论文部分内容阅读
目的 探讨表没食子儿茶素没食子酸酯 (EGCG )对大肠癌LoVo细胞、胃癌MGC 80 3细胞和肝癌BEL 740 2细胞细胞毒作用 ,及其作用的差异性和可能的分子机制。方法 在有或无谷胱甘肽合成酶抑制剂DL buthionine [S ,R ] sulfoximine(BSO )预处理的情况下 ,采用MTT法和台盼蓝拒染法测定EGCG对 3株肿瘤细胞的细胞毒作用。采用紫外分光光度法和流式细胞术分别测定经BSO处理的 3株肿瘤细胞的细胞内谷胱甘肽含量和bcl 2蛋白表达水平的变化。结果 EGCG对 3株肿瘤细胞均有细胞毒作用 ,但作用的强弱有所不同 ,其中LoVo细胞较为敏感 ,MGC 80 3细胞次之 ,而BEL 740 2细胞的敏感性最差。他们的IC5 0值分别为 12 5 .30 μg/ml、188.5 2 μg/ml和 2 6 4.5 3μg/ml。用BSO降低这些肿瘤细胞内谷胱甘肽的含量 ,可明显地增强EGCG对 3株肿瘤细胞细胞毒作用的敏感性。BSO以时间依赖的方式下调MGC 80 3和BEL 740 2细胞中bcl 2蛋白表达水平。结论 EGCG对 3株肿瘤细胞细胞毒作用的差异性与细胞内谷胱甘肽含量有关 ,谷胱甘肽和bcl 2蛋白的相互作用可能是这种差异性的分子机制。
Objective To investigate the cytotoxic effects of epigallocatechin gallate (EGCG) on colorectal cancer LoVo cells, gastric cancer MGC 80 3 cells and hepatocellular carcinoma BEL 740 2 cells, and the differences in their effects and possible molecular mechanisms. Methods MTT assay and trypan blue exclusion assay were used to determine the cytotoxicity of EGCG against 3 tumor cells in the presence or absence of glutathione synthetase inhibitor DL buthionine [S,R] sulfoximine (BSO). effect. UV spectrophotometry and flow cytometry were used to determine the intracellular glutathione (GSH) content and bcl 2 protein expression in 3 BSO-treated tumor cells. RESULTS: EGCG had cytotoxic effects on 3 tumor cells, but the effects were different. Among them, LoVo cells were more sensitive, followed by MGC 80 3 cells, and BEL 740 2 cells had the lowest sensitivity. Their IC50 values were 12 5 .30 μg/ml, 188.5 2 μg/ml, and 264.5 3 μg/ml, respectively. Using BSO to reduce the content of glutathione in these tumor cells can significantly enhance the sensitivity of EGCG to the cytotoxicity of the three tumor cells. BSO down-regulates bcl 2 protein expression in MGC803 and BEL7402 cells in a time-dependent manner. Conclusion The cytotoxic effect of EGCG on three tumor cells is related to the intracellular glutathione content. The interaction of glutathione and bcl 2 protein may be the molecular mechanism of this difference.