A new study has found strong evidence that tobacco use can chemically modify and affect the activity of genes known to increase the risk of developing cancer.
Chemical compounds that affect the functioning of genes can bind to our genetic material, turning certain genes on or off.
These so-called epigenetic modifications can influence a variety of traits, such as obesity and sexual preference.
In the new study, published in Human Molecular Genetics, researchers analyzed epigenetic signatures in blood cells from 374 individuals enrolled in the European Prospective Investigation into Cancer and Nutrition.
EPIC, as it's known, is a massive study aimed at linking diet, lifestyle, and environmental factors to the incidence of cancer and other chronic diseases. Half of the group consisted of people who went on to develop colon or breast cancer 5 to 7 years after first joining the study, whereas the other half remained healthy.
|Epigenetic mechanisms (Photo credit: Wikipedia)|
The lead researcher James Flanagan of Imperial College London discovered that in comparison to the people who never smoked, there were chemicals tags in form of methyl groups on 20 different regions of DNA who smoked.
When the researchers extended the analysis to a separate group of patients and mice that had been exposed to tobacco smoke, they narrowed down the epigenetic modifications to several sites located in four genes that have been weakly linked to cancer before.
All of these changes should increase the activity of these genes, but it's unclear why increasing the activity of the genes would cause cancer, the researchers wondered; but individuals who don't have cancer tend not to have these modifications.