DIFFERENTIATION OF RAT NEONATAL VENTRAL PROSTATES GROWN IN A SERUM-FREE ORGAN-CULTURE SYSTEM

BACKGROUND. Organ culture methods have long been used in the study of the prostate because effects of drugs and hormones can be examined in the absence of systemic effects. METHODS. Neonatal rat ventral prostat es (VP) were grown on Millipore filters floating on fluid medium compo sed of Dulbecco's modified Eagle's medium/Ham's F-12 supplemented with insulin, transferrin, and hydrocortisone, and in the presence or abse nce of testosterone (T, 10(-8) M). RESULTS. Ln the presence of T, duct al lumen formation occurred, ductal branching was extensive, and basal and luminal epithelial cells were identified by immunocytochemistry b ased on their distinctive cytokeratin profile. In the absence of T, du ctal lumen formation did not occur, basal and luminal epithelial cells failed to differentiate, and there was a marked decrease in prostatic organ size relative to glands grown with T. Interestingly, DNA synthe sis, as measured by counts per min (CPM) for H-3-thymidine incorporati on, showed that DNA synthesis per mu g DNA at 7 days of organ culture was not inhibited by lack of T. Androgen receptor expression is anothe r marker of prostatic epithelial differentiation, and it occurred in b oth the presence and absence of T. CONCLUSIONS. Growth and differentia tion of the neonatal rat prostate in vitro occur in a manner similar t o that of the developing prostate in vivo, demonstrating that organ cu ltures of neonatal rat ventral prostates provide a faithful model for studying rat prostatic development and differentiation under serum-fre e conditions. (C) 1997 Wiley-Liss, Inc.