MG-132对肝癌细胞BEL7402凋亡及超微结构影响的实验研究

目的:探讨泛素-蛋白酶体通路阻断剂MG-132对肝癌细胞BEL7402细胞凋亡和超微结构的影响。方法:以5和10μmol／L MG-132分别处理人肝癌BEL7402细胞24和48h,用流式细胞术检测细胞凋亡;DNA片段分析进一步证实凋亡存在,Western印迹检测Bax蛋白表达,比色法测Caspase-3活性变化,用透射电镜观察细胞超微结构的变化。结果:随着MG-132浓度的增加和处理时间延长,细胞凋亡率增加;细胞DNA抽提电泳发现特征性凋亡梯状条带;Bax蛋白表达增加;Caspase-3活化;电镜观察到典型凋亡细胞,线粒体等细胞器的形态变化与MG-132浓度和作用时间有关。结论:蛋白酶体抑制剂MG-132可诱导肝癌细胞BEL7402凋亡;线粒体损伤、Bax蛋白上调、Caspase-3激活可能在MG-132 诱导BEL7402细胞凋亡起重要作用。

Effect of MG-132 on ultramicrostructure and apoptosis of human hepatocelluar cancer cell line BEL7402

Objective: To explore the mechanism of the apoptosls of human hepatocellular cancer cells BEL7402 induced by MG-132. Method:BEL7402 cells were treated with MG-132,apoptosis rate was detected with flow cytometry (FCM),DNA fragment analysis was used for confirming the presence of apoptosis,expression of Bax was dectected by Western blotting,the activity of caspase-3 was determined by colorirnetric assay,the morphologic change was observed by transmission electron microscope. Result:Cell apoptosis percentage of BEL-7402 cell increased with raised concentrations and prolonged treatment of MG-132,agarose electrophoresis showed marked ladder,expression of Bax was up-regulated,caspase-3 was activited, the typic structure of apoptosis cells was found,different features of ultrastructure changes of mitochondria and other organellae were observed in cells exposed to different concentration and treating time of MG-132. Conelusion: Proteasome inhibitor MG-132 can induce apoptosis of BEL7402 cells,Bax protein and caspase-3 and mitochondria injury were responsible for apoptosis of BEL7402 cell induced by MG-132.