| Title | EGFR regulates the side population in head and neck squamous cell carcinoma. | | Author(s) | Chen JS, Pardo FS, Wang-Rodriguez J, Chu TS, Lopez JP, Aguilera J, Altuna X, Weisman RA, Ongkeko WM | | Institution | Division of Head and Neck Surgery, Department of Surgery, University of California, San Diego, San Diego, California 92093, USA. | | Source | Laryngoscope 2006 Mar; 116(3):401-6. | | MeSH | ATP-Binding Cassette Transporters
Antineoplastic Agents
Carcinoma, Squamous Cell
Cell Line, Tumor
Cell Proliferation
Comparative Study
Flow Cytometry
Fluorescent Antibody Technique
Gene Expression Regulation, Neoplastic
Head and Neck Neoplasms
Humans
Immunohistochemistry
In Vitro
Neoplasm Proteins
Quinazolines
Receptor, Epidermal Growth Factor
Research Support, Non-U.S. Gov't
| | Abstract | OBJECTIVE: To identify the presence of side population (SP) cells in established head and neck squamous carcinoma cell (HNSCC) lines and to determine the role of EGFR in the regulation of the side population of these cells.
METHODS: SP cells were identified using flow cytometry analysis by the ability of these cells to extrude the Hoechst 33342 dye via the drug transporter BCRP1/ABCG2. Effect of EGFR on the side population was determined also by difference in Hoechst extrusion and by immunofluorescence. Immunohistochemical staining was performed to show the presence of the BCRP1/ABCG2 transporter and the phosphorylated form of EGFR in HNSCC tissue.
RESULTS: SP cells are present in HNSCC cell lines. With the Hoechst 33342 extrusion assay, SP cells were found to comprise an average of 0.69% of the UMSCC10B cells and 0.91% of HN12 cells. Addition of the EGF ligand increased the SP population while inactivation of the EGFR kinase by Iressa significantly decreased SP.
CONCLUSION: In established head and neck squamous cell carcinoma cell lines, SP cells were found using methods that determine expression and function of the drug transporter BCRP1/ABCG2. Activation of EGFR, a gene implicated in tumorigenesis in HNSCC leads to increased SP, and conversely, inhibition of EGFR leads to decrease in SP. This finding could help explain the role of EGFR in regulating cancer stem cells and thus tumorigenesis in HNSCC. | | Language | eng | | Pub Type(s) | Journal Article
| | PubMed ID | 16540898 |
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