold or tungsten are coated with DNA and then shot into young plant cells,[61] and electroporation, which involves using an electric shock to make the cell membrane permeable to plasmid DNA. Due to the damage caused to the cells and DNA the transformation efficiency of biolistics and electroporation is lower than agrobacterial transformation and microinjection.[62]

As only a single cell is transformed with genetic material, the organism must be regenerated from that single cell. In plants this is accomplished through the use of tissue culture.[63][64] In animals it is necessary to ensure that the inserted DNA is present in the embryonic stem cells.[65] Bacteria consist of a single cell and reproduce clonally so regeneration is not necessary. Selectable markers are used to easily differentiate transformed from untransformed cells. These markers are usually present in the transgenic organism, although a number of strategies have been developed that can remove the selectable marker from the mature transgenic plant.[66]

Further testing using PCR, Southern hybridization, and DNA sequencing is conducted to confirm that an organism contains the new gene.[67] These tests can also confirm the chromosomal location and copy number of the inserted gene. The presence of the gene does not guarantee it will be expressed at appropriate levels in the target tissue so methods that look for and measure the gene products (RNA and protein) are also used. These include northern hybridisation, quantitative RT-PCR, Western blot, immunofluorescence, ELISA and phenotypic analysis.[68]

The new genetic material can be inserted randomly within the host genome or targeted to a specific location. The technique of gene targeting uses homologous recombination to make desired changes to a specific endogenous gene. This tends to occur at a relatively low frequency in plants and animals and generally requires the use of selectable markers. The frequency of gene targeting can be greatly enhanced through genome editing. Genome editing uses artificially engineered nucleases that create specific double-stranded breaks at desired locations in the genome, and use the cells endogenous mechanisms to repair the induced break by the natural processes of homologous recombination and nonhomologous end-joining. There are four families of engineered nucleases: meganucleases,[69][70] zinc finger nucleases,[71][72] transcription activator-like effector nucleases (TALENs),[73][74] and the Cas9-guideRNA system (adapted from CRISPR).[75][76] TALEN and CRISPR are the two most commonly used and each has its own advantages.[77] TALENs have greater target specificity, while CRISPR is easier to design and more efficient.[77] In addition to enhancing gene targeting, engineered nucleases can be used to introduce mutations at endogenous genes that generate a gene knockout.[78][79]

Genetic engineering has applications in medicine, research, industry and agriculture and can be used on a wide range of plants, animals and micro organisms. Bacteria, the first organisms to be genetically modified, can have plasmid DNA inserted containing new genes that code for medicines or enzymes that process food and other substrates.[80][81] Plants have been modified for insect protection, herbicide resistance, virus resistance, enhanced nutrition, tolerance to environmental pressures and the production of edible vaccines.[82] Most commercialised GMOs are insect resistant or herbicide tolerant crop plants.[83] Genetically modified animals have been used for research, model animals and the production of agricultural or pharmaceutical products. The genetically modified animals include animals with genes knocked out, increased susceptibility to disease, hormones for extra growth and the ability to express proteins in their milk.[84]

Genetic engineering has many applications to medicine that include the manufacturing of drugs, creation of model animals that mimic human conditions and gene therapy. One of the earliest uses of genetic engineering was to mass-produce human insulin in bacteria.[31] This application has now been applied to, human growth hormones, follicle stimulating hormones (for treating infertility), human albumin, monoclonal antibodies, antihemophilic factors, vaccines and many other drugs.[85][86] Mouse hybridomas, cells fused together to create monoclonal antibodies, have been adapted through genetic engineering to create human monoclonal antibodies.[87] In 2017, genetic engineering of chimeric antigen receptors on a patient’s own T-cells was approved by the U.S. FDA as a treatment for the cancer acute lymphoblastic leukemia. Genetically engineered viruses are being developed that can still confer immunity, but lack the infectious sequences.[88]

Genetic engineering is also used to create animal models of human diseases. Genetically modified mice are the most common genetically engineered animal model.[89] They have been used to study and model cancer (the oncomouse), obesity, heart disease, diabetes, arthritis, substance abuse, anxiety, aging and Parkinson disease.[90] Potential cures can be tested against these mouse models. Also genetically modified pigs have been bred with the aim of increasing the success of pig to human organ transplantation.[91]

Gene therapy is the genetic engineering of humans, generally by replacing defective genes with effective ones. Clinical research using somatic gene therapy has been conducted with several diseases, including X-linked SCID,[92] chronic lymphocytic leukemia (CLL),[93][94] and Parkinson’s disease.[95] In 2012, Alipogene tiparvovec became the first gene therapy treatment to be approved for clinical use.[96][97] In 2015 a virus was used to insert a healthy gene into the skin cells of a boy suffering from a rare skin disease, epidermolysis bullosa, in order to grow, and then graft healthy skin onto 80 percent of the boy’s body which was affected by the illness.[98] Germline gene therapy would result in any change being inheritable, which has raised concerns within the scientific community.[99][100] In 2015, CRISPR was used to edit the DNA of non-viable human embryos,[101][102] leading scientists of major world academies to call for a moratorium on inheritable human genome edits.[103] There are also concerns that the technology could be used not just for treatment, but for enhancement, modification or alteration of a human beings’ appearance, adaptability, intelligence, character or behavior.[104] The distinction between cure and enhancement can also be difficult to establish.[105]

Researchers are altering the genome of pigs to induce the growth of human organs to be used in transplants. Scientists are creating “gene drives”, changing the genomes of mosquitoes to make them immune to malaria, and then spreading the genetically altered mosquitoes throughout the mosquito population in the hopes of eliminating the disease.[106]

Genetic engineering is an important tool for natural scientists. Genes and other genetic information from a wide range of organisms can be inserted into bacteria for storage and modification, creating genetically modified bacteria in the process. Bacteria are cheap, easy to grow, clonal, multiply quickly, relatively easy to transform and can be stored at -80C almost indefinitely. Once a gene is isolated it can be stored inside the bacteria providing an unlimited supply for research.[107]

Organisms are genetically engineered to discover the functions of certain genes. This could be the effect on the phenotype of the organism, where the gene is expressed or what other genes it interacts with. These experiments generally involve loss of function, gain of function, tracking and expression.

Organisms can have their cells transformed with a gene coding for a useful protein, such as an enzyme, so that they will overexpress the desired protein. Mass quantities of the protein can then be manufactured by growing the transformed organism in bioreactor equipment using industrial fermentation, and then purifying the protein.[111] Some genes do not work well in bacteria, so yeast, insect cells or mammalians cells can also be used.[112] These techniques are used to produce medicines such as insulin, human growth hormone, and vaccines, supplements such as tryptophan, aid in the production of food (chymosin in cheese making) and fuels.[113] Other applications with genetically engineered bacteria could involve making them perform tasks outside their natural cycle, such as making biofuels,[114] cleaning up oil spills, carbon and other toxic waste[115] and detecting arsenic in drinking water.[116] Certain genetically modified microbes can also be used in biomining and bioremediation, due to their ability to extract heavy metals from their environment and incorporate them into compounds that are more easily recoverable.[117]

In materials science, a genetically modified virus has been used in a research laboratory as a scaffold for assembling a more environmentally friendly lithium-ion battery.[118][119] Bacteria have also been engineered to function as sensors by expressing a fluorescent protein under certain environmental conditions.[120]

One of the best-known and controversial applications of genetic engineering is the creation and use of genetically modified crops or genetically modified livestock to produce genetically modified food. Crops have been developed to increase production, increase tolerance to abiotic stresses, alter the composition of the food, or to produce novel products.[122]

The first crops to be realised commercially on a large scale provided protection from insect pests or tolerance to herbicides. Fungal and virus resistant crops have also been developed or are in development.[123][124] This make the insect and weed management of crops easier and can indirectly increase crop yield.[125][126] GM crops that directly improve yield by accelerating growth or making the plant more hardy (by improving salt, cold or drought tolerance) are also under development.[127] In 2016 Salmon have been genetically modified with growth hormones to reach normal adult size much faster.[128]

GMOs have been developed that modify the quality of produce by increasing the nutritional value or providing more industrially useful qualities or quantities.[127] The Amflora potato produces a more industrially useful blend of starches. Soybeans and canola have been genetically modified to produce more healthy oils.[129][130] The first commercialised GM food was a tomato that had delayed ripening, increasing its shelf life.[131]

Plants and animals have been engineered to produce materials they do not normally make. Pharming uses crops and animals as bioreactors to produce vaccines, drug intermediates, or the drugs themselves; the useful product is purified from the harvest and then used in the standard pharmaceutical production process.[132] Cows and goats have been engineered to express drugs and other proteins in their milk, and in 2009 the FDA approved a drug produced in goat milk.[133][134]

Genetic engineering has potential applications in conservation and natural area management. Gene transfer through viral vectors has been proposed as a means of controlling invasive species as well as vaccinating threatened fauna from disease.[135] Transgenic trees have been suggested as a way to confer resistance to pathogens in wild populations.[136] With the increasing risks of maladaptation in organisms as a result of climate change and other perturbations, facilitated adaptation through gene tweaking could be one solution to reducing extinction risks.[137] Applications of genetic engineering in conservation are thus far mostly theoretical and have yet to be put into practice.

Genetic engineering is also being used to create microbial art.[138] Some bacteria have been genetically engineered to create black and white photographs.[139] Novelty items such as lavender-colored carnations,[140] blue roses,[141] and glowing fish[142][143] have also been produced through genetic engineering.

The regulation of genetic engineering concerns the approaches taken by governments to assess and manage the risks associated with the development and release of GMOs. The development of a regulatory framework began in 1975, at Asilomar, California.[144] The Asilomar meeting recommended a set of voluntary guidelines regarding the use of recombinant technology.[145] As the technology improved USA established a committee at the Office of Science and Technology,[146] which assigned regulatory approval of GM food to the USDA, FDA and EPA.[147] The Cartagena Protocol on Biosafety, an international treaty that governs the transfer, handling, and use of GMOs,[148] was adopted on 29 January 2000.[149] One hundred and fifty-seven countries are members of the Protocol and many use it as a reference point for their own regulations.[150]

The legal and regulatory status of GM foods varies by country, with some nations banning or restricting them, and others permitting them with widely differing degrees of regulation.[151][152][153][154] Some countries allow the import of GM food with authorisation, but either do not allow its cultivation (Russia, Norway, Israel) or have provisions for cultivation even though no GM products are yet produced (Japan, South Korea). Most countries that do not allow GMO cultivation do permit research.[155] Some of the most marked differences occurring between the USA and Europe. The US policy focuses on the product (not the process), only looks at verifiable scientific risks and uses the concept of substantial equivalence.[156] The European Union by contrast has possibly the most stringent GMO regulations in the world.[157] All GMOs, along with irradiated food, are considered “new food” and subject to extensive, case-by-case, science-based food evaluation by the European Food Safety Authority. The criteria for authorisation fall in four broad categories: “safety,” “freedom of choice,” “labelling,” and “traceability.”[158] The level of regulation in other countries that cultivate GMOs lie in between Europe and the United States.

One of the key issues concerning regulators is whether GM products should be labeled. The European Commission says that mandatory labeling and traceability are needed to allow for informed choice, avoid potential false advertising[169] and facilitate the withdrawal of products if adverse effects on health or the environment are discovered.[170] The American Medical Association[171] and the American Association for the Advancement of Science[172] say that absent scientific evidence of harm even voluntary labeling is misleading and will falsely alarm consumers. Labeling of GMO products in the marketplace is required in 64 countries.[173] Labeling can be mandatory up to a threshold GM content level (which varies between countries) or voluntary. In Canada and the USA labeling of GM food is voluntary,[174] while in Europe all food (including processed food) or feed which contains greater than 0.9% of approved GMOs must be labelled.[157]

Critics have objected to the use of genetic engineering on several grounds, that include ethical, ecological and economic concerns. Many of these concerns involve GM crops and whether food produced from them is safe and what impact growing them will have on the environment. These controversies have led to litigation, international trade disputes, and protests, and to restrictive regulation of commercial products in some countries.[175]

Accusations that scientists are “playing God” and other religious issues have been ascribed to the technology from the beginning.[176] Other ethical issues raised include the patenting of life,[177] the use of intellectual property rights,[178] the level of labeling on products,[179][180] control of the food supply[181] and the objectivity of the regulatory process.[182] Although doubts have been raised,[183] economically most studies have found growing GM crops to be beneficial to farmers.[184][185][186]

Gene flow between GM crops and compatible plants, along with increased use of selective herbicides, can increase the risk of “superweeds” developing.[187] Other environmental concerns involve potential impacts on non-target organisms, including soil microbes,[188] and an increase in secondary and resistant insect pests.[189][190] Many of the environmental impacts regarding GM crops may take many years to be understood and are also evident in conventional agriculture practices.[188][191] With the commercialisation of genetically modified fish there are concerns over what the environmental consequences will be if they escape.[192]

There are three main concerns over the safety of genetically modified food: whether they may provoke an allergic reaction; whether the genes could transfer from the food into human cells; and whether the genes not approved for human consumption could outcross to other crops.[193] There is a scientific consensus[194][195][196][197] that currently available food derived from GM crops poses no greater risk to human health than conventional food,[198][199][200][201][202] but that each GM food needs to be tested on a case-by-case basis before introduction.[203][204][205] Nonetheless, members of the public are much less likely than scientists to perceive GM foods as safe.[206][207][208][209]

The literature about Biodiversity and the GE food/feed consumption has sometimes resulted in animated debate regarding the suitability of the experimental designs, the choice of the statistical methods or the public accessibility of data. Such debate, even if positive and part of the natural process of review by the scientific community, has frequently been distorted by the media and often used politically and inappropriately in anti-GE crops campaigns.

Panchin, Alexander Y.; Tuzhikov, Alexander I. (14 January 2016). “Published GMO studies find no evidence of harm when corrected for multiple comparisons”. Critical Reviews in Biotechnology: 15. doi:10.3109/07388551.2015.1130684. ISSN0738-8551. PMID26767435. Here, we show that a number of articles some of which have strongly and negatively influenced the public opinion on GM crops and even provoked political actions, such as GMO embargo, share common flaws in the statistical evaluation of the data. Having accounted for these flaws, we conclude that the data presented in these articles does not provide any substantial evidence of GMO harm.

