Smoking leaves its “footprint” on the human genome in the form of DNA methylation, a process by which cells control gene activity, according to new research in Circulation: Cardiovascular Genetics, an American Heart Association journal.
“These results are important because methylation, as one of the mechanisms of the regulation of gene expression, affects what genes are turned on, which has implications for the development of smoking-related diseases,” said Stephanie J. London, M.D., Dr.P.H., last author and deputy chief of the Epidemiology Branch at the National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina. “Equally important is our finding that even after someone stops smoking, we still see the effects of smoking on their DNA.”>
Even decades after stopping, former smokers are at long-term risk of developing diseases including some cancers, chronic obstructive pulmonary disease, and stroke. While the molecular mechanisms responsible for these long-term effects remain poorly understood, previous studies linking DNA methylation sites to genes involved with coronary heart disease and pulmonary disease suggest it may play an important role. More. Paper. (paywall) – Roby Joehanes et al. Epigenetic Signatures of Cigarette Smoking. Circulation: Cardiovascular Genetics, 2016; CIRCGENETICS.116.001506 DOI: 10.1161/CIRCGENETICS.116.001506
Lightening the mood a bit: Your news writer was sitting in a doctor’s office some years back with a very old fellow, and the doctor asked, routinely, “Has he ever smoked?” I spoke up and said, “Yes, during the War [WWII], but then he quit in 1955.” The doctor entered in his chart, “Never smoked.” Epigenetic damage an issue, for sure, but the old fellow was often heard to say over many decades that he could buy three cars today with the money not smoking had saved him.
See also: Epigenetic change: Lamarck, wake up, you’re wanted in the conference room!
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