Category Archives: Gene Medicine

Washington, October 1 (ANI): Researchers have discovered a new genetic mutation responsible for deafness and hearing loss associated with Usher syndrome type 1.

These findings could help researchers develop new therapeutic targets for those at risk for this syndrome.

For the study, researchers at the University of Cincinnati (UC) and Cincinnati Children's Hospital Medical Center work together with the National Institute on Deafness and other Communication Disorders (NIDCD), Baylor College of Medicine and the University of Kentucky.

Usher syndrome is a genetic defect that causes deafness, night-blindness and a loss of peripheral vision through the progressive degeneration of the retina.

"In this study, researchers were able to pinpoint the gene which caused deafness in Usher syndrome type 1 as well as deafness that is not associated with the syndrome through the genetic analysis of 57 humans from Pakistan and Turkey," said Zubair Ahmed, PhD, assistant professor of ophthalmology who conducts research at Cincinnati Children's and is the lead investigator on this study.

Ahmed stated that a protein, called CIB2, which binds to calcium within a cell, is associated with deafness in Usher syndrome type 1 and non-syndromic hearing loss.

"To date, mutations affecting CIB2 are the most common and prevalent genetic cause of non-syndromic hearing loss in Pakistan. However, we have also found another mutation of the protein that contributes to deafness in Turkish populations," he said.

"In animal models, CIB2 is found in the mechanosensory stereocilia of the inner ear-hair cells, which respond to fluid motion and allow hearing and balance, and in retinal photoreceptor cells, which convert light into electrical signals in the eye, making it possible to see," explained Saima Riazuddin, PhD, assistant professor in UC's department of otolaryngology who conducts research at Cincinnati Children's and is co-lead investigator on the study.

Researchers found that CIB2 staining is often brighter at shorter row stereocilia tips than the neighboring stereocilia of a longer row, where it may be involved in calcium signaling that regulates mechano-electrical transduction, a process by which the ear converts mechanical energy-or energy of motion-into a form of energy that the brain can recognize as sound.

"With this knowledge, we are one step closer to understanding the mechanism of mechano-electrical transduction and possibly finding a genetic target to prevent non-syndromic deafness as well as that associated with Usher syndrome type 1," Ahmed said.

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Gene that causes deafness pinpointed

NEW YORK Scientists reported Sunday that they have completed a major analysis of the genetics of breast cancer, finding four major classes of the disease. They hope their work will lead to more effective treatments, perhaps with some drugs already in use.

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Trampolines are too dangerous for children to use, the American Academy of Pediatrics warned Monday. There were nearly 100,000 trampoline injuries in 2009 -- and safety nets don't offer much protection, doctors say.

The new finding offers hints that one type of breast cancer might be vulnerable to drugs that already work against ovarian cancer.

The study, published online Sunday by the journal Nature, is the latest example of research into the biological details of tumors, rather than focusing primarily on where cancer arises in the body.

The hope is that such research can reveal cancer's genetic weaknesses for better drug targeting.

"With this study, we're one giant step closer to understanding the genetic origins of the four major subtypes of breast cancer," Dr. Matthew Ellis of the Washington University School of Medicine said in a statement. He is a co-leader of the research.

"Now we can investigate which drugs work best for patients based on the genetic profiles of their tumors," he said.

The researchers analyzed DNA of breast cancer tumors from 825 patients, looking for abnormalities. Altogether, they reported, breast cancers appear to fall into four main classes when viewed in this way.

One class showed similarities to ovarian cancers, suggesting it may be driven by similar biological developments.

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Gene clues offer new hope for treating breast cancer

19 September 2012 Last updated at 01:39 ET

Dundee University researchers believe they have found a way to predict the effectiveness of chemotherapy drugs in fighting ovarian cancer.

Scientists have discovered a gene called FGF1 was highly active in aggressive, advanced ovarian cancers.

They observed it was present at higher levels in cancer cells that were resistant to a common treatment for the disease.

