EGCG对人结肠癌HT-29细胞凋亡的影响以及对MMP-2,RECK的调节作用

目的：观察表没食子儿茶素没食子酸酯（Epigallaocatechin-3-gallate,EGCG）对人结肠癌HT-29细胞增殖和凋亡的影响,并探讨其对MMP-2,RECK的调节作用。方法：体外培养人结肠癌HT-29细胞,MTT比色法检测EGCG对HT-29细胞的生长抑制作用;Histone/DNA ELISA检测细胞凋亡;FITC标记Annexin-V/PI双染流式细胞术分析凋亡细胞百分率;Western Blot和RT-PCR方法检测EGCG对MMP-2,RECK蛋白和mRNA表达的影响。结果：EGCG呈浓度和时间依赖性抑制HT-29细胞的增殖,并且增加HT-29细胞Histone/DNA碎片的渗漏;EGCG诱导HT-29细胞凋亡百分率增高;EGCG抑制MMP-2蛋白和mRNA的表达,促进RECK蛋白和mRNA的表达。结论：EGCG抑制人结肠癌HT-29细胞的增殖,促进其凋亡,并且呈浓度和时间依赖性;其作用机制可能与其下调MMP-2蛋白和mRNA的表达、上调RECK蛋白和mRNA的表达有关。

Effects of Epigallaocatechin-3-gallate on Apoptosis of Human Colon Cancer HT-29 Cell and MMP-2,RECK

Objective：To investigate the effects of green tea extract epigallocatechin-3-gallate（EGCG） on proliferation and apoptosis of human colon cancer cell line HT-29,explore it＇s regulation of MMP-2,RECK.Methods：HT-29 cells were cultured in vitro.MTT assay was used to test the inhibitory effects of EGCG on proliferation in HT-29 cells.Histone/DNA fragments in medium were determined using ELISA assay.Flow cytometry with FITC labeled annexin V staining was used to determine the percentage of apoptotic cells.Western Blotting was used to analyze the expression of MMP-2 and RECK.And the mRNA expression was detected by RT-PCR.Results：MTT assay has shown that EGCG inhibited HT-29 cells and exhibited a dose-time-dependent modal,and increased leakage of the histone/DNA fragments in HT-29 cells.EGCG significantly induced increase of the percentage of apoptotic cells,down-regulated the expression of MMP-2 protein and mRNA levels,and up-regulated the expression of RECK protein and mRNA levels.Conclusion：EGCG inhibits proliferation and promotes apoptosis of HT-29 cells in a concentration dependent manner,and the mechanism is associated with downregulation of MMP-2 and upregulation of RECK in protein and mRNA levels.