Immunohistochemical Eexpression of Endothelin A Receptor in Dysplastic Oral Mucosa

Background: Recent researches have provided evidences of the importance of endothelin axis in carcinogenesis. According to our knowledge, no data exists about endothelin A receptor (ETA) expression in dysplastic oral mucosa (DOM). Therefore, the aim of the present study was to evaluate immunohistochemical expression of ETA in DOM. Methods:In this cross-sectional study, paraffin-embedded tissue blocks of 20 cases of DOM and 20 cases of normal oral mucosa (NOM) were studied. Three-micron sections were prepared from tissue blocks and stained with ETA antibody using immunohistochemistry. Percentage of stained cells and staining intensity were compared between DOM and NOM groups and also between different grades of DOM using Mann-Whitney, Chi-Square and Kruskal-Wallis statistical tests. Results:In DOM group, 11 cases were stained positive for ETA and in NOM group 17 cases were not stained. Comparison of percentage of stained cells and staining intensity for ETA revealed significant difference between DOM and NOM groups (P=0.01 and 0.02, respectively). There were significant differences among different grades of DOM with respect to the percentage of stained cells (P=0.001) and staining intensity (P=0.02), so that higher grades showed greater expression for ETA. Conclusion:Our results supported ETA receptor role in the initiation of carcinogenesis process in oral cavity.