Abstract: Objective　The purpose of this study was to invest the effect of epidermal growth factor receptor monoclonal anti- body MAb225 on radiosensitivity of tongue squamous cell carcinoma cell Tca8113.Methods　Tca8113 cells were treated with different concentrations of MAb225. Radiation dose survival curve was generated from clonogenic survival assay. SERD0and sur- vival faction (SF2) was analysed by single hit multi-target (SHMT) radiobiological model using RADMEDIC software. Nude mice with Tca8113 tumor xenografts were treated withMAb225, radiation treatment or both of them. Tumor responses were assessed by tumor growth delay, andttestwas used for statistical analysis.Results　MAb225 enhanced the radiosensitivity ofTca8113 cells. SERD0of Tca8113 cells treated with 0·5 mg/LMAb225 was 1·23. The survival fraction of cells treated withMAb225 was signifi- cantly decreased. Tumor radioresponse could be enhanced by MAb225 (P<0·05).Conclusion　MAb225 could enhance ra- diosensitivity of tongue squamous cell carcinoma cell.

Key words: epidermal growth factor receptor, monoclonal antibody, radiosensitivity, squamous cell carcinoma