Estrogen Receptors α And β In The Normal,Benign Prostatic Hyperplasia And Prostate Cancer

BackgroundWhile the androgen-dependence of the prostate gland has been accepted, the participation of estrogen,mediated via the estrogen receptors in the pathogenesis of benign prostatic hyperplasia (BPH) and prostate cancer(Pca)have only recently been recognized. The exact mechanism of estrogen action in the prostate is not yet completely understood.This might be partially attributed to be lack of functional studies,together with localization controversial immunocytochemical data regarding the localization of Estrogen receptor(ER).ERs are members of a nuclear receptor superfamily of ligand-activated transcription factors, for a long time, ERα was assumed to be the only Estrogen receptor, several authors have confined this to the stroma of the prostate,whereas others have also localized it in the epithelium .there is also no agreement on the association between Estrogen receptors a and prostatic neoplasia.Recently ,a gene that encodes another receptor(ER β) have been cloned,this finding of this second receptor prompts a re-evaluation about the different effects of both ER types.PurposeTo obtain the information about the different effects of both ER types in BPH and Pca ,We have investigated their localizatin and levels in normal, hyperplastic and prostate cancer by immunohistochmistry(IHC).Materials and MethodsTen normal prastate from organ donors; suprapulic prostatectomy speciments for 20 men diagnosed clinically and histopathologically to have BPH;prostatic biopsies or radical prostatectomy for 30 men diagnosed forprostatic cancer.all of the speciments were assessed for ERα , ER β expression using immunohistochemistry, ERα and ERβ positiviry was defined as > 10% of cells demonstrating nuclear immunoreactivity.Results60% (12/20) normal prostate showed ER β nuclear staining of the epithelium ,The number of ER β -positive cases decline to 50%(10/20)in BPH and 23.33% (7/30) in Pca.there is a positive association among the normal, hyperplasia and prostatic cancer.(P=0.0384).The stroma was also positive in three speciments with 10-13.3% of stromal nuclear immunoreactive for ERβ .In contrast, ERα was not found in the epithelium,but 15-20% of stromal cell nuclear immunoreactivity in all of the cases. High grad (Gleason scores 2-6)tumors revead ERβ expression in 38.8%,but there is no ERβ stained in low-grade(7-10) rumors.(P=0.0242).42.8% Pea in clinical stage A and B showed the staining of the epithelium,the number of ERβ - positive cases declined to 6.25% in the stage C and D.(P=0.0309).Conclusion1. Immunostaining of ER β was predominately localized in the nuclear of epithelium and to a lesser extent to the stroma;2. ER a immunostaining was only observed in the stroma nuclear;3. Frequent loss of ER β expression in the epithelium is associated with the pathogenesis of prostate cancer;4. Changes in expression of ER β were associated with the prostate Gleason scores and clinical stage.