We all know Smoking is injurious, it harms not just lungs, heart, immune system, bladder, eyes, skin, every organ and also our fundamental core- our genetic material, DNA. Along with creating mutation in DNA it also affects the expression of our genes, therefore it modifies our epigenome.
Major epigenetic changes observed in smokers-
•Smoke causes oxidative stress by forming Reactive Oxygen Species (ROS) which causes overexpression of DNMTs, further causing hypermethylation of tumor suppressor genes like in AHRR (Aryl hydrocarbon Receptor Repressor), p16 and RASSF1A; increasing risk of developing cancer.
•Smoking also ignites inflammatory response throughout body, which might cause hypomethylation triggering a cascade which upregulates oncogenes; another factor influencing cancer development.
•Cigarette Smoking (CS) alters histone acetyletion.
•Smoking increases activity of miR-21 (microRNA) which contributes in lung cancer progression.
The above mentioned are just a few of the changes observed in gene expression of smokers.
Most of these are reversible but are inheritable as well. Smokers create risk factors for cancer, COPD and wide range of diseases which are inheritable and effects F3 generation even when F1 generation didn’t smoke, in other words, imagine if a person’s grandmother smoked maybe not for lifetime but enough to acquire epigenetics changes, which will be inherited by her grandchildren even when her kids never smoked and all of her descendants are at higher risk of developing huge range of complications in life or even before birth. Smoking cause implications for generations by modifying our Epigenome.
Why it matters?
Epigenome decides if the ‘good’ genes will be expressed or ‘bad’ and also to what extent. So if you have had a wonderful family history of very healthy genes and someone makes unhealthy choices it will decide if your ‘strong genes’ will actually be express or not.
The biggest concern is passive smoking also results in epigenetic changes. Smoking is not injurious just for the smoker but also for his family, descendants and fellow beings as well. If they quit they make a healthy decision not just for themselves but for many others as well.
This is true for all our lifestyle choices. Are you aware of any other lifestyle choices which can alter our epigenome?
MBH/PS