青蒿素通过线粒体途径诱导人肝癌细胞HepG2凋亡的分子机制研究

Possible molecular mechanisms of artemisinin-induced human hepatocellular carcinoma HepG2 cell apoptosis by mitochondria-dependent pathway

目的探讨青蒿素能否通过激活人肝癌细胞HepG2的线粒体凋亡途径,诱导细胞凋亡。方法不同浓度青蒿素与人肝癌细胞HepG2共培养24 h,采用MTT法检测细胞增殖活性,流式细胞仪检测HepG2细胞周期与凋亡,Hoechst荧光染色法观察细胞凋亡形态,Western blot检测HepG2细胞内线粒体凋亡途径相关蛋白Bax、Bcl-2、Caspase-3、Caspase-9和细胞色素C(Cytochrame,Cyto-C)表达水平。结果与对照组相比,青蒿素作用HepG2细胞24 h后,细胞增殖明显受到抑制,差异有统计学意义(P<0.05)。0.2、0.4和0.8 mmol/L青蒿素给药组,细胞G_2/M期比例明显升高(P<0.05),细胞核出现染色质不均匀,核浓缩聚集、碎裂凋亡形态,细胞凋亡比例升高,上述差异均有统计学意义(P<0.05)。Western blot结果显示,青蒿素作用后细胞内Bcl-2蛋白表达下调,Bax蛋白表达上调,Bax/Bcl-2蛋白表达比例升高,Caspase-3、Caspase-9和Cyto C蛋白表达升高,上述差异均有统计学意义(P<0.05)。结论青蒿素对HepG2细胞增殖具有抑制作用并能诱发细胞凋亡,其机制可能与线粒体凋亡途径相关,使细胞周期阻滞于G_2/M期。

Objective To investigate whether artemisinin can induce human hepatoma cell line（ HepG2） apoptosis by mitochondrial apoptosis pathway. Method Different concentrations of artemisinin were co-cultured with HepG2 for 24 h. Cell proliferation was detected by MTT assay. Flow cytometry was used to detect the cell cycle and apoptosis. Hoechst fluorescent staining was used to observe the morphology of apoptotic cells. The expressions of mitochondrial apoptosis pathway-related protein of Bax,Bcl-2,Caspase-3,Caspase-9 and Cyto-C were detected by Western blot. Results Compared with the control group,the rate of cell proliferation was significantly inhibited after treatment with artemisinin for 24 h（ P〈 0. 05）. The G2/M phase ratio was significantly increased in 0. 2,0. 4 and 0. 8 mmol/L artemisinin treatment group（ P〈 0. 05）. The apoptotic morphology including shrinkage,chromatin condensation,and nuclear fragmentation were observed,The apoptosis rate was significantly increased（ P〈 0. 05）. Western blot result showed that the expression of Bcl-2 protein was down-regulated,the expression of Bax protein was up-regulated,the ratio of Bax/Bcl-2 protein was increased and the expressions of Caspase-3,Caspase-9 and Cyto-C protein were increased after treatment with artemisinin. Conclusion Artemisinin can inhibit the proliferation of HepG2 cells and induce apoptosis. The mechanism may be related to the mitochondrial apoptosis pathway and block the cell cycle in G2/M phase.