Relationship Between EGFR Expression in Oral Cancer Cell Lines and Cetuximab Antibody-dependent Cell-mediated Cytotoxicity

Background/Aim: Cetuximab treatment targets the epidermal growth factor receptor (EGFR) overexpressed in oral cancer. This study aimed to investigate the antitumour activity of cetuximab against oral cancer cell lines with respect to antibody-dependent cell-mediated cytotoxicity (ADCC), and determine the correlation between ADCC and EGFR expression. Materials and Methods: EGFR expression in oral cancer cells was measured by quantitative flow cytometric analysis and immunohistochemistry. ADCC activity was measured by 4-h calcein release assays. Results: Cetuximab-mediated ADCC against oral cancer cells was detectable at a concentration of 0.1 mu g/ml. A high correlation was observed between the number of EGFR molecules on the surface of oral cancer cells and ADCC (correlation coefficient: 0.847; p=0.032). Conclusion: ADCC is an important mechanism underlying the therapeutic effect of cetuximab, and EGFR expression in tumour cells might serve as a predictive marker to evaluate the effect of cetuximab treatment.