Christine Posted September 19, 2007 Share Posted September 19, 2007 Sept. 18, 2007 Courtesy American Association for Cancer Research and World Science staff When it’s quiet—almost “too quiet”—in movies, it’s often a sign something is about to go wrong for the good guys. The same may be true of genes that guard against lung cancer, researchers have found. They identified 15 such genes, adding that these could help predict cancer: if their collective activity becomes too quiet, it suggests other factors in the cell are suppressing them, a possible step toward cancer. A test for these genes in normal cells sampled via bronchoscopy could identify people at risk for lung cancer, said James C. Willey of the University of Toledo, Ohio, the lead researcher. In a study of 49 people, about half of whom had lung cancer, Willey and his colleagues said they identified those patients correctly 96 percent of the time. Willey cautioned that more, larger studies will need to be done to see if such a test can identify future cancer sufferers before they become sick. “Smoking causes about 90 percent of all lung cancer cases, yet only about 10 to 15 percent of heavy smokers will develop lung cancer,” said Willey. “We are looking for new techniques that will allow us to pick out the 10 to 15 percent of individuals at highest risk for lung cancer from the enormous pool of current and former smokers.” The United States alone has more than 40 million current or former heavy smokers, he added. And although increasingly powerful screening tools are available to detect lung cancer early, it’s very costly to screen all these people. The new test could lead to better targeted screening, Willey said. To find which genes are active in lung cancer, Willey and his colleagues look for levels of messenger RNA transcripts—instructions copied from DNA that direct cells to create specific protein molecules. Previously, the researchers had found that genes that protect lung cells from damage caused by smoke or toxins are poorly regulated in lung cancer patients. In the new work, the team tested their theories by measuring “transcript abundance” of 15 genes that encode protective antioxidant and DNA repair proteins in lung airway cells. Transcript abundance is an indicator of gene activity. The findings were presented Sept. 18 at the American Association for Cancer Research’s International Conference on Molecular Diagnostics in Cancer Therapeutic Development, in Atlanta, Ga. Quote Link to comment Share on other sites More sharing options...
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