Parameters describing exponential decay curves generated by nonlinear regression for each posttreatment kinetics
| Parameters | DMSO | DNA-PKi | ATMi | DNA-PKi + ATMi |
| Plateau ± SD (%) | 10.71 ± 3.25 | 50.87 ± 8.79 | 4.56 ± 6.99 | 65.21 ± 8.31 |
| Significance of difference to control | − | P < 0.01 | ns | P < 0.001 |
| Corresponding p-value | − | 0.0018 | 0.2393 | 0.0005 |
| Significance of difference to DNA-PKi | − | − | P < 0.01 | ns |
| Corresponding p-value | − | − | 0.002 | 0.1094 |
| K ± SD | 0.0436 ± 0.0057 | 0.0254 ± 0.0138 | 0.0178 ± 0.0036 | 0.0176 ± 0.0115 |
| Significance of difference to control | − | ns | P < 0.01 | P < 0.05 |
| Corresponding p-value | − | 0.103 | 0.0027 | 0.0248 |
| Significance of difference to DNA-PKi | − | − | ns | ns |
| Corresponding p-value | − | − | 0.4114 | 0.496 |
| Half-life (minutes; ln(2)/K) | 15.91 | 27.29 | 38.83 | 39.28 |
| Regression R2 | 0.9463 | 0.4856 | 0.8888 | 0.4073 |
| Parameters | DMSO | DNA-PKi | ATMi | DNA-PKi + ATMi |
| Plateau ± SD (%) | 10.71 ± 3.25 | 50.87 ± 8.79 | 4.56 ± 6.99 | 65.21 ± 8.31 |
| Significance of difference to control | − | P < 0.01 | ns | P < 0.001 |
| Corresponding p-value | − | 0.0018 | 0.2393 | 0.0005 |
| Significance of difference to DNA-PKi | − | − | P < 0.01 | ns |
| Corresponding p-value | − | − | 0.002 | 0.1094 |
| K ± SD | 0.0436 ± 0.0057 | 0.0254 ± 0.0138 | 0.0178 ± 0.0036 | 0.0176 ± 0.0115 |
| Significance of difference to control | − | ns | P < 0.01 | P < 0.05 |
| Corresponding p-value | − | 0.103 | 0.0027 | 0.0248 |
| Significance of difference to DNA-PKi | − | − | ns | ns |
| Corresponding p-value | − | − | 0.4114 | 0.496 |
| Half-life (minutes; ln(2)/K) | 15.91 | 27.29 | 38.83 | 39.28 |
| Regression R2 | 0.9463 | 0.4856 | 0.8888 | 0.4073 |
For each condition, the number of Ku foci 5 min after IR was set to 100% and considered as t = 0 min. Nonlinear regressions were then applied using Prism v6.0b to generate curves fitting to a one-phase exponential decay using the formula %RemainingFoci(t) = (100 − Plateau) × exp(−K × t) + Plateau. Minus signs indicate not applicable. K, decay constant; ns, no significant difference.