Regulation of estrogen,progesterone and mifepristone on the expression of two human progesterone receptor isoforms in endometrial carcinoma cells

OBJECTIVE: To investigate the regulatory effects of strogen,progesterone and mifepristone on the expression of two human progesterone receptor isoforms in endometrial carcinoma cells in vitro.METHODS: Three endometrial carcinoma cell lines were cultured in vitro: HECCA-A(PRA+),HECCA-B(PRB+) and HECCA-AB(PRA+,PRB+).The cells were incubated with estrogen,progesterone and mifepristone for 24 hours and 48 hours individually.The expressions of two progesterone receptor isoforms were detected by Western Blot.RESULTS: When stimulated by estrogen for 48 hours,the expression of PRA and the ratio of PRA/PRB in HECCA-A and HECCA-AB cells raised significantly(P0.05),while after being stimulated by progesterone or mifepristone,the expression of PRB in HECCA-B and HECCA-AB cells decreased,and the ratio of PRA/PRB raised significiantly(P0.05).CONCLUSION: Estrogen can up-regulate the expression of PRA at protein level,progesterone or mifepristone can decrease the protein expression of PRB.