三氧化二砷诱导人肝癌细胞株HepG2凋亡的机制研究

目的:探讨三氧化二砷(As2O3)诱导人肝癌细胞株HepG2凋亡的作用及机制。方法:采用MTT法观察不同浓度的As2O3对人类肝癌细胞株HepG2细胞生长的抑制作用;以流式细胞术观察细胞的凋亡率;以Western blot法检测JNK、p-JNK、Caspase-3及PARP蛋白在As2O3作用下及SP600125阻断JNK信号转导通路情况下的表达。结果:As2O3均对体外生长的肝癌细胞HepG2具有明显抑制作用,并可诱导细胞凋亡。Western Bloting结果显示,As2O3诱导肝癌细胞HepG2凋亡伴随着Caspase-3和PARP的活化:As2O3作用于HepG2细胞10min后p-JNK蛋白表达开始增加,20分钟达到高峰,30分钟开始减少,总JNK蛋白的含量无明显改变,JNK的激活早于细胞凋亡;用SP600125预处理HepG2细胞株后,可以明显减少Caspase-3和PARP的活化。结论:As2O3可以体外通过诱导细胞凋亡抑制肝癌细胞株HepG2的增殖,细胞凋亡通过Caspase-3途径实现。JNK信号转导通路参与了As2O3诱导的HepG2凋亡反应,并位于Caspase-3的上游。

Studies on the mechanism of arsenic trioxide-induced apoptosis in HepG2 human hepatocellular carcinoma cells

OBJECTIVE To study the anti-tumor effect of arsenic trioxide on the HepG 2 human hepatocel ular carcinoma cel line,and to explore its mecha- nism of action. METHODS The MTT assay was used to determine the inhibitory effect of As 2 O 3 on HepG 2 cells at various As 2 O 3 concentrations.The expression of p-JNK,caspase-3 and PARP was detected by Western blots. RESULTS As 2 O 3 markedly inhibited the growth of the HepG 2 cel s and induced apoptosis.The results of Western blot analysis showed that the As 2 O 3 -induced apoptosis was accompanied by caspase-3 and PARP activa- tion.p-JNK was detected at 10 min following As 2 O 3 treatment,and preceded to peak at 20 min,and decreased by 30 min.The total protein content did not obviously change.The activation of JNK occurred prior to cell apoptosis. SP600125,a JNK inhibitor,suppressed the As 2 O 3 -induced activation of cas- pase-3 and PARP cleavage. CONCLUSION As 2 O 3 inhibits the proliferation of human HepG 2 hepato- cellular carcinoma cells by inducing apoptosis in vitro.As 2 O 3 -induced apopto- sis is accessed through the caspase-3 pathway.The JNK signal-transduction pathway and caspase-3 are involved upstream in the As 2 O 3 -induced HepG 2 apoptotic response.