The Study On The Expression Of Keratinocyte Growth Factor(KGF) And Keratinocyte Growth Factor Receptor (KGFR) In OLP

Objective:Lichen planus (LP) is a chronic inflammatory disease of the skin and/or oral mucosa with abnormal keratosis . The prevalence of oral lichen planus (OLP) ranks second in oral mucosal diseases. In the oral mucosa, it shows reticular white lesion with mucosal atrophy and erosions usually distributed bilaterally on the buccal mucosa and occasionally the tongue. Histopathologically, OLP is characterized by subepithelial band-like inflammatory infiltrate, variable numbers of intraepithelial mononuclear cells focused to the basal keratinocytes and degeneration/destruction of basal cells. OLP has various clinical manifestation such as texture type, papular type, plaque type, blister type, atrophy type and dissipated type. OLP is an elusive issue both clinically and etiologically. Now this lesion is recognized a T-cells-mediated immunoreaction with a potentially premalignant property. Much effort has been spent on OLP therapy, but the outcome is still far from satisfaction. Previous reports revealed that keratinocyte growth factor (KGF) might promote the epithelial proliferation specifically with no effect on fibroblasts or endotheliocyte, thus could be used to treat ulceration caused by epithelial damage. To explore the role of KGF and KGFR in OLP, we assess the expression of KGF and KGFR in OLP and normal oral mucosa at the level of mRNA and protein by ISH and immunohistochemistry respectively. Methods:1. OLP (n=30) and normal control (n=10) tissues were defined clinically and pathologically. Seven serial sections were cut for HE staining, immunohistochemical staining, ISH and negative control (3 sections) respectively. We observed the expression of KGF and KGFR in different tissues at the levels of mRNA and protein using ISH and IH respectively.2. Digital image processing was used to analysis the expression of KGF and KGFR. The optical density (OD) of the different tissue sections was obtained by the means of semi-quantitation. The numbers of KGF mRNA and protein positive cells were counted in five random highpower fields of each section.3. Data were analyzed by ANOVA and Student-t test ,and expressed as the means ± SD. Values of P<0.05 were considered statistically significant.Results:1. IH results of KGF: KGF was positive in the full-thickness of epithelium with weak expression in basal layer and intense expression in the cytoplasma of spinous layer cells. KGF could also be seen in the cytoplasma of some of fibroblasts and vascular endothelial cells. In OLP, KGF had similar expression with normal mucosa in epithelium but with a weaker staining. KGF was positive mainly in the cytoplasma of spinous layer cells and had weak expression in basal layer. KGF could also be seen in the cytoplasma of some of fibroblasts and vascular endothelial cells but with a weaker staining.2. IH results of KGFR: In normal mucosa, KGFR was positive in the cell membranes and some of the cytoplasma of the full-thickness of epithelium with intense expression in basal layer and even expression in other layers. KGFR was also positive in some vascular endothelial cells and negative in fibroblasts. In OLP, KGFR was positive mainly in the cell membranes and some of the cytoplasma of the basal layer cells and spinous layer cells. In OLP, KGFR was positive in more vascular endothelial cells but also negative in fibroblasts.3. Results of OD in IH: KGF in OLP showed a significantly (P<0.05) weaker expression both in epithelium and mesenchyma compared to normal controls. KGFR in OLP showed a significantly (P<0.01) weaker expression in epithelium and a significantly (P<0.05) intenser expression in mesenchyma.4. ISH results: Positive expression was seen in some of fibroblasts and vascular endothelial cells of connective tissues and not seen in epithelium in the two tissue. OLP had a significantly lower (P<0.05) positive cell count and OD values (P<0.05) than the normal control. Conclusion:The reduction and distribution difference of KGF and KGFR expression in OLP suggested KGF may play an important role in OLP development and progression.