Effects of down-regulated α5-nicotinic acetylcholine receptor expression on HIF-1α expression in lung cancer cells

Objective To explore the influence of small interfering RNA (siRNA) down-regulated α5-nicotinic acetylcholine receptor (α5-nAChR) expression on hypoxia-induced factor-1α(HIF-1α) expression during the process of nicotine-induced lung cancer A549 cell proliferation in vitro. Methods Expressions of α5-nAChR and HIF-1α at mRNA and protein levels in A549 cells were detected by FQ-PCR and Western blotting after treatment with various concentrations of nicotine. After CHRNA5-siRNA transfection,nicotine-induced A549 cell proliferation and expression of HIF1α were detected by MTT,FQ-PCR and Western blotting respectively. Results Expressions of α5-nAChR and HIF1α were significantly enhanced with 1 μmol /L nicotine treatment compared with the other concentrations(P < 0. 05), which presented a nicotine dose-dependent manner. After CHRNA5-siRNA transfection,the expressions of α5-nAChR mRNA and protein decreased obviously(P < 0. 05) . Nicotine-induced A549 cell proliferation was significantly inhibited (P <0. 05) . Conclusion α5-nAchR plays an important role in nicotine-induced A549 cell proliferation via regulating 祖珊珊,等. α5-烟碱型乙酰胆碱受体表达下调对肺癌细胞 HIF-1α表达的影响 9 HIF-1α expression,which suggests that α5-nAChR /HIF-1α axis may be one of the important molecular mechanisms for nicotine-related lung cancer.