Localization of androgen receptor and cell-specific cytokeratins in basal cells of rat ventral prostate

Immunocytochemical techniques labeled androgen receptor and cell-specific cytokeratins in the basal cells of rat ventral prostate. In addition, nonradioactive in situ hybridization verified the production of androgen receptor transcripts in the basal cells. Androgen receptors and transcripts were localized in the nuclei and cytoplasm of the adult basal cells using these two techniques. Monoclonal anti-cytokeratin antibodies identified temporal changes in the expression of basal cell-specific intermediate filaments of fetal, neonatal, normal adult, orchidectomized adult, and testosterone-treated orchidectomized adult prostates. Labeling intensity of the basal cells was elevated during development when compared to the staining in normal adult tissue. Orchidectomized adults exhibited the greatest intensity of labeling, which decreased after testosterone treatment. The detection of androgen receptor and its transcripts in the basal cells supports the hypothesis that these cells are androgen responsive. The observed change in the anti-cytokeratin staining patterns of these cells during development, growth, and regression is an indirect measure of androgenic influence. The androgen-repressed cytokeratin expression in basal cells is similar to that found in prostatic luminal cells.