The presented articles suggesting possible harm of GMOs received high public attention. However, despite their claims, they actually weaken the evidence for the harm and lack of substantial equivalency of studied GMOs. We emphasize that with over 1783 published articles on GMOs over the last 10 years it is expected that some of them should have reported undesired differences between GMOs and conventional crops even if no such differences exist in reality.and

Yang, Y.T.; Chen, B. (2016). “Governing GMOs in the USA: science, law and public health”. Journal of the Science of Food and Agriculture. 96: 18511855. doi:10.1002/jsfa.7523. PMID26536836. It is therefore not surprising that efforts to require labeling and to ban GMOs have been a growing political issue in the USA (citing Domingo and Bordonaba, 2011).

Overall, a broad scientific consensus holds that currently marketed GM food poses no greater risk than conventional food… Major national and international science and medical associations have stated that no adverse human health effects related to GMO food have been reported or substantiated in peer-reviewed literature to date.

Despite various concerns, today, the American Association for the Advancement of Science, the World Health Organization, and many independent international science organizations agree that GMOs are just as safe as other foods. Compared with conventional breeding techniques, genetic engineering is far more precise and, in most cases, less likely to create an unexpected outcome.

GM foods currently available on the international market have passed safety assessments and are not likely to present risks for human health. In addition, no effects on human health have been shown as a result of the consumption of such foods by the general population in the countries where they have been approved. Continuous application of safety assessments based on the Codex Alimentarius principles and, where appropriate, adequate post market monitoring, should form the basis for ensuring the safety of GM foods.

“Genetically modified foods and health: a second interim statement” (PDF). British Medical Association. March 2004. Retrieved 21 March 2016. In our view, the potential for GM foods to cause harmful health effects is very small and many of the concerns expressed apply with equal vigour to conventionally derived foods. However, safety concerns cannot, as yet, be dismissed completely on the basis of information currently available.

When seeking to optimise the balance between benefits and risks, it is prudent to err on the side of caution and, above all, learn from accumulating knowledge and experience. Any new technology such as genetic modification must be examined for possible benefits and risks to human health and the environment. As with all novel foods, safety assessments in relation to GM foods must be made on a case-by-case basis.

Members of the GM jury project were briefed on various aspects of genetic modification by a diverse group of acknowledged experts in the relevant subjects. The GM jury reached the conclusion that the sale of GM foods currently available should be halted and the moratorium on commercial growth of GM crops should be continued. These conclusions were based on the precautionary principle and lack of evidence of any benefit. The Jury expressed concern over the impact of GM crops on farming, the environment, food safety and other potential health effects.

The Royal Society review (2002) concluded that the risks to human health associated with the use of specific viral DNA sequences in GM plants are negligible, and while calling for caution in the introduction of potential allergens into food crops, stressed the absence of evidence that commercially available GM foods cause clinical allergic manifestations. The BMA shares the view that that there is no robust evidence to prove that GM foods are unsafe but we endorse the call for further research and surveillance to provide convincing evidence of safety and benefit.

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Genetic engineering – Wikipedia

Genetic engineering – Wikipedia

Genetic engineering, also called genetic modification or genetic manipulation, is the direct manipulation of an organism’s genes using biotechnology. It is a set of technologies used to change the genetic makeup of cells, including the transfer of genes within and across species boundaries to produce improved or novel organisms. New DNA is obtained by either isolating and copying the genetic material of interest using recombinant DNA methods or by artificially synthesising the DNA. A construct is usually created and used to insert this DNA into the host organism. The first recombinant DNA molecule was made by Paul Berg in 1972 by combining DNA from the monkey virus SV40 with the lambda virus. As well as inserting genes, the process can be used to remove, or “knock out”, genes. The new DNA can be inserted randomly, or targeted to a specific part of the genome.

An organism that is generated through genetic engineering is considered to be genetically modified (GM) and the resulting entity is a genetically modified organism (GMO). The first GMO was a bacterium generated by Herbert Boyer and Stanley Cohen in 1973. Rudolf Jaenisch created the first GM animal when he inserted foreign DNA into a mouse in 1974. The first company to focus on genetic engineering, Genentech, was founded in 1976 and started the production of human proteins. Genetically engineered human insulin was produced in 1978 and insulin-producing bacteria were commercialised in 1982. Genetically modified food has been sold since 1994, with the release of the Flavr Savr tomato. The Flavr Savr was engineered to have a longer shelf life, but most current GM crops are modified to increase resistance to insects and herbicides. GloFish, the first GMO designed as a pet, was sold in the United States in December 2003. In 2016 salmon modified with a growth hormone were sold.

Genetic engineering has been applied in numerous fields including research, medicine, industrial biotechnology and agriculture. In research GMOs are used to study gene function and expression through loss of function, gain of function, tracking and expression experiments. By knocking out genes responsible for certain conditions it is possible to create animal model organisms of human diseases. As well as producing hormones, vaccines and other drugs genetic engineering has the potential to cure genetic diseases through gene therapy. The same techniques that are used to produce drugs can also have industrial applications such as producing enzymes for laundry detergent, cheeses and other products.

The rise of commercialised genetically modified crops has provided economic benefit to farmers in many different countries, but has also been the source of most of the controversy surrounding the technology. This has been present since its early use, the first field trials were destroyed by anti-GM activists. Although there is a scientific consensus that currently available food derived from GM crops poses no greater risk to human health than conventional food, GM food safety is a leading concern with critics. Gene flow, impact on non-target organisms, control of the food supply and intellectual property rights have also been raised as potential issues. These concerns have led to the development of a regulatory framework, which started in 1975. It has led to an international treaty, the Cartagena Protocol on Biosafety, that was adopted in 2000. Individual countries have developed their own regulatory systems regarding GMOs, with the most marked differences occurring between the USA and Europe.

Genetic engineering is a process that alters the genetic structure of an organism by either removing or introducing DNA. Unlike traditionally animal and plant breeding, which involves doing multiple crosses and then selecting for the organism with the desired phenotype, genetic engineering takes the gene directly from one organism and inserts it in the other. This is much faster, can be used to insert any genes from any organism (even ones from different domains) and prevents other undesirable genes from also being added.[3]

Genetic engineering could potentially fix severe genetic disorders in humans by replacing the defective gene with a functioning one.[4] It is an important tool in research that allows the function of specific genes to be studied.[5] Drugs, vaccines and other products have been harvested from organisms engineered to produce them.[6] Crops have been developed that aid food security by increasing yield, nutritional value and tolerance to environmental stresses.[7]

The DNA can be introduced directly into the host organism or into a cell that is then fused or hybridised with the host.[8] This relies on recombinant nucleic acid techniques to form new combinations of heritable genetic material followed by the incorporation of that material either indirectly through a vector system or directly through micro-injection, macro-injection or micro-encapsulation.[9]

Genetic engineering does not normally include traditional breeding, in vitro fertilisation, induction of polyploidy, mutagenesis and cell fusion techniques that do not use recombinant nucleic acids or a genetically modified organism in the process.[8] However, some broad definitions of genetic engineering include selective breeding.[9] Cloning and stem cell research, although not considered genetic engineering,[10] are closely related and genetic engineering can be used within them.[11] Synthetic biology is an emerging discipline that takes genetic engineering a step further by introducing artificially synthesised material into an organism.[12]

Plants, animals or micro organisms that have been changed through genetic engineering are termed genetically modified organisms or GMOs.[13] If genetic material from another species is added to the host, the resulting organism is called transgenic. If genetic material from the same species or a species that can naturally breed with the host is used the resulting organism is called cisgenic.[14] If genetic engineering is used to remove genetic material from the target organism the resulting organism is termed a knockout organism.[15] In Europe genetic modification is synonymous with genetic engineering while within the United States of America and Canada genetic modification can also be used to refer to more conventional breeding methods.[16][17][18]

Humans have altered the genomes of species for thousands of years through selective breeding, or artificial selection[19]:1[20]:1 as contrasted with natural selection, and more recently through mutagenesis. Genetic engineering as the direct manipulation of DNA by humans outside breeding and mutations has only existed since the 1970s. The term “genetic engineering” was first coined by Jack Williamson in his science fiction novel Dragon’s Island, published in 1951[21] one year before DNA’s role in heredity was confirmed by Alfred Hershey and Martha Chase,[22] and two years before James Watson and Francis Crick showed that the DNA molecule has a double-helix structure though the general concept of direct genetic manipulation was explored in rudimentary form in Stanley G. Weinbaum’s 1936 science fiction story Proteus Island.[23][24]

In 1972, Paul Berg created the first recombinant DNA molecules by combining DNA from the monkey virus SV40 with that of the lambda virus.[25] In 1973 Herbert Boyer and Stanley Cohen created the first transgenic organism by inserting antibiotic resistance genes into the plasmid of an Escherichia coli bacterium.[26][27] A year later Rudolf Jaenisch created a transgenic mouse by introducing foreign DNA into its embryo, making it the worlds first transgenic animal.[28] These achievements led to concerns in the scientific community about potential risks from genetic engineering, which were first discussed in depth at the Asilomar Conference in 1975. One of the main recommendations from this meeting was that government oversight of recombinant DNA research should be established until the technology was deemed safe.[29][30]

In 1976 Genentech, the first genetic engineering company, was founded by Herbert Boyer and Robert Swanson and a year later the company produced a human protein (somatostatin) in E.coli. Genentech announced the production of genetically engineered human insulin in 1978.[31] In 1980, the U.S. Supreme Court in the Diamond v. Chakrabarty case ruled that genetically altered life could be patented.[32] The insulin produced by bacteria was approved for release by the Food and Drug Administration (FDA) in 1982.[33]

In 1983, a biotech company, Advanced Genetic Sciences (AGS) applied for U.S. government authorisation to perform field tests with the ice-minus strain of Pseudomonas syringae to protect crops from frost, but environmental groups and protestors delayed the field tests for four years with legal challenges.[34] In 1987, the ice-minus strain of P. syringae became the first genetically modified organism (GMO) to be released into the environment[35] when a strawberry field and a potato field in California were sprayed with it.[36] Both test fields were attacked by activist groups the night before the tests occurred: “The world’s first trial site attracted the world’s first field trasher”.[35]

The first field trials of genetically engineered plants occurred in France and the USA in 1986, tobacco plants were engineered to be resistant to herbicides.[37] The Peoples Republic of China was the first country to commercialise transgenic plants, introducing a virus-resistant tobacco in 1992.[38] In 1994 Calgene attained approval to commercially release the first genetically modified food, the Flavr Savr, a tomato engineered to have a longer shelf life.[39] In 1994, the European Union approved tobacco engineered to be resistant to the herbicide bromoxynil, making it the first genetically engineered crop commercialised in Europe.[40] In 1995, Bt Potato was approved safe by the Environmental Protection Agency, after having been approved by the FDA, making it the first pesticide producing crop to be approved in the USA.[41] In 2009 11 transgenic crops were grown commercially in 25 countries, the largest of which by area grown were the USA, Brazil, Argentina, India, Canada, China, Paraguay and South Africa.[42]

In 2010, scientists at the J. Craig Venter Institute created the first synthetic genome and inserted it into an empty bacterial cell. The resulting bacterium, named Mycoplasma laboratorium, could replicate and produce proteins.[43][44] Four years later this was taken a step further when bacterium was developed that replicated a plasmid containing a unique base pair, creating the first organism engineered to use an expanded genetic alphabet.[45][46] In 2012, Jennifer Doudna and Emmanuelle Charpentier collaborated to develop the CRISPR/Cas9 system,[47][48] a technique which can be used to easily and specifically alter the genome of almost any organism.[49]

Creating a GMO is a multi-step process. Genetic engineers must first choose what gene they wish to insert into the organism. This is driven by what the aim is for the resultant organism and is built on earlier research. Genetic screens can be carried out to determine potential genes and further tests then used to identify the best candidates. The development of microarrays, transcriptomics and genome sequencing has made it much easier to find suitable genes.[50] Luck also plays its part; the round-up ready gene was discovered after scientists noticed a bacterium thriving in the presence of the herbicide.[51]

The next step is to isolate the candidate gene. The cell containing the gene is opened and the DNA is purified.[52] The gene is separated by using restriction enzymes to cut the DNA into fragments[53] or polymerase chain reaction (PCR) to amplify up the gene segment.[54] These segments can then be extracted through gel electrophoresis. If the chosen gene or the donor organism’s genome has been well studied it may already be accessible from a genetic library. If the DNA sequence is known, but no copies of the gene are available, it can also be artificially synthesised.[55] Once isolated the gene is ligated into a plasmid that is then inserted into a bacterium. The plasmid is replicated when the bacteria divide, ensuring unlimited copies of the gene are available.[56]

Before the gene is inserted into the target organism it must be combined with other genetic elements. These include a promoter and terminator region, which initiate and end transcription. A selectable marker gene is added, which in most cases confers antibiotic resistance, so researchers can easily determine which cells have been successfully transformed. The gene can also be modified at this stage for better expression or effectiveness. These manipulations are carried out using recombinant DNA techniques, such as restriction digests, ligations and molecular cloning.[57]

There are a number of techniques available for inserting the gene into the host genome. Some bacteria can naturally take up foreign DNA. This ability can be induced in other bacteria via stress (e.g. thermal or electric shock), which increases the cell membrane’s permeability to DNA; up-taken DNA can either integrate with the genome or exist as extrachromosomal DNA. DNA is generally inserted into animal cells using microinjection, where it can be injected through the cell’s nuclear envelope directly into the nucleus, or through the use of viral vectors.[58]

In plants the DNA is often inserted using Agrobacterium-mediated recombination,[59] taking advantage of the Agrobacteriums T-DNA sequence that allows natural insertion of genetic material into plant cells.[60] Other methods include biolistics, where particles of gold or tungsten are coated with DNA and then shot into young plant cells,[61] and electroporation, which involves using an electric shock to make the cell membrane permeable to plasmid DNA. Due to the damage caused to the cells and DNA the transformation efficiency of biolistics and electroporation is lower than agrobacterial transformation and microinjection.[62]

As only a single cell is transformed with genetic material, the organism must be regenerated from that single cell. In plants this is accomplished through the use of tissue culture.[63][64] In animals it is necessary to ensure that the inserted DNA is present in the embryonic stem cells.[65] Bacteria consist of a single cell and reproduce clonally so regeneration is not necessary. Selectable markers are used to easily differentiate transformed from untransformed cells. These markers are usually present in the transgenic organism, although a number of strategies have been developed that can remove the selectable marker from the mature transgenic plant.[66]

