Table 1. Summary of clonogenic assay results.
| Cell line | Treatment | Clonogenic assays performed (n) | Mean LD50 (+/–SEM) |
Mean DRF50 (+/–SEM) |
2-way ANOVA |
|---|---|---|---|---|---|
| VH-64 | Doxorubicin Doxorubicin + NU7441 |
4 | 12.2 nM (1.3) 5.5 nM (0.26) |
2.2 (0.2) | P < 0.0001 |
| Etoposide Etoposide + NU7441 |
3 | 0.10 μM (0.01) 0.04 μM (0.01) |
2.7 (0.4) | P < 0.0001 | |
| IR IR + NU7441 |
3 | 0.99 Gy (0.24) 0.36 Gy (0.02) |
2.8 (0.7) | P < 0.0001 | |
| TC-71 | Doxorubicin Doxorubicin + NU7441 |
3 | 13.4 nM (2.3) 6.3 nM (0.6) |
2.1 (0.2) | P = 0.0008 |
| Etoposide Etoposide + NU7441 |
3 | 0.28 μM (0.05) 0.04 μM (0.01) |
6.7 (0.8) | P < 0.0001 | |
| IR IR + NU7441 |
3 | 1.32 Gy (0.07) 0.39 Gy (0.02) |
3.4 (0.2) | P < 0.0001 | |
| Temozolomide Temozolomide + rucaparib |
3 | 0.28 (0.09) 0.01 (0.00) |
29 (9) | P < 0.0001 | |
| Camptothecin Camptothecin + rucaparib |
3 | 5.5 nM (0.6) 4.1 nM (0.8) |
1.4 (0.3) | P = 0.2 | |
| Ionizing radiation Ionizing radiation + rucaparib |
4 | 1.08 Gy (0.24) 0.68 Gy (0.07) |
1.7 (0.4) | P = 0.002 | |
| CADO-ES1 | Temozolomide Temozolomide +rucaparib |
3 | 0.33 mM (0.07) 0.02 mM (0.003) |
15 (3) | P < 0.0001 |
| Camptothecin Camptothecin + rucaparib |
2 | 6.0 nM (1.3) 2.9 nM (0.3) |
2.0 (0.2) | P = 0.02 | |
| Ionizing radiation Ionizing radiation + rucaparib |
3 | 1.06 Gy (0.47) 0.74 Gy (0.31) |
1.4 (0.1) | P = 0.08 |
LD50: concentration of drug necessary to inhibit colony formation by 50%. SEM = Standard Error of Mean. DRF = dose reduction factor, calculated by dividing the LD50 results for the cells treated with cytotoxic alone and those of the corresponding cells treated with cytotoxic plus inhibitor.
Summary of all clonogenic assays in Ewing sarcoma cell lines evaluated for combinations of NU7441 (1.0 μM) or rucaparib (0.4 μM) with chemotherapeutic agents or ionizing radiation.