Objective: To investigate the expressions of estrogen receptor (ER) and progesterone receptor (PR) subtypes in human endometrial carcinoma tissues.
Methods: Thirty samples of normal endometrial tissue and 66 endometrial carcinomas were investigated using western blot assays and reverse-transcription polymerase chain reaction.
Results: (1) Both ERalpha and ERbeta mRNA were significantly increased in endometrial carcinoma compared with that in normal endometrium tissues. The relative value of ERalpha and ERbeta mRNA in endometrial carcinoma was 8.00 +/- 7.77, 3.84 +/- 2.57 and that in normal endometrium tissues was 4.15 +/- 3.55, 0.41 +/- 0.29, respectively. (2) Decreased levels of PR, PRA, PRB protein and PR mRNA were associated with endometrium carcinogenesis (P < 0.05), while PRB mRNA expression and the ratio of PRA/PRB was not. (3) Expression of PRB mRNA was associated with ERbeta mRNA (r = 0.43, P < 0.01).
Conclusion: Overexpression of ER subtypes and down-regulation of PR may be involved in the pathogenesis of endometrial carcinoma, and expression of PRB mRNA is associated with ERbeta but not ERalpha mRNA.