A subpopulation of CD133⁺ cancer stem-like cells characterized in human oral squamous cell carcinoma confer resistance to chemotherapy

The potential role of cancer stem-like cells (CSCs) in chemoresistance of human oral squamous cell carcinoma (OSCC) was examined. A small subpopulation (1-2%) of CD133⁺ CSCs was identified in OSCC cell lines and tissues. These CD133⁺ CSCs possess higher clonogenicity, invasiveness, and increased in vivo tumorigenicity as compared to CD133^- counterparts. Meanwhile, CD133⁺ CSCs were substantially resistant to standard chemotherapy, wherein both in vitro and in vivo treatment with paclitaxel resulted in a marked enrichment for CD133⁺ CSCs. Our data suggest that CD133⁺ cells represent a small subpopulation of CSCs that may contribute to chemoresistance in human OSCC.