[Effect of estrogen on mismatch repair gene expression in colon cancer cells].

ABSTRACT

AIM: To investigate the effect of estrogen on MMR gene expression in colon cancer cells COLO205. METHODS: By employing semi-quantitative RT-PCR and Western blotting techniques, changes in the expression of MMR genes (hMLH1 and hMSH2) induced by different levels of estradiol (E2) and ICI182.780, an estrogen receptor inhibitor, was investigated in cultured COLO205 cells. The effect was then verified by real time RT-PCR. RESULTS: E2 enhanced the expression of hMLH1 in COLO205 cells at transcriptional level, and a dose-response relationship was established when the concentration of E2 was between 10(-12);-10(-8); mol/L. The enhancement was suppressed by the estrogen receptor inhibitor ICI182.780. On the other hand, there was no significant effect of E2 on hMSH2 expression in COLO205 cells. CONCLUSION: E2 can increase the expression of hMLH1 in colon cancer cells COLO205, and this finding sheds new light on the mechanism of estrogen protecting against colon cancer by regulating MMR system.