Immunohistochemical Eexpression of Endothelin A Receptor in Dysplastic Oral Mucosa

Abstract

<strong>Background:</strong> Recent researches have provided evidences of the importance of endothelin axis in carcinogenesis. According to our knowledge, no data exists about endothelin A receptor (ET_A) expression in dysplastic oral mucosa (DOM). Therefore, the aim of the present study was to evaluate immunohistochemical expression of ET_A in DOM. <strong>Methods:</strong>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 ET_A 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. <strong>Results:</strong>In DOM group, 11 cases were stained positive for ET_A and in NOM group 17 cases were not stained. Comparison of percentage of stained cells and staining intensity for ET_Arevealed 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 ET_A. <strong>Conclusion:</strong>Our results supported ET_A receptor role in the initiation of carcinogenesis process in oral cavity.