亚砷酸诱导肺腺癌A549细胞凋亡及对MAPK／ERK信号通路的影响

目的探讨亚砷酸对肺腺癌A549细胞凋亡、MAPK／ERK信号通路的影响及其作用机制。方法体外培养肺腺癌A549细胞,实验组采用不同浓度(1、3、6 μmol／L)亚砷酸处理,对照组加入等体积的二甲基亚砜(DMSO),MTT法检测细胞增殖率,FMC法检测细胞周期分布与细胞凋亡率,Hoechst 33342观察凋亡小体,Western blotting检测Bcl 2、Bax、p53、Caspase 3及MAPK／ERK信号通路相关蛋白表达水平,RT PCR检测PCNA、CDK2、CyclinA1表达量。结果实验组肺腺癌A549细胞增殖率、凋亡率、凋亡小体数量随着亚砷酸处理时间延长而降低,且存在剂量反应效应(P<005);Western blotting结果显示，实验组肺腺癌A549细胞中Bax、p53、Caspase 3、p JNK／JNK及p38蛋白水平高于对照组,而Bcl 2、p ERK／ERK蛋白含量低于对照组,均呈剂量依赖性,差异均有统计学意义(P<005);RT PCR结果显示实验组肺腺癌A549细胞PCNA、CDK2、CyclinA1表达量低于对照组,均呈剂量依赖性,差异均有统计学意义(P<005)。结论亚砷酸可以通过下调细胞周期基因水平、上调细胞凋亡相关因子含量、降低MAPK／ERK信号传导,来诱导肺腺癌A549细胞凋亡。

Arsenous acid in the induction of apoptosis of lung adenocarcinoma A549 cells and its effects on MAPK/ERK signaling pathway

Objective To investigate the effects and mechanism of arsenous acid (AA) on apoptosis of lung adenocarcinoma A549 cells and MAPK/ERK signaling pathway. Methods The lung adenocarcinoma A549 cells were cultured in vitro and treated with different concentrations of arsenous acid. The cell proliferation rate was detected by MTT assay, and the cell cycle distribution and apoptosis rate were detected by FMC assay, and the apoptotic bodies were observed by Hoechst 33342. Western-blot was used to detect the expression levels of Bcl-2, Bax, p53, Caspase-3 and MAPK/ERK signaling pathway-related proteins. The expression levels of PCNA, CDK2 and CyclinA1 were detected by RT-PCR. Results The proliferation rate, apoptosis rate and apoptotic bodies quantity of lung adenocarcinoma A549 cells in experimental group were decreased with the prolongation of AA treatment time, and they showed dose effect (P<0.05). The results of Western-blot test showed that the levels of Bax, p53, Caspase-3, p-JNK and p38 proteins in lung adenocarcinomaA549 cells in experimental group were higher than those in control group (P<0.05) while the levels of Bcl-2 and p-ERK proteins were lower than those in control group (P<0.05). RT-PCR results showed that the expression levels of PCNA, CDK2 and CyclinA1 in lung adenocarcinoma A549 cells in experimental group were lower than those in control group (P<0.05). Conclusions Arsenous acid can induce apoptosis of lung adenocarcinoma A549 cells by down-regulating cell cycle gene level, up-regulating apoptosis-related factors and decreasing MAPK/ERK signaling transduction.