Investigating Immunohistochemical Expression of cyclooxygenase-2 in oral lichen planus

Background and goal: (cox2) Cyclooxygenase -2 as an enzyme is not present in normal tissues and in fact is a type of inductive enzyme during pathological phenomena such as inflammation and cancer are significantly increased. Increased expression of cox-2 in gastric carcinoma, pancreatic, lung and oral squamous cell carcinoma has been shown and seems to be one of the performance mechanisms of the inhibition of apoptosis in tumor cells. Regarding the role of cox-2 in apoptosis mechanisms and the creation of dysplastic changes and malignant, the study aimed to evaluate the immunohistochemical expression of cox-2 in oral lichen planus and were compared with normal mucosa and gingivitis. Methods: The study was performed on 30 paraffin blocks related to patients referred to oral and maxillofacial pathology department in Dental School of Babol with confirmed diagnosis of oral lichen planus was done. The same number of samples of normal mucosa and samples of gingivitis were studied. Slices prepared from the above blocks bycoloring immunostaining cox-2 were stained and after reviewing the slides obtained, data using statistical software spss20 and x2 tests, Mann-Whitney and parametric tests such as T test was analyzed and P. 0.05 was considered significant Results: In this study, significantly percentage of stained cells and staining intensity of cells in the basal layer of lichen planus was higher than normal mucosa (p < 0.001). In parabasal layer the results were similar (p < 0.001). This results in comparison to lichen planus and gingivitis in basal layer (p < 0.001) and parabasal was seen (p < 10.0). On the other hand, significantly the percentage of stained cells and staining intensity of cells in the basal layer of gingivitis was more than normal mucosa (p < 0.001). In above comparison, similar result in the parabasal layer was seen (p < 0.001). The percentage of stained cells and staining intensity of cells in lymphocytic infiltration was significantly higher in oral lichen planus compared to gingivitis (p < 0.001). Conclusion: According to the results of this study may be differences in the expression of COX2 in oral lichen planus and normal mucosa attributed to malignant potential of the lesion. However, further studies in the field with larger sample size and painting method is necessary.