Prostate cells express two isoforms of fibroblast growth factor receptor 1 with different affinities for fibroblast growth factor-2.
BACKGROUND
Fibroblast growth factor receptor 1 (FGFR1) mRNA can be alternatively spliced to generate isoforms containing (FGFR1alpha) or lacking (FGFR1beta) the first immunoglobulin-like domain. We examined which isoforms are expressed by cultured prostate cells, their affinities for FGF-2, and the effect of heparin on FGF-2 binding.


METHODS
FGFR1 isoform expression was examined by RT-PCR. FGFR1alpha and FGFR1beta were expressed in CHO cells mutant in heparan sulfate synthesis, and their affinities for FGF-2, FGF-1, FGF-4, and FGF-6 were determined in the presence and absence of heparin.


RESULTS
FGFR1alpha was expressed in luminal epithelial cells, whereas FGFR1beta was expressed in basal epithelial and smooth muscle cells. FGFR1beta bound FGF-2 with three-fourfold higher affinity than FGFR1alpha both in the presence and absence of heparin. Heparin increased affinity of both receptor isoforms for FGF-2 approximately four-fivefold.


CONCLUSIONS
Prostate smooth muscle and basal epithelial cells are likely to be more sensitive than luminal epithelial cells to the low concentrations of FGFs present in vivo.
Roghani
Monireh
M
Department of Cell Biology, New York University School of Medicine, New York, New York 10016, USA.
Moscatelli
David
D
D017398:Alternative Splicing; D000818:Animals; D016466:CHO Cells; D049109:Cell Proliferation / Q000187:drug effects; D006224:Cricetinae; D003412:Cricetulus; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004847:Epithelial Cells / Q000378:metabolism*; D016222:Fibroblast Growth Factor 2 / Q000235:genetics / Q000378:metabolism*; D006493:Heparin / Q000494:pharmacology; D006801:Humans; D008297:Male; D051379:Mice; D009130:Muscle, Smooth / Q000378:metabolism*; D011467:Prostate / Q000166:cytology* / Q000187:drug effects; D011485:Protein Binding; D020033:Protein Isoforms; D012333:RNA, Messenger / Q000378:metabolism; D051496:Receptor, Fibroblast Growth Factor, Type 1 / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection
D020033:Protein Isoforms; D012333:RNA, Messenger; D016222:Fibroblast Growth Factor 2; D006493:Heparin; D051496:Receptor, Fibroblast Growth Factor, Type 1