Widespread distribution of nuclear androgen receptors in the basal cell layer of the normal and hyperplastic human prostate.

The role of the basal cell layer in organogenesis, epithelial renewal and development of benign prostatic disorders is largely unknown. The objective of the present study was to investigate whether or not basal cells express the nuclear androgen receptor (AR). Computer-assisted image analyses of immunohistochemical double stainings were performed to localize AR and basal-cell-specific cytokeratins in identical sections. The results showed that the basal cells express nuclear AR widely in normal and hyperplastic conditions. When compared with the staining intensities detected in secretory luminal cells, the receptor was most frequently expressed at lower levels in basal cells, which may exhibit strong AR immunoreactivity focally. Basal cells with increased AR expression were most frequently detected in hyperplastic lesions including post-atrophic and atypical hyperplasia. The presence of nuclear receptors for both androgens and oestrogens or progestins in basal cells may indicate that these cells are targets of the hormonal imbalance which has frequently been implicated in the aetiology of benign prostatic hyperplasia.