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 anti-tumour 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 mug/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.