Comparing Endothelin A Receptor Expression in Dysplasia and Oral Squamous Cell Carcinoma

Background and Endothelin axis (endothelin or ET) including endothelin A receptor (ETA) play a major role as the regulator of vessels tone and tissue differentiation and development. There are evidences of the importance of endothelin axis in carcinogenesis. No data exists about comparison of ETA expression between dysplasia and oral squamous cell carcinoma (OSCC). So, the aim of this study was to compare immunohistochemical expression of ETA between these two groups. In this cross-sectional study, the paraffin-embedded tissue blocks of 20 cases of dysplastic oral mucosa and 21 cases of OSCCs were investigated. 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 the groups applying Mann-Whitney and Chi-Square tests. In dysplasia group, 11 cases stained for ETA while in OSCC group all cases stained. Comparison of percentage of stained cells and their semi quantitative classification showed significant differences between the two groups (P=0.02 and P=0.005, respectively) such that ETA expression was higher in OSCC than dysplasia. Staining intensity for ETA was significantly higher in OSCC group (P=0.006). There were significant differences between ETA expression in mild and moderate dysplasia with carcinoma. Our results support the role of ETA receptor in progression of dysplasia toward OSCC