Cyt-C 依赖的线粒体途径在T42诱导肝癌HepG2细胞凋亡中的作用

目的 检测重组肿瘤抑素42肽(T42)诱导肝癌HepG2细胞凋亡及与线粒体凋亡途径的关系,探讨T42诱导肿瘤细胞凋亡的可能机制.方法 吖啶橙/溴化乙锭(AO/EB)荧光染色观察细胞凋亡的形态学变化;流式细胞仪检测凋亡率;JC-1荧光染色检测线粒体膜电位的变化;Western印迹检测细胞色素C(Cyt-C)的分布.结果 18 μmol/LT42作用下,HepG2细胞出现明显凋亡形态学变化,凋亡率为22.4%,与对照组比较差异有统计学意义(t=7.75,P＜0.05);T42降低了HepG2细胞线粒体膜电势,明显减少了线粒体Cyt-C.结论 T42通过降低线粒体膜电势,促进Cyt-C由线粒体膜释放到胞浆中,激活 caspase-3途径诱导人肝癌细胞系HepG2细胞凋亡.

Abstract：

Objective The aim of the present article is to detect the apoptosis of hepatocarcinoma cells HepG2 induced by recombinant tumor endostatin 42 peptide (T42) ,with an emphasis on the signaling pathways involved. Methods Observed the morphological changes associated with the apoptosis of HepG2 cells by using AO/EB. Apoptosis rate were dentified by using flow cytometry. Mitochondrial membrane potential was evaluated by using JC-1 fluorescent staining. The distribution of cytochrome C(Cytc ) was estimated by using western blot. Results Compared with the control group, there was significant difference in apoptosis rate of cells HepG2 under 18μmol /L of T42. (22.4% vs 3.70% ,t =7.75, P＜0.05). Mitochondrial membrane potential was decreased by T42, and cytochrome c was reduced significantly compared with the control group. Conclusions The result demonstrated that the T42 enhanced the apoptosis of HepG2 cells and its potential mechanism was related to the decreased of mitochondrial membrane potential, an increase in Cytochrome C released into the cytosol, and reduced activation of Caspase-3 channels.

Tumor endostatin T42 promotes the apoptosis of hepatocarcinoma cells HepG2 through cytochrome C-dependent mitochondrial pathway

Objective The aim of the present article is to detect the apoptosis of hepatocarcinoma cells HepG2 induced by recombinant tumor endostatin 42 peptide (T42) ,with an emphasis on the signaling pathways involved. Methods Observed the morphological changes associated with the apoptosis of HepG2 cells by using AO/EB. Apoptosis rate were dentified by using flow cytometry. Mitochondrial membrane potential was evaluated by using JC-1 fluorescent staining. The distribution of cytochrome C(Cytc ) was estimated by using western blot. Results Compared with the control group, there was significant difference in apoptosis rate of cells HepG2 under 18μmol /L of T42. (22.4% vs 3.70% ,t =7.75, P＜0.05). Mitochondrial membrane potential was decreased by T42, and cytochrome c was reduced significantly compared with the control group. Conclusions The result demonstrated that the T42 enhanced the apoptosis of HepG2 cells and its potential mechanism was related to the decreased of mitochondrial membrane potential, an increase in Cytochrome C released into the cytosol, and reduced activation of Caspase-3 channels.