Abstract:

Objective   To explore the influence of small interfering RNA (siRNA) down-regulating α5-nAChR expression on nicotine-induced proliferation of human lung cancer cells and expression of VEGF in vitro. Methods  The cells were divided into 0μmol/L nicotine group, 1μmol/L nicotine group, si-NC group (1μmol/L nicotine+si-NC) and siRNA group (1μmol/L nicotine+CHRNA5-siRNA). siRNA fragment of CHRNA5 encoding α5-nAChR was constructed and transfected into human lung cancer A549 cell line with lipofectamine 2000. After CHRNA5-siRNA transfection, expressions of α5-nAChR and VEGF in A549 cell were detected by RT-PCR, Western blotting and ELISA. The nicotine-induced A549 cell proliferation was detected by CCK-8. Results  After CHRNA5-siRNA transfection, expressions of α5-nAChR and VEGF on mRNA and protein levels were significantly decreased compared with the si-NC group (P＜0.05), and nicotine-induced A549 cell proliferation was significantly inhibited (P＜0.05). Conclusion  Down-regulation of α5-nAChR expression could inhibit nicotine-induced cell proliferation and decrease VEGF expression of lung cancer. α5-nAChR and its signal transduction system may play an important role in the development of smoking-related lung cancer and can be used as predictors of lung cancer prognosis and therapeutic targets.

Key words: CHRNA5 gene； &alpha, 5-nicotinic acetylcholine receptor； Vascular endothelial growth factor； Nicotine； Lung neoplasm