Identification, expansion and characterization of cancer cells with stem cell properties from head and neck squamous cell carcinomas

Exp Cell Res. 2016 Oct 15;348(1):75-86. doi: 10.1016/j.yexcr.2016.09.003. Epub 2016 Sep 9.


Head and neck squamous cell carcinoma (HNSCC) is a major public health concern. Recent data indicate the presence of cancer stem cells (CSC) in many solid tumors, including HNSCC. Here, we assessed the stem cell (SC) characteristics, including cell surface markers, radioresistance, chromosomal instability, and in vivo tumorigenic capacity of CSC isolated from HNSCC patient specimens. We show that spheroid enrichment of CSC from early and short-term HNSCC cell cultures was associated with increased expression of CD44, CD133, SOX2 and BMI1 compared with normal oral epithelial cells. On immunophenotyping, five of 12 SC/CSC markers were homogenously expressed in all tumor cultures, while one of 12 was negative, four of 12 showed variable expression, and two of the 12 were expressed heterogeneously. We showed that irradiated CSCs survived and retained their self-renewal capacity across different ionizing radiation (IR) regimens. Fluorescence in situ hybridization (FISH) analyses of parental and clonally-derived tumor cells revealed different chromosome copy numbers from cell to cell, suggesting the presence of chromosomal instability in HNSCC CSC. Further, our in vitro and in vivo mouse engraftment studies suggest that CD44+/CD66- is a promising, consistent biomarker combination for HNSCC CSC. Overall, our findings add further evidence to the proposed role of HNSCC CSCs in therapeutic resistance.

Keywords: Cancer stem cells; Cell surface markers; Chromosomal instability; Head and neck squamous cell carcinoma; Radioresistance.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Animals
  • Antigens, CD / metabolism
  • Biomarkers, Tumor / metabolism
  • Carcinogenesis / pathology
  • Carcinoma, Squamous Cell / metabolism
  • Carcinoma, Squamous Cell / pathology*
  • Cell Line, Tumor
  • Cell Proliferation
  • Cell Self Renewal
  • Cell Separation
  • Chromosomal Instability
  • Clone Cells
  • Feeder Cells / cytology
  • Female
  • Fluorescent Antibody Technique
  • Head and Neck Neoplasms / metabolism
  • Head and Neck Neoplasms / pathology*
  • Humans
  • In Situ Hybridization, Fluorescence
  • Male
  • Mice
  • Middle Aged
  • Neoplastic Stem Cells / metabolism
  • Neoplastic Stem Cells / pathology*
  • Radiation Tolerance
  • Squamous Cell Carcinoma of Head and Neck


  • Antigens, CD
  • Biomarkers, Tumor