AUTHOR=Yu Helen H. , Featherston Therese , Tan Swee T. , Chibnall Alice M. , Brasch Helen D. , Davis Paul F. , Itinteang Tinte 

TITLE=Characterization of Cancer Stem Cells in Moderately Differentiated Buccal Mucosal Squamous Cell Carcinoma

JOURNAL=Frontiers in Surgery

VOLUME=3

YEAR=2016

URL=https://www.frontiersin.org/journals/surgery/articles/10.3389/fsurg.2016.00046

DOI=10.3389/fsurg.2016.00046

ISSN=2296-875X

ABSTRACT=<sec id="ST1"><title>Aim</title><p>To identify and characterize cancer stem cells (CSC) in moderately differentiated buccal mucosa squamous cell carcinoma (MDBMSCC).</p></sec><sec id="ST2"><title>Methods</title><p>Four micrometer-thick, formalin-fixed, paraffin-embedded MDBMSCC samples from six patients underwent 3,3-diaminobenzidine (DAB) immunohistochemical (IHC) staining for the embryonic stem cell (ESC) markers, NANOG, OCT4, SALL4, SOX2, and pSTAT3; cancer stem cell marker, CD44; squamous cell carcinoma (SCC) marker, EMA; and endothelial marker, CD34. The transcriptional activities of the genes encoding NANOG, OCT4, SOX2, SALL4, STAT3, and CD44 were studied using NanoString gene expression analysis and colorimetric <italic>in situ</italic> hybridization (CISH) for NANOG, OCT4, SOX2, SALL4, and STAT3.</p></sec><sec id="ST3"><title>Results</title><p>Diaminobenzidine and immunofluorescent (IF) IHC staining demonstrated the presence of (1) an EMA<sup>+</sup>/CD44<sup>+</sup>/SOX2<sup>+</sup>/SALL4<sup>+</sup>/OCT4<sup>+</sup>/pSTAT3<sup>+</sup>/NANOG<sup>+</sup> CSC subpopulation within the tumor nests; (2) an EMA<sup>−</sup>/CD44<sup>−</sup>/CD34<sup>−</sup>/SOX2<sup>+</sup>/OCT4<sup>+</sup>/pSTAT3<sup>+</sup>/NANOG<sup>+</sup> subpopulation within the stroma between the tumor nests; and (3) an EMA<sup>−</sup>/CD44<sup>−</sup>/CD34<sup>+</sup>/SOX2<sup>+</sup>/SALL4<sup>+</sup>/OCT4<sup>+</sup>/pSTAT3<sup>+</sup>/NANOG<sup>+</sup> subpopulation on the endothelium of the microvessels within the stroma. The expression of CD44, SOX2, SALL4, OCT4, pSTAT3, and NANOG was confirmed by the presence of mRNA transcripts, using NanoString analysis and NANOG, OCT4, SOX2, SALL4, and STAT3 by CISH staining.</p></sec><sec id="ST4"><title>Conclusion</title><p>This study demonstrated a novel finding of three separate CSC subpopulations within MDBMSCC: (1) within the tumor nests expressing EMA, CD44, SOX2, SALL4, OCT4, pSTAT3, and NANOG; (2) within the stroma expressing SOX2, SALL4, OCT4, pSTAT3, and NANOG; and (3) on the endothelium of the microvessels within the stroma expressing CD34, SOX2, SALL4, OCT4, pSTAT3, and NANOG.</p></sec>