Mucin-4: A novel marker for oral cancer

Background: Mucins are high-molecular-weight glycoproteins and are implicated in diverse biological functions. MUC4, a member of transmembrane mucin family, is expressed in airway epithelial cells and body fluids such as the saliva, tear film, ear fluid and breast milk. In addition to its normal expression, an aberrant expression of MUC4 has been reported in a variety of carcinomas. Till date, very few studies have discussed about MUC4 expression in normal and cancerous oral mucosa. Aim: The aim of the study is to evaluate the expression of MUC4 in varying grades of oral squamous cell carcinoma (OSCC) and also to analyze its role played in oral carcinogenesis. Materials and Methods: Formalin-fixed paraffin-embedded tissues of five cases of normal tissue, ten cases of well-differentiated OSCC, ten cases of moderately differentiated OSCC and ten cases of poorly differentiated OSCC were retrieved from the archives of the department, and MUC4 antigen was immunohistochemically localized. Statistical Analysis: The result was subjected to statistical analysis using Pearson's Chi-square test and one-way analysis of variance. Results: About 70% of OSCC were stained positive with MUC4 antigen. Maximum intensity of staining was noted in well-differentiated OSCC. A steady decrease in MUC4 staining was noted with the increase in histological grading of OSCC. Conclusion: The findings of the study suggest that MUC4 plays a vital role in the pathogenesis of OSCC and can be regarded as a novel marker for OSCC.