Category Archives: Gene Medicine

Source: Illumina Inc.

President Obama has released more details about his plans to fund a precision medicine initiative that the administration hopes will mean that doctors can deliver the right medicine to the right patient at the right dose at the right time .

The plan to advance personalized medicine includes $215 million in funding that could accelerate demand for Illumina 's gene sequencing solutions.

First, a bit of background The idea of using genetics to create new medicines and determine which patients would respond best to them isn't new. Cancer treatment has been at the forefront of this research for years, both in innovating patient screening and revolutionizing drug development.

For example, the University of California San Diego Moores Cancer Center runs the Center for Personalized Cancer Therapy.

That center runs genetic tests on tumors in a bid to match up patients with the most effective cancer treatments, including both FDA-approved medicines such as Bristol-Myers Squibb 's Opdivo and drugs that are currently in clinical trials, such as BioMarin Pharmaceutical 's BMN-673.

At the center's Institute for Genomic Medicine, or IGM, a lot of that genetic research is being conducted with the help of Illumina's gene sequencing machines. According to the IGM, the Illumina HiSeq 2000, Illumina HiSeq 2500, Illumina MiSeq, and Illumina HiScan System are all used at the facility.

At the tipping point According to the MD Anderson Cancer Center's Sheikh Khalifa Bin Zayed Al Nahyan Institute for Personalized Cancer Therapy, we are converging on a "perfect storm" in personalized cancer treatment that could be"offering the opportunity to make a bold leap forward in personalizing cancer care."

One of the driving forces of this opportunity is the significant advances in speed and cost that have been made over the past decade in sequencing genes.

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Is This Company the Big Winner in Obama's Push for Precision Medicine?

Medical genetics is the specialty of medicine that involves the diagnosis and management of hereditary disorders. Medical genetics differs from human genetics in that human genetics is a field of scientific research that may or may not apply to medicine, but medical genetics refers to the application of genetics to medical care. For example, research on the causes and inheritance of genetic disorders would be considered within both human genetics and medical genetics, while the diagnosis, management, and counseling of individuals with genetic disorders would be considered part of medical genetics.

In contrast, the study of typically non-medical phenotypes such as the genetics of eye color would be considered part of human genetics, but not necessarily relevant to medical genetics (except in situations such as albinism). Genetic medicine is a newer term for medical genetics and incorporates areas such as gene therapy, personalized medicine, and the rapidly emerging new medical specialty, predictive medicine.

Medical genetics encompasses many different areas, including clinical practice of physicians, genetic counselors, and nutritionists, clinical diagnostic laboratory activities, and research into the causes and inheritance of genetic disorders. Examples of conditions that fall within the scope of medical genetics include birth defects and dysmorphology, mental retardation, autism, and mitochondrial disorders, skeletal dysplasia, connective tissue disorders, cancer genetics, teratogens, and prenatal diagnosis. Medical genetics is increasingly becoming relevant to many common diseases. Overlaps with other medical specialties are beginning to emerge, as recent advances in genetics are revealing etiologies for neurologic, endocrine, cardiovascular, pulmonary, ophthalmologic, renal, psychiatric, and dermatologic conditions.

In some ways, many of the individual fields within medical genetics are hybrids between clinical care and research. This is due in part to recent advances in science and technology (for example, see the Human genome project) that have enabled an unprecedented understanding of genetic disorders.

Clinical genetics is the practice of clinical medicine with particular attention to hereditary disorders. Referrals are made to genetics clinics for a variety of reasons, including birth defects, developmental delay, autism, epilepsy, short stature, and many others. Examples of genetic syndromes that are commonly seen in the genetics clinic include chromosomal rearrangements, Down syndrome, DiGeorge syndrome (22q11.2 Deletion Syndrome), Fragile X syndrome, Marfan syndrome, Neurofibromatosis, Turner syndrome, and Williams syndrome.

