Evaluation of CD44 and TGF-B Expression in Oral Carcinogenesis

Statement of the Problem: Oral squamous cell carcinoma (OSCC) is the most common malignancy of the oral cavity. Early diagnosis of OSCC by using biomarkers provides pre-ventive treatment approach to suppress the disease in early stages. CD44 as a cancer stem cell (CSC) marker may be cleaved by MT1-MMP and plays an important role in migration of cancer cells. TGF-B promotes formation of invasive cancer cells phenotype through epithelial mesenchymal transition (EMT) and induces MT1-MMP formation. Purpose: The aim of this study was to evaluate the expression of TGF-B and CD44 in leukoplakia (premalignant lesion), squamous cell carcinoma (SCC), and normal oral muco-sa to determine the role of these markers in the carcinogenesis process of the oral mucosa. Materials and Method: In this retrospective study, the expression of TGF-B and CD44 were evaluated in 55 paraffin-embedded specimens (10normal mucosa, 15 non-dysplastic leukoplakia, 15 dysplastic leukoplakia, and 15 OSCC) by immunohistochemistry. Statistical analyses were performed using Kruskal-Wallis, Mann-Whitney, and Spearman’s rank cor-relation tests. Results: Evaluation of CD44 and TGF-B expression in the four studied groups showed statistical significant difference for each marker (p 0.001). Pairwise comparison of CD44 and TGF-B expression in all groups except normal mucosa and non-dysplastic leukoplakia demonstrated statistical significant difference. In addition, there was positive significant correlation between two markers (r= 0.914, p 0.001). Diagnostic test’s accuracy for identi-fication of OSCC and dysplastic leukoplakia from non-dysplastic leukoplakia and normal tissues and recognition of OSCC from dysplastic leukoplakia showed optimum sensitivity and specificity. Conclusion: Increased expression of CD44 as a cancer stem cell marker and TGF-B as an EMT marker from normal mucosa to non-dysplastic leukoplakia, dysplastic leukoplakia, and OSCC and also the significant correlation between these two markers indicated their role in carcinogenesis of oral mucosa.