Nuclear androgen receptors recur in the epithelial and stromal compartments of malignant and non-malignant human prostate tissue several months after castration therapy.

BACKGROUND: As changed paracrine support from androgen receptor (AR)-positive cells in the prostate stroma contribute to castration-induced glandular involution, we examined if the subsequent relapse to androgen-independent epithelial cell growth could be related to reactivation of AR signaling in the stroma.
MATERIALS AND METHODS: Human prostate tissue taken before, within 14 days, and at suspected local tumor relapse after surgical castration therapy was immunostained for AR.
RESULTS: Castration initially decreased nuclear AR staining in epithelial and stroma cells, in both tumor and non-malignant tissue, but after some months, it reappeared.
CONCLUSIONS: Local tumor relapse was associated with reappearance of nuclear AR not only in tumor epithelial cells but also in the tumor stroma. Reappearance of nuclear AR in non-malignant prostate cells may be a physiological response to long-term systemic androgen ablation that could influence tumor growth.