KERATINOCYTE GROWTH-FACTOR AND ITS RECEPTOR MESSENGER-RNA EXPRESSION IN NASAL-MUCOSA AND NASAL POLYPS

To examine the potential biologic role of fibroblast growth factors (F GFs) in nasal polyps and nasal mucosa during chronic inflammatory cond itions, we investigated messenger RNA (mRNA) expression of three membe rs of the FGF family - acidic FGF, basic FGF, and keratinocyte growth factor (KGF) - in nasal polyp tissues, as well as in hyperplastic nasa l mucosa. Using the sensitive method reverse transcription-polymerase chain reaction (RT-PCR), we demonstrated that of the examined FGFs, KG F had the most abundant mRNA expression in nasal polyps and nasal muco sa. We also found that significantly higher levels of KGF mRNA were ex pressed in nasal polyps than in nasal mucosa, whereas mRNA expression of acidic FGF and basic FGF was relatively low in these tissues. In ad dition, we showed that KGF receptor mRNA was present in most of the na sal mucosa; however, none or little was expressed in nasal polyps. The se results suggest that KGF might play an important role in nasal epit helial proliferation and that excessive synthesis of KGF in nasal poly p stroma may contribute to hypertrophy of the nasal mucosa in patients with chronic sinusitis associated with nasal polyposis.