Background: Cancer stem cells (CSCs) represent a subpopulation of cells responsible for tumor growth. Their role in head and neck squamous cell carcinoma (HNSCC) tumorigenesis and metastasis remains uncertain.
Methods: Wound healing and an orthotopic animal model were used to study cells expressing the CSC phenotype (CD44(high) and aldehyde dehydrogenase [ALDH](+)) and assess mobility, tumorigenesis, and metastasis. A prospective collection of 40 patient-derived primary HNSCC specimens were analyzed for CSC-proportion compared to clinical variables.
Results: CSCs exhibited significantly faster wound closure and greater tumorigenesis and regional metastasis in vivo than non-CSCs. In primary patient tumors, size and advanced stage were correlated with elevated proportion of CSCs, however, not with survival.
Conclusion: HNSCC stem cells mediate tumorigenesis and regional metastasis in vivo. In primary patient tumors, CSC-proportion was associated with tumor size and stage, but not with metastatic spread or survival. CSC burden alone may only represent a minor variable in understanding CSCs and metastasis.
Keywords: CD44; animal model; cancer stem cells; head and neck squamous cell carcinoma; metastasis.
© 2014 Wiley Periodicals, Inc.