The Epigenetics of Smoking

Everyone know that smoking causes an increased risk of cancer, but researchers have also found direct evidence that smoking causes epigenetic changes in genes that block tumors, says The New Scientist's Nic Fleming. Reversing the changes could lead researchers down a new road to treat cancer, he adds. The researchers, led by Yuk Ting Ma of the University of Birmingham in the UK, looked back at a series of cervical samples from more than 1,000 women taken over four years, and found evidence of methylation in the p16 gene — which is known to suppress tumors — in the cells of 37 percent of the smokers in the test group, as compared to 9.3 percent of the nonsmokers, Fleming says. Moreover, he adds, women who started smoking during the trial were 3.7 percent more likely to develop methylation and the methylation disappeared in some of the women who gave up smoking during the study.