The team hope the findings help to develop new cancer treatments.

Researchers measured amounts of a variety of genes in 187 ovarian cancer patients and found each cancer had a unique range of active genes.

However, FGF1 appeared to playing the greatest role in determining how cancers behave.

The team, based at the University's School of Medicine, found the gene called FGF1 was found at higher levels in cancer cells that are resistant to platinum chemotherapy treatments, such as carboplatin and cisplatin.

As a result, women with high levels of FGF1 are less likely to respond to these drugs and have a poorer prognosis.

The scientist believe measuring how active the gene is could predict which women with ovarian cancer will benefit from the drugs.

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Gene key to chemotherapy efficacy

SUNDAY, Sept. 23 (HealthDay News) -- A comprehensive look at the genetic blueprint of breast cancer has revealed new insights into the disease -- including the discovery that certain breast and ovarian tumors may be closely related.

Basal-like breast tumors -- one of the most deadly subtypes of breast cancer -- are genetically more similar to ovarian cancer than to other breast cancers, the new research found.

In this study, the scientists used six different technologies to analyze 348 tumors from women with breast cancer. They looked for defects in DNA, RNA and proteins in the tumors.

They confirmed the existence of four main subtypes of breast cancer -- luminol A, luminal B, HER2 and basal-like -- and found unique genetic and molecular signatures within each of the subtypes.

The findings add to growing evidence suggesting that tumors should be catalogued and treated based on the genes that are disrupted rather than their location in the body, the researchers said.

"With this study, we're one giant step closer to understanding the genetic origins of the four major subtypes of breast cancer," study co-leader Dr. Matthew Ellis, chair of medical oncology at Washington University School of Medicine in St. Louis, said in a university news release.

One oncologist said the findings on breast cancer's diversity echo her own experience in treating patients.

"The diversity of breast cancer is instinctual to a practicing breast surgeon who has seen women with breast cancer, presumably the same stage, have differing outcomes with respect to recurrence and survival," said Dr. Donna-Marie Manasseh, director of breast surgery at the Maimonides Breast Cancer Center in New York City. "This research validates what we have suspected."

According to Ellis, the new study suggests that most basal-like breast tumors and ovarian tumors have similar genetic origins and potentially could be treated with the same drugs.

Basal-like tumors account for about 10 percent of all breast cancers and disproportionately affect younger and black women in the United States. Basal-like tumors include most triple-negative breast tumors, which are often aggressive and do not respond to therapies that target hormone receptors or to standard chemotherapies.

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Gene Study Yields New Clues to Breast Cancer

Public release date: 30-Sep-2012 [ | E-mail | Share ]

Contact: Katie Pence katie.pence@uc.edu 513-558-4561 University of Cincinnati Academic Health Center

CINCINNATIResearchers at the University of Cincinnati (UC) and Cincinnati Children's Hospital Medical Center have found a new genetic mutation responsible for deafness and hearing loss associated with Usher syndrome type 1.

These findings, published in the Sept. 30 advance online edition of the journal Nature Genetics, could help researchers develop new therapeutic targets for those at risk for this syndrome.

Partners in the study included the National Institute on Deafness and other Communication Disorders (NIDCD), Baylor College of Medicine and the University of Kentucky.

Usher syndrome is a genetic defect that causes deafness, night-blindness and a loss of peripheral vision through the progressive degeneration of the retina.

"In this study, researchers were able to pinpoint the gene which caused deafness in Usher syndrome type 1 as well as deafness that is not associated with the syndrome through the genetic analysis of 57 humans from Pakistan and Turkey," says Zubair Ahmed, PhD, assistant professor of ophthalmology who conducts research at Cincinnati Children's and is the lead investigator on this study.

Ahmed says that a protein, called CIB2, which binds to calcium within a cell, is associated with deafness in Usher syndrome type 1 and non-syndromic hearing loss.

