冬凌草甲素通过改变Bax/Bcl-xL表达激活caspase-3诱导A375-S2细胞凋亡

目的　研究冬凌草甲素诱导人黑色素瘤A375 S2细胞凋亡的作用原理。方法　形态学观察 ,DNA凝胶电泳法及WesternBlot法。结果　冬凌草甲素能明显诱导A375 S2细胞发生凋亡 ,其作用呈明显的量效关系和时间依赖性。形态学观察可见凋亡小体的形成 ,琼脂糖凝胶电泳可见凋亡典型的DNA梯带 ;caspase 3的抑制剂能阻止caspase 3的活力升高 ;免疫印迹结果显示冬凌草甲素作用A375 S2细胞 12h改变Bax与Bcl xL蛋白的表达 ;且发现caspase 3的底物PARP蛋白在 12h时被降解。结论　冬凌草甲素 (34 3μmol·L-1)诱导A375 S2细胞凋亡 ,这种作用是通过改变了Bax/Bcl xL的表达比率 ,激活caspase 3而实现的。

Oridonin induced A375-S2 cell apoptosis through caspase-3 pathway after altered expression of Bax/Bcl-xL

AIM To study the apoptotic pathway of oridonin-induced A375-S2 cell apoptosis. METHODS Morphological observation, agarose gel electrophoresis, caspase inhibitors and Western Blot analysis were applied. RESULTS Oridonin had significant apoptotic effect on A375-S2 cells in a dose-and a time-dependent manners. The marked morphological changes including condensed chromatin, nuclear fragmentation and apoptotic bodies and DNA ladder in agarose gel was observed. The activity of caspase-3 was increased about 6 times of control value after treatment with oridonin. Furthermore, treatment of A375-S2 cells with oridonin for 12 h increased the protein expression ratio of Bax/Bcl-xL, and PARP, a substrate of caspase-3, was activated at 12 h. CONCLUSION Oridonin induces A375-S2 cell apoptosis via mitochondria-regulated caspase pathway activation.