冬凌草甲素对HL-60细胞的诱导凋亡作用及其作用机制

目的:探讨冬凌草甲素对白血病HL-60细胞的诱导凋亡作用及其作用机制.方法:以不同浓度的冬凌草甲素作用于体外培养的HL-60细胞,应用MTT法检测细胞生长抑制率,流式细胞术(FCM)检测细胞凋亡率,Hoechst 33258荧光染色法观察细胞凋亡,TRAP-PCR-ELISA及FCM法检测细胞凋亡前后端粒酶活性及P53蛋白表达水平的变化.结果:8 umol/L以上的冬凌草甲素对HL-60细胞具有显著的诱导凋亡及增殖抑制作用,并呈现出明显的量-效与时-效关系.药物作用48小时后细胞的凋亡率达高峰,在Hoechst染色图片上可见核浓缩及核碎裂等典型的凋亡改变.在细胞凋亡过程中,端粒酶活性下降,同时P53蛋白的表达水平显著升高.结论:冬凌草甲素对HL-60细胞具有显著的诱导凋亡及增殖抑制作用,升高P53蛋白的表达水平及降低细胞端粒酶活性可能是其重要作用机制之一;这为冬凌草甲素进一步应用于临床治疗急性白血病提供了有力的试验依据.

Apoptotic effect of oridonin on HL-60 cells and its mechanism

AIM: To investigate apoptotic effect of oridonin on leukemic HL-60 cells and its mechanism. METHODS: HL-60 cells in culture medium in vitro were given different concentrations of oridonin. The inhibitory rate of the cells was measured by MTT assay, cell apoptotic rate was detected by flow cytometry(FCM), morphology of cell apoptosis was observed by hoechst 33258 fluorescence staining , and the activity of telomerase as well as P53 protein expression were detected using TRAP-PCR-ELISA and FCM before and after apoptosis occurred. RESULTS: Oridonin(over 8μmol/L) could inhibit the growth of HL-60 cells and cause apoptosis significantly. The suppression was both in time-and dose-dependent manner.Marked morphological changes of cell apoptosis including condensation of chromatin and nuclear fragmentation were observed very clearly, and telomerase activity was down-regulated as well as P53 protein expression was up-regulated concurrently. CONCLUSION: Oridonin has apparent anti-proliferation and apoptotic effects on HL-60 cells in vitro, down-regulating the telomerase activity and up-regulating the P53 protein expression of HL-60 cells may be one of its most important anti-leukemia mechanisms.