Expression of fibroblast growth factors (FGFs) and FGF receptors in human prostate.

To evaluate the expression of fibroblast growth factors (FGFs) and FGF receptors (FGFRs) in human prostate. RNA was extracted from surgically excised human prostate glands and from primary cultures of human prostatic epithelial and stromal cells. Expression of FGFs and FGF receptors was evaluated by Northern blotting and reverse-transcriptase polymerase chain reaction (RT-PCR) techniques. FGF7 (KGF) is the major FGF mRNA expressed in the human prostate, with smaller amounts of FGF2 and extremely small amounts of FGF1. For all three FGFs, the prostatic stromal cells were the primary site of expression. Prostatic epithelial cells express primarily the FGFR-3 IIIc isoform, which preferentially binds FGF1 over FGF2, with smaller amounts of the FGFR-2 IIIb (FGF7 binding) isoform. Prostatic stromal cells express primarily the FGFR-3 IIIc isoform and smaller amounts of FGFR-1 IIIc and FGFR-2 IIIc isoforms, which bind both FGF1 and FGF2. The pattern of expression of FGFs and FGF receptors in the prostate is consistent with a paracrine stimulation of epithelial growth by stromal-derived FGFs and potential autocrine stimulation of stromal cell proliferation by stromal FGFs.