Further testing using PCR, Southern hybridization, and DNA sequencing is conducted to confirm that an organism contains the new gene.[67] These tests can also confirm the chromosomal location and copy number of the inserted gene. The presence of the gene does not guarantee it will be expressed at appropriate levels in the target tissue so methods that look for and measure the gene products (RNA and protein) are also used. These include northern hybridisation, quantitative RT-PCR, Western blot, immunofluorescence, ELISA and phenotypic analysis.[68]

The new genetic material can be inserted randomly within the host genome or targeted to a specific location. The technique of gene targeting uses homologous recombination to make desired changes to a specific endogenous gene. This tends to occur at a relatively low frequency in plants and animals and generally requires the use of selectable markers. The frequency of gene targeting can be greatly enhanced through genome editing. Genome editing uses artificially engineered nucleases that create specific double-stranded breaks at desired locations in the genome, and use the cells endogenous mechanisms to repair the induced break by the natural processes of homologous recombination and nonhomologous end-joining. There are four families of engineered nucleases: meganucleases,[69][70] zinc finger nucleases,[71][72] transcription activator-like effector nucleases (TALENs),[73][74] and the Cas9-guideRNA system (adapted from CRISPR).[75][76] TALEN and CRISPR are the two most commonly used and each has its own advantages.[77] TALENs have greater target specificity, while CRISPR is easier to design and more efficient.[77] In addition to enhancing gene targeting, engineered nucleases can be used to introduce mutations at endogenous genes that generate a gene knockout.[78][79]

Genetic engineering has applications in medicine, research, industry and agriculture and can be used on a wide range of plants, animals and micro organisms. Bacteria, the first organisms to be genetically modified, can have plasmid DNA inserted containing new genes that code for medicines or enzymes that process food and other substrates.[80][81] Plants have been modified for insect protection, herbicide resistance, virus resistance, enhanced nutrition, tolerance to environmental pressures and the production of edible vaccines.[82] Most commercialised GMOs are insect resistant or herbicide tolerant crop plants.[83] Genetically modified animals have been used for research, model animals and the production of agricultural or pharmaceutical products. The genetically modified animals include animals with genes knocked out, increased susceptibility to disease, hormones for extra growth and the ability to express proteins in their milk.[84]

Genetic engineering has many applications to medicine that include the manufacturing of drugs, creation of model animals that mimic human conditions and gene therapy. One of the earliest uses of genetic engineering was to mass-produce human insulin in bacteria.[31] This application has now been applied to, human growth hormones, follicle stimulating hormones (for treating infertility), human albumin, monoclonal antibodies, antihemophilic factors, vaccines and many other drugs.[85][86] Mouse hybridomas, cells fused together to create monoclonal antibodies, have been adapted through genetic engineering to create human monoclonal antibodies.[87] In 2017, genetic engineering of chimeric antigen receptors on a patient’s own T-cells was approved by the U.S. FDA as a treatment for the cancer acute lymphoblastic leukemia. Genetically engineered viruses are being developed that can still confer immunity, but lack the infectious sequences.[88]

Genetic engineering is also used to create animal models of human diseases. Genetically modified mice are the most common genetically engineered animal model.[89] They have been used to study and model cancer (the oncomouse), obesity, heart disease, diabetes, arthritis, substance abuse, anxiety, aging and Parkinson disease.[90] Potential cures can be tested against these mouse models. Also genetically modified pigs have been bred with the aim of increasing the success of pig to human organ transplantation.[91]

Gene therapy is the genetic engineering of humans, generally by replacing defective genes with effective ones. Clinical research using somatic gene therapy has been conducted with several diseases, including X-linked SCID,[92] chronic lymphocytic leukemia (CLL),[93][94] and Parkinson’s disease.[95] In 2012, Alipogene tiparvovec became the first gene therapy treatment to be approved for clinical use.[96][97] In 2015 a virus was used to insert a healthy gene into the skin cells of a boy suffering from a rare skin disease, epidermolysis bullosa, in order to grow, and then graft healthy skin onto 80 percent of the boy’s body which was affected by the illness.[98] Germline gene therapy would result in any change being inheritable, which has raised concerns within the scientific community.[99][100] In 2015, CRISPR was used to edit the DNA of non-viable human embryos,[101][102] leading scientists of major world academies to call for a moratorium on inheritable human genome edits.[103] There are also concerns that the technology could be used not just for treatment, but for enhancement, modification or alteration of a human beings’ appearance, adaptability, intelligence, character or behavior.[104] The distinction between cure and enhancement can also be difficult to establish.[105]

Researchers are altering the genome of pigs to induce the growth of human organs to be used in transplants. Scientists are creating “gene drives”, changing the genomes of mosquitoes to make them immune to malaria, and then spreading the genetically altered mosquitoes throughout the mosquito population in the hopes of eliminating the disease.[106]

Genetic engineering is an important tool for natural scientists. Genes and other genetic information from a wide range of organisms can be inserted into bacteria for storage and modification, creating genetically modified bacteria in the process. Bacteria are cheap, easy to grow, clonal, multiply quickly, relatively easy to transform and can be stored at -80C almost indefinitely. Once a gene is isolated it can be stored inside the bacteria providing an unlimited supply for research.[107]

Organisms are genetically engineered to discover the functions of certain genes. This could be the effect on the phenotype of the organism, where the gene is expressed or what other genes it interacts with. These experiments generally involve loss of function, gain of function, tracking and expression.

Organisms can have their cells transformed with a gene coding for a useful protein, such as an enzyme, so that they will overexpress the desired protein. Mass quantities of the protein can then be manufactured by growing the transformed organism in bioreactor equipment using industrial fermentation, and then purifying the protein.[111] Some genes do not work well in bacteria, so yeast, insect cells or mammalians cells can also be used.[112] These techniques are used to produce medicines such as insulin, human growth hormone, and vaccines, supplements such as tryptophan, aid in the production of food (chymosin in cheese making) and fuels.[113] Other applications with genetically engineered bacteria could involve making them perform tasks outside their natural cycle, such as making biofuels,[114] cleaning up oil spills, carbon and other toxic waste[115] and detecting arsenic in drinking water.[116] Certain genetically modified microbes can also be used in biomining and bioremediation, due to their ability to extract heavy metals from their environment and incorporate them into compounds that are more easily recoverable.[117]

In materials science, a genetically modified virus has been used in a research laboratory as a scaffold for assembling a more environmentally friendly lithium-ion battery.[118][119] Bacteria have also been engineered to function as sensors by expressing a fluorescent protein under certain environmental conditions.[120]

One of the best-known and controversial applications of genetic engineering is the creation and use of genetically modified crops or genetically modified livestock to produce genetically modified food. Crops have been developed to increase production, increase tolerance to abiotic stresses, alter the composition of the food, or to produce novel products.[122]

The first crops to be realised commercially on a large scale provided protection from insect pests or tolerance to herbicides. Fungal and virus resistant crops have also been developed or are in development.[123][124] This make the insect and weed management of crops easier and can indirectly increase crop yield.[125][126] GM crops that directly improve yield by accelerating growth or making the plant more hardy (by improving salt, cold or drought tolerance) are also under development.[127] In 2016 Salmon have been genetically modified with growth hormones to reach normal adult size much faster.[128]

GMOs have been developed that modify the quality of produce by increasing the nutritional value or providing more industrially useful qualities or quantities.[127] The Amflora potato produces a more industrially useful blend of starches. Soybeans and canola have been genetically modified to produce more healthy oils.[129][130] The first commercialised GM food was a tomato that had delayed ripening, increasing its shelf life.[131]

Plants and animals have been engineered to produce materials they do not normally make. Pharming uses crops and animals as bioreactors to produce vaccines, drug intermediates, or the drugs themselves; the useful product is purified from the harvest and then used in the standard pharmaceutical production process.[132] Cows and goats have been engineered to express drugs and other proteins in their milk, and in 2009 the FDA approved a drug produced in goat milk.[133][134]

Genetic engineering has potential applications in conservation and natural area management. Gene transfer through viral vectors has been proposed as a means of controlling invasive species as well as vaccinating threatened fauna from disease.[135] Transgenic trees have been suggested as a way to confer resistance to pathogens in wild populations.[136] With the increasing risks of maladaptation in organisms as a result of climate change and other perturbations, facilitated adaptation through gene tweaking could be one solution to reducing extinction risks.[137] Applications of genetic engineering in conservation are thus far mostly theoretical and have yet to be put into practice.

Genetic engineering is also being used to create microbial art.[138] Some bacteria have been genetically engineered to create black and white photographs.[139] Novelty items such as lavender-colored carnations,[140] blue roses,[141] and glowing fish[142][143] have also been produced through genetic engineering.

The regulation of genetic engineering concerns the approaches taken by governments to assess and manage the risks associated with the development and release of GMOs. The development of a regulatory framework began in 1975, at Asilomar, California.[144] The Asilomar meeting recommended a set of voluntary guidelines regarding the use of recombinant technology.[145] As the technology improved USA established a committee at the Office of Science and Technology,[146] which assigned regulatory approval of GM food to the USDA, FDA and EPA.[147] The Cartagena Protocol on Biosafety, an international treaty that governs the transfer, handling, and use of GMOs,[148] was adopted on 29 January 2000.[149] One hundred and fifty-seven countries are members of the Protocol and many use it as a reference point for their own regulations.[150]

The legal and regulatory status of GM foods varies by country, with some nations banning or restricting them, and others permitting them with widely differing degrees of regulation.[151][152][153][154] Some countries allow the import of GM food with authorisation, but either do not allow its cultivation (Russia, Norway, Israel) or have provisions for cultivation even though no GM products are yet produced (Japan, South Korea). Most countries that do not allow GMO cultivation do permit research.[155] Some of the most marked differences occurring between the USA and Europe. The US policy focuses on the product (not the process), only looks at verifiable scientific risks and uses the concept of substantial equivalence.[156] The European Union by contrast has possibly the most stringent GMO regulations in the world.[157] All GMOs, along with irradiated food, are considered “new food” and subject to extensive, case-by-case, science-based food evaluation by the European Food Safety Authority. The criteria for authorisation fall in four broad categories: “safety,” “freedom of choice,” “labelling,” and “traceability.”[158] The level of regulation in other countries that cultivate GMOs lie in between Europe and the United States.

One of the key issues concerning regulators is whether GM products should be labeled. The European Commission says that mandatory labeling and traceability are needed to allow for informed choice, avoid potential false advertising[169] and facilitate the withdrawal of products if adverse effects on health or the environment are discovered.[170] The American Medical Association[171] and the American Association for the Advancement of Science[172] say that absent scientific evidence of harm even voluntary labeling is misleading and will falsely alarm consumers. Labeling of GMO products in the marketplace is required in 64 countries.[173] Labeling can be mandatory up to a threshold GM content level (which varies between countries) or voluntary. In Canada and the USA labeling of GM food is voluntary,[174] while in Europe all food (including processed food) or feed which contains greater than 0.9% of approved GMOs must be labelled.[157]

Critics have objected to the use of genetic engineering on several grounds, that include ethical, ecological and economic concerns. Many of these concerns involve GM crops and whether food produced from them is safe and what impact growing them will have on the environment. These controversies have led to litigation, international trade disputes, and protests, and to restrictive regulation of commercial products in some countries.[175]

Accusations that scientists are “playing God” and other religious issues have been ascribed to the technology from the beginning.[176] Other ethical issues raised include the patenting of life,[177] the use of intellectual property rights,[178] the level of labeling on products,[179][180] control of the food supply[181] and the objectivity of the regulatory process.[182] Although doubts have been raised,[183] economically most studies have found growing GM crops to be beneficial to farmers.[184][185][186]

Gene flow between GM crops and compatible plants, along with increased use of selective herbicides, can increase the risk of “superweeds” developing.[187] Other environmental concerns involve potential impacts on non-target organisms, including soil microbes,[188] and an increase in secondary and resistant insect pests.[189][190] Many of the environmental impacts regarding GM crops may take many years to be understood and are also evident in conventional agriculture practices.[188][191] With the commercialisation of genetically modified fish there are concerns over what the environmental consequences will be if they escape.[192]

There are three main concerns over the safety of genetically modified food: whether they may provoke an allergic reaction; whether the genes could transfer from the food into human cells; and whether the genes not approved for human consumption could outcross to other crops.[193] There is a scientific consensus[194][195][196][197] that currently available food derived from GM crops poses no greater risk to human health than conventional food,[198][199][200][201][202] but that each GM food needs to be tested on a case-by-case basis before introduction.[203][204][205] Nonetheless, members of the public are much less likely than scientists to perceive GM foods as safe.[206][207][208][209]

The literature about Biodiversity and the GE food/feed consumption has sometimes resulted in animated debate regarding the suitability of the experimental designs, the choice of the statistical methods or the public accessibility of data. Such debate, even if positive and part of the natural process of review by the scientific community, has frequently been distorted by the media and often used politically and inappropriately in anti-GE crops campaigns.

Panchin, Alexander Y.; Tuzhikov, Alexander I. (14 January 2016). “Published GMO studies find no evidence of harm when corrected for multiple comparisons”. Critical Reviews in Biotechnology: 15. doi:10.3109/07388551.2015.1130684. ISSN0738-8551. PMID26767435. Here, we show that a number of articles some of which have strongly and negatively influenced the public opinion on GM crops and even provoked political actions, such as GMO embargo, share common flaws in the statistical evaluation of the data. Having accounted for these flaws, we conclude that the data presented in these articles does not provide any substantial evidence of GMO harm.

The presented articles suggesting possible harm of GMOs received high public attention. However, despite their claims, they actually weaken the evidence for the harm and lack of substantial equivalency of studied GMOs. We emphasize that with over 1783 published articles on GMOs over the last 10 years it is expected that some of them should have reported undesired differences between GMOs and conventional crops even if no such differences exist in reality.and

Yang, Y.T.; Chen, B. (2016). “Governing GMOs in the USA: science, law and public health”. Journal of the Science of Food and Agriculture. 96: 18511855. doi:10.1002/jsfa.7523. PMID26536836. It is therefore not surprising that efforts to require labeling and to ban GMOs have been a growing political issue in the USA (citing Domingo and Bordonaba, 2011).

