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.