东亚钳蝎蝎毒多肽组分Ⅲ对肝癌细胞凋亡的影响

Effects of anti-cancer peptide fraction Ⅲ from Buthus Martensii Karsch on apoptosis of human liver cancer cells

目的:探讨东亚钳蝎蝎毒多肽组分Ⅲ对肝癌细胞凋亡的影响及其诱导凋亡的初步机制。方法:将人肝癌细胞株Hep G2浸润在不同浓度的蝎毒多肽组分Ⅲ溶液中,应用DNA凋亡梯状带分析法和DNA末端转移酶介导的末端标记法(TUNEL法)测定凋亡的发生及凋亡率;用Western blotting方法观察Bcl-2蛋白和Caspase-3的表达量。结果:蝎毒多肽组分Ⅲ引起的肝癌细胞株Hep G2凋亡呈剂量依赖性变化。DNA凋亡呈现明显的梯状带电泳行为。经5、10、50、100及200 mg.L-1蝎毒多肽组分Ⅲ处理12 h后,肝癌细胞凋亡率分别为(6.1±3.0)%、(15.3±4.9)%、(48.5±5.2)%、(66.7±6.5)%和(91.2±6.9)%。凋亡伴随着bcl-2基因的表达下调,在凋亡过程中Caspase-3被激活。结论:东亚钳蝎蝎毒多肽组分Ⅲ可以促进人肝癌细胞株Hep G2的凋亡,并且这种凋亡可能与通过下调bcl-2基因和激活Caspase-3途径有关。

Objective To study the inhibitory effect of anti-cancer peptide fraction m from crew scorpion venom ot Buthus Martensii Karsch on apoptosis of Hep G2 liver cancer cells and its mechanism. Methods Human Hep G2 liver cancer cells were treated with various concentrations of scorpion venom fraction Ⅲ for different durations. Apoptosis was assessed by terminal deoxynucleotidyl transferase-mediated nick end-labeling （TUNEL） and DNA fragmentation assays. Caspase-3 and proteins of Bcl-2 family were assayed by Western blotting. Results Anticancer peptide fraction Ⅲ induced endothelial apoptosis in a dose-dependent manner. After treatment for 12 h, in scorpin venom fraction Ⅲ groups with different concentrations of 5, 10, 50, 100, 200 mg·L^-1 , the apoptotic rates were （6.1±3.0）%, （15.3±4.9）%, （48.5±5.2）%, （66.7±6.5）% and （91.2±6.9）%, respectively. The apoptosis was accompanied by down-regulation of Bcl-2 protein synthesis. Caspase-3 was activated during apoptosis. Conclusion The anti-cancer peptide fraction Ⅲ can induce apoptosis in human Hep G2 liver cancer cells through down-regulation of Bcl-2 protein and activation of Caspase-3 pathways.