Overall, a broad scientific consensus holds that currently marketed GM food poses no greater risk than conventional food… Major national and international science and medical associations have stated that no adverse human health effects related to GMO food have been reported or substantiated in peer-reviewed literature to date.

Despite various concerns, today, the American Association for the Advancement of Science, the World Health Organization, and many independent international science organizations agree that GMOs are just as safe as other foods. Compared with conventional breeding techniques, genetic engineering is far more precise and, in most cases, less likely to create an unexpected outcome.

GM foods currently available on the international market have passed safety assessments and are not likely to present risks for human health. In addition, no effects on human health have been shown as a result of the consumption of such foods by the general population in the countries where they have been approved. Continuous application of safety assessments based on the Codex Alimentarius principles and, where appropriate, adequate post market monitoring, should form the basis for ensuring the safety of GM foods.

“Genetically modified foods and health: a second interim statement” (PDF). British Medical Association. March 2004. Retrieved 21 March 2016. In our view, the potential for GM foods to cause harmful health effects is very small and many of the concerns expressed apply with equal vigour to conventionally derived foods. However, safety concerns cannot, as yet, be dismissed completely on the basis of information currently available.

When seeking to optimise the balance between benefits and risks, it is prudent to err on the side of caution and, above all, learn from accumulating knowledge and experience. Any new technology such as genetic modification must be examined for possible benefits and risks to human health and the environment. As with all novel foods, safety assessments in relation to GM foods must be made on a case-by-case basis.

Members of the GM jury project were briefed on various aspects of genetic modification by a diverse group of acknowledged experts in the relevant subjects. The GM jury reached the conclusion that the sale of GM foods currently available should be halted and the moratorium on commercial growth of GM crops should be continued. These conclusions were based on the precautionary principle and lack of evidence of any benefit. The Jury expressed concern over the impact of GM crops on farming, the environment, food safety and other potential health effects.

The Royal Society review (2002) concluded that the risks to human health associated with the use of specific viral DNA sequences in GM plants are negligible, and while calling for caution in the introduction of potential allergens into food crops, stressed the absence of evidence that commercially available GM foods cause clinical allergic manifestations. The BMA shares the view that that there is no robust evidence to prove that GM foods are unsafe but we endorse the call for further research and surveillance to provide convincing evidence of safety and benefit.

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Genetic engineering – Wikipedia

genetic engineering | Definition, Process, & Uses …

Genetic engineering, the artificial manipulation, modification, and recombination of DNA or other nucleic acid molecules in order to modify an organism or population of organisms.

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origins of agriculture: Genetic engineering

The application of genetics to agriculture since World War II has resulted in substantial increases in the production of many crops. This has been most notable in hybrid strains of maize and grain sorghum. At the same time, crossbreeding has resulted in much

The term genetic engineering initially referred to various techniques used for the modification or manipulation of organisms through the processes of heredity and reproduction. As such, the term embraced both artificial selection and all the interventions of biomedical techniques, among them artificial insemination, in vitro fertilization (e.g., test-tube babies), cloning, and gene manipulation. In the latter part of the 20th century, however, the term came to refer more specifically to methods of recombinant DNA technology (or gene cloning), in which DNA molecules from two or more sources are combined either within cells or in vitro and are then inserted into host organisms in which they are able to propagate.

The possibility for recombinant DNA technology emerged with the discovery of restriction enzymes in 1968 by Swiss microbiologist Werner Arber. The following year American microbiologist Hamilton O. Smith purified so-called type II restriction enzymes, which were found to be essential to genetic engineering for their ability to cleave a specific site within the DNA (as opposed to type I restriction enzymes, which cleave DNA at random sites). Drawing on Smiths work, American molecular biologist Daniel Nathans helped advance the technique of DNA recombination in 197071 and demonstrated that type II enzymes could be useful in genetic studies. Genetic engineering based on recombination was pioneered in 1973 by American biochemists Stanley N. Cohen and Herbert W. Boyer, who were among the first to cut DNA into fragments, rejoin different fragments, and insert the new genes into E. coli bacteria, which then reproduced.

Most recombinant DNA technology involves the insertion of foreign genes into the plasmids of common laboratory strains of bacteria. Plasmids are small rings of DNA; they are not part of the bacteriums chromosome (the main repository of the organisms genetic information). Nonetheless, they are capable of directing protein synthesis, and, like chromosomal DNA, they are reproduced and passed on to the bacteriums progeny. Thus, by incorporating foreign DNA (for example, a mammalian gene) into a bacterium, researchers can obtain an almost limitless number of copies of the inserted gene. Furthermore, if the inserted gene is operative (i.e., if it directs protein synthesis), the modified bacterium will produce the protein specified by the foreign DNA.

A subsequent generation of genetic engineering techniques that emerged in the early 21st century centred on gene editing. Gene editing, based on a technology known as CRISPR-Cas9, allows researchers to customize a living organisms genetic sequence by making very specific changes to its DNA. Gene editing has a wide array of applications, being used for the genetic modification of crop plants and livestock and of laboratory model organisms (e.g., mice). The correction of genetic errors associated with disease in animals suggests that gene editing has potential applications in gene therapy for humans.

Genetic engineering has advanced the understanding of many theoretical and practical aspects of gene function and organization. Through recombinant DNA techniques, bacteria have been created that are capable of synthesizing human insulin, human growth hormone, alpha interferon, a hepatitis B vaccine, and other medically useful substances. Plants may be genetically adjusted to enable them to fix nitrogen, and genetic diseases can possibly be corrected by replacing dysfunctional genes with normally functioning genes. Nevertheless, special concern has been focused on such achievements for fear that they might result in the introduction of unfavourable and possibly dangerous traits into microorganisms that were previously free of theme.g., resistance to antibiotics, production of toxins, or a tendency to cause disease. Likewise, the application of gene editing in humans has raised ethical concerns, particularly regarding its potential use to alter traits such as intelligence and beauty.

In 1980 the new microorganisms created by recombinant DNA research were deemed patentable, and in 1986 the U.S. Department of Agriculture approved the sale of the first living genetically altered organisma virus, used as a pseudorabies vaccine, from which a single gene had been cut. Since then several hundred patents have been awarded for genetically altered bacteria and plants. Patents on genetically engineered and genetically modified organisms, particularly crops and other foods, however, were a contentious issue, and they remained so into the first part of the 21st century.

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genetic engineering | Definition, Process, & Uses …

Genetic Engineering | Definition of Genetic Engineering by …

: the group of applied techniques of genetics and biotechnology used to cut up and join together genetic material and especially DNA from one or more species of organism and to introduce the result into an organism in order to change one or more of its characteristics

genetically engineered adjective

genetic engineer noun

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Genetic Engineering | Definition of Genetic Engineering by …

What is Genetic Engineering? – Definition and Examples …

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What is Genetic Engineering? – Definition and Examples …

Genetic Engineering: What is Genetic Engineering?

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Futurist Keynote Speaker: Posts, Slides, Videos – BioTech, MedTech, Gene Therapy and Stem Cells

Video on Genetic Engineering

Genetic engineering is the alteration of genetic code by artificial means, and is therefore different from traditional selective breeding.

Huge number of other resources on this site about Genetic engineering.

Genetic engineering examples include taking the gene that programs poison in the tail of a scorpion, and combining it with a cabbage. These genetically modified cabbages kill caterpillers because they have learned to grow scorpion poison (insecticide) in their sap.

Genetic engineering also includes insertion of human genes into sheep so that they secrete alpha-1 antitrypsin in their milk – a useful substance in treating some cases of lung disease.

Genetic engineering has created a chicken with four legs and no wings.

Genetic engineering has created a goat with spider genes that creates “silk” in its milk.

Genetic engineering works because there is one language of life: human genes work in bacteria, monkey genes work in mice and earthworms. Tree genes work in bananas and frog genes work in rice. There is no limit in theory to the potential of genetic engineering.

Genetic engineering has given us the power to alter the very basis of life on earth.

Genetic engineering has been said to be no different than ancient breeding methods but this is untrue. For a start, breeding or cross-breeding, or in-breeding (for example to make pedigree dogs) all work by using the same species. In contrast genetic engineering allows us to combine fish, mouse, human and insect genes in the same person or animal.

Genetic engineering therefore has few limits – except our imagination, and our moral or ethical code.

Genetic engineering makes the whole digital revolution look nothing. Digital technology changes what we do. Genetic engineering has the power to change who we are.

Human cloning is a type of genetic engineering, but is not the same as true genetic manipulation. In human cloning, the aim is to duplicate the genes of an existing person so that an identical set is inside a human egg. The result is intended to be a cloned twin, perhaps of a dead child. Genetic engineering in its fullest form would result in the child produced having unique genes – as a result of laboratory interference, and therefore the child will not be an identikit twin.

Genetic engineering could create crops that grow in desert heat, or without fertiliser. Genetic engineering could make bananas or other fruit which contain vaccines or other medical products.

Genetic engineering is helped by the fact that it only costs $1000 to analyse someone’s genetic code (sequencing of genome) – down from $800m in 2001.

Genetic engineering is aided by techniques such as Crispr which allow scientists to swop genes between humans or between animals and humans or between animals, in a very precise and controlled way.

Genetic engineering will alter the basis of life on earth – permanently – unless controlled. This could happen if – say – mutant viruses, or bacteria, or fish or reptiles are released into the general environment.

READ FREE BOOK on Genetic Engineering – by Patrick Dixon, author of 16 books and creator of this website – read now: Chapters 1 and 2 explain basics in way which is easy to understand.

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Genetic Engineering: What is Genetic Engineering?

Gene therapy – Wikipedia

In the medicine field, gene therapy (also called human gene transfer) is the therapeutic delivery of nucleic acid into a patient’s cells as a drug to treat disease.[1][2] The first attempt at modifying human DNA was performed in 1980 by Martin Cline, but the first successful nuclear gene transfer in humans, approved by the National Institutes of Health, was performed in May 1989.[3] The first therapeutic use of gene transfer as well as the first direct insertion of human DNA into the nuclear genome was performed by French Anderson in a trial starting in September 1990.

Between 1989 and February 2016, over 2,300 clinical trials had been conducted, more than half of them in phase I.[4]

Not all medical procedures that introduce alterations to a patient’s genetic makeup can be considered gene therapy. Bone marrow transplantation and organ transplants in general have been found to introduce foreign DNA into patients.[5] Gene therapy is defined by the precision of the procedure and the intention of direct therapeutic effect.

Gene therapy was conceptualized in 1972, by authors who urged caution before commencing human gene therapy studies.

The first attempt, an unsuccessful one, at gene therapy (as well as the first case of medical transfer of foreign genes into humans not counting organ transplantation) was performed by Martin Cline on 10 July 1980.[6][7] Cline claimed that one of the genes in his patients was active six months later, though he never published this data or had it verified[8] and even if he is correct, it’s unlikely it produced any significant beneficial effects treating beta-thalassemia.

After extensive research on animals throughout the 1980s and a 1989 bacterial gene tagging trial on humans, the first gene therapy widely accepted as a success was demonstrated in a trial that started on 14 September 1990, when Ashi DeSilva was treated for ADA-SCID.[9]

The first somatic treatment that produced a permanent genetic change was performed in 1993.[citation needed]

Gene therapy is a way to fix a genetic problem at its source. The polymers are either translated into proteins, interfere with target gene expression, or possibly correct genetic mutations.

The most common form uses DNA that encodes a functional, therapeutic gene to replace a mutated gene. The polymer molecule is packaged within a “vector”, which carries the molecule inside cells.

Early clinical failures led to dismissals of gene therapy. Clinical successes since 2006 regained researchers’ attention, although as of 2014[update], it was still largely an experimental technique.[10] These include treatment of retinal diseases Leber’s congenital amaurosis[11][12][13][14] and choroideremia,[15] X-linked SCID,[16] ADA-SCID,[17][18] adrenoleukodystrophy,[19] chronic lymphocytic leukemia (CLL),[20] acute lymphocytic leukemia (ALL),[21] multiple myeloma,[22] haemophilia,[18] and Parkinson’s disease.[23] Between 2013 and April 2014, US companies invested over $600 million in the field.[24]

The first commercial gene therapy, Gendicine, was approved in China in 2003 for the treatment of certain cancers.[25] In 2011 Neovasculgen was registered in Russia as the first-in-class gene-therapy drug for treatment of peripheral artery disease, including critical limb ischemia.[26]In 2012 Glybera, a treatment for a rare inherited disorder, became the first treatment to be approved for clinical use in either Europe or the United States after its endorsement by the European Commission.[10][27]

Following early advances in genetic engineering of bacteria, cells, and small animals, scientists started considering how to apply it to medicine. Two main approaches were considered replacing or disrupting defective genes.[28] Scientists focused on diseases caused by single-gene defects, such as cystic fibrosis, haemophilia, muscular dystrophy, thalassemia, and sickle cell anemia. Glybera treats one such disease, caused by a defect in lipoprotein lipase.[27]

DNA must be administered, reach the damaged cells, enter the cell and either express or disrupt a protein.[29] Multiple delivery techniques have been explored. The initial approach incorporated DNA into an engineered virus to deliver the DNA into a chromosome.[30][31] Naked DNA approaches have also been explored, especially in the context of vaccine development.[32]

Generally, efforts focused on administering a gene that causes a needed protein to be expressed. More recently, increased understanding of nuclease function has led to more direct DNA editing, using techniques such as zinc finger nucleases and CRISPR. The vector incorporates genes into chromosomes. The expressed nucleases then knock out and replace genes in the chromosome. As of 2014[update] these approaches involve removing cells from patients, editing a chromosome and returning the transformed cells to patients.[33]

Gene editing is a potential approach to alter the human genome to treat genetic diseases,[34] viral diseases,[35] and cancer.[36] As of 2016[update] these approaches were still years from being medicine.[37][38]

Gene therapy may be classified into two types:

In somatic cell gene therapy (SCGT), the therapeutic genes are transferred into any cell other than a gamete, germ cell, gametocyte, or undifferentiated stem cell. Any such modifications affect the individual patient only, and are not inherited by offspring. Somatic gene therapy represents mainstream basic and clinical research, in which therapeutic DNA (either integrated in the genome or as an external episome or plasmid) is used to treat disease.

