MAINTENANCE OF HUMAN BENIGN PROSTATIC HYPERPLASIA TISSUES IN THE NUDE-MOUSE

Human benign hyperplastic prostate (BHP) tissues were implanted subcut aneously in male Beige nude mice for up to 16 weeks. The implants main tained the normal histological appearance of BPH without signs of atro phy for up to 6 weeks. Their epithelium expressed proliferating cell n uclear antigen (PCNA), demonstrating that these cells actively underwe nt cell division. Thereafter the tissues gradually became atrophic, an d some tissues maintained for 16 weeks completely lost recognizable pr ostatic epithelium. The glandular epithelium tended to undergo squamou s cell metaplasia associated with atrophy. The epithelial linings of t he implants consistently expressed prostate-specific antigen and prost ate acid phosphatase as demonstrated by immunohistochemistry, except i n areas of severe atrophy and squamous metaplasia. The nuclei of the i mplants 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 epithe lial cells within the glandular alveoli of implanted tissues or of nor mal mouse prostates.