A competitive PCR-based method to measure human fibroblast growth factor receptor 1-4 (FGFR1-4) gene expression

The four members of the fibroblast growth factor receptor (FGFR) family are cell-surface membrane-spanning tyrosine kinase receptors involved in a wid e spectrum of biologic processes. Much evidence also indicates that mutatio ns in FGFR genes result in several craniosynostotic disorders and chondrody splasias, and that changes in qualitative and quantitative FGFR expression profiles are implicated in tumor induction or progression. Here, we describ e a precise and reliable competitive PCR-based assay to evaluate human FGFR 1-4 gene expression. A single multispecific synthetic competitive template was designed to amplify FGFR1-4 homologous stretches and constructed to con tain FGFR1/FGFR2/FGFR3/FGFR4/GAPDH tandemly arranged forward and reverse pr imers that allow competition for cDNA-specific primer annealing. The housek eeping GAPDH transcript was utilized as a reference for comparing the expre ssion profiles of different RNA pools. The assay herein described allows th e comparison of relative FGFR expression levels, both within a single RNA p ool and among multiple RNA pool samples. The major advantages of such a PCR -based approach are its ability to obtain unbiased FGFR mRNA expression pat terns and to detect transcripts present in low copy number. Qualitative and semiquantitative analyses of the FGFR1-4 transcript repertoire in mesenchy mal- and epithelial-derived primary cell cultures and cell lines demonstrat ed the utility of such a method to investigate the FGFR1-4 functional role in FGF signal transduction.