Over 600 clinical trials utilizing SCGT are underway[when?] in the US. Most focus on severe genetic disorders, including immunodeficiencies, haemophilia, thalassaemia, and cystic fibrosis. Such single gene disorders are good candidates for somatic cell therapy. The complete correction of a genetic disorder or the replacement of multiple genes is not yet possible. Only a few of the trials are in the advanced stages.[39]

In germline gene therapy (GGT), germ cells (sperm or egg cells) are modified by the introduction of functional genes into their genomes. Modifying a germ cell causes all the organism’s cells to contain the modified gene. The change is therefore heritable and passed on to later generations. Australia, Canada, Germany, Israel, Switzerland, and the Netherlands[40] prohibit GGT for application in human beings, for technical and ethical reasons, including insufficient knowledge about possible risks to future generations[40] and higher risks versus SCGT.[41] The US has no federal controls specifically addressing human genetic modification (beyond FDA regulations for therapies in general).[40][42][43][44]

The delivery of DNA into cells can be accomplished by multiple methods. The two major classes are recombinant viruses (sometimes called biological nanoparticles or viral vectors) and naked DNA or DNA complexes (non-viral methods).

In order to replicate, viruses introduce their genetic material into the host cell, tricking the host’s cellular machinery into using it as blueprints for viral proteins. Retroviruses go a stage further by having their genetic material copied into the genome of the host cell. Scientists exploit this by substituting a virus’s genetic material with therapeutic DNA. (The term ‘DNA’ may be an oversimplification, as some viruses contain RNA, and gene therapy could take this form as well.) A number of viruses have been used for human gene therapy, including retroviruses, adenoviruses, herpes simplex, vaccinia, and adeno-associated virus.[4] Like the genetic material (DNA or RNA) in viruses, therapeutic DNA can be designed to simply serve as a temporary blueprint that is degraded naturally or (at least theoretically) to enter the host’s genome, becoming a permanent part of the host’s DNA in infected cells.

Non-viral methods present certain advantages over viral methods, such as large scale production and low host immunogenicity. However, non-viral methods initially produced lower levels of transfection and gene expression, and thus lower therapeutic efficacy. Later technology remedied this deficiency.[citation needed]

Methods for non-viral gene therapy include the injection of naked DNA, electroporation, the gene gun, sonoporation, magnetofection, the use of oligonucleotides, lipoplexes, dendrimers, and inorganic nanoparticles.

Some of the unsolved problems include:

Three patients’ deaths have been reported in gene therapy trials, putting the field under close scrutiny. The first was that of Jesse Gelsinger, who died in 1999 because of immune rejection response.[51] One X-SCID patient died of leukemia in 2003.[9] In 2007, a rheumatoid arthritis patient died from an infection; the subsequent investigation concluded that the death was not related to gene therapy.[52]

In 1972 Friedmann and Roblin authored a paper in Science titled “Gene therapy for human genetic disease?”[53] Rogers (1970) was cited for proposing that exogenous good DNA be used to replace the defective DNA in those who suffer from genetic defects.[54]

In 1984 a retrovirus vector system was designed that could efficiently insert foreign genes into mammalian chromosomes.[55]

The first approved gene therapy clinical research in the US took place on 14 September 1990, at the National Institutes of Health (NIH), under the direction of William French Anderson.[56] Four-year-old Ashanti DeSilva received treatment for a genetic defect that left her with ADA-SCID, a severe immune system deficiency. The defective gene of the patient’s blood cells was replaced by the functional variant. Ashantis immune system was partially restored by the therapy. Production of the missing enzyme was temporarily stimulated, but the new cells with functional genes were not generated. She led a normal life only with the regular injections performed every two months. The effects were successful, but temporary.[57]

Cancer gene therapy was introduced in 1992/93 (Trojan et al. 1993).[58] The treatment of glioblastoma multiforme, the malignant brain tumor whose outcome is always fatal, was done using a vector expressing antisense IGF-I RNA (clinical trial approved by NIH protocolno.1602 November 24, 1993,[59] and by the FDA in 1994). This therapy also represents the beginning of cancer immunogene therapy, a treatment which proves to be effective due to the anti-tumor mechanism of IGF-I antisense, which is related to strong immune and apoptotic phenomena.

In 1992 Claudio Bordignon, working at the Vita-Salute San Raffaele University, performed the first gene therapy procedure using hematopoietic stem cells as vectors to deliver genes intended to correct hereditary diseases.[60] In 2002 this work led to the publication of the first successful gene therapy treatment for adenosine deaminase deficiency (ADA-SCID). The success of a multi-center trial for treating children with SCID (severe combined immune deficiency or “bubble boy” disease) from 2000 and 2002, was questioned when two of the ten children treated at the trial’s Paris center developed a leukemia-like condition. Clinical trials were halted temporarily in 2002, but resumed after regulatory review of the protocol in the US, the United Kingdom, France, Italy, and Germany.[61]

In 1993 Andrew Gobea was born with SCID following prenatal genetic screening. Blood was removed from his mother’s placenta and umbilical cord immediately after birth, to acquire stem cells. The allele that codes for adenosine deaminase (ADA) was obtained and inserted into a retrovirus. Retroviruses and stem cells were mixed, after which the viruses inserted the gene into the stem cell chromosomes. Stem cells containing the working ADA gene were injected into Andrew’s blood. Injections of the ADA enzyme were also given weekly. For four years T cells (white blood cells), produced by stem cells, made ADA enzymes using the ADA gene. After four years more treatment was needed.[62]

Jesse Gelsinger’s death in 1999 impeded gene therapy research in the US.[63][64] As a result, the FDA suspended several clinical trials pending the reevaluation of ethical and procedural practices.[65]

The modified cancer gene therapy strategy of antisense IGF-I RNA (NIH n 1602)[59] using antisense / triple helix anti-IGF-I approach was registered in 2002 by Wiley gene therapy clinical trial – n 635 and 636. The approach has shown promising results in the treatment of six different malignant tumors: glioblastoma, cancers of liver, colon, prostate, uterus, and ovary (Collaborative NATO Science Programme on Gene Therapy USA, France, Poland n LST 980517 conducted by J. Trojan) (Trojan et al., 2012). This anti-gene antisense/triple helix therapy has proven to be efficient, due to the mechanism stopping simultaneously IGF-I expression on translation and transcription levels, strengthening anti-tumor immune and apoptotic phenomena.

Sickle-cell disease can be treated in mice.[66] The mice which have essentially the same defect that causes human cases used a viral vector to induce production of fetal hemoglobin (HbF), which normally ceases to be produced shortly after birth. In humans, the use of hydroxyurea to stimulate the production of HbF temporarily alleviates sickle cell symptoms. The researchers demonstrated this treatment to be a more permanent means to increase therapeutic HbF production.[67]

A new gene therapy approach repaired errors in messenger RNA derived from defective genes. This technique has the potential to treat thalassaemia, cystic fibrosis and some cancers.[68]

Researchers created liposomes 25 nanometers across that can carry therapeutic DNA through pores in the nuclear membrane.[69]

In 2003 a research team inserted genes into the brain for the first time. They used liposomes coated in a polymer called polyethylene glycol, which unlike viral vectors, are small enough to cross the bloodbrain barrier.[70]

Short pieces of double-stranded RNA (short, interfering RNAs or siRNAs) are used by cells to degrade RNA of a particular sequence. If a siRNA is designed to match the RNA copied from a faulty gene, then the abnormal protein product of that gene will not be produced.[71]

Gendicine is a cancer gene therapy that delivers the tumor suppressor gene p53 using an engineered adenovirus. In 2003, it was approved in China for the treatment of head and neck squamous cell carcinoma.[25]

In March researchers announced the successful use of gene therapy to treat two adult patients for X-linked chronic granulomatous disease, a disease which affects myeloid cells and damages the immune system. The study is the first to show that gene therapy can treat the myeloid system.[72]

In May a team reported a way to prevent the immune system from rejecting a newly delivered gene.[73] Similar to organ transplantation, gene therapy has been plagued by this problem. The immune system normally recognizes the new gene as foreign and rejects the cells carrying it. The research utilized a newly uncovered network of genes regulated by molecules known as microRNAs. This natural function selectively obscured their therapeutic gene in immune system cells and protected it from discovery. Mice infected with the gene containing an immune-cell microRNA target sequence did not reject the gene.

In August scientists successfully treated metastatic melanoma in two patients using killer T cells genetically retargeted to attack the cancer cells.[74]

In November researchers reported on the use of VRX496, a gene-based immunotherapy for the treatment of HIV that uses a lentiviral vector to deliver an antisense gene against the HIV envelope. In a phase I clinical trial, five subjects with chronic HIV infection who had failed to respond to at least two antiretroviral regimens were treated. A single intravenous infusion of autologous CD4 T cells genetically modified with VRX496 was well tolerated. All patients had stable or decreased viral load; four of the five patients had stable or increased CD4 T cell counts. All five patients had stable or increased immune response to HIV antigens and other pathogens. This was the first evaluation of a lentiviral vector administered in a US human clinical trial.[75][76]

In May researchers announced the first gene therapy trial for inherited retinal disease. The first operation was carried out on a 23-year-old British male, Robert Johnson, in early 2007.[77]

Leber’s congenital amaurosis is an inherited blinding disease caused by mutations in the RPE65 gene. The results of a small clinical trial in children were published in April.[11] Delivery of recombinant adeno-associated virus (AAV) carrying RPE65 yielded positive results. In May two more groups reported positive results in independent clinical trials using gene therapy to treat the condition. In all three clinical trials, patients recovered functional vision without apparent side-effects.[11][12][13][14]

In September researchers were able to give trichromatic vision to squirrel monkeys.[78] In November 2009, researchers halted a fatal genetic disorder called adrenoleukodystrophy in two children using a lentivirus vector to deliver a functioning version of ABCD1, the gene that is mutated in the disorder.[79]

An April paper reported that gene therapy addressed achromatopsia (color blindness) in dogs by targeting cone photoreceptors. Cone function and day vision were restored for at least 33 months in two young specimens. The therapy was less efficient for older dogs.[80]

In September it was announced that an 18-year-old male patient in France with beta-thalassemia major had been successfully treated.[81] Beta-thalassemia major is an inherited blood disease in which beta haemoglobin is missing and patients are dependent on regular lifelong blood transfusions.[82] The technique used a lentiviral vector to transduce the human -globin gene into purified blood and marrow cells obtained from the patient in June 2007.[83] The patient’s haemoglobin levels were stable at 9 to 10 g/dL. About a third of the hemoglobin contained the form introduced by the viral vector and blood transfusions were not needed.[83][84] Further clinical trials were planned.[85] Bone marrow transplants are the only cure for thalassemia, but 75% of patients do not find a matching donor.[84]

Cancer immunogene therapy using modified antigene, antisense/triple helix approach was introduced in South America in 2010/11 in La Sabana University, Bogota (Ethical Committee 14 December 2010, no P-004-10). Considering the ethical aspect of gene diagnostic and gene therapy targeting IGF-I, the IGF-I expressing tumors i.e. lung and epidermis cancers were treated (Trojan et al. 2016).[86][87]

In 2007 and 2008, a man (Timothy Ray Brown) was cured of HIV by repeated hematopoietic stem cell transplantation (see also allogeneic stem cell transplantation, allogeneic bone marrow transplantation, allotransplantation) with double-delta-32 mutation which disables the CCR5 receptor. This cure was accepted by the medical community in 2011.[88] It required complete ablation of existing bone marrow, which is very debilitating.

In August two of three subjects of a pilot study were confirmed to have been cured from chronic lymphocytic leukemia (CLL). The therapy used genetically modified T cells to attack cells that expressed the CD19 protein to fight the disease.[20] In 2013, the researchers announced that 26 of 59 patients had achieved complete remission and the original patient had remained tumor-free.[89]

Human HGF plasmid DNA therapy of cardiomyocytes is being examined as a potential treatment for coronary artery disease as well as treatment for the damage that occurs to the heart after myocardial infarction.[90][91]

In 2011 Neovasculgen was registered in Russia as the first-in-class gene-therapy drug for treatment of peripheral artery disease, including critical limb ischemia; it delivers the gene encoding for VEGF.[92][26] Neovasculogen is a plasmid encoding the CMV promoter and the 165 amino acid form of VEGF.[93][94]

The FDA approved Phase 1 clinical trials on thalassemia major patients in the US for 10 participants in July.[95] The study was expected to continue until 2015.[85]

In July 2012, the European Medicines Agency recommended approval of a gene therapy treatment for the first time in either Europe or the United States. The treatment used Alipogene tiparvovec (Glybera) to compensate for lipoprotein lipase deficiency, which can cause severe pancreatitis.[96] The recommendation was endorsed by the European Commission in November 2012[10][27][97][98] and commercial rollout began in late 2014.[99] Alipogene tiparvovec was expected to cost around $1.6 million per treatment in 2012,[100] revised to $1 million in 2015,[101] making it the most expensive medicine in the world at the time.[102] As of 2016[update], only one person had been treated with drug.[103]

In December 2012, it was reported that 10 of 13 patients with multiple myeloma were in remission “or very close to it” three months after being injected with a treatment involving genetically engineered T cells to target proteins NY-ESO-1 and LAGE-1, which exist only on cancerous myeloma cells.[22]

In March researchers reported that three of five adult subjects who had acute lymphocytic leukemia (ALL) had been in remission for five months to two years after being treated with genetically modified T cells which attacked cells with CD19 genes on their surface, i.e. all B-cells, cancerous or not. The researchers believed that the patients’ immune systems would make normal T-cells and B-cells after a couple of months. They were also given bone marrow. One patient relapsed and died and one died of a blood clot unrelated to the disease.[21]

Following encouraging Phase 1 trials, in April, researchers announced they were starting Phase 2 clinical trials (called CUPID2 and SERCA-LVAD) on 250 patients[104] at several hospitals to combat heart disease. The therapy was designed to increase the levels of SERCA2, a protein in heart muscles, improving muscle function.[105] The FDA granted this a Breakthrough Therapy Designation to accelerate the trial and approval process.[106] In 2016 it was reported that no improvement was found from the CUPID 2 trial.[107]

In July researchers reported promising results for six children with two severe hereditary diseases had been treated with a partially deactivated lentivirus to replace a faulty gene and after 732 months. Three of the children had metachromatic leukodystrophy, which causes children to lose cognitive and motor skills.[108] The other children had Wiskott-Aldrich syndrome, which leaves them to open to infection, autoimmune diseases, and cancer.[109] Follow up trials with gene therapy on another six children with Wiskott-Aldrich syndrome were also reported as promising.[110][111]

In October researchers reported that two children born with adenosine deaminase severe combined immunodeficiency disease (ADA-SCID) had been treated with genetically engineered stem cells 18 months previously and that their immune systems were showing signs of full recovery. Another three children were making progress.[18] In 2014 a further 18 children with ADA-SCID were cured by gene therapy.[112] ADA-SCID children have no functioning immune system and are sometimes known as “bubble children.”[18]

Also in October researchers reported that they had treated six hemophilia sufferers in early 2011 using an adeno-associated virus. Over two years later all six were producing clotting factor.[18][113]

In January researchers reported that six choroideremia patients had been treated with adeno-associated virus with a copy of REP1. Over a six-month to two-year period all had improved their sight.[114][115] By 2016, 32 patients had been treated with positive results and researchers were hopeful the treatment would be long-lasting.[15] Choroideremia is an inherited genetic eye disease with no approved treatment, leading to loss of sight.

