MAINTENANCE OF HUMAN HYPERPLASTIC PROSTATE IMPLANTS AT DIFFERENT SITES IN ATHYMIC MICE

The present study determined the influence of implantation sites, andr ogens, and the graft's fibrovasculnr elements on the maintenance of ep ithelial elements of human benign hyperplastic prostate tissue (BPH) i n the node mouse. BPH fragments prepared from fresh surgical specimens were implanted subcutaneously (s.c.), intraperitoneally (i.p.), ol un der the renal capsules (r.c.) into male Beige nude mice, which had bee n implanted s.c. with a Silastic tube filled with 4-dihydrotestosteron e (DHT) or cholesterol. Two weeks later the BPH tissues were removed f rom the mouse and examined microscopically The implants from all three sites maintained a comparable morphology, with epithelial and/or angi o-leiomyomatous stromal hyperplastic appearance, without striking sign s of atrophy, irrespective of supplementation with DHT. Expression of proliferating cell nuclear antigen in the implants was comparable indi cating that there was no significant influence of implantation site on the proliferative ability of either epithelia or the stromal fibrobla sts. The PCNA-positive cells in the implants, including the vascular a nd myofibrous elements, hybridized in situ to a human-specific repeate d-sequence DNA probe, indicating that these proliferating cells were o f human origin. Our data suggest that during the early phases of the a daptation and maintenance of BPH implants, survival of epithelial cell s is actively supported by fibro-vascular mesenchymal elements of the prostate grafts in a manner apparently unaffected by DHT supplements.