表没食子儿茶素没食子酸酯对乳腺癌细胞凋亡的影响

Effect of epigallocatechin-3-gallate on apoptosis of breast cancer cells

目的探讨表没食子儿茶素没食子酸酯(EGCG)对乳腺癌细胞凋亡的影响及其可能机制。方法采用EGCG处理培养的正常乳腺上皮细胞株MCF-10A和乳腺癌细胞株MCF-7,采用CCK-8分析EGCG的临床使用安全浓度和毒性IC50、对MCF-7细胞的增殖抑制率及时效关系。采用吖啶橙/溴化乙锭双荧光染色细胞,通过荧光显微镜观察EGCG对MCF-7细胞凋亡的影响。采用qRT-PCR分析EGCG对MCF-7细胞凋亡相关基因(Bax、Bcl-2、Caspase-3和p53)mRNA表达的影响。结果 EGCG对MCF-10A细胞的IC50为63.6μmol/L,其临床安全浓度为20μmol/L。EGCG 20μmol/L可抑制MCF-7细胞增殖(P<0.05),且在0~72 h,抑制作用随时间的延长而提高(P<0.05)。EGCG可以诱导MCF-7细胞的染色质浓缩和凋亡小体产生。EGCG能够上调Bax、p53和Caspase-3 mRNA的表达和下调Bcl-2 mRNA的表达(P<0.05)。结论 EGCG能够抑制MCF-7细胞的增殖并促进凋亡,其促凋亡机制可能与p53/Bcl-2信号传导途径有关。

Objective To explore the effect and underlying mechanism of epigallocatechin-3-gallate(EGCG) on the apoptosis of breast cancer cells.Methods Normal mammary epithelial cell line MCF-10A and breast cancer cell line MCF-7 were treated with EGCG.The CCK-8 was used to analyze the safe concentration and toxicity IC50 of EGCG and the inhibition of EGCG on the proliferation of MCF-7 cells.The cells were stained with acridine orange/ethidium bromide,and the effect of EGCG on the apoptosis of MCF-7 cells was observed under fluorescence microscopy.Further,real-time quantitative PCR was used to analyze the expression levels of apoptosis-related genes Bax,Bcl-2,Caspase-3 and p53 in MCF-7 cells.Results EGCG showed some degree of toxicity to MCF-10A cells with IC50 63.6 μmol/L.Its clinical safe concentration was 20 μmol/L.The proliferation of MCF-7 cells was significantly inhibited by EGCG 20 μmol/L(P<0.05),and the inhibition was increased significantly as the time prolonged from 0 to 72 hours(P<0.05).EGCG could induce the chromatin condensation and apoptotic body production in MCF-7 cells.Furthermore,EGCG significantly up-regulated the expressions of Bax,p53 and Caspase-3 mRNA and down-regulated the expression of Bcl-2 mRNA(P<0.05).Conclusion EGCG can inhibit the proliferation and promote the apoptosis of MCF-7 cells.Its pro-apoptotic mechanism might be related to the p53/Bcl-2 signaling pathway.