In March researchers reported that 12 HIV patients had been treated since 2009 in a trial with a genetically engineered virus with a rare mutation (CCR5 deficiency) known to protect against HIV with promising results.[116][117]

Clinical trials of gene therapy for sickle cell disease were started in 2014.[118][119] There is a need for high quality randomised controlled trials assessing the risks and benefits involved with gene therapy for people with sickle cell disease.[120]

In February LentiGlobin BB305, a gene therapy treatment undergoing clinical trials for treatment of beta thalassemia gained FDA “breakthrough” status after several patients were able to forgo the frequent blood transfusions usually required to treat the disease.[121]

In March researchers delivered a recombinant gene encoding a broadly neutralizing antibody into monkeys infected with simian HIV; the monkeys’ cells produced the antibody, which cleared them of HIV. The technique is named immunoprophylaxis by gene transfer (IGT). Animal tests for antibodies to ebola, malaria, influenza, and hepatitis were underway.[122][123]

In March, scientists, including an inventor of CRISPR, Jennifer Doudna, urged a worldwide moratorium on germline gene therapy, writing “scientists should avoid even attempting, in lax jurisdictions, germline genome modification for clinical application in humans” until the full implications “are discussed among scientific and governmental organizations”.[124][125][126][127]

In October, researchers announced that they had treated a baby girl, Layla Richards, with an experimental treatment using donor T-cells genetically engineered using TALEN to attack cancer cells. One year after the treatment she was still free of her cancer (a highly aggressive form of acute lymphoblastic leukaemia [ALL]).[128] Children with highly aggressive ALL normally have a very poor prognosis and Layla’s disease had been regarded as terminal before the treatment.[129]

In December, scientists of major world academies called for a moratorium on inheritable human genome edits, including those related to CRISPR-Cas9 technologies[130] but that basic research including embryo gene editing should continue.[131]

In April the Committee for Medicinal Products for Human Use of the European Medicines Agency endorsed a gene therapy treatment called Strimvelis[132][133] and the European Commission approved it in June.[134] This treats children born with adenosine deaminase deficiency and who have no functioning immune system. This was the second gene therapy treatment to be approved in Europe.[135]

In October, Chinese scientists reported they had started a trial to genetically modify T-cells from 10 adult patients with lung cancer and reinject the modified T-cells back into their bodies to attack the cancer cells. The T-cells had the PD-1 protein (which stops or slows the immune response) removed using CRISPR-Cas9.[136][137]

A 2016 Cochrane systematic review looking at data from four trials on topical cystic fibrosis transmembrane conductance regulator (CFTR) gene therapy does not support its clinical use as a mist inhaled into the lungs to treat cystic fibrosis patients with lung infections. One of the four trials did find weak evidence that liposome-based CFTR gene transfer therapy may lead to a small respiratory improvement for people with CF. This weak evidence is not enough to make a clinical recommendation for routine CFTR gene therapy.[138]

In February Kite Pharma announced results from a clinical trial of CAR-T cells in around a hundred people with advanced Non-Hodgkin lymphoma.[139]

In March, French scientists reported on clinical research of gene therapy to treat sickle-cell disease.[140]

In August, the FDA approved tisagenlecleucel for acute lymphoblastic leukemia.[141] Tisagenlecleucel is an adoptive cell transfer therapy for B-cell acute lymphoblastic leukemia; T cells from a person with cancer are removed, genetically engineered to make a specific T-cell receptor (a chimeric T cell receptor, or “CAR-T”) that reacts to the cancer, and are administered back to the person. The T cells are engineered to target a protein called CD19 that is common on B cells. This is the first form of gene therapy to be approved in the United States. In October, a similar therapy called axicabtagene ciloleucel was approved for non-Hodgkin lymphoma.[142]

In December the results of using an adeno-associated virus with blood clotting factor VIII to treat nine haemophilia A patients were published. Six of the seven patients on the high dose regime increased the level of the blood clotting VIII to normal levels. The low and medium dose regimes had no effect on the patient’s blood clotting levels.[143][144]

In December, the FDA approved Luxturna, the first in vivo gene therapy, for the treatment of blindness due to Leber’s congenital amaurosis.[145] The price of this treatment was 850,000 US dollars for both eyes.[146][147]

Speculated uses for gene therapy include:

Gene therapy techniques have the potential to provide alternative treatments for those with infertility. Recently, successful experimentation on mice has proven that fertility can be restored by using the gene therapy method, CRISPR.[148] Spermatogenical stem cells from another organism were transplanted into the testes of an infertile male mouse. The stem cells re-established spermatogenesis and fertility.[149]

Athletes might adopt gene therapy technologies to improve their performance.[150] Gene doping is not known to occur, but multiple gene therapies may have such effects. Kayser et al. argue that gene doping could level the playing field if all athletes receive equal access. Critics claim that any therapeutic intervention for non-therapeutic/enhancement purposes compromises the ethical foundations of medicine and sports.[151]

Genetic engineering could be used to cure diseases, but also to change physical appearance, metabolism, and even improve physical capabilities and mental faculties such as memory and intelligence. Ethical claims about germline engineering include beliefs that every fetus has a right to remain genetically unmodified, that parents hold the right to genetically modify their offspring, and that every child has the right to be born free of preventable diseases.[152][153][154] For parents, genetic engineering could be seen as another child enhancement technique to add to diet, exercise, education, training, cosmetics, and plastic surgery.[155][156] Another theorist claims that moral concerns limit but do not prohibit germline engineering.[157]

Possible regulatory schemes include a complete ban, provision to everyone, or professional self-regulation. The American Medical Associations Council on Ethical and Judicial Affairs stated that “genetic interventions to enhance traits should be considered permissible only in severely restricted situations: (1) clear and meaningful benefits to the fetus or child; (2) no trade-off with other characteristics or traits; and (3) equal access to the genetic technology, irrespective of income or other socioeconomic characteristics.”[158]

As early in the history of biotechnology as 1990, there have been scientists opposed to attempts to modify the human germline using these new tools,[159] and such concerns have continued as technology progressed.[160][161] With the advent of new techniques like CRISPR, in March 2015 a group of scientists urged a worldwide moratorium on clinical use of gene editing technologies to edit the human genome in a way that can be inherited.[124][125][126][127] In April 2015, researchers sparked controversy when they reported results of basic research to edit the DNA of non-viable human embryos using CRISPR.[148][162] A committee of the American National Academy of Sciences and National Academy of Medicine gave qualified support to human genome editing in 2017[163][164] once answers have been found to safety and efficiency problems “but only for serious conditions under stringent oversight.”[165]

Regulations covering genetic modification are part of general guidelines about human-involved biomedical research. There are no international treaties which are legally binding in this area, but there are recommendations for national laws from various bodies.

The Helsinki Declaration (Ethical Principles for Medical Research Involving Human Subjects) was amended by the World Medical Association’s General Assembly in 2008. This document provides principles physicians and researchers must consider when involving humans as research subjects. The Statement on Gene Therapy Research initiated by the Human Genome Organization (HUGO) in 2001 provides a legal baseline for all countries. HUGOs document emphasizes human freedom and adherence to human rights, and offers recommendations for somatic gene therapy, including the importance of recognizing public concerns about such research.[166]

No federal legislation lays out protocols or restrictions about human genetic engineering. This subject is governed by overlapping regulations from local and federal agencies, including the Department of Health and Human Services, the FDA and NIH’s Recombinant DNA Advisory Committee. Researchers seeking federal funds for an investigational new drug application, (commonly the case for somatic human genetic engineering,) must obey international and federal guidelines for the protection of human subjects.[167]

NIH serves as the main gene therapy regulator for federally funded research. Privately funded research is advised to follow these regulations. NIH provides funding for research that develops or enhances genetic engineering techniques and to evaluate the ethics and quality in current research. The NIH maintains a mandatory registry of human genetic engineering research protocols that includes all federally funded projects.

An NIH advisory committee published a set of guidelines on gene manipulation.[168] The guidelines discuss lab safety as well as human test subjects and various experimental types that involve genetic changes. Several sections specifically pertain to human genetic engineering, including Section III-C-1. This section describes required review processes and other aspects when seeking approval to begin clinical research involving genetic transfer into a human patient.[169] The protocol for a gene therapy clinical trial must be approved by the NIH’s Recombinant DNA Advisory Committee prior to any clinical trial beginning; this is different from any other kind of clinical trial.[168]

As with other kinds of drugs, the FDA regulates the quality and safety of gene therapy products and supervises how these products are used clinically. Therapeutic alteration of the human genome falls under the same regulatory requirements as any other medical treatment. Research involving human subjects, such as clinical trials, must be reviewed and approved by the FDA and an Institutional Review Board.[170][171]

Gene therapy is the basis for the plotline of the film I Am Legend[172] and the TV show Will Gene Therapy Change the Human Race?.[173] In 1994, gene therapy was a plot element in The Erlenmeyer Flask, The X-Files’ first-season finale. It is also used in Stargate as a means of allowing humans to use Ancient technology.[174]

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Gene therapy – Wikipedia

Gene therapy – Wikipedia

In the medicine field, gene therapy (also called human gene transfer) is the therapeutic delivery of nucleic acid into a patient’s cells as a drug to treat disease.[1][2] The first attempt at modifying human DNA was performed in 1980 by Martin Cline, but the first successful nuclear gene transfer in humans, approved by the National Institutes of Health, was performed in May 1989.[3] The first therapeutic use of gene transfer as well as the first direct insertion of human DNA into the nuclear genome was performed by French Anderson in a trial starting in September 1990.

Between 1989 and February 2016, over 2,300 clinical trials had been conducted, more than half of them in phase I.[4]

Not all medical procedures that introduce alterations to a patient’s genetic makeup can be considered gene therapy. Bone marrow transplantation and organ transplants in general have been found to introduce foreign DNA into patients.[5] Gene therapy is defined by the precision of the procedure and the intention of direct therapeutic effect.

Gene therapy was conceptualized in 1972, by authors who urged caution before commencing human gene therapy studies.

The first attempt, an unsuccessful one, at gene therapy (as well as the first case of medical transfer of foreign genes into humans not counting organ transplantation) was performed by Martin Cline on 10 July 1980.[6][7] Cline claimed that one of the genes in his patients was active six months later, though he never published this data or had it verified[8] and even if he is correct, it’s unlikely it produced any significant beneficial effects treating beta-thalassemia.

After extensive research on animals throughout the 1980s and a 1989 bacterial gene tagging trial on humans, the first gene therapy widely accepted as a success was demonstrated in a trial that started on 14 September 1990, when Ashi DeSilva was treated for ADA-SCID.[9]

The first somatic treatment that produced a permanent genetic change was performed in 1993.[citation needed]

Gene therapy is a way to fix a genetic problem at its source. The polymers are either translated into proteins, interfere with target gene expression, or possibly correct genetic mutations.

The most common form uses DNA that encodes a functional, therapeutic gene to replace a mutated gene. The polymer molecule is packaged within a “vector”, which carries the molecule inside cells.

Early clinical failures led to dismissals of gene therapy. Clinical successes since 2006 regained researchers’ attention, although as of 2014[update], it was still largely an experimental technique.[10] These include treatment of retinal diseases Leber’s congenital amaurosis[11][12][13][14] and choroideremia,[15] X-linked SCID,[16] ADA-SCID,[17][18] adrenoleukodystrophy,[19] chronic lymphocytic leukemia (CLL),[20] acute lymphocytic leukemia (ALL),[21] multiple myeloma,[22] haemophilia,[18] and Parkinson’s disease.[23] Between 2013 and April 2014, US companies invested over $600 million in the field.[24]

The first commercial gene therapy, Gendicine, was approved in China in 2003 for the treatment of certain cancers.[25] In 2011 Neovasculgen was registered in Russia as the first-in-class gene-therapy drug for treatment of peripheral artery disease, including critical limb ischemia.[26]In 2012 Glybera, a treatment for a rare inherited disorder, became the first treatment to be approved for clinical use in either Europe or the United States after its endorsement by the European Commission.[10][27]

Following early advances in genetic engineering of bacteria, cells, and small animals, scientists started considering how to apply it to medicine. Two main approaches were considered replacing or disrupting defective genes.[28] Scientists focused on diseases caused by single-gene defects, such as cystic fibrosis, haemophilia, muscular dystrophy, thalassemia, and sickle cell anemia. Glybera treats one such disease, caused by a defect in lipoprotein lipase.[27]

DNA must be administered, reach the damaged cells, enter the cell and either express or disrupt a protein.[29] Multiple delivery techniques have been explored. The initial approach incorporated DNA into an engineered virus to deliver the DNA into a chromosome.[30][31] Naked DNA approaches have also been explored, especially in the context of vaccine development.[32]

Generally, efforts focused on administering a gene that causes a needed protein to be expressed. More recently, increased understanding of nuclease function has led to more direct DNA editing, using techniques such as zinc finger nucleases and CRISPR. The vector incorporates genes into chromosomes. The expressed nucleases then knock out and replace genes in the chromosome. As of 2014[update] these approaches involve removing cells from patients, editing a chromosome and returning the transformed cells to patients.[33]

Gene editing is a potential approach to alter the human genome to treat genetic diseases,[34] viral diseases,[35] and cancer.[36] As of 2016[update] these approaches were still years from being medicine.[37][38]

Gene therapy may be classified into two types:

In somatic cell gene therapy (SCGT), the therapeutic genes are transferred into any cell other than a gamete, germ cell, gametocyte, or undifferentiated stem cell. Any such modifications affect the individual patient only, and are not inherited by offspring. Somatic gene therapy represents mainstream basic and clinical research, in which therapeutic DNA (either integrated in the genome or as an external episome or plasmid) is used to treat disease.

