A low level of nicotine-induced chemoresistance in a KB cell line

Cigarette smoking is closely associated with the induction of head and neck squamous cell carcinomas (HNSCC). Nicotine is an important component in cigarette smoke that can activate the growth-promoting pathways and facilitate the development of cancer. As nicotine is currently used in replacement therapy for smoking cessation in different forms, from skin patches to the oral route, numerous studies have investigated the effect of nicotine on the body, but the results have been equivocal. The aim of this study was to investigate the effect of nicotine on cancer chemotherapy. The status of the cell death-related proteins after treatment with nicotine was determined and compared to the effect of anticancer drugs such as cisplatin and etoposide in the presence or absence of nicotine in the KB cell line. Nicotine induced Bad phosphorylation in association with the suppression of apoptosis. The inhibition rate of cells pre-treated with nicotine prior to anticancer drug exposure was significantly decreased when compared to cells exposed to anticancer drugs only (P<0.01). Collectively, this suggests that nicotine may alter chemo-resistance and carcinogenesis via the anti-apoptotic pathway in HNSCC, and chemotherapy for HNSCC should be performed in the absence of nicotine in patient blood.