Metabolic (or biochemical) genetics involves the diagnosis and management of inborn errors of metabolism in which patients have enzymatic deficiencies that perturb biochemical pathways involved in metabolism of carbohydrates, amino acids, and lipids. Examples of metabolic disorders include galactosemia, glycogen storage disease, lysosomal storage disorders, metabolic acidosis, peroxisomal disorders, phenylketonuria, and urea cycle disorders.

Cytogenetics is the study of chromosomes and chromosome abnormalities. While cytogenetics historically relied on microscopy to analyze chromosomes, new molecular technologies such as array comparative genomic hybridization are now becoming widely used. Examples of chromosome abnormalities include aneuploidy, chromosomal rearrangements, and genomic deletion/duplication disorders.

Molecular genetics involves the discovery of and laboratory testing for DNA mutations that underlie many single gene disorders. Examples of single gene disorders include achondroplasia, cystic fibrosis, Duchenne muscular dystrophy, hereditary breast cancer (BRCA1/2), Huntington disease, Marfan syndrome, Noonan syndrome, and Rett syndrome. Molecular tests are also used in the diagnosis of syndromes involving epigenetic abnormalities, such as Angelman syndrome, Beckwith-Wiedemann syndrome, Prader-willi syndrome, and uniparental disomy.

Mitochondrial genetics concerns the diagnosis and management of mitochondrial disorders, which have a molecular basis but often result in biochemical abnormalities due to deficient energy production.

There exists some overlap between medical genetic diagnostic laboratories and molecular pathology.

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Medical genetics - Wikipedia, the free encyclopedia

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Newswise CHAPEL HILL, NC The force is strong with this one. UNC School of Medicine researchers discovered a gene called R2d2 Responder to meiotic drive 2 that breaks Gregor Mendels century-old law of segregation, which states that you have an equal probability of inheriting each of two copies of every gene from both parents.

For years, scientists had evidence that this law was being broken in mammals, but they didnt know how. Now theyve implicated R2d2, a so-called selfish gene. Led by UNC School of Medicine scientists, researchers from across the country used data from thousands of genetically diverse mice to show that female mice pass on one copy of the R2d2 gene more frequently than the other copy.

The discovery, published in PLoS Genetics, has wide ranging implications. For instance, when doctors calculate the probability of a person inheriting the genes responsible for a disease, the calculations are based on Mendels law. Findings from the fields of evolutionary genetics and population genetics are also based on Mendels law. And the discovery could have implications for the fields of biomedical science, infectious diseases, and even agriculture.

R2d2 is a good example of a poorly understood phenomenon known as female meiotic drive when an egg is produced and a selfish gene is segregated to the egg more than half the time, said Fernando Pardo-Manuel de Villena, PhD, professor of genetics and senior author of the paper. One notable but poorly understood example of this in humans involves the transmission fused chromosomes that can contribute to trisomies when three chromosomes are passed on to offspring instead of two.

Trisomies are associated with miscarriages or can lead to developmental disorders, including Down, Edwards, and Patau syndromes.

Understanding how meiotic drive works may shed light on the meiotic abnormalities underlying these disorders, Pardo-Manuel de Villena said. Now, we finally have an easily controlled and manageable system so we can study meiotic drive.

The researchers, including John Didion, PhD, a postdoctoral fellow at the NIH, former UNC graduate student, and first author of the paper, first discovered R2d2 while developing the Collaborative Cross (CC) and Diversity Outbred (DO) two related populations of laboratory mice that were derived by mixing eight genetically-diverse inbred lines. They examined genotype data from hundreds of CC lines and thousands of DO mice and found that in every place in the genome save one, each of the eight parent lines made equal contributions to the population. The one exception occurred in the middle of mouse chromosome 2.

Using whole-genome sequences from the parent lines, the scientists found that R2d2 was responsible for the gain of many copies of a gene sequence present in all females with meiotic drive. Deletion of most of the R2d2 gene copies restored the expected pattern of inheritance. This provided solid evidence that the R2d2 gene was indeed the cause of the unusual mutation found on chromosome 2.