Over 600 clinical trials utilizing SCGT are underway[when?] in the US. Most focus on severe genetic disorders, including immunodeficiencies, haemophilia, thalassaemia, and cystic fibrosis. Such single gene disorders are good candidates for somatic cell therapy. The complete correction of a genetic disorder or the replacement of multiple genes is not yet possible. Only a few of the trials are in the advanced stages.[39]

In germline gene therapy (GGT), germ cells (sperm or egg cells) are modified by the introduction of functional genes into their genomes. Modifying a germ cell causes all the organism’s cells to contain the modified gene. The change is therefore heritable and passed on to later generations. Australia, Canada, Germany, Israel, Switzerland, and the Netherlands[40] prohibit GGT for application in human beings, for technical and ethical reasons, including insufficient knowledge about possible risks to future generations[40] and higher risks versus SCGT.[41] The US has no federal controls specifically addressing human genetic modification (beyond FDA regulations for therapies in general).[40][42][43][44]

The delivery of DNA into cells can be accomplished by multiple methods. The two major classes are recombinant viruses (sometimes called biological nanoparticles or viral vectors) and naked DNA or DNA complexes (non-viral methods).

In order to replicate, viruses introduce their genetic material into the host cell, tricking the host’s cellular machinery into using it as blueprints for viral proteins. Retroviruses go a stage further by having their genetic material copied into the genome of the host cell. Scientists exploit this by substituting a virus’s genetic material with therapeutic DNA. (The term ‘DNA’ may be an oversimplification, as some viruses contain RNA, and gene therapy could take this form as well.) A number of viruses have been used for human gene therapy, including retroviruses, adenoviruses, herpes simplex, vaccinia, and adeno-associated virus.[4] Like the genetic material (DNA or RNA) in viruses, therapeutic DNA can be designed to simply serve as a temporary blueprint that is degraded naturally or (at least theoretically) to enter the host’s genome, becoming a permanent part of the host’s DNA in infected cells.

Non-viral methods present certain advantages over viral methods, such as large scale production and low host immunogenicity. However, non-viral methods initially produced lower levels of transfection and gene expression, and thus lower therapeutic efficacy. Later technology remedied this deficiency.[citation needed]

Methods for non-viral gene therapy include the injection of naked DNA, electroporation, the gene gun, sonoporation, magnetofection, the use of oligonucleotides, lipoplexes, dendrimers, and inorganic nanoparticles.

Some of the unsolved problems include:

Three patients’ deaths have been reported in gene therapy trials, putting the field under close scrutiny. The first was that of Jesse Gelsinger, who died in 1999 because of immune rejection response.[51] One X-SCID patient died of leukemia in 2003.[9] In 2007, a rheumatoid arthritis patient died from an infection; the subsequent investigation concluded that the death was not related to gene therapy.[52]

In 1972 Friedmann and Roblin authored a paper in Science titled “Gene therapy for human genetic disease?”[53] Rogers (1970) was cited for proposing that exogenous good DNA be used to replace the defective DNA in those who suffer from genetic defects.[54]

In 1984 a retrovirus vector system was designed that could efficiently insert foreign genes into mammalian chromosomes.[55]

The first approved gene therapy clinical research in the US took place on 14 September 1990, at the National Institutes of Health (NIH), under the direction of William French Anderson.[56] Four-year-old Ashanti DeSilva received treatment for a genetic defect that left her with ADA-SCID, a severe immune system deficiency. The defective gene of the patient’s blood cells was replaced by the functional variant. Ashantis immune system was partially restored by the therapy. Production of the missing enzyme was temporarily stimulated, but the new cells with functional genes were not generated. She led a normal life only with the regular injections performed every two months. The effects were successful, but temporary.[57]

Cancer gene therapy was introduced in 1992/93 (Trojan et al. 1993).[58] The treatment of glioblastoma multiforme, the malignant brain tumor whose outcome is always fatal, was done using a vector expressing antisense IGF-I RNA (clinical trial approved by NIH protocolno.1602 November 24, 1993,[59] and by the FDA in 1994). This therapy also represents the beginning of cancer immunogene therapy, a treatment which proves to be effective due to the anti-tumor mechanism of IGF-I antisense, which is related to strong immune and apoptotic phenomena.

In 1992 Claudio Bordignon, working at the Vita-Salute San Raffaele University, performed the first gene therapy procedure using hematopoietic stem cells as vectors to deliver genes intended to correct hereditary diseases.[60] In 2002 this work led to the publication of the first successful gene therapy treatment for adenosine deaminase deficiency (ADA-SCID). The success of a multi-center trial for treating children with SCID (severe combined immune deficiency or “bubble boy” disease) from 2000 and 2002, was questioned when two of the ten children treated at the trial’s Paris center developed a leukemia-like condition. Clinical trials were halted temporarily in 2002, but resumed after regulatory review of the protocol in the US, the United Kingdom, France, Italy, and Germany.[61]

In 1993 Andrew Gobea was born with SCID following prenatal genetic screening. Blood was removed from his mother’s placenta and umbilical cord immediately after birth, to acquire stem cells. The allele that codes for adenosine deaminase (ADA) was obtained and inserted into a retrovirus. Retroviruses and stem cells were mixed, after which the viruses inserted the gene into the stem cell chromosomes. Stem cells containing the working ADA gene were injected into Andrew’s blood. Injections of the ADA enzyme were also given weekly. For four years T cells (white blood cells), produced by stem cells, made ADA enzymes using the ADA gene. After four years more treatment was needed.[62]

Jesse Gelsinger’s death in 1999 impeded gene therapy research in the US.[63][64] As a result, the FDA suspended several clinical trials pending the reevaluation of ethical and procedural practices.[65]

The modified cancer gene therapy strategy of antisense IGF-I RNA (NIH n 1602)[59] using antisense / triple helix anti-IGF-I approach was registered in 2002 by Wiley gene therapy clinical trial – n 635 and 636. The approach has shown promising results in the treatment of six different malignant tumors: glioblastoma, cancers of liver, colon, prostate, uterus, and ovary (Collaborative NATO Science Programme on Gene Therapy USA, France, Poland n LST 980517 conducted by J. Trojan) (Trojan et al., 2012). This anti-gene antisense/triple helix therapy has proven to be efficient, due to the mechanism stopping simultaneously IGF-I expression on translation and transcription levels, strengthening anti-tumor immune and apoptotic phenomena.

Sickle-cell disease can be treated in mice.[66] The mice which have essentially the same defect that causes human cases used a viral vector to induce production of fetal hemoglobin (HbF), which normally ceases to be produced shortly after birth. In humans, the use of hydroxyurea to stimulate the production of HbF temporarily alleviates sickle cell symptoms. The researchers demonstrated this treatment to be a more permanent means to increase therapeutic HbF production.[67]

A new gene therapy approach repaired errors in messenger RNA derived from defective genes. This technique has the potential to treat thalassaemia, cystic fibrosis and some cancers.[68]

Researchers created liposomes 25 nanometers across that can carry therapeutic DNA through pores in the nuclear membrane.[69]

In 2003 a research team inserted genes into the brain for the first time. They used liposomes coated in a polymer called polyethylene glycol, which unlike viral vectors, are small enough to cross the bloodbrain barrier.[70]

Short pieces of double-stranded RNA (short, interfering RNAs or siRNAs) are used by cells to degrade RNA of a particular sequence. If a siRNA is designed to match the RNA copied from a faulty gene, then the abnormal protein product of that gene will not be produced.[71]

Gendicine is a cancer gene therapy that delivers the tumor suppressor gene p53 using an engineered adenovirus. In 2003, it was approved in China for the treatment of head and neck squamous cell carcinoma.[25]

In March researchers announced the successful use of gene therapy to treat two adult patients for X-linked chronic granulomatous disease, a disease which affects myeloid cells and damages the immune system. The study is the first to show that gene therapy can treat the myeloid system.[72]

In May a team reported a way to prevent the immune system from rejecting a newly delivered gene.[73] Similar to organ transplantation, gene therapy has been plagued by this problem. The immune system normally recognizes the new gene as foreign and rejects the cells carrying it. The research utilized a newly uncovered network of genes regulated by molecules known as microRNAs. This natural function selectively obscured their therapeutic gene in immune system cells and protected it from discovery. Mice infected with the gene containing an immune-cell microRNA target sequence did not reject the gene.

In August scientists successfully treated metastatic melanoma in two patients using killer T cells genetically retargeted to attack the cancer cells.[74]

In November researchers reported on the use of VRX496, a gene-based immunotherapy for the treatment of HIV that uses a lentiviral vector to deliver an antisense gene against the HIV envelope. In a phase I clinical trial, five subjects with chronic HIV infection who had failed to respond to at least two antiretroviral regimens were treated. A single intravenous infusion of autologous CD4 T cells genetically modified with VRX496 was well tolerated. All patients had stable or decreased viral load; four of the five patients had stable or increased CD4 T cell counts. All five patients had stable or increased immune response to HIV antigens and other pathogens. This was the first evaluation of a lentiviral vector administered in a US human clinical trial.[75][76]

In May researchers announced the first gene therapy trial for inherited retinal disease. The first operation was carried out on a 23-year-old British male, Robert Johnson, in early 2007.[77]

Leber’s congenital amaurosis is an inherited blinding disease caused by mutations in the RPE65 gene. The results of a small clinical trial in children were published in April.[11] Delivery of recombinant adeno-associated virus (AAV) carrying RPE65 yielded positive results. In May two more groups reported positive results in independent clinical trials using gene therapy to treat the condition. In all three clinical trials, patients recovered functional vision without apparent side-effects.[11][12][13][14]

In September researchers were able to give trichromatic vision to squirrel monkeys.[78] In November 2009, researchers halted a fatal genetic disorder called adrenoleukodystrophy in two children using a lentivirus vector to deliver a functioning version of ABCD1, the gene that is mutated in the disorder.[79]

An April paper reported that gene therapy addressed achromatopsia (color blindness) in dogs by targeting cone photoreceptors. Cone function and day vision were restored for at least 33 months in two young specimens. The therapy was less efficient for older dogs.[80]

In September it was announced that an 18-year-old male patient in France with beta-thalassemia major had been successfully treated.[81] Beta-thalassemia major is an inherited blood disease in which beta haemoglobin is missing and patients are dependent on regular lifelong blood transfusions.[82] The technique used a lentiviral vector to transduce the human -globin gene into purified blood and marrow cells obtained from the patient in June 2007.[83] The patient’s haemoglobin levels were stable at 9 to 10 g/dL. About a third of the hemoglobin contained the form introduced by the viral vector and blood transfusions were not needed.[83][84] Further clinical trials were planned.[85] Bone marrow transplants are the only cure for thalassemia, but 75% of patients do not find a matching donor.[84]

Cancer immunogene therapy using modified antigene, antisense/triple helix approach was introduced in South America in 2010/11 in La Sabana University, Bogota (Ethical Committee 14 December 2010, no P-004-10). Considering the ethical aspect of gene diagnostic and gene therapy targeting IGF-I, the IGF-I expressing tumors i.e. lung and epidermis cancers were treated (Trojan et al. 2016).[86][87]

In 2007 and 2008, a man (Timothy Ray Brown) was cured of HIV by repeated hematopoietic stem cell transplantation (see also allogeneic stem cell transplantation, allogeneic bone marrow transplantation, allotransplantation) with double-delta-32 mutation which disables the CCR5 receptor. This cure was accepted by the medical community in 2011.[88] It required complete ablation of existing bone marrow, which is very debilitating.

In August two of three subjects of a pilot study were confirmed to have been cured from chronic lymphocytic leukemia (CLL). The therapy used genetically modified T cells to attack cells that expressed the CD19 protein to fight the disease.[20] In 2013, the researchers announced that 26 of 59 patients had achieved complete remission and the original patient had remained tumor-free.[89]

Human HGF plasmid DNA therapy of cardiomyocytes is being examined as a potential treatment for coronary artery disease as well as treatment for the damage that occurs to the heart after myocardial infarction.[90][91]

In 2011 Neovasculgen was registered in Russia as the first-in-class gene-therapy drug for treatment of peripheral artery disease, including critical limb ischemia; it delivers the gene encoding for VEGF.[92][26] Neovasculogen is a plasmid encoding the CMV promoter and the 165 amino acid form of VEGF.[93][94]

The FDA approved Phase 1 clinical trials on thalassemia major patients in the US for 10 participants in July.[95] The study was expected to continue until 2015.[85]

In July 2012, the European Medicines Agency recommended approval of a gene therapy treatment for the first time in either Europe or the United States. The treatment used Alipogene tiparvovec (Glybera) to compensate for lipoprotein lipase deficiency, which can cause severe pancreatitis.[96] The recommendation was endorsed by the European Commission in November 2012[10][27][97][98] and commercial rollout began in late 2014.[99] Alipogene tiparvovec was expected to cost around $1.6 million per treatment in 2012,[100] revised to $1 million in 2015,[101] making it the most expensive medicine in the world at the time.[102] As of 2016[update], only one person had been treated with drug.[103]

In December 2012, it was reported that 10 of 13 patients with multiple myeloma were in remission “or very close to it” three months after being injected with a treatment involving genetically engineered T cells to target proteins NY-ESO-1 and LAGE-1, which exist only on cancerous myeloma cells.[22]

In March researchers reported that three of five adult subjects who had acute lymphocytic leukemia (ALL) had been in remission for five months to two years after being treated with genetically modified T cells which attacked cells with CD19 genes on their surface, i.e. all B-cells, cancerous or not. The researchers believed that the patients’ immune systems would make normal T-cells and B-cells after a couple of months. They were also given bone marrow. One patient relapsed and died and one died of a blood clot unrelated to the disease.[21]

Following encouraging Phase 1 trials, in April, researchers announced they were starting Phase 2 clinical trials (called CUPID2 and SERCA-LVAD) on 250 patients[104] at several hospitals to combat heart disease. The therapy was designed to increase the levels of SERCA2, a protein in heart muscles, improving muscle function.[105] The FDA granted this a Breakthrough Therapy Designation to accelerate the trial and approval process.[106] In 2016 it was reported that no improvement was found from the CUPID 2 trial.[107]

In July researchers reported promising results for six children with two severe hereditary diseases had been treated with a partially deactivated lentivirus to replace a faulty gene and after 732 months. Three of the children had metachromatic leukodystrophy, which causes children to lose cognitive and motor skills.[108] The other children had Wiskott-Aldrich syndrome, which leaves them to open to infection, autoimmune diseases, and cancer.[109] Follow up trials with gene therapy on another six children with Wiskott-Aldrich syndrome were also reported as promising.[110][111]

In October researchers reported that two children born with adenosine deaminase severe combined immunodeficiency disease (ADA-SCID) had been treated with genetically engineered stem cells 18 months previously and that their immune systems were showing signs of full recovery. Another three children were making progress.[18] In 2014 a further 18 children with ADA-SCID were cured by gene therapy.[112] ADA-SCID children have no functioning immune system and are sometimes known as “bubble children.”[18]

Also in October researchers reported that they had treated six hemophilia sufferers in early 2011 using an adeno-associated virus. Over two years later all six were producing clotting factor.[18][113]

In January researchers reported that six choroideremia patients had been treated with adeno-associated virus with a copy of REP1. Over a six-month to two-year period all had improved their sight.[114][115] By 2016, 32 patients had been treated with positive results and researchers were hopeful the treatment would be long-lasting.[15] Choroideremia is an inherited genetic eye disease with no approved treatment, leading to loss of sight.

