Radiosensitization of cetuximab on human tongue cancer cell line Tca8113

Objective To investigate the mechanism of radiosensitization by cetuximab (C225) on human tongue cancer Tca8113 cell line in vitro.Methods Tca8113 cell line with and without C225 treatment received 6 MV X-ray irradiation of different doses (0, 2,4,6, 8 and 10 Gy). Cell proliferation,cell-cycle distribution and clonogenic survival were analyzed through cell counting,MTT,colony formation assay,and flow cytometry,respectively.Results After irradiation of different doses,the growth inhibition rates in C225 group were higher than control (t =- 15.6 - -3.0,P＜0.05),the radiobiological parameters (D0,Dq,N,and SF2 ) in C225 group were lower than control so that SER of C225 group was 1.353,and the proportions of G0/G1 cells in C225 group were higher than control ( t =-7.64,-7.89,-4.78,P ＜0.05 ) at 4,6,8 Gy.When the irradiation doses increased,the early phase apoptosis in both groups increased at first and then decreased with the maximum difference at 4 Gy [(7.96±0.36)％ in C225 group and (4.13 ±0.29)％ in control group,t =-12.75,P＜0.01 ].Conclusions C225 has radiosensitization effect on Tca8113 cell line,possible through Go/G1 arrest and induction of apoptosia. Key words: Cetuximab;  Tca8113;  Radiosensitization;  Cell cycle;  Apoptosis