EXPRESSION OF FIBROBLAST GROWTH-FACTORS (FGFS) AND FGF RECEPTORS IN HUMAN PROSTATE

Purpose: To evaluate the expression of fibroblast growth factors (FGFs ) and FGF receptors (FGFRs) in human prostate. Materials and Methods: RNA was extracted from surgically excised human prostate glands and fr om primary cultures of human prostatic epithelial and stromal cells. E xpression of FGFs and FGF receptors was evaluated by Northern blotting and reverse-transcriptase polymerase chain reaction (RT-PCR) techniqu es. Results: FGF7 (KGF) is the major FGF mRNA expressed in the human p rostate, with smaller amounts of FGF2 and extremely small amounts of F GF1. For all three FGFs, the prostatic stromal cells were the primary site of expression. Prostatic epithelial cells express primarily the F GFR-3 IIIc isoform, which preferentially binds FGF1 over FGF2, with sm aller amounts of the FGFR-2 IIIb (FGF7 binding) isoform. Prostatic str omal cells express primarily the FGFR-3 IIIc isoform and smaller amoun ts of FGFR-1 IIIc and FGFR-2 IIIc isoforms, which bind both FGF1 and F GF2. Conclusion: The pattern of expression of FGFs and FGF receptors i n the prostate is consistent with a paracrine stimulation of epithelia l growth by stromal-derived FGFs and potential autocrine stimulation o f stromal cell proliferation by stromal FGFs.