title: EGFR kinase promotes acquisition of stem cell-like properties: a potential therapeutic target in head and neck squamous cell carcinoma stem cells.
abstract: Members of the EGFR/ErbB family of tyrosine kinases are found to be highly expressed and deregulated in many cancers, including head and neck squamous cell carcinoma (HNSCC). The ErbB family, including EGFR, has been demonstrated to play key roles in metastasis, tumorigenesis, cell proliferation, and drug resistance. Recently, these characteristics have been linked to a small subpopulation of cells classified as cancer stem cells (CSCs) which are believed to be responsible for tumor initiation and maintenance. In this study, we investigated the possible role of EGFR as a regulator of "stemness" in HNSCC cells. Activation of EGFR by the addition of EGF ligand or ectopic expression of EGFR in two established HNSCC cell lines (UMSCC-22B and HN-1) resulted in the induction of CD44, BMI-1, Oct-4, NANOG, CXCR4, and SDF-1. Activation of EGFR also resulted in increased tumorsphere formation, a characteristic ability of cancer stem cells. Conversely, treatment with the EGFR kinase inhibitor, Gefinitib (Iressa), resulted in decreased expression of the aforementioned genes, and loss of tumorsphere-forming ability. Similar trends were observed in a 99.9% CD44 positive stem cell culture derived from a fresh HNSCC tumor, confirming our findings for the cell lines. Additionally, we found that these putative cancer stem cells, when treated with Gefitinib, possessed a lower capacity to invade and became more sensitive to cisplatin-induced death in vitro. These results suggest that EGFR plays critical roles in the survival, maintenance, and function of cancer stem cells. Drugs that target EGFR, perhaps administered in combination with conventional chemotherapy, might be an effective treatment for HNSCC.
authors.affiliation: Division of Otolaryngology-Head and Neck Surgery, Department of Surgery, University of California San Diego, San Diego, California, United States of America.
authors.forename: Eric L
authors.initials: EL
authors.lastname: Abhold
authors.forename: Alan
authors.initials: A
authors.lastname: Kiang
authors.forename: Elham
authors.initials: E
authors.lastname: Rahimy
authors.forename: Selena Z
authors.initials: SZ
authors.lastname: Kuo
authors.forename: Jessica
authors.initials: J
authors.lastname: Wang-Rodriguez
authors.forename: Jay Patrick
authors.initials: JP
authors.lastname: Lopez
authors.forename: Katherine J
authors.initials: KJ
authors.lastname: Blair
authors.forename: Michael Andrew
authors.initials: MA
authors.lastname: Yu
authors.forename: Martin
authors.initials: M
authors.lastname: Haas
authors.forename: Kevin T
authors.initials: KT
authors.lastname: Brumund
authors.forename: Xabier
authors.initials: X
authors.lastname: Altuna
authors.forename: Andrew
authors.initials: A
authors.lastname: Patel
authors.forename: Robert A
authors.initials: RA
authors.lastname: Weisman
authors.forename: Weg M
authors.initials: WM
authors.lastname: Ongkeko
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D002294:Carcinoma, Squamous Cell / Q000378:metabolism*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002945:Cisplatin / Q000494:pharmacology; D066246:ErbB Receptors / Q000378:metabolism*; D005434:Flow Cytometry / Q000379:methods; D000077156:Gefitinib; D006258:Head and Neck Neoplasms / Q000378:metabolism*; D006801:Humans; D018960:Hyaluronan Receptors / Q000096:biosynthesis; D009361:Neoplasm Invasiveness; D014411:Neoplastic Stem Cells / Q000166:cytology*; D011799:Quinazolines / Q000494:pharmacology; D015398:Signal Transduction
chemical_list: D000970:Antineoplastic Agents; D018960:Hyaluronan Receptors; D011799:Quinazolines; C512478:EGFR protein, human; D066246:ErbB Receptors; D002945:Cisplatin; D000077156:Gefitinib