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R2d2 Beats Mendel: Scientists Discover Selfish Gene That Breaks Long-Held Law of Genetic Inheritance

Coining the term "Gene Rank" (GR), Dartmouth's Norris Cotton Cancer Center investigator Eugene Demidenko, PhD, captured and described a new characterization of gene connectivity in "Microarray Enriched Gene Rank," published in BioData Mining. The effective computer algorithm can be used to compare tissues across or within organisms at great speed with a simple laptop computer.

"This paper introduces a new bioinformatics concept called Gene Rank (GR)," explained Demidenko. "GR is computed based on gene expression data and reflects how well a particular gene is connected to other genes. Our GR is built along the lines of PageRank used by Google to rank and display web pages upon key word search."

As a new scientific concept, GR looks at genetic networks from a different angle that may lead to new biological insights and formulation of new scientific hypothesis with important clinical applications. Many other studies in bioinformatics have tested their concepts using computer simulation. Demidenko tested GR on various de novo studies, resulting in plausible biological findings. For example, one series tested the complexity of genes in four stages of the development of rice, showing that it gradually increased over time. A subsequent test of Drosophila flies showed their genes to be more complex than rice, but less complex than human genes. These are expected findings, and meeting biological expectations is respected validation of concept.

Demidenko applied the GR concept to several cancer-related gene expression data sets, and discovered that disconnected genes in tumors are cancer associated. "It's a provocative statement, but we can say that cancer genes are lonely killers," said Demidenko. Further investigation revealed that GR of the same gene changes during cancer development, and that this can be used for disease prognosis as well as early cancer detection.

"The devised computer algorithm allows the computation of GR for 50 thousand genes and 500 samples within just a few minutes on a personal computer," said Demidenko. "Our GR can be used by researchers on a daily basis to investigate and characterize the dynamic complexity of living bodies. In particular, this will be helpful to characterize malignant tumors."

Future work for Demidenko includes applying the new GR to other data sets to determine how gene connectivity changes in the course of a tumor's development, and how gene connectivity varies across tumors.

Eugene Demidenko, PhD is professor of the recently-established department of Biomedical Data Science at Dartmouth's Geisel School of Medicine, and an adjunct professor at both the Thayer School of Engineering and the Department of Mathematics at Dartmouth College. His work in cancer is facilitated by Dartmouth's Norris Cotton Cancer Center. This work was supported by National Institutes of Health grants P20RR024475 and P20GM103534 with additional support from Dr. Jason Moore, director of Dartmouth's Institute for Quantitative Biological Sciences.

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The above story is based on materials provided by Norris Cotton Cancer Center Dartmouth-Hitchcock Medical Center. Note: Materials may be edited for content and length.

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Google-style ranking used to describe gene connectivity

Jerome Silberman, known professionally as Gene Wilder (born June 11, 1933), is an American stage and screen comic actor, director, screenwriter, author, and activist.

Wilder began his career on stage, and made his screen debut in the TV-series Armstrong Circle Theatre in 1962. Although his first film role was portraying a hostage in the 1967 motion picture Bonnie and Clyde, Wilder's first major role was as Leopold Bloom in the 1968 film The Producers for which he was nominated for an Academy Award for Best Supporting Actor. This was the first in a series of collaborations with writer/director Mel Brooks, including 1974's Blazing Saddles and Young Frankenstein, which Wilder co-wrote, garnering the pair an Academy Award nomination for Best Adapted Screenplay. Wilder is known for his portrayal of Willy Wonka in Willy Wonka & the Chocolate Factory (1971) and for his four films with Richard Pryor: Silver Streak (1976), Stir Crazy (1980), See No Evil, Hear No Evil (1989), and Another You (1991). Wilder has directed and written several of his films, including The Woman in Red (1984).

His third wife was actress Gilda Radner, with whom he starred in three films. Her death from ovarian cancer led to his active involvement in promoting cancer awareness and treatment, helping found the Gilda Radner Ovarian Cancer Detection Center in Los Angeles and co-founding Gilda's Club.

