The Role of CD44 AND SOX-2 Cancer Stem cell Markers in The Development and Progression of Mucoepidermoid Carcinoma and Primary Squamous Cell Carcinoma of Salivary Glands

Abstract

One of the greatest difficulties to reach a successful treatment of mucoepidermoid carcinoma(MEC) and primary squamous cell carcinoma (PSSC) of salivary glands is the resistance to differenttherapeutic procedures which advocate the existence of a subpopulation of cancer stem cell (CSC).In salivary gland tumors the hypothesis of cancer stem cell has not been fully understood.Aim: To assess the expression of cancer stem cell markers CD44 and SOX2 in low and highgradesMEC and PSSC and to determine whether the expression of these markers can be used topredict tumor aggressiveness.Materials and Methods: 4μm sections were prepared from paraffin-embedded blocks of16 samples of MEC and 16 samples of PSSC of salivary glands (8 low-grade and 8 high- gradecarcinomas for each of them). Staining of each specimen with hematoxylin and eosin, CD44 andSOX2 was done.Results: All lesions of MEC and PSSC showed membranous CD44 and nuclear SOX2expression. CD44 and SOX 2 expression were significantly higher in high-grade tumors than inlow-grade tumors. A strong positive correlation between CD44 and SOX2 expression was detected.Conclusion: Cancer stem cells can be identified in MEC and PSS C using CD44 and SOX 2markers and may participate in tumor aggressiveness. The present study also suggests that patientswith MEC and PSS C may benefit from therapies that comprise a combination of the two markers.