Immunoexpression of REGγ and apoptosis-related proteins in oral tongue squamous cell carcinoma

The aim of this study was to investigate the immunohistochemical expression of REGγ, p53, MDM-2, Bcl-2, and Bax in oral tongue squamous cell carcinoma (OTSCC), and to correlate the findings with clinicopathological parameters. Fifty-eight OTSCC cases were selected for the study. The percentages of nuclear (REGγ, p53, and MDM-2) and cytoplasmic (Bcl-2 and Bax) staining in epithelial cells were determined and correlated with clinicopathological parameters (regional lymph node metastasis, clinical stage, clinical outcome, and histopathological grade of malignancy). Expression of REGγ was observed in all cases studied. Significantly lower percentages were observed in tumours with lymph node metastasis (P = 0.036) and in high-grade tumours (P = 0.013). No significant differences in p53, MDM-2, or Bax expression were observed according to the clinicopathological parameters. Lower percentages of Bcl-2 staining were found in high-grade OTSCC (P = 0.040) and in cases of disease-related death (P = 0.032). The expression of REGγ showed a weak positive correlation with the expression of MDM-2 (P = 0.001) and Bcl-2 (P = 0.014). The results of this study suggest that lower expression of REGγ may contribute to the progression of OTSCC. The role of REGγ in the development of OTSCC does not appear to be primarily related to the modulation of apoptosis in neoplastic cells.