The China Post/Asia News Network
Wed, Feb 10, 2010
TAIPEI, Taiwan – A Taiwanese research had further identified the reason why tobacco causes lung cancer and other smoking-related diseases and was made the cover story of the February issue of the world is leading biomedical journal, The Journal of Clinical Investigation.
The study revealed the mechanism of how tobacco-specific carcinogen causes lung tumors. It showed that the key ingredient of tobacco carcinogen, nicotine-derived nitrosamine ketone (NNK), would induce the accumulation of a protein, DNA methyltranferase 1 (DNMT1), which inhibits the tumor suppressor genes, and lead to lung cancer.
It also showed that the accumulation of DNMT1 in lung cancer patients who smoked continuously correlates with poor recovery. If lung cancer patients quit smoking, after two to four weeks, the level of DNMT1 would decrease and this would greatly increase the life span of the patients. Lung cancer patients who quit smoking outlived those who do not quit by eight-to-ten months.
Also, in the future, doctors can extract lung cancer samples and test for the level of DNMT1. Lung cancer patients who have a low level of DNMT1 can avoid going through chemotherapy and radiotherapy.
The research article was jointly written by researchers from National Cheng Kung University, National Taiwan Normal University, National Health Research Institute, National Yang-Ming University, China Medical University Hospital and National Taiwan University.