J Korean Assoc Oral Maxillofac Surg.  2009 Oct;35(5):287-293.

Growth inhibition in head and neck cancer cell lines by gefitinib, an epidermal growth factor receptor tyrosine kinase inhibitor

• Song SI
• Kim MJ

Abstract

Cell survival is the result of a balance between programmed cell death and cellular proliferation. Cell membrane receptors and their associated signal transducing proteins control these processes. Of the numerous receptors and signaling proteins, epidermal growth factor receptor (EGFR) is one of the most important receptors involved in signaling pathways implicated in the proliferation and survival of cancer cells. EGFR is often highly expressed in human tumors including oral squamous cell carcinomas, and there is increasing evidence that high expression of EGFR is correlated with poor clinical outcome of common human cancers. Therefore, we examined the antiproliferative activity of gefitinib, epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI), in head and neck cancer cell lines. SCC-9, KB cells were cultured and growth inhibition activity of gefitinib was measured with MTT assay. To study influence of gefitinib in cell cycle, we performed cell cycle analysis with flow cytometry. Western blot was done to elucidate the expression of EGFR in cell lines and phosphorylation of EGFR and downstream kinase protein, Erk and Akt. Significant growth inhibition was observed in SCC-9 cells in contrast with KB cells. Also, flow cytometric analysis showed G1 phase arrest only in SCC-9 cells. In Western blot analysis for investigation of EGFR expression and downstream molecule phosphorylation, gefitinib suppressed phosphorylation of EGFR and downstream protein kinase Erk, Akt in SCC-9. However, in EGFR positive KB cells, weak expression of active form of Erk and Akt and no inhibitory activity of phosphorylation in Erk and Akt was observed. The antiproliferative activity of gefitinib was not correlated with EGFR expression and some possibility of phosphorylation of Erk and Akt as a predictive factor of gefitinib response was emerged. Further investigations on more reliable predictive factor indicating gefitinib response are awaited to be useful gefitinib treatment in head and neck cancer patients.

Keyword

Epidermal growth factor receptor; Head and neck cancer; Gefitinib; Epidermal growth factor receptor tyrosine kinase inhibitor

MeSH Terms

Blotting, Western
Carcinoma, Squamous Cell
Cell Cycle
Cell Death
Cell Line
Cell Membrane
Cell Proliferation
Cell Survival
Epidermal Growth Factor
Flow Cytometry
G1 Phase
Head
Head and Neck Neoplasms
Humans
KB Cells
Phosphorylation
Phosphotransferases
Protein Kinases
Protein-Tyrosine Kinases
Proteins
Quinazolines
Receptor, Epidermal Growth Factor
Epidermal Growth Factor
Phosphotransferases
Protein Kinases
Protein-Tyrosine Kinases
Proteins
Quinazolines
Receptor, Epidermal Growth Factor