Expression of oestrogen receptor-α and oestrogen receptor-β in prostate cancer

<正> Background Recent studies have suggested that estrogens are involved in normal and abnormal prostate growth,though their exact role is still controversial.Oestrogens exert inhibitory and stimulatory effects on prostate gland,but theexpression of oestrogen receptor-α (ERα) and oestrogen receptor-13 (ERβ) in malignant prostate tissue remainsunresolved.We determined ERa and ERβ in prostate cancer and investigated the relationship between expression of ERand pathological features of prostate carcinoma.Methods Thirty-two cases of prostate cancer,12 cases of normal prostate tissue and 32 cases of benign prostatehyperplasia were analyzed for the expression of ERa and ERβ using semiquantitative,reverse transcription polymerasechain reaction (RT-PCR) and the products sequenced.Results Comparisons of the normal,hyperplastic and tumour prostate tissues indicated an overexpression of ERa intumour specimens (P<0.01).However,the expression of ERβ significantly reduced in tumour tissues compared withnormal and hyperplastic specimens (P<0.01),suggesting that severe pathological features of prostate cancer wereassociated with lower ERβ expression.Spearman analysis showed negative correlation between ERβ expression andtumour stage,grade (-0.67,-0.43,respectively,both P<0.05),and a positive correlation between ERα expression andtumour stage,grade (0.51,0.57,respectively,both P<0.01).Our analysis also showed that hormone refractory,prostatecancer,compared with hormone dependent,prostate cancer,displayed a decreased expression of ERβ(P<0.01) and anincreased expression of ERα.Conclusions ERα and ERβmay play important roles in the development of prostate cancer.The decrease in ERβexpression is associated with higher Gleason grade tumours and prostate cancer with higher metastatic potential.Theloss of ERβ could be one of the key processes leading to uncontrolled growth of prostate epithelial cells.