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作 者 ：王光辉,陈海峰,王乃利,姚新生

期 刊 ：中国中药杂志 2009年 34卷 24期 页码：3286.

关键词：Protobioside；HepG2；细胞周期阻滞；细胞凋亡；

Keywords:Protobioside, HepG2, cell cycle arrest, apoptosis,

摘 要 ：目的：通过体外实验研究Protobioside对人肝癌细胞株HepG2的细胞增殖抑制作用，并进一步研究其作用机制。方法：采用噻唑兰（MTT）比色法测定Protobioside对3种肿瘤细胞生长增殖的影响；采用Hoechst33528染色观察Protobioside对HepG2细胞凋亡的影响；采用流式细胞仪技术检测Protobioside对HepG2细胞周期的影响；采用蛋白质电泳技术检测Protobioside对HepG2细胞的细胞周期相关蛋白及凋亡相关蛋白表达的影响。结果：Protobioside对HepG2细胞的生长抑制作用最强，IC₅₀为20 μmol·L^-1；形态学观察可见Protobioside处理36 h时细胞核发生皱缩扭曲、胞膜完整。细胞周期分析显示，Protobioside将HepG2细胞抑制在G₂/M期，具有良好的时效、量效关系；蛋白质电泳结果表明Protobioside下调了周期蛋白Cyclin B1、上调了促凋亡蛋白Bax、下调了抑凋亡蛋白Bcl-2。结论：Protobioside通过下调周期蛋白Cyclin B1将人肝癌细胞HepG2细胞阻滞在G₂/M期，通过上调促凋亡蛋白Bax、下调抑凋亡蛋白Bcl-2诱导HepG2细胞凋亡，从而抑制HepG2细胞的增殖。

Abstract:Objective： To investigate the anti-proliferative effect of Protobioside on the HepG2 cells and its mechanism. Method： The inhibitory effects of Protobioside on 3 kinds of human cancer cell line was measured by MTT assay. Apoptotic morphological changes was observed by Hoechst33528 staining technique. Cell cycle were analyzed using flow cytometry. The expression of cell cycle related protein and apoptosis related protein were determined using Western blotting. Result： Protobiside shows strong cytotoxic power on HepG2 cells and IC₅₀ were 20 μmol·L^-1. The nucleus became pyknosis at 36 hours. The cells in G₂/M phase increase in a dose-dependent and time-dependent manner. And the protein level of CyclinB1 was down-regulated， that of Bax was up-regulated and that of Bcl-2 was down-regulated. Conclusion： The growth inhibition of Protobioside on HepG2 cells is highly related to cell cycle arrest at G₂/M phase which was well correlated with the down-regulation of expression of Cyclin B1， and the induction of apoptosis via up-regulating of Bax and down-regulating Bcl-2 expression.

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