Table 4. Combination indices describing the nature of the interaction between gemcitabine, DSF:Cu and ionising radiation.
| SK-N-BE(2c) | |||
|---|---|---|---|
| Affected fraction | Schedule 1 | Schedule 2 | Schedule 3 |
| 0.25 | 2.67 | 2.49 | 2.54 |
| 0.5 | 1.37 | 1.33 | 1.31 |
| 0.75 | 0.82 | 0.81 | 0.81 |
| 0.95 | 0.42 | 0.42 | 0.46 |
| UVW | |||
|---|---|---|---|
| Affected fraction | Schedule 1 | Schedule 2 | Schedule 3 |
| 0.25 | 0.96 | 1.81 | 2.25 |
| 0.5 | 0.82 | 1.10 | 3.36 |
| 0.75 | 0.73 | 0.79 | 5.21 |
| 0.95 | 0.65 | 0.62 | 11.7 |
| SH-SY5Y | |||
|---|---|---|---|
| Affected fraction | Schedule 1 | Schedule 2 | Schedule 3 |
| 0.25 | 2.87 | 4.65 | 3.08 |
| 0.5 | 1.55 | 2.91 | 2.63 |
| 0.75 | 1.11 | 2.17 | 2.86 |
| 0.95 | 0.91 | 1.96 | 4.71 |
| T98G | |||
|---|---|---|---|
| Affected fraction | Schedule 1 | Schedule 2 | Schedule 3 |
| 0.25 | 3.55 | 5.53 | 3.21 |
| 0.5 | 1.69 | 2.13 | 2.80 |
| 0.75 | 1.13 | 1.36 | 3.96 |
| 0.95 | 0.92 | 1.04 | 11.3 |
The clonogenic assay was used to construct radiation survival curves. SK-N-BE(2c): ionising radiation, 1-2-3 Gy, 0.15 μM DSF:Cu, 450 nM gemcitabine; UVW: ionising radiation, 1-2-3 Gy, 0.1 μM DSF:Cu, 20 nM gemcitabine; SH-SY5Y: ionising radiation, 0.5-1-1.5 Gy, 0.05 μM DSF:Cu, 40 nM gemcitabine; T98G: ionising radiation, 1-2-3 Gy, 1 μM DSF:Cu, 50 nM gemcitabine. Combination index analysis was carried out to evaluate the nature of the interaction between ionising radiation, DSF:Cu and gemcitabine following administration schedules 1, 2 and 3.