Since his most recent contribution to acting in 2003, Wilder has turned his attention to writing. He has produced a memoir in 2005, Kiss Me Like a Stranger: My Search for Love and Art; a collection of stories, What Is This Thing Called Love? (2010); and the novels My French Whore (2007), The Woman Who Wouldn't (2008) and Something to Remember You By (2013).

He continues to receive critical acclaim, and is regarded as one of the most influential comedic actors of the second half of the 20th century.

Born Jerome Silberman in Milwaukee, Wisconsin, on June 11, 1933, Gene Wilder is the son of William J. and Jeanne (Baer) Silberman. He adopted "Gene Wilder" for his professional name at the age of 26, later explaining, "I had always liked Gene because of Thomas Wolfe's character Eugene Gant in Look Homeward, Angel and Of Time and the River. And I was always a great admirer of Thornton Wilder."[2][3] Wilder first became interested in acting at age 8, when his mother was diagnosed with rheumatic fever and the doctor told him to "try and make her laugh."[4] At the age of 11, he saw his sister, who was studying acting, performing onstage and was enthralled by the experience. He asked her teacher if he could become his student, and the teacher said that if he was still interested at age 13, he would take Wilder on as a student. The day after Wilder turned 13, he called the teacher, who accepted him; Wilder studied with him for 2 years.[5]

When Jeanne Silberman felt that her son's potential was not being fully realized in Wisconsin, she sent him to Black-Foxe, a military institute in Hollywood, where he wrote that he was bullied and sexually assaulted, primarily because he was the only Jewish boy in the school.[6] After an unsuccessful short stay at Black-Foxe, Wilder returned home and became increasingly involved with the local theatre community. At age fifteen, he performed for the first time in front of a paying audience, as Balthasar (Romeo's manservant) in a production of Shakespeare's Romeo and Juliet.[7] Gene Wilder graduated from Washington High School in Milwaukee in 1951.

Wilder was raised Jewish but holds only the Golden Rule as his philosophy. He described himself as a "Jewish-Buddhist-Atheist" in an interview published in 2005.[1]

Wilder studied Communication and Theatre Arts at the University of Iowa, where he was a member of the Alpha Epsilon Pi Fraternity.[8] Following his 1955 graduation from Iowa, he was accepted at the Bristol Old Vic Theatre School in Bristol, England. After six months of studying fencing, Wilder became the first freshman to win the All-School Fencing Championship.[9] Desiring to study Stanislavski's system, he returned to the U.S., living with his sister and her family in Queens. Wilder enrolled at the HB Studio.[10]

Wilder was drafted into the Army on September 10, 1956. At the end of recruit training, he was assigned to the medical corps and sent to Fort Sam Houston for training. He was then given the opportunity to choose any post that was open, and wanting to stay near New York City to attend acting classes at the HB Studio, he chose to serve as paramedic in the Department of Psychiatry and Neurology at Valley Forge Army Hospital, in Phoenixville, Pennsylvania.[11] In November 1957, his mother died from ovarian cancer. He was discharged from the army a year later and returned to New York. A scholarship to the HB Studio allowed him to become a full-time student. At first living on unemployment insurance and some savings, he later supported himself with odd jobs such as a limousine driver and fencing instructor. Wilder's first professional acting job was in Cambridge, Massachusetts, where he played the Second Officer in Herbert Berghof's production of Twelfth Night. He also served as a fencing choreographer.[12]

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Gene Wilder - Wikipedia, the free encyclopedia

Precision medicine seems to be the new hot topic in the research world. President Obama spoke about precision medicine in his State of the Union speech on January 20, his budget released today requests $215M for precision medicine, and NIH just announced plans for a study of a million or more volunteers to explore precision medicine. What precisely is it? The White House website has a useful definition: getting the right treatment at the right time to the right person. The President, in an event devoted to precision medicine in the East Room last Friday [January 30, see video, below], told the story of ivacaftor, a drug that effectively treats the underlying causenot the symptomsof cystic fibrosis, but works in only 4% of patients who have a specific mutation in the gene causing this disease.

