Immunohistochemical expression of Cyclooxygenase 2 and Caspase 7 in oral lichen planus

Oral lichen planus (OLP) is one of the most common dermatological diseases presenting in the oral cavity. Although relatively frequent, OLP is the target of much controversy, especially in relation to its potential for malignancy. This study was conducted to find biological changes in the expression of caspase 7 and cyclooxygenase 2(cox2) in OLP by immuohistochemistry and to explore the correlation between them. Materials and Methods: Fifteen cases of randomly chosen paraffin embedded tissue blocks of OLP with 5 normal oral mucosa cases were included in this study. Immunohistochemistry was performed to evaluate Cox2 and caspase 7 proteins expression. Results: The expression of cox2 was positive in all studied cases of OLP with negative expression in normal oral mucosa. Caspase 7 expression was positive in (73%) of the cases of which (36.5%) showed strong positive expression score. Non-significant positive correlation was found between the two markers. Conclusion: This study provided further evidence that epithelial cells in OLP undergo apoptotic death, on the other hand they develop high rate of inflammation which may create a good environment for malignant transformation.