DNAction

A gene believed to play a major role in more than half of all breast cancers and a significant portion of other tumors has been identified by scientists.

This particular gene came to light after researchers noticed it was missing from tissues that had been removed from breast cancers for testing. The lack of the gene has also been implicated in half of all cases of colon and prostate cancer, and a quarter of ovarian and bladder tumors.

Paul Edwards, a molecular biologist at Cambridge University, claims this could be the most important cancer-suppressing gene discovery of the past 20 years. “This is a gene lost in a quarter to a half of common cancers, so it is clearly playing a really important role,” says Edwards.

Tissues from 54 breast tumors were examined by Edwards and his colleagues and they found part of chromosome 8 was missing in more than half of them. After cross-checking against the Human Genome Project they were able to identify a gene called NRG1 that was lost.

The discovery of NRG1 is thought to be the most significant step forward in the field since another gene, p53, was discovered in the 1970s and found to be implicated in cancers in the late 1980s. The gene was the first “tumor suppressor” gene found in cells and is known to be faulty or inactivated in many types of the disease.

Check out the entire story at zerocancer.org

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UK scientists say people who carry rare mutations within both copies of a gene called MUTYH are 28 times more likely to develop bowel cancer compared to the general population.

These findings, which helped validate previous discoveries, showed this risk increase only exists if mutations are in both copies of the gene. The research also adds important insights into the controversy surrounding whether or not having just one mutation raises an individual’s risk of bowel cancer.

Researchers observed those who carried biallelic mutations were more likely to develop bowel cancer when relatively young - in their 50s. Most bowel cancers, over 80 per cent, occur in people aged 60 and over. Although the contribution of biallelic mutations to the overall incidence of bowel cancer is not high, the risk of developing the disease is substantial.

Check out the entire article at Medical News Today

jwoodman News & Features bowel cancer, cancer, colon cancer, genetic testing, genetics, new research

Traditionally chemotherapy has been the treatment of choice for those diagnosed with non-small cell lung cancer, which accounts for 80 percent of all lung cancers. Recently, however, researchers in Japan, Hong Kong and Spain have found that people with specific mutations in genes for the epidermal growth factor receptor (EGFR), can survive over twice as long by taking AstraZeneca’s target drug Iressa (gefitinib) instead of chemotherapy.

“This basically confirmed what we have thought, that in selected populations (light smokers or those who never smoked), those testing positive for EGFR mutations will do much better in progression-free survival than if you put the patient on chemo,” said Dr. Edgardo Santos, an assistant professor of medicine in the hematology and oncology section at the University of Miami’s Sylvester Comprehensive Cancer Center. “For the first time in a selected population, you have a drug which can compete with systemic chemotherapy—there is a pill that matches systemic chemotherapy.”

Read the full story at HealthNews.com.

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Check out the excellent article from Smithsonian.com on Carlo Croce, a 64-year-old eccentric Italian scientist whose out-of-the-box thinking has created fascinating new insights into MicroRNA, a smaller than normal gene with fascinating potential

In a nutshell, MicroRNAs can help doctors learn where a cancer originated and may be able to estimate a cancer’s severity. Croce and his collaborators found that the levels of two microRNAs predicted survival in lung cancer patients. Croce’s group has also found microRNAs that predict whether a patient’s cancer will become aggressive or stay mild. In the future, a patient’s microRNA profile might indicate whether they should undergo aggressive and risky treatment or a milder, safer one.

Today, researchers have identified about 40 microRNA genes associated with cancers, including those of the breast, lung, pancreas and colon. Like conventional genes that produce proteins, microRNA genes can also be cancer promoters if they produce too many microRNAs. Or they can be cancer suppressors; if they are damaged or lost, cancer ensues. Most exciting is that scientists are starting to understand how microRNAs interact with traditional cancer genes. It’s like a complex switchboard of connections that occurs inside cells as cancer spreads.

Croce’s biggest hope is that microRNAs might one day be used as therapies. “I am convinced, absolutely convinced,” he says, “that microRNAs will become drugs.” In some recent experiments, he and a colleague have injected microRNAs into mice with leukemia or lung cancer. The injections, he says, stopped the cancer growth.

Cancer is not the only disease in which microRNAs are emerging as important players. Studies now suggest these miniature genes are involved in immune system function, heart disease, schizophrenia, Alzheimer’s disease and Tourette’s syndrome. Beyond that, there is a long list of diseases that appear to have a genetic basis, but for which no conventional gene has been identified. Thomas Gingeras, a genome researcher at Cold Spring Harbor Laboratory in New York, believes some of these diseases will ultimately be linked to microRNAs. “I think it’s undoubtedly going to be the case,” he says.

Perhaps that’s because the tiny molecules exert so much influence over the rest of the body. Scientists estimate that humans have around 1,000 microRNA genes, which seem to control the activity of at least a quarter of our 25,000 protein-coding genes. “We are astounded by that number and believe it’s a minimum,” says Nobel laureate Phillip Sharp of M.I.T., in whose laboratory microRNAs are studied.

No wonder, then, that some scientists express embarrassment and regret that they failed to find microRNA genes sooner—chiefly because they didn’t challenge basic assumptions about genes.

Read the entire Frontiers of Science account at Smithsonian.com.

jwoodman Health Care, News & Features cancer, MicroRNA, new research

Scientists believe a new DNA test for human papillomavirus, or HPV, the virus that causes cervical cancer, is much more effective than the traditional Pap smear.

What’s most promising is that women over 30 could drop annual Pap smears and instead have the DNA test just once every 3, 5 or even 10 years, depending on which expert is asked.

An eight-year study of 130,000 women in India, published in The New England Journal of Medicine, is the first to show that a single screening with the DNA test beats all other methods at preventing advanced cancer and death.

The study is “another nail in the coffin” for Pap smears, which will “soon be of mainly historical interest,” said Dr. Paul D. Blumenthal, a professor of gynecology at Stanford medical school who has tested screening techniques in Africa and Asia and was not involved in the study.

Read the comprehensive report in the New York Times article.

jwoodman DNA Testing, News & Features cancer, cervical cancer, DNA test, new research, Pap smear