Xenografts 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. Thereafter the tissues gradually became atrophic, with the tendency to undergo squamous cell metaplasia, but some tissues still maintained normal epithelium at 16 weeks. 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. Continued feeding of the mice with dihydrotestosterone or hydrocortisone did not change significantly the morphology or the proliferation index of the epithelial cells within implants or host prostates.