Evaluation of androgen, estrogen (ER alpha and ER beta), and progesterone receptor expression in human prostate cancer by real-time quantitative reverse transcription-polymerase chain reaction assays

Steroid hormones can have profound effects on prostate tumor development ma king it important to define steroid receptor expression in prostate tissues . For this purpose, androgen receptor (AR) and estrogen receptor (ER alpha and ER beta) expression was quantified in 12 clinically localized and 11 ho rmone-refractory sporadic prostate tumors, using real-time quantitative rev erse transcription-PCR assays. To gain more insight into hormone-responsive ness. estrogen-regulated progesterone receptor (PGR) and androgen-regulated prostatic acid phosphatase (PAP) mRNA levels were also quantified, There i s a decrease in expression of ERP in both clinically localized and hormone- refractory tumors relative to normal prostate tissues. Moreover, hormone-re fractory tumors display a decreased expression of ER alpha and an increased expression of AR. There is a positive association between ER alpha, ER bet a, and PGR expression (P < 0.0001) and a negative association between AR an d the androgen-regulated gene PAP expression in hormone-refractory tumors. Taken together, these data indicate that, although increased expression of the AR gene might play a key role in endocrine treatment failure, it cannot he considered as the sole actor of this unresolved dilemma, and abnormalit ies in ER<alpha> and/or ER beta expression may also modulate the growth res ponse of prostate cancer to hormone withdrawal. Our results also suggest th at ER alpha and ER beta expression status could he used to identify advance d prostate tumor patients who ma respond to antiestrogen therapy.