Most of the conversation about precision medicine focuses on cancer. Because cancer is a disease of genetic mutations leading to unregulated cell division, defining the precise mutations in the affected tissue have already led to breakthrough treatments for both blood and solid tissue cancers. In fact, the same mutation can occur in different parts of the body, so cancer is increasingly diagnosed in terms of its genetic and molecular signature rather than the tissue of origin. Part of the proposed precision medicine plan will involve scaling up efforts at the National Cancer Institute to find these mutations and to develop drugs or biologics as treatments.

What does precision medicine mean for mental health? Our version is the Research Domain Criteria (RDoC) project, which aims to develop more precise diagnostic categories based on biological, psychological, and socio-cultural variables. It is certainly possible that we may find specific mutations in relevant brain circuits that explain some cases of schizophrenia, bipolar disorder, or autism, just as mutations in the tumor explain cancer. NIMH has supported research on inherited genetic risk for several years; a new initiative on another class of mutations, somatic mosaicism (the term for mutations that develop after fertilization), will launch this year. But more likely, precision medicine for mental disorders will not come from a single genomic glitch. Rather, like many other areas of medicine, many genes each contribute only a small amount of vulnerability as part of an overall risk profile that includes life experiences, neurodevelopment, and social and cultural factors. RDoC assumes that we will need many kinds of data to reach precision, more like triangulating to find your position on a map. These data will draw from many sources, including symptoms, genotype, physiology, cognitive assessment, family dynamics, environmental exposures, and cultural background.

I know that RDoC sounds more complex than the cancer version of precision medicine, but that is the nature of the problem. For now, we need to embrace the complexity to identify the simpler, actionable categories that can be used in the clinic. The rationale for this approach is no different from what the President talked about for cancer or cystic fibrosisgetting the right treatment at the right time to the right person.

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Precision Medicine for Mental Disorders

10.02.2015 - (idw) Paul-Ehrlich-Institut - Bundesinstitut fr Impfstoffe und biomedizinische Arzneimittel

Therapeutic gene transfer is considered as a promising novel strategy to treat genetic disorders and cancer. So far, target cells are often isolated from patients for this purpose, and re-administered after gene transfer. In collaboration with colleagues from the Universities of Cologne and Zurich, researchers at the Paul-Ehrlich-Institut have succeeded in developing gene transfer vehicles that target the therapy relevant cell type directly in the organism. The resulting gene transfer occurs with an extremely high degree of selectivity. A report on the research results can be found in Nature Communications in its online edition of 10.02.2015. Vectors derived from adeno-associated viruses (AAV) were used as vehicles for targeted gene transfer by the research group of Professor Christian J. Buchholz, Principal Investigator at the LOEWE Centre for Cell and Gene Therapy at Frankfurt am Main and head of the Section Molecular Biotechnology and Gene Therapy of the President of the Paul-Ehrlich-Institut. AAV is a non-pathogenic parvovirus. The only gene therapy medicinal product authorised in Europe so far, is also based on AAV gene vectors and intended for the treatment of a rare metabolic disorder.

The strategy for the generation of the new precision gene vectors was developed and implemented jointly with Dr Hildegard Bning, head of the AAV Vector Development Research Group at the ZMMK (Zentrum fr Molekulare Medizin Kln, Center for Molecular Medicine Cologne) of the University of Cologne: Through exchange of two amino acids, AAV lost its ability to bind to its natural receptor and became thereby unable to penetrate its broad range of natural target cells. Novel target structures (DARPins, designed ankyrin repeat proteins) were then attached to the surface of the modified vector particles. These structures were developed at Zurich University. The structures can be selected in such a way that they mediate a selective binding of the DARPin-containing AAV vector particles to the therapy relevant cell type only. This is what enables the AAV vector to attach to and penetrate the desired target cell. The paper referenced here reports on the use of three different DARPins, which equipped AAV vectors either with a specificity for Her2/neu, a tumour marker in breast cancer, for EpCAM, an epithelial surface protein, or for a marker of particular blood cells (CD4 on the surface of lymphocytes with distinct immunological functions).

