Estrogen receptors alpha and beta in the normal, hyperplastic and carcinomatous human prostate

Abstract

Two different estrogen receptors (ER-and ER-) have been described, which are differentially involved in regulating the normal function of reproductive tissues. ERwas considered for a long time to be the only estrogen receptor, and it has been detected in the stromal cells of the human prostate but not in the epithelium. To obtain new information about the differential effects of both receptor types, we have investigated their localization in normal prostates, benign prostatic hyperplasia (BPH), and prostatic cancer (PC) by immunohistochemistry, ELISA and Western blot. Epithelial immunostaining was absent in normal prostates and was present in BPH (10% of cells) and PC (80% of cells), whereas about 15% of stromal cells were positively immunostained for ER-in the three types of prostatic specimens studied. Epithelial immunostaining for ER-was detected in normal prostates (13% of cells), BPH (30% of cells) and PC (79% of cells), whereas stromal immunostaining for ER-was absent in normal and hyperplastic prostates and was present in PC (12% of cells). The complementary presence of both receptor types in the normal prostate (ER-in the epithelium and ER-in the stroma) might explain the mechanism of estrogen action in the development of BPH. The increased epithelial immunostaining for both ERand ER-in BPH and PC suggests that the involvement of estrogen receptors in hyperplasia and cancer concerns mainly the epithelium.

Effect of selective estrogen receptor modulators on cell proliferation and estrogen receptor activities in normal human prostate stromal and epithelial cells

“…2 Since the discovery of the ERb, 3 expression of estrogen receptors a and b has been extensively studied using RT-PCR or immunohistochemical technique in several prostate cancer cell lines as well as in normal and malignant prostatic tissues, those authors associating the expression of each estrogen receptor (ER) in various cells with its possible function and role. [4][5][6][7][8][9] Effect of ligands and selective estrogen receptor modulators (SERMs) on the growth of several prostate cancer cells has also been investigated; the results indicate the possible involvement of estrogen receptors (ERs) in prostate cancer cell proliferation. 5,10 BPH is the most common prostatic disease that will affect many men as they age.…”

Differential expression of steroid receptors in prostate tissues before and after radiation therapy for prostatic adenocarcinoma

“…[8][9][10][11] The role of ER-b in prostate carcinogenesis has been described only recently. 4,[12][13][14] Even though its function is not fully understood, and the data in the literature is conflicting, recent evidence suggests that it may have a role in tumor progression. The ER-b is expressed frequently in metastatic prostate adenocarcinomas 8 and was also found to be associated positively with both Gleason score and primary Gleason grade.…”

Antagonism of estrogen-mediated cell proliferation by raloxifene in prevention of ageing-related prostatic hyperplasia

“…Estrogen effects are tissueand cell-specific, which is in part due to the differential expression of ERα and ERβ in different cell types. In the prostate, ERα is expressed mainly in stromal cells, and mediates estrogenic effect in promoting cell proliferation, whereas ERβ is expressed mainly in epithelial cells and mediates estrogenic effect on inhibiting proliferation [21][22][23]. Under pathological conditions, an increase in ERα expression in epithelial cells can mediate estrogenic effects to promote proli feration.…”