One possible mechanism that has the potential for mediating the harmful effects of tobacco smoking is DNA methylation. DNA methylation, the attachment of methyl groups to specific sites within a section of DNA, is recognized as an important mechanism for regulating gene function and may play a significant role in diseases with a complex phenotype. Although previous studies have linked nicotine and smoking with altered methylation of several genes, comparison of methylation status between heavy smokers who do not have cancer and individuals who have never smoked has not been fully examined.

Dr. Breitling and colleagues used a recently developed genetic screening technique to conduct a genome-wide search for differential methylation correlated with tobacco smoking in 177 current, former, and never smokers. The researchers discovered a single section of DNA that exhibited lower methylation in smokers. The site was located within a gene called coagulation factor II receptor-like 3 (F2RL3). F2RL3 has been linked with the process of blood clotting and with other cardiovascular functions. Interestingly, the protein coded by this gene has never been mentioned in the smoking literature.

"Our results show that the gene coding for a potential drug target of cardiovascular importance features altered methylation patterns in smokers," concludes Dr. Breitling. "Intriguing perspectives lie in the possibility that this gene could be causally involved at a very initial stage of smoking-related cardiovascular pathology. A better understanding of its role might open up avenues for preventing the development of associated disease in subjects unable to quit smoking."



Source: Eurekalert