Abstract
BACKGROUND/PURPOSE: Oral lichen planus (OLP) is a chronic inflammatory disease with unknown mechanisms of pathogenesis. Keratin 17 (KRT17) is a protein that regulates numerous cellular processes. This study aimed to explore the expression of KRT17 in OLP and its correlation with the severity of OLP. MATERIALS AND METHODS: RNA sequencing using epithelium from 5 OLP patients and 5 health control (HC) was performed, followed by functional analysis. The validation cohort of 20 OLP and 20 HC tissues were used to investigate positive area value of KRT17 by immunohistochemical analysis. Reticular, erosive and ulcerative (REU) scores were used for measuring the severity of OLP. RESULTS: A total of 15493 genes were detected, of which 1492 genes were significantly up-regulated in OLP and 622 were down-regulated. The mRNA expression of KRT17 was elevated by 13.09-fold in OLP compared to that in HC. Pathway analysis demonstrated high KRT17 expression was associated with multiple biological processes. The median of percentage of KRT17 positive area value was 19.30 % in OLP and 0.01 % in HC (P < 0.001). Percentage of KRT17 positive area value was higher in erosive OLP patients (27.25 %) compared to that in non-erosive patients (15.02 %, P = 0.006). REU scores were positively correlated with percentage of KRT17 positive area value (r = 0.628, P = 0.003). CONCLUSION: The mRNA expression of KRT17 was elevated in OLP tissues compared to that in HC. KRT17 was positively correlated with the severity of OLP, indicating KRT17 might play a vital role in the pathogenesis of OLP.