Title: E-cigarette smoke damages DNA and reduces repair activity in mouse lung, heart, and bladder as well as in human lung and bladder cells.
Authors: Lee, Hyun-Wook; Park, Sung-Hyun; Weng, Mao-Wen; Wang, Hsiang-Tsui; Huang, William C; Lepor, Herbert; Wu, Xue-Ru; Chen, Lung-Chi; Tang, Moon-Shong
Published In Proc Natl Acad Sci U S A, (2018 02 13)
Abstract: E-cigarette smoke delivers stimulant nicotine as aerosol without tobacco or the burning process. It contains neither carcinogenic incomplete combustion byproducts nor tobacco nitrosamines, the nicotine nitrosation products. E-cigarettes are promoted as safe and have gained significant popularity. In this study, instead of detecting nitrosamines, we directly measured DNA damage induced by nitrosamines in different organs of E-cigarette smoke-exposed mice. We found mutagenic O6-methyldeoxyguanosines and γ-hydroxy-1,N 2 -propano-deoxyguanosines in the lung, bladder, and heart. DNA-repair activity and repair proteins XPC and OGG1/2 are significantly reduced in the lung. We found that nicotine and its metabolite, nicotine-derived nitrosamine ketone, can induce the same effects and enhance mutational susceptibility and tumorigenic transformation of cultured human bronchial epithelial and urothelial cells. These results indicate that nicotine nitrosation occurs in vivo in mice and that E-cigarette smoke is carcinogenic to the murine lung and bladder and harmful to the murine heart. It is therefore possible that E-cigarette smoke may contribute to lung and bladder cancer, as well as heart disease, in humans.
PubMed ID: 29378943
MeSH Terms: Animals; Carcinogenesis/drug effects; Cell Line; DNA Damage/drug effects*; DNA Repair/drug effects*; Electronic Nicotine Delivery Systems; Heart/drug effects*; Humans; Lung/drug effects*; Lung/metabolism; Male; Mice; Mutation/drug effects; Nicotine/chemistry; Nicotine/toxicity*; Nitrosamines/chemistry; Nitrosamines/toxicity*; Smoke/adverse effects*; Urinary Bladder/drug effects*; Urinary Bladder/metabolism