金喜素诱导HL-60细胞凋亡依赖caspase活化

目的　探讨金喜素诱导急性白血病细胞凋亡的生化机制。方法　采用MTT法测定金喜素对HL 6 0细胞的杀伤作用 ;通过形态学、DNA凝胶电泳及AnnexinVFITC染色 ,研究金喜素对靶细胞的促凋亡活性 ;采用caspase 8、3特异性抑制剂IETD fmk、DEVD CHO ,分析金喜素介导的靶细胞凋亡与caspase活化的关系。结果　经 0 1μmol·L-1金喜素处理至 8、12及 16h时 ,HL 6 0细胞的存活率依次降至6 2 %± 12 %、、43%± 15 %及 32 %± 10 % ,低于对照 (P <0 0 5 ) ,同时 ,靶细胞逐渐出现磷脂酰丝氨酸外化 ,并产生梯状DNA及凋亡小体 ;经caspase抑制剂与金喜素联合处理12、16h时 ,HL 6 0细胞的存活率高于单用金喜素组 ,分别为77%± 14%、6 5 %± 16 % (IETD fmk组 )与 74%± 12 %、6 0 %± 11% (DEVD CHO组 ) ,同时 ,靶细胞的梯状DNA与凋亡小体的诱生也明显受抑。结论　金喜素对HL 6 0细胞具有较强的促凋亡作用 ,该过程可能依赖caspase 8、caspase 3的活化

Topotecan induces caspase-dependent apoptosis in HL-60 cells

AIM To gain insight into the biochemical mechanisms of Topotecan induced apoptosis in leukemia cells. METHODS The cytotoxic effect of Topotecan on HL 60 cells was measured by using MTT assay; Topotecan induced apoptosis in HL 60 cells was identified by morphological analysis, DNA agarose gel electropheresis and Annexin V FITC staining; correlation between Topotecan mediated apoptosis and caspase activation was investigated by caspase 8 or caspase 3 inhibitor. RESULTS After incubated with 0 1 μmol·L -1 TPT for 8,12 and 16 h, survival rate in HL 60 cells significantly reduced to 62%±12%( P <0 05), 43%±15%( P <0 05) and 32%±10%( P <0 05), respectively, and HL 60 cells, meanwhile, were broken down into apoptotic bodies and demonstrated ladder DNA formation and phosphatydilserine externalization; after exposure to Topotecan in combination with IETD fmk or DEVD CHO for 12 and 16 h, survival rates in HL 60 cells were remarkably raised to 77%±14%( P <0 05)?65%±16%( P <0 05) and 74%±12%( P <0 05)?60%±11%( P <0 05), and, in the meantime, formation of ladder DNA and apoptotic bodies was notably inhibited. CONCLUSION Topotecan is most potent in inducing apoptosis in HL 60 cells, which depends on activation of caspase 8 and caspase 3,consecutively.