Fig. 1

Establishment and identification of a radio-resistant cell subline, named CARF. A Schematic diagram shows the construction of CAFR. B The cell morphology of CAFR and CAF. C Radiation cell survival curves for CAF and CAFR. D Expression of the apoptosis-related proteins in CAF and CAFR at different time points detected by western blot after X-Ray irradiation (12 Gy). The band density was quantified using Image J software and normalized to corresponding CAF group. E Irradiation-induced apoptosis in CAF and CAFR cells by flow cytometry analysis (12 Gy). The percentage of apoptotic cells was counted. Similar results were obtained in three independent experiments. Errors bar represent the standard error of the mean (*, p < 0.05; **, p < 0.01; ***, p < 0.001)