Characterization of the FGF axis and identification of a novel FGFR1iiic isoform during prostate cancer progression in the TRAMP model

Expression of the fibroblast growth factor (FGF) axis was examined during prostate cancer progression in the autochthonous Transgenic Adenocarcinoma of Mouse Prostate (TRAMP) model, including TRAMP derived cell lines. Transcripts for FGF-7 and FGF-10 that are normally expressed by the stroma were detected in all samples, including the epithelial cell lines, suggesting that elaboration of these factors by the epithelium may be an essential event during transformation. Interestingly FGFR2iiib, the FGF-7 and FGF-10 receptor, was downregulated during tumor progression whereas a novel FGFR1iiic (Phi) inframe splice form was found to be expressed. These observations support the hypothesis that specific changes in FGF axis correlate with, and probably facilitate, tumor progression.