"To date, mutations affecting CIB2 are the most common and prevalent genetic cause of non-syndromic hearing loss in Pakistan," he says. "However, we have also found another mutation of the protein that contributes to deafness in Turkish populations.

"In animal models, CIB2 is found in the mechanosensory stereocilia of the inner earhair cells, which respond to fluid motion and allow hearing and balance, and in retinal photoreceptor cells, which convert light into electrical signals in the eye, making it possible to see," says Saima Riazuddin, PhD, assistant professor in UC's department of otolaryngology who conducts research at Cincinnati Children's and is co-lead investigator on the study.

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Researchers discover gene that causes deafness

WEDNESDAY, Sept. 26 (HealthDay News) -- A colorectal gene database will help further research into the disease, a new study suggests.

The CRCgene database gathers all genetic association studies on colorectal cancer. It allows researchers to accurately interpret the risk factors of the disease and provides insight into the direction of further research, according to Julian Little, with the department of epidemiology and community medicine at the University of Ottawa, and colleagues.

To determine the genetic factors associated with colorectal cancer, they analyzed data from all published genetic association studies on colorectal cancer.

The researchers identified 16 independent gene variants with the strongest links to colorectal cancer, among 23 variants, a number lower than expected. Unfortunately, the researchers say, this reduces the feasibility of combining variants as a profile in a prediction tool to identity people who are at increased risk for colorectal cancer and who should be screened for the disease.

Even so, the analysis "provides a resource for mining available data and puts into context the sample sizes required for the identification of true associations," the researchers wrote in the Sept. 27 issue of the Journal of the National Cancer Institute.

About 950,000 new cases of colorectal cancer are diagnosed each year, according to a journal news release. Risk factors for the disease include age, diet, lifestyle and possibly genetics.

-- Robert Preidt

Copyright 2012 HealthDay. All rights reserved.

SOURCE: Journal of the National Cancer Institute, news release, Sept. 27, 2012

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Colon Cancer Gene Database May Assist Research Efforts

Public release date: 18-Sep-2012 [ | E-mail | Share ]

Contact: Mattias Lorentzon, University of Gothenburg mattias.lorentzon@medic.gu.se 46-031-342-4929 University of Gothenburg

A big international study has identified a special gene that regulates bone density and bone strength. The gene can be used as a risk marker for fractures and opens up opportunities for preventive medicine against fractures. The study, led by the Sahlgrenska Academy, University of Gothenburg, Sweden, was published in the journal PLoS Genetics.

The international study, which involved more than 50 researchers from Europe, North America and Australia and was led by Associate Professor Mattias Lorentzon and Professor Claes Ohlsson at the Sahlgrenska Academy, University of Gothenburg, is based on extensive genetic analyses of the genetic material of 10,000 patients and experimental studies in mice.

Through the combined studies, researchers have succeeded in identifying a special gene, Wnt16, with a strong link to bone density and so-called cortical bone thickness, which is decisive to bone strength.

The genetic variation studied by the international research network could predict, for example, the risk of a forearm fracture in a large patient group of older women.

"In the experimental study, we could then establish that the gene had a crucial effect on the thickness and density of the femur. In mice without the Wnt16 gene, the strength of the femur was up to 61 per cent lower," according to Mattias Lorentzon at the Institute of Medicine, the Sahlgrenska Academy, University of Gothenburg.

The discovery opens up opportunities to develop new medicines to prevent the most common fractures.

"Low cortical bone mass is a decisive factor in, for example, hip and forearm fractures. Unfortunately, the treatments currently used for brittleness of the bones have very little effect on the cortical bone mass," says Mattias Lorentzon.

"If we can learn to stimulate the signaling routes of the Wnt16 gene, we could strengthen the skeleton in these parts too, thereby preventing the most common and serious fractures. The discovery of Wnt16 and its regulation of cortical bone mass is therefore very important," according to Mattias Lorentzon.

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New gene offers hope for preventive medicine against fractures