In March researchers reported that 12 HIV patients had been treated since 2009 in a trial with a genetically engineered virus with a rare mutation (CCR5 deficiency) known to protect against HIV with promising results.[116][117]

Clinical trials of gene therapy for sickle cell disease were started in 2014.[118][119] There is a need for high quality randomised controlled trials assessing the risks and benefits involved with gene therapy for people with sickle cell disease.[120]

In February LentiGlobin BB305, a gene therapy treatment undergoing clinical trials for treatment of beta thalassemia gained FDA “breakthrough” status after several patients were able to forgo the frequent blood transfusions usually required to treat the disease.[121]

In March researchers delivered a recombinant gene encoding a broadly neutralizing antibody into monkeys infected with simian HIV; the monkeys’ cells produced the antibody, which cleared them of HIV. The technique is named immunoprophylaxis by gene transfer (IGT). Animal tests for antibodies to ebola, malaria, influenza, and hepatitis were underway.[122][123]

In March, scientists, including an inventor of CRISPR, Jennifer Doudna, urged a worldwide moratorium on germline gene therapy, writing “scientists should avoid even attempting, in lax jurisdictions, germline genome modification for clinical application in humans” until the full implications “are discussed among scientific and governmental organizations”.[124][125][126][127]

In October, researchers announced that they had treated a baby girl, Layla Richards, with an experimental treatment using donor T-cells genetically engineered using TALEN to attack cancer cells. One year after the treatment she was still free of her cancer (a highly aggressive form of acute lymphoblastic leukaemia [ALL]).[128] Children with highly aggressive ALL normally have a very poor prognosis and Layla’s disease had been regarded as terminal before the treatment.[129]

In December, scientists of major world academies called for a moratorium on inheritable human genome edits, including those related to CRISPR-Cas9 technologies[130] but that basic research including embryo gene editing should continue.[131]

In April the Committee for Medicinal Products for Human Use of the European Medicines Agency endorsed a gene therapy treatment called Strimvelis[132][133] and the European Commission approved it in June.[134] This treats children born with adenosine deaminase deficiency and who have no functioning immune system. This was the second gene therapy treatment to be approved in Europe.[135]

In October, Chinese scientists reported they had started a trial to genetically modify T-cells from 10 adult patients with lung cancer and reinject the modified T-cells back into their bodies to attack the cancer cells. The T-cells had the PD-1 protein (which stops or slows the immune response) removed using CRISPR-Cas9.[136][137]

A 2016 Cochrane systematic review looking at data from four trials on topical cystic fibrosis transmembrane conductance regulator (CFTR) gene therapy does not support its clinical use as a mist inhaled into the lungs to treat cystic fibrosis patients with lung infections. One of the four trials did find weak evidence that liposome-based CFTR gene transfer therapy may lead to a small respiratory improvement for people with CF. This weak evidence is not enough to make a clinical recommendation for routine CFTR gene therapy.[138]

In February Kite Pharma announced results from a clinical trial of CAR-T cells in around a hundred people with advanced Non-Hodgkin lymphoma.[139]

In March, French scientists reported on clinical research of gene therapy to treat sickle-cell disease.[140]

In August, the FDA approved tisagenlecleucel for acute lymphoblastic leukemia.[141] Tisagenlecleucel is an adoptive cell transfer therapy for B-cell acute lymphoblastic leukemia; T cells from a person with cancer are removed, genetically engineered to make a specific T-cell receptor (a chimeric T cell receptor, or “CAR-T”) that reacts to the cancer, and are administered back to the person. The T cells are engineered to target a protein called CD19 that is common on B cells. This is the first form of gene therapy to be approved in the United States. In October, a similar therapy called axicabtagene ciloleucel was approved for non-Hodgkin lymphoma.[142]

In December the results of using an adeno-associated virus with blood clotting factor VIII to treat nine haemophilia A patients were published. Six of the seven patients on the high dose regime increased the level of the blood clotting VIII to normal levels. The low and medium dose regimes had no effect on the patient’s blood clotting levels.[143][144]

In December, the FDA approved Luxturna, the first in vivo gene therapy, for the treatment of blindness due to Leber’s congenital amaurosis.[145] The price of this treatment was 850,000 US dollars for both eyes.[146][147]

Speculated uses for gene therapy include:

Gene therapy techniques have the potential to provide alternative treatments for those with infertility. Recently, successful experimentation on mice has proven that fertility can be restored by using the gene therapy method, CRISPR.[148] Spermatogenical stem cells from another organism were transplanted into the testes of an infertile male mouse. The stem cells re-established spermatogenesis and fertility.[149]

Athletes might adopt gene therapy technologies to improve their performance.[150] Gene doping is not known to occur, but multiple gene therapies may have such effects. Kayser et al. argue that gene doping could level the playing field if all athletes receive equal access. Critics claim that any therapeutic intervention for non-therapeutic/enhancement purposes compromises the ethical foundations of medicine and sports.[151]

Genetic engineering could be used to cure diseases, but also to change physical appearance, metabolism, and even improve physical capabilities and mental faculties such as memory and intelligence. Ethical claims about germline engineering include beliefs that every fetus has a right to remain genetically unmodified, that parents hold the right to genetically modify their offspring, and that every child has the right to be born free of preventable diseases.[152][153][154] For parents, genetic engineering could be seen as another child enhancement technique to add to diet, exercise, education, training, cosmetics, and plastic surgery.[155][156] Another theorist claims that moral concerns limit but do not prohibit germline engineering.[157]

Possible regulatory schemes include a complete ban, provision to everyone, or professional self-regulation. The American Medical Associations Council on Ethical and Judicial Affairs stated that “genetic interventions to enhance traits should be considered permissible only in severely restricted situations: (1) clear and meaningful benefits to the fetus or child; (2) no trade-off with other characteristics or traits; and (3) equal access to the genetic technology, irrespective of income or other socioeconomic characteristics.”[158]

As early in the history of biotechnology as 1990, there have been scientists opposed to attempts to modify the human germline using these new tools,[159] and such concerns have continued as technology progressed.[160][161] With the advent of new techniques like CRISPR, in March 2015 a group of scientists urged a worldwide moratorium on clinical use of gene editing technologies to edit the human genome in a way that can be inherited.[124][125][126][127] In April 2015, researchers sparked controversy when they reported results of basic research to edit the DNA of non-viable human embryos using CRISPR.[148][162] A committee of the American National Academy of Sciences and National Academy of Medicine gave qualified support to human genome editing in 2017[163][164] once answers have been found to safety and efficiency problems “but only for serious conditions under stringent oversight.”[165]

Regulations covering genetic modification are part of general guidelines about human-involved biomedical research. There are no international treaties which are legally binding in this area, but there are recommendations for national laws from various bodies.

The Helsinki Declaration (Ethical Principles for Medical Research Involving Human Subjects) was amended by the World Medical Association’s General Assembly in 2008. This document provides principles physicians and researchers must consider when involving humans as research subjects. The Statement on Gene Therapy Research initiated by the Human Genome Organization (HUGO) in 2001 provides a legal baseline for all countries. HUGOs document emphasizes human freedom and adherence to human rights, and offers recommendations for somatic gene therapy, including the importance of recognizing public concerns about such research.[166]

No federal legislation lays out protocols or restrictions about human genetic engineering. This subject is governed by overlapping regulations from local and federal agencies, including the Department of Health and Human Services, the FDA and NIH’s Recombinant DNA Advisory Committee. Researchers seeking federal funds for an investigational new drug application, (commonly the case for somatic human genetic engineering,) must obey international and federal guidelines for the protection of human subjects.[167]

NIH serves as the main gene therapy regulator for federally funded research. Privately funded research is advised to follow these regulations. NIH provides funding for research that develops or enhances genetic engineering techniques and to evaluate the ethics and quality in current research. The NIH maintains a mandatory registry of human genetic engineering research protocols that includes all federally funded projects.

An NIH advisory committee published a set of guidelines on gene manipulation.[168] The guidelines discuss lab safety as well as human test subjects and various experimental types that involve genetic changes. Several sections specifically pertain to human genetic engineering, including Section III-C-1. This section describes required review processes and other aspects when seeking approval to begin clinical research involving genetic transfer into a human patient.[169] The protocol for a gene therapy clinical trial must be approved by the NIH’s Recombinant DNA Advisory Committee prior to any clinical trial beginning; this is different from any other kind of clinical trial.[168]

As with other kinds of drugs, the FDA regulates the quality and safety of gene therapy products and supervises how these products are used clinically. Therapeutic alteration of the human genome falls under the same regulatory requirements as any other medical treatment. Research involving human subjects, such as clinical trials, must be reviewed and approved by the FDA and an Institutional Review Board.[170][171]

Gene therapy is the basis for the plotline of the film I Am Legend[172] and the TV show Will Gene Therapy Change the Human Race?.[173] In 1994, gene therapy was a plot element in The Erlenmeyer Flask, The X-Files’ first-season finale. It is also used in Stargate as a means of allowing humans to use Ancient technology.[174]

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Gene therapy – Wikipedia

genetic engineering | Definition, Process, & Uses …

Genetic engineering, the artificial manipulation, modification, and recombination of DNA or other nucleic acid molecules in order to modify an organism or population of organisms.

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origins of agriculture: Genetic engineering

The application of genetics to agriculture since World War II has resulted in substantial increases in the production of many crops. This has been most notable in hybrid strains of maize and grain sorghum. At the same time, crossbreeding has resulted in much

The term genetic engineering initially referred to various techniques used for the modification or manipulation of organisms through the processes of heredity and reproduction. As such, the term embraced both artificial selection and all the interventions of biomedical techniques, among them artificial insemination, in vitro fertilization (e.g., test-tube babies), cloning, and gene manipulation. In the latter part of the 20th century, however, the term came to refer more specifically to methods of recombinant DNA technology (or gene cloning), in which DNA molecules from two or more sources are combined either within cells or in vitro and are then inserted into host organisms in which they are able to propagate.

The possibility for recombinant DNA technology emerged with the discovery of restriction enzymes in 1968 by Swiss microbiologist Werner Arber. The following year American microbiologist Hamilton O. Smith purified so-called type II restriction enzymes, which were found to be essential to genetic engineering for their ability to cleave a specific site within the DNA (as opposed to type I restriction enzymes, which cleave DNA at random sites). Drawing on Smiths work, American molecular biologist Daniel Nathans helped advance the technique of DNA recombination in 197071 and demonstrated that type II enzymes could be useful in genetic studies. Genetic engineering based on recombination was pioneered in 1973 by American biochemists Stanley N. Cohen and Herbert W. Boyer, who were among the first to cut DNA into fragments, rejoin different fragments, and insert the new genes into E. coli bacteria, which then reproduced.

Most recombinant DNA technology involves the insertion of foreign genes into the plasmids of common laboratory strains of bacteria. Plasmids are small rings of DNA; they are not part of the bacteriums chromosome (the main repository of the organisms genetic information). Nonetheless, they are capable of directing protein synthesis, and, like chromosomal DNA, they are reproduced and passed on to the bacteriums progeny. Thus, by incorporating foreign DNA (for example, a mammalian gene) into a bacterium, researchers can obtain an almost limitless number of copies of the inserted gene. Furthermore, if the inserted gene is operative (i.e., if it directs protein synthesis), the modified bacterium will produce the protein specified by the foreign DNA.

A subsequent generation of genetic engineering techniques that emerged in the early 21st century centred on gene editing. Gene editing, based on a technology known as CRISPR-Cas9, allows researchers to customize a living organisms genetic sequence by making very specific changes to its DNA. Gene editing has a wide array of applications, being used for the genetic modification of crop plants and livestock and of laboratory model organisms (e.g., mice). The correction of genetic errors associated with disease in animals suggests that gene editing has potential applications in gene therapy for humans.

Genetic engineering has advanced the understanding of many theoretical and practical aspects of gene function and organization. Through recombinant DNA techniques, bacteria have been created that are capable of synthesizing human insulin, human growth hormone, alpha interferon, a hepatitis B vaccine, and other medically useful substances. Plants may be genetically adjusted to enable them to fix nitrogen, and genetic diseases can possibly be corrected by replacing dysfunctional genes with normally functioning genes. Nevertheless, special concern has been focused on such achievements for fear that they might result in the introduction of unfavourable and possibly dangerous traits into microorganisms that were previously free of theme.g., resistance to antibiotics, production of toxins, or a tendency to cause disease. Likewise, the application of gene editing in humans has raised ethical concerns, particularly regarding its potential use to alter traits such as intelligence and beauty.

In 1980 the new microorganisms created by recombinant DNA research were deemed patentable, and in 1986 the U.S. Department of Agriculture approved the sale of the first living genetically altered organisma virus, used as a pseudorabies vaccine, from which a single gene had been cut. Since then several hundred patents have been awarded for genetically altered bacteria and plants. Patents on genetically engineered and genetically modified organisms, particularly crops and other foods, however, were a contentious issue, and they remained so into the first part of the 21st century.

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genetic engineering | Definition, Process, & Uses …


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