Expression of keratinocyte growth factor and its receptor in oral lichen planus

This study aimed to investigate the expression of keratinocyte growth factor (KGF) and its receptor KGFR in oral lichen planus (OLP). Oral mucosa specimens from 30 OLP patients and ten healthy controls were collected. The expression of KGF and KGFR proteins was detected by immunohistochemistry and the expression of KGF mRNA was detected by in situ hybridization. We observed KGF protein expression but not KGF mRNA expression in the epithelium of both OLP and normal oral mucosa. The expression intensity of KGF protein was much lower in the epithelium of OLP than in that of normal oral mucosa. KGF protein was also expressed in the cytoplasm of some fibroblasts and vascular endothelial cells in the connective tissues underlying the epithelium for both OLP and normal oral mucosa, but the expression intensity of KGF was lower in the connective tissues for OLP. KGF mRNA was expressed in the cytoplasm of some fibroblasts and vascular endothelial cells in the connective tissues underlying the epithelium for both OLP and normal oral tissues. Although KGFR was expressed in vascular endothelial cells of connective tissue and in all epithelium of normal oral mucosa, it was only expressed in the basal layer and prickle layer of the epithelium and in vascular endothelial cells of the connective tissue of OLP. Compared to normal oral mucosa, OLP had lower expression of KGFR in the epithelium but higher expression of KGFR in the connective tissue underlying the epithelium. In conclusion, this study revealed significant differences in the expression intensity and distribution of both KGF and KGFR between OLP and normal oral mucosa tissues. KGF and its receptor KGRF may play an important role in the development and progression of OLP.