Abstract: Abstract: Objective Exploring the role of mismatch repair gene hMLH1 played in the estrogen-induced colon cancer cell apoptosis. Methods: Transmit wild-type hMLH1-cDNA plasmid into hMLH1-deficient colon cancer cells (HCT116 cells) then treat cells with different concentrations of estrogen. Detect the rate of apoptosis and the activity of cells with flow cytometry and cell counting kit-8 respectively; Results:With the no-transfection group compared, after transfection , Estrogen can decreased the the activity and increase the apoptosis rate of HCT116 cells obviously .Conclusion: hMLH1 is involved in estrogen-induced apoptosis of colon cancer cell line HCT116.

Key words: Key words: Estrogen, MMR , colon cancer , apoptosis