【摘要】 目的 :研究单链核糖体失活蛋白天花粉蛋白 (TCS)诱导人类白血病细胞株HL - 6 0细胞发生凋亡的作用及放线菌酮 (CHX)对此作用的影响。方法 :采用流式细胞术分析及荧光显微镜观察研究TCS诱导HL - 6 0细胞发生凋亡的情况。结果 :流式细胞术分析表明TCS能够诱导HL - 6 0细胞发生明显的凋亡现象 ,TCS (2 0mg/L)处理48h细胞凋亡百分率为 48 7%± 2 3% ( x±s) ,明显高于对照组的凋亡率 (6 3%± 1 0 % ) (P <0 0 5 ) ,而CHX (5mg/L)相同条件下诱导的凋亡率为 6 5 3%± 3 9%。TCS诱导的凋亡现象进一步为荧光显微镜的观察及DNA凝胶电泳所证实 ,TCS处理的细胞中有许多细胞呈现典型的凋亡细胞核形态改变 ,如染色体凝缩、核碎裂等 ;DNA凝胶电泳显示TCS处理的细胞呈典型的梯级格局。进一步研究表明预先以低浓度CHX (0 2mg/L)处理可显著加强TCS的作用 ,而在这个浓度下单独CHX并不诱导明显的细胞凋亡。TCS诱导HL - 6 0细胞的凋亡呈时间和剂量依赖关系。结论 :TCS能够诱导HL - 6 0细胞发生明显的凋亡 ,CHX可加强这种作用。这些结果提示TCS诱导的凋亡不依赖于新的蛋白质合成更多还原

【Abstract】 AIM: To study the effect of trichosanthin (TCS), a type I ribosome-inactivating protein, on the induction of apoptosis in human leukemic cell line HL-60 cells and the influence of cycloheximide (CHX) on TCS-induced apoptosis. METHODS: Flow cytometry together with fluorescent microscopy were adopted to investigate the apoptotic cell death in HL-60 cells treated with TCS. RESULTS: Flow cytometric analysis indicated that TCS was able to induce significant apoptosis in HL-60 cells. The rates of apoptotic cells in HL-60 cells treated with TCS (20 mg/L) for 48 h was 48.7%±2.3%(±s), which was significantly higher than that of control (6.3%±1.0%)(P<0.05). Under the same condition, the rate of apoptosis caused by CHX (5 mg/L) was 65.3%±3 9%. TCS-induced apoptosis was further confirmed by fluorescent microscopy observation and DNA gel electrophoresis, in which typical nuclear morphological changes such as chromatin condensation, nuclear fragmentation, were observed in many of the cells treated with TCS, and DNA extracted from these cells displayed typical ladder pattern. Furthermore, the effect of TCS was significantly enhanced with the pretreatment of CHX (0.2 mg/L) which did not induce any significant apoptosis when used at 0.2 mg/L seperately. TCS-induced apoptosis was time- and dose-dependent. CONCLUSION: TCS was able to induce apoptosis in HL-60 cells, which was enhanced by CHX. It was suggested that TCS-induced apoptosis was independent of new protein synthesis.更多还原