Head and neck cancer stem cells: The side population

• Published in: The Laryngoscope Vol. 121; no. 3; pp. 527 - 533
• Main Authors: Tabor, Mark H., Clay, Matthew R., Owen, John H., Bradford, Carol R., Carey, Thomas E., Wolf, Gregory T., Prince, Mark E.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01-03-2011; Wiley-Blackwell
• Subjects: Animals; Antimetabolites, Antineoplastic - pharmacology; Biological and medical sciences; Bmi-1; cancer stem cell; Carcinoma, Squamous Cell - pathology; Cell Division - drug effects; Cell Division - physiology; Cell Line, Tumor; Cell Separation; Drug Screening Assays, Antitumor; Fluorouracil - pharmacology; Head and neck cancer; Hoechst 33342; Humans; Laryngeal Neoplasms - pathology; Level of Evidence: 1c; Medical sciences; Mice; Mice, Inbred NOD; Mice, SCID; Neoplasm Transplantation; Neoplastic Stem Cells - drug effects; Neoplastic Stem Cells - pathology; Otorhinolaryngologic Neoplasms - pathology; Otorhinolaryngology (head neck, general aspects and miscellaneous); Otorhinolaryngology. Stomatology; side population; Side-Population Cells - drug effects; Side-Population Cells - pathology; Tumor Stem Cell Assay; Tumors; side population; cancer stem cell; Stem cell; Bmi-1; ENT disease; Head and neck cancer; ENT; Malignant tumor; Tumor cell; Cancer; Hoechst 33342
• ISSN: 0023-852X; 1531-4995
• DOI: 10.1002/lary.21032

Objectives/Hypothesis:
The cancer stem cell (CSC) theory concludes that a subpopulation of cancer cells, the cancer stem cells, can self‐renew and are responsible for tumor growth. Previous studies have identified cells able to efflux Hoechst 33342 dye as the side population (SP). SP cells and CSCs share many characteristics, suggesting the SP isolated from malignant tumors contains CSCs.
Study Design:
Experimental Study.
Methods:
The SP was isolated from a head and neck cancer cell line and analyzed for CSC‐like characteristics.
Results:
The SP demonstrated the ability to reproduce both SP and non‐side population (NSP) cells from as few as one cell. The SP had lower expression of active β‐catenin and more resistance to 5‐fluorouracil; the SP also demonstrated greater expression of Bmi‐1 (4.3‐fold) and ABCG2 (1.4‐fold). SP cells were able to produce tumors in an animal model, whereas NSP were not. SPs were identified in two primary human tumors.
Conclusions:
This work adds to the evidence that the SP in head and neck cancer represents cells with CSC properties and provides a method by which CSCs can be isolated and studied. Laryngoscope, 2011