Estrogen Receptor Messenger RNA Expression in Human Benign Prostatic Hyperplasia: Detection, Localization, and Modulation with a Long‐Acting Gonadotropin‐Releasing Hormone Agonist

ABSTRACT: We have analyzed human benign prostatic hyperplastic (BPH) tissue derived from eight radical prostatectomy specimens from patients with prostate cancer for the expression of the estrogen receptor (ER) messenger RNA. Four of the eight patients received a long‐acting gonadotropin‐releasing hormone agonist (GnRHa) for 4 months prior to surgery. An RNase protection assay utilizing six riboprobes spanning most of the ER protein‐coding sequences demonstrated expression of the ER mRNA in human BPH tissue. A comparison of ER mRNA expression in four patients who had received 4 months pretreatment with the GnRHa vs. the four untreated patients suggested that there is upregulation of ER mRNA expression with the GnRHa treatment. The combined techniques of in situ hybridization and immunocytochemistry localized the ER mRNA expression to the prostatic basal epithelial cells and stroma. We conclude that ER mRNA is expressed in human BPH tissue and that this expression is modulated by treatment with a long‐acting GnRH agonist. 1994 American Society of Andrology