EXPRESSION OF SOX2 AND CLINICOPATHOLOGICAL SIGNIFICANCE IN SALIVARY GLAND TUMORS

Abstract

<h3>Objectives</h3> To analyze the expression of the sex-determining region of Y chromosome-related high-mobility-group box 2 (SOX2), a putative marker of cancer stem cells in salivary gland tumors (SGTs). <h3>Study Design</h3> One hundred fifty-four cases of SGT were selected (103 malignant and 51 benign neoplasms). SOX2 expression was detected by immunohistochemistry and confirmed by Western blotting, following a semiquantitative evaluation. <h3>Results</h3> SOX2 was identified in the parenchyma of malignant (<i>n</i> = 54; 52.4%) and benign (<i>n</i> = 12; 23.5%) neoplasms, especially in tumors without myoepithelial differentiation (canalicular adenoma, Warthin's tumor, mucoepidermoid carcinoma, clear cell carcinoma; <i>P</i> < .05). Tumors with myoepithelial differentiation showed negative or low expression of SOX2 (pleomorphic adenoma, basal cell adenoma, myoepithelioma, adenoid cystic carcinoma, basal cell adenocarcinoma, epithelial-myoepithelial carcinoma). No association was found between SOX2 expression and clinicopathologic parameters (<i>P</i> > .05). A positive correlation between SOX2 expression by immunohistochemistry and Western blotting techniques was observed (<i>r</i> = 0.967; <i>P</i> < .001). <h3>Conclusions</h3> These results indicate that SOX2 was differentially expressed among the SGTs studied, predominantly in malignant tumors, suggesting that cells with cancer stem cell–like phenotype may be involved in the carcinogenesis and progression of SGT.