Comparative Evaluation of Immunohistochemical Expression of Endothelin A Receptor between Oral Squamous Cell Carcinoma and Normal Oral Mucosa

Recent research has provided evidences indicating the importance of endothelin axis in carcinogenesis. According to our knowledge, there are little information about endothelin A receptor (ETA) expression in oral squamous cell carcinoma (OSCC). So, the aim of the present study was to evaluate the immunohistochemical expression of ETA in OSCC and normal oral mucosa (NOM). In this cross-sectional study, studied group composed of paraffin-embedded tissue blocks of 21 OSCCs and 20 NOMs. Four micron sections were prepared from tissue blocks and stained with ETA antibody using immunohistochemistry (IHC). Percentage of stained cells and staining intensity were compared between OSCC and NOM groups and also between different grades of OSCC using Mann-Whitney, Chi-Square and Kruskal-Wallis statistical tests. In OSCC group, all cases showed positive staining for ETA while in NOM group, 17 cases showed no staining. Comparison of the percentage of stained cells and staining intensity for ETA revealed a significant difference between OSCC and NOM groups (P 0.001). There was also a significant difference between different grades of OSCC with respect to the percentage of stained cells (P=0.01) so that with increase in grade, ETA expression was also increased. The results of this study support the role of ETA receptor in carcinogenesis process and progression of OSCC.