下调G6PD表达对肝癌细胞增殖、凋亡的影响及其机制

Down-regulation of G6PD expression on proliferation and apoptosis of hepatocellular carcinoma cells and its mechanism

目的探究葡萄糖-6-磷酸脱氢酶(G6PD)对肝癌细胞增殖、凋亡的影响及其作用机制。方法 siRNA技术下调肝癌HepG2细胞中G6PD基因的表达;实验分为对照组、siRNA阴性组、siRNA G6PD组;用MTT实验检测下调G6PD基因对细胞增殖的影响,流式细胞术检测细胞的凋亡率,免疫印迹法(Western blotting)检测G6PD、B细胞淋巴瘤/白血病-2(B cell lymphoma/lewkmia-2,Bcl-2)、Bcl-2相关X蛋白(Bcl-2 associated X protein,Bax)、含半胱氨酸的天冬氨酸蛋白水解酶3(Cysteinyl aspartate specific proteinase3,Caspase-3)、含半胱氨酸的天冬氨酸蛋白水解酶9(Cysteinyl aspartate specific proteinase 9,Caspase-9)蛋白水平。结果与对照组相比,siRNA G6PD组细胞中G6PD蛋白的表达量显著下降(P <0. 05)。下调G6PD表达显著抑制HepG2细胞的增殖(P <0. 05),促进其凋亡(P <0. 05),显著增加Bax、Caspase-9、Caspase-3蛋白水平(P <0. 05),降低Bcl-2蛋白水平(P <0. 05)。结论下调G6PD通过调控线粒体凋亡通路,抑制肝癌细胞的增殖,促进其凋亡。

Objective To investigate the effect of glucose-6-phosphate dehydrogenase (G6PD) on the proliferation and apoptosis of hepatocellular carcinoma cells and its mechanism. Methods siRNA was transfected into HepG2 cells to down-regulate the expression of G6PD gene. The experiments were divided into control group, siRNA-negative group, siRNA G6PD group. The proliferation of cells was measured by MTT assay and the apoptotic rate was analyzed by flow cytometry. The protein levels of G6PD, B cell lymphoma/lewkmia-2 (Bcl-2), Bcl-2 associated X protein (Bax), Cysteinyl aspartate specific proteinase 3 (Caspase-3), Cysteinyl aspartate specific proteinase 9 (Caspase-9) were examined by Western blotting. Results Compared with the control group, the G6PD protein expression in the siRNA G6PD group was significantly decreased ( P <0.05). Down-regulation of G6PD had the significantly effects on inhibiting HepG2 cell proliferation ( P <0.05), promoting cell apoptosis ( P <0.05), increasing the levels of Bax, Caspase-9, Caspase-3 proteins ( P <0.05), and decreasing the level of Bcl-2 protein ( P <0.05). Conclusion Down-regulation of G6PD inhibits the proliferation and promotes apoptosis of hepatocellular carcinoma cells by regulating mitochondrial apoptosis pathway.