Immunohistochemical Expression of Epithelial Mesenchymal Transition Proteins in Squamous Cell Carcinoma of the Oral Cavity

BACKGROUND & OBJECTIVE: Epithelial-Mesenchymal transition (EMT) is known to be a possible mechanism in tumor progression; however, there is insufficient evidence to support the contribution of this process in human cancers. The present study aimed to evaluate the expression of EMT markers in normal oral epithelium and oral squamous cell carcinoma and also correlates with some clinicopathological parameters. METHODS: This study was conducted on 70 samples, including 20 cases of normal epithelium and 50 cases of Oral Squamous cell Carcinoma (OSCC). To examine the expression level of these proteins, immunohistochemical staining was performed for samples using E-cadherin and N-cadherin monoclonal antibodies. RESULTS: Reduced expression of E-cadherin was observed in 74% of OSCC and 15% of normal epithelium samples; this difference was statistically significant (P˂0.000). With the progression of SCC from well towards poor differentiation, the E-cadherin expression decreased; however, this difference was not statistically significant (P=0.642). Normal epithelial specimens were negative for N-cadherin expression in 75% of cases, whereas OSCC specimens showed high expression of N-cadherin in 46% of cases, this difference was statistically significant (P=0.01). Although 62.5% of poorly differentiated OSCC showed high expression of N-cadherin, the difference between the histopathological grades was not significant (P=0.586). No significant relationship was found between markers expression and patient’s age, gender, and tumor location. CONCLUSION: This study showed that OSCC tissues showed high EMT phenotype (reduced E-cadherin expression and high expression of N-cadherin) compared to normal oral mucosa which may indicate the possible key role of EMT mechanism during oral carcinogenesis.