Abstract
INTRODUCTION: Oral lichen planus (OLP) is a common skin disease of indeterminate etiology that can affect the oral mucosa. Epithelial-mesenchymal transition (EMT) is a critical biological event that plays an essential role in several functions, such as development, tissue repair, and stem cell dynamics, but also in cancer progression. Claudin-10, an EMT-related protein, is encoded by the CLDN10 gene in humans. In the present work, we studied the immunohistological expression of Claudin-10 in OLP compared to normal oral mucosa. METHODS: Fifty-one formalin-fixed, paraffin-embedded samples diagnosed as OLP from patients who did not receive any medications for the treatment of OLP until the initial biopsy and ten formalin-fixed, paraffin-embedded samples diagnosed as comprising histologically normal oral mucosa tissue from resection margins of fibromas were immunohistochemically stained and analyzed for Claudin-10. RESULTS: The expression of Claudin-10 was evaluated as significantly enhanced in OLP epithelium compared to controls (p<0.001). In the superficial epithelial layer, the staining was markedly higher in OLP than in the controls (p=0.008), and in the stroma, the staining was significantly stronger in OLP (p=0.027). In the intermediate epithelial layer, the staining was significantly weaker in OLP than in the controls (p=0.001), and in the basal layer, the staining was markedly reduced in OLP (p<0.001). CONCLUSIONS: The immunohistological expression of Claudin-10 has been described and analyzed in oral mucosal disease for the first time. Our findings indicate that the expression of Claudin-10 is dysregulated in OLP, possibly showing an interaction between the epithelium and the underlying tissue.