Deng Jing, Jin Jie
Department of Hematology, The First Affiliated Hospital, College of Medicine of Zhejiang University, Zhejiang Institution of Hematology, Hangzhou 310003, China.
Zhongguo Shi Yan Xue Ye Xue Za Zhi. 2005 Jun;13(3):434-9.
To investigate the apoptotic effect of triptolide on MDS cell line MUTZ-1 cells and its mechanism, MUTZ-1 cells were incubated with indicated concentrations of triptolide. The growth of MUTZ-1 cells was observed by MTT assay and apoptosis was detected by DNA fragmentation analysis and flow cytometry using Annexin V-FITC/PI staining. The gene and protein expressions were determined by reverse transcription polymerase chain reaction (RT-PCR) and Western blot, respectively. The results showed that MUTZ-1 cell viability in presence of triptolide decreased markedly in a dose- and time-dependent manner. The growth-inhibitory IC50 value for triptolide treatment was 55.06 ng/ml. A DNA ladder pattern of internucleosomal fragmentation was observed. The translocation of phosphatidylserine at the outer surface of the cell plasma membrane could be induced by triptolide and its level increased following the augmentation of the drug concentration. Treatment of MUTZ-1 cells with triptolide for 12 hours resulted in the activation of caspase-3, cleavage of PARP and decrease of c-IAP2 mRNA. The expressions of pro-caspase 3 and c-IAP2 were inversely correlated with the incidence of apoptosis. (r = -0.907, P = 0.000; r = -0.919, P = 0.000 respectively). In conclusion, Triptolide inhibits MUTZ-1 cell growth by inducing apoptosis. The apoptotic effect of triptolide in MUTZ-1 cells is mediated by the caspase-3 activation and PARP cleavage. Moreover, the activation of caspase-3 may be associated with the down-regulation of c-IAP2.
为研究雷公藤甲素对骨髓增生异常综合征（MDS）细胞系MUTZ-1细胞的凋亡作用及其机制，将MUTZ-1细胞与不同浓度的雷公藤甲素孵育。采用MTT法观察MUTZ-1细胞的生长情况，运用DNA片段化分析以及Annexin V-FITC/PI染色的流式细胞术检测细胞凋亡。分别通过逆转录聚合酶链反应（RT-PCR）和蛋白质免疫印迹法测定基因和蛋白表达。结果显示，在雷公藤甲素作用下，MUTZ-1细胞活力呈剂量和时间依赖性显著下降。雷公藤甲素处理的生长抑制IC50值为55.06 ng/ml。观察到核小体间断裂的DNA梯形条带模式。雷公藤甲素可诱导细胞膜外表面磷脂酰丝氨酸的易位，且随着药物浓度增加其水平升高。用雷公藤甲素处理MUTZ-1细胞12小时导致caspase-3激活、PARP裂解以及c-IAP2 mRNA水平降低。前体caspase 3和c-IAP2的表达与凋亡发生率呈负相关（r分别为-0.907，P = 0.000；r为-0.919，P = 0.000）。综上所述，雷公藤甲素通过诱导凋亡抑制MUTZ-1细胞生长。雷公藤甲素在MUTZ-1细胞中的凋亡作用由caspase-3激活和PARP裂解介导。此外，caspase-3的激活可能与c-IAP2的下调有关。
