Influence of epidermal growth factor receptor expression on the cetuximab and panitumumab response rates of head and neck carcinoma cells

Objectives: To examine the impact of epidermal growth factor receptor (EGFR) expression level on the efficacy of monoclonal antibodies against the EGFR. Methods: In four human head and neck carcinoma cell lines, epidermal growth factor expression was knocked down by lentiviral RNA interference. Next, the efficacies of cetuximab and panitumumab at concentrations of 4, 40, and 400 mu g/ml were measured by real time cell analysis for a 48-h duration. Finally, the different response rates to the drugs were statistically analyzed. Results: The lentiviral EGFR knockdown efficiency ranged from 18 to 54 % across all of the cell lines. All original cell lines exhibited rather poor or inverse responses with regard to EGFR-AB treatment. In contrast, inhibiting EGFR expression in the same cell lines yielded statistically significant better responses to cetuximab or panitumumab treatment. Conclusions: The cell lines used in this study responded poorly to cetuximab and panitumumab. Better anti-EGFR treatment efficacy was related to lower EGFR expression in head and neck cancer cell lines. These findings might influence the selection of patients to receive cetuximab and panitumumab treatment for head and neck cancer. (C) 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.