The desired goal of a cell type specific in vivo gene transfer was also achieved with the blood cell targeted vector: AAV transferred the gene only into lymphocytes present in spleen carrying the CD4 protein target structure.

The method developed by us jointly is a very promising tool both in fundamental research and for the targeted gene transfer in medicine, explained Dr Buchholz with regard to the current research results.

Original Publication

Mnch RC, Muth A, Muik A, Friedel T, Schmatz J, Dreier B, Trkola A, Plckthun A, Bning H, Buchholz CJ (2015): Off-target-free gene delivery by affinity-purified receptor-targeted viral vectors. Nat Commun Feb 10 [Epub ahead of print]. http://www.nature.com/ncomms/2015/150210/ncomms7246/full/ncomms7246.html

The Paul-Ehrlich-Institut, Federal Institute for Vaccines and Biomedicines in Langen near Frankfurt/Main, is a senior federal authority reporting to the Federal Ministry of Health (Bundesministerium fr Gesundheit, BMG). It is responsible for the research, assessment, and marketing authorisation of biomedicines for human use and veterinary vaccines. Its remit also includes the authorisation of clinical trials and pharmacovigilance, i.e. recording and evaluation of potential adverse effects. Other duties of the institute include official batch control, scientific advice and inspections. In-house experimental research in the field of biomedicines and life science form an indispensable basis for the varied and many tasks performed at the institute. The PEI, with its roughly 800 staff, also has advisory functions at a national level (federal government, federal states (Lnder)), and at an international level (World Health Organisation, European Medicines Agency, European Commission, Council of Europe etc.). Weitere Informationen:http://www.pei.de

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Precise gene transfer into therapy relevant cells after vector injection into blood

Posted: Wednesday, February 11, 2015, 2:00 AM

(HealthDay News) -- An investigational drug designed to stop Ebola in its tracks has shown early promise in a study involving rhesus monkeys, researchers say.

The drug in question, for now dubbed AVI-7537, appeared to safely protect 75 percent of treated monkeys from Ebola after exposure to the virus. However, it has not been tested in humans, and trials in animals often fail to translate to success in people, experts note.

The search for viable medicines against Ebola has gained urgency as an outbreak in West Africa continues. According to the World Health Organization, by Feb. 9 almost 23,000 cases of Ebola illness have been recorded in Guinea, Liberia and Sierra Leone, including almost 9,200 deaths.

The experimental medication under study is part of the so-called PMO class of drugs, which are designed to attack the genetic code of viruses like Ebola, and short-circuit the ability to reproduce and take hold.

Prior research has already shown that a PMO drug that simultaneously targeted two Ebola genes -- VP35 and VP24 -- provided monkeys with substantial protection against the virus.

But the current study reveals that the VP35 gene is actually a false target, and that a drug aimed solely at the VP24 gene is sufficient to do the job.

"The study demonstrates that we can protect non-human primates from Ebola virus, using only a single . . . agent," study lead author Travis Warren said in a news release from the American Society for Microbiology.

Warren is an investigator at the U.S. Army Medical Research Institute of Infectious Diseases (AMRIID), in Fort Detrick, Md. His team published their findings online Feb. 10 in the journal mBio.

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Ebola Drug Shows Promise in Monkey Trial

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Newswise BUFFALO, N.Y. The Jewels in our Genes study, led by University at Buffalo researcher Heather Ochs-Balcom, has uncovered previously unknown segments of DNA shared by African American family members who have breast cancer.

The discovery of these regions supports our hypothesis that there are still undiscovered breast cancer genes that may be unique to African Americans, says Ochs-Balcom, PhD, a genetic epidemiologist in the UB Department of Epidemiology and Environmental Health. We can now focus on these specific chromosomes to learn if they house genetic mutations linked to breast cancer.

We also need to determine whether those mutations are found in other racial groups or if they are unique to African Americans. If they are unique, it could explain why young African American women have a higher risk of pre-menopausal breast cancer compared to other groups, she says.

