Fig. 2

Cell cycle distribution and apoptotic rates of the two cell lines. a – Flow cytometry was performed and data were analyzed using FlowJo 7.6. A representative series of cell cycle FACS histogramsfor C6 cells are shown. The cell cycle distribution (b) and apoptotic rate (c) were assessed. b – The percentage of cells at each stage of the cell cycle are shown for C6 and U251 cells.*p < 0.05, **p < 0.01. c – The apoptotic rate increased with increasing X-ray irradiation. *p < 0.05, **p < 0.01: comparisons with the previous group (e.g., 5 Gy and 1 Gy; 10 Gy and 5 Gy); ^#p < 0.05, ^##p < 0.01: comparisons with the control group. The apoptotic rates of C6 were also compared with those for U251 cells for the same radiation dose. Statistical significance was determined as p < 0.05. This is shown in the bars under the x-axis