Azim Nejatizadeh - PHD, Human Genetics, Faculty of Medicine Molecular, Medicine Research Center, Hormozgan University Of Medical Sciences, Bandar Abbas, Iran

Smoking is well known to be destructive to health and cause disease in nearly every organ of the body, exposing smokers to multiple harmful components in tobacco. Of note, family and twin studies have also revealed a high degree of heritability of smoking and nicotine dependence. Compelling evidence showed that people who smoke a pack a day develop a considerable number of mutations in their lungs, mouth, pharynx, larynx, bladder predisposing to a higher risk of developing various cancers. The amount of DNA damage caused by smoking in any individual may be greatly influenced by their underlying genetic profile, lifestyle, environment, and the type of tobacco smoked. Furthermore, some studies revealed a large number of genes that were altered in smokers but found no such effect of non-smoke tobacco. This means that the epigenetic modifications are likely not caused by substances in the tobacco, however by the hundreds of various elements that are formed when the tobacco is burnt. Remarkably, finding of smoking-related DNA methylation sites raises the likelihood of developing biomarkers to appraise a patient's smoking history, as well as new treatments. Persuasive evidence also showed that smoking has a long-term impact on the molecular machinery, an impact that can last more than ۳۰ years. Once smoking stops, the majority of DNA methylation signals return to never smoker levels after five years. Next-generation sequencing may provide means to discover more rare variants explaining differences in smoking-related behavior and predisposition to smoking-related diseases. A better understanding of the molecular mechanism behind diseases and reduced body function might lead to improved novel drugs and therapies in the future.

Smoking, Genetic, DNA Methylation, Mutation, Disease