EXPRESSION OF HEPATOCYTE NUCLEAR FACTOR-3-ALPHA IN RAT PROSTATE, SEMINAL-VESICLE, AND BLADDER

Hepatocyte nuclear factor-3 alpha (HNF-3 alpha), a member of the hepat ocyte-forkhead-homolog family of transcription factors, regulates gene expression in the endoderm-derived liver and lung. To determine if HN F-3 alpha might also play a role in endodermal derivatives of the urog enital sinus, the expression of HNF-3 alpha in male accessory sex orga ns was assessed by Northern blotting, in situ hybridization, and elect rophoretic mobility shift, analysis. RNA from the dorsolateral prostat e (DP), ventral prostate (VP), anterior prostate (AP), seminal vesicle (SV), and bladder was compared with RNA from the liver and spleen as positive and negative controls, respectively. HNF-3 alpha mRNA levels in the DP VP, AP, and bladder were 20, 14, 5, and 6 times higher than the SV equivalent in the liver. HNF-3 alpha mRNA was detected in 8 of 10 prostate epithelial cell lines (rat NRP 152 and 154, mouse Pr14, an d human DU-145, PC3, LNCaP, ND-1, and BPH-1) but not in rat Dunning ep ithelial or mouse Pr12 cells. Addition of testosterone to castrated ra ts was found to prevent a drastic loss of HNF-3 alpha mRNA in the VP. This result suggests that HNF-3 alpha mRNA levels are at least indirec tly regulated by testosterone. The HNF-3 alpha mRNA is expressed in ep ithelial cells of the urogenital sinus derivatives VP,AP, DP, and blad der and Wolffian duct derivative, the SV. To confirm that functional H NF-3 alpha protein is produced in the VP, electrophoretic mobility shi ft assays were performed with whole-cell extracts and high-affinity ol igonucleotide (TTR-S) from the transthyretin promoter. Binding to TTR- S was disrupted when the extract was incubated with HNF-3 alpha, but n ot with HNF-3 beta, antibody. Taken together, the results using VP, AP , DP, SV, and bladder suggest that HNF-3 alpha may play an important r ole in development and maintenance of urogenital tract epithelial cell s. (C) 1998 Wiley-Liss, Inc.