Expression of acidic fibroblast growth factor and basic fibroblast growth factor in nasal polyps

Conclusion. Up-regulated expression of acidic fibroblast growth factor (aFGF) and basic fibroblast growth factor (bFGF) in nasal polyps may be related to epithelial proliferation and neoangiogenesis associated with nasal polyp growth. Background and objectives. aFGF and bFGF are polypeptides that effect mitogenesis, neoangiogenesis and tissue repair. The purpose of this study was to investigate the expression of aFGF and bFGF at both the mRNA and protein levels in nasal polyps. Materials and methods. Tissue samples of nasal polyp and inferior turbinate mucosae were obtained. Reverse transcriptase (RT)-PCR, in situ hybridization, and Western blotting for aFGF and bFGF were performed in nasal polyp and nasal inferior turbinate. Results. RT-PCR showed 50% aFGF and 29% bFGF expression positivity in 14 nasal polyps; however, 13 turbinates revealed no PCR products. aFGF and bFGF expression was localized to some inflammatory cells of nasal polyps by in situ hybridization. Western blotting identified aFGF and bFGF molecular masses of 18 kDa and 24 kDa, respectively, in nasal polyps, and these levels were higher than those observed in nasal turbinates. aFGF and bFGF proteins were also localized in some inflammatory cells of nasal polyps by immunostaining.