Increased expression of p16 in both oral and genital lichen planus

BACKGROUND: Lichen Planus, LP, is an inflammatory disease of possible autoimmune origin affecting mainly oral and genital mucosa and skin. According to the WHO oral LP is considered a potentially malignant disorders. The p16 tumour suppressor protein can act as an inhibitor of cyclin dependent kinases 4 and 6 and thus down regulate cell cycle progression. Since the discovery of p16 several studies have evaluated its expression in various forms of human cancers. The aim of this study was to evaluate and compare the expression of p16 in oral and genital LP and corresponding healthy mucosa. MATERIAL AND METHODS: A total of 76 cases of oral LP (OLP), 34 cases of genital LP (GLP), 12 cases of healthy oral and 9 cases of healthy genital mucosa were analysed by the use of immunohistochemistry. RESULTS: Data showed p16 to be highly expressed in both oral and genital LP, higher than in oral (p=0.000), and genital controls (p=0.002). CONCLUSIONS: Results suggest that the over-expression of p16 seen in LP play a part in the histopathology of the disease. Key words:p16, inflammation, oral, genital, lichen planus, malignant risk.