Our study used linkage analysis, a powerful tool that helps to detect the chromosomal location of disease genes by examining genetic markers across the entire human genome. Our family-based gene hunt is similar to the groundbreaking study among women with European ancestry done in the early 1990s that led to the discovery of BRCA1 and BRCA2 gene mutations, which greatly increase susceptibility to breast and ovarian cancer.

African American women can also carry the BRCA mutations, but Ochs-Balcom suspects there may be additional, undiscovered mutations linked to breast cancer in this population.

Family studies like this one have been difficult to conduct in the past, Ochs-Balcom says, in part because its difficult to get multiple family members to commit the time needed to participate. We found here that approaching the recruitment of African Americans by using a multi-pronged approach that included collaboration from our community partnerships greatly facilitated success.

She points out that African American women have a higher incidence of pre-menopausal breast cancer and a higher breast cancer mortality rate than European Americans. They also more likely to develop early-onset cancers that are aggressive and difficult to treat. Some of these may be caused by unknown genetic anomalies that if found, could lead to early screening, detection and treatment.

The study was funded by a grant from the Susan G. Komen for the Cure Foundation and is the subject of two recent papers published by the team in the journal Cancer, Epidemiology, Biomarkers and Prevention and the Journal of Community Genetics.

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Study Links New Genetic Anomalies to Breast Cancer in African American Families

3 hours ago RGEN-induced digenome sequencing to capture off-target sites. (a) Overview of Digenome-seq. Forward and reverse sequence reads are shown in pink and blue, respectively. Red triangles and vertical lines indicate cleavage positions. WT, wild type. (b) Representative IGV images obtained using the HBB-specific RGEN at the on-target site.

The IBS research team (Center for Genome Engineering) has successfully confirmed that CRISPR-Cas9 has accurate on-target effects in human cells, through joint research with the Seoul National University College of Medicine and ToolGen, Inc.

There has been great interest in CRISPR-Cas9 as a tool to develop anticancer cell therapies or to correct genetic defects that cause hereditary in stem and somatic cells. However, since there has been no reliable and sensitive method to measure the accuracy of CRISPR-Cas9 genome-wide, its safety has remained in question. Consequently, it has been difficult to eliminate the possibility that CRISPR-Cas9 may induce mutations in off-target sequences that are similar to on-target sequences. Off-target mutations in tumor suppressor genes, for example, can cause cancer.

The researchers have developed a technique termed Digenome-seq to locate both on-target and off-target sequences that can be mutated by CRISPR-Cas9 via genome sequencing. They digested human genomic DNA using Cas9 nucleases in a test tube, which was then subjected by whole genome sequencing. This in vitro digest yielded a unique pattern at both on-target and off-target sequences that can be computationally identified. Furthermore, by adding guanine nucleotides at the end of sgRNA(single guided RNA) that composes CRISPR-Cas9, they have successfully created this highly-developed programmable nuclease, which has no measurable off-target effects in the human genome.

Jin-Soo Kim, the director of the Center for Genome Engineering at IBS, as well as the professor of the Department of Chemistry at Seoul National University says, "If CRISPR-Cas9 truncates off-target DNA sequences, it might induce unwanted mutations. Since we have succeeded in confirming the accuracy of CRISPR-Cas9, we anticipate that there will be a great progress in the development of gene or cell therapies," emphasizing the significance of this research achievement.

Nature Methods has also highlighted this achievement as one of the "2015 Methods to Watch" in its January issue.

Explore further: Revolutionizing genome engineering: Review on history and future of the CRISPR-Cas9 system published

More information: Daesik Kim, Sangsu Bae, Jeongbin Park, Eunji Kim, Seokjoong Kim, Hye Ryeong Yu, Jinha Hwang, Jong-Il Kim & Jin-Soo Kim.(2015) Nature Methods. DOI: 10.1038/nmeth.3284

Journal reference: Nature Methods

Provided by Institute for Basic Science

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End of CRISPR-CAS9 controversy