Cell kinetics and differentiation after hormonal-induced prostatic hyperplasia in the dog

BACKGROUND. Our aim was to characterize the immunophenotypical changes in c anine prostate epithelium after hormonal-induced benign prostatic hyperplas ia (BPH). METHODS. Castrated dogs (aged 1-2 and 9-12 years) were treated with vehicle (group C), androstanediol (group A), or androstanediol plus estradiol (gro up AE). Surgical prostate biopsies were obtained before and after castratio n and after hormonal treatment. Tissue sections were stained using antibodi es specific for basal cells (34 beta E12), transiently proliferating (TP)/a mplifying cells (RCK103), and luminal exocrine cells (RGE53). RESULTS. Castration resulted in a marked reduction in specific immunoreacti vity associated with luminal secretory cells and basal cells in young dogs. In older dogs the number of basal cells remained constant. Hormonal treatm ent (AE) resulted in an increased number of cells with an immunophenotype t hat was associated with the TP/amplifying cell compartment and hyperplastic luminal epithelium. CONCLUSIONS. The relative increase in TP/amplifying cells in hormonally ind uced BPH in the dog is in line with a stem-cell-derived proliferation. More over, the finding of androgen-independent basal cells in the prostate of ol der dogs may contribute to the enhanced risk of development of BPH with inc reasing age. (C) 2000 Wiley-Liss, Inc.