Maintenance of human benign prostatic hyperplasia tissues in the nude mouse

Human benign hyperplastic prostate (BHP) tissues were implanted subcutaneously in male Beige nude mice for up to 16 weeks. The implants maintained the normal histological appearance of BPH without signs of atrophy for up to 6 weeks. Their epithelium expressed proliferating cell nuclear antigen (PCNA), demonstrating that these cells actively underwent cell division. Thereafter the tissues gradually became atrophic, and some tissues maintained for 16 weeks completely lost recognizable prostatic epithelium. The glandular epithelium tended to undergo squamous cell metaplasia associated with atrophy. The epithelial linings of the implants consistently expressed prostate-specific antigen and prostate acid phosphatase as demonstrated by immunohistochemistry, except in areas of severe atrophy and squamous metaplasia. The nuclei of the implants hybridized with a human-specific DNA probe. Continuous feeding of the mice with dihydrotestosterone or hydrocortisone did not change significantly the morphology or the proliferation index of the epithelial cells within the glandular alveoli of implanted tissues or of normal mouse prostates.