土贝母苷甲诱导HeLa细胞周期阻滞和凋亡

目的 :研究土贝母苷甲 (下称苷甲 )抗肿瘤作用的机制 ,探索它对细胞周期和细胞凋亡的影响。方法 :采用MTT法检测苷甲对细胞生长的抑制作用 ;采用流式细胞术 ,光学、荧光和电子显微镜 ,以及DNA琼脂糖凝胶电泳检查和分析苷甲对细胞周期和细胞凋亡的影响 ;采用蛋白免疫印迹法检测凋亡相关基因bcl 2和bax表达的变化。结果 :苷甲对HeLa细胞的生长有强抑制作用 ,其 2 4、4 8和 72h的IC50 值分别为 35 .7,2 3.6 ,17.4 μmol·L-1。在苷甲的作用下 ,细胞周期阻滞在G2 M期 ,细胞在形态学和生物化学上都出现了细胞凋亡的典型证据。蛋白免疫印迹结果揭示bcl 2下调 ,bax过表达。结论 :苷甲诱导的细胞周期阻滞和凋亡在苷甲的抗肿瘤效果中可能起着重要作用 ,而苷甲诱导的细胞凋亡与bcl 2的下调及bax的过表达密切相关。

Induction of cell cycle arrest and apoptosis by tubeimoside I isolated from Bolbostemma paniculatum in HeLa cells

AIM: To study the antitumor mechanism of tubeimoside I (TBMS1), and to investigate its effects on cell division cycle and cell death in HeLa cells. METHODS: Cell growth inhibition of TBMS1 was measured by MTT assay; the induction of cell cycle arrest and apoptosis by TBMS1 was determined by flow cytometry, light, fluorescence and electron microscopies, and gel electrophoresis of fragmented DNA. Western blotting was performed for detecting the apoptosis-related genes. RESULTS: TBMS1 displayed strong growth inhibitory effect against HeLa cells with estimated IC50 values of 35.7, 23.6, and 17.4 μmol*L-1. HeLa cells underwent G2/M arrest with exposure to TBMS1, and had typical morphologic and biochemical evidence of apoptosis. Western blot analysis of TBMS1-treated cells revealed downregulation of bcl-2, and overexpression of bax. CONCLUSION: TBMS1-induced cell cycle arrest and apoptosis may play an important role in antitumor effect of TBMS1, and TBMS1-induced apoptosis is closely related to downregulation of bcl-2 and overexpression of bax.