Table 1. NAMPT is a suitable target in both monolayer tumor cells and tumorspheres cytotoxic analysis of the NAMPT inhibitor FK866 and TMZ shows IC50s of SF268 and U251MG alone or in combination in monolayer culture or Tumorsphere specific assays.
| Monolayer - Monotherapy | ||||
|---|---|---|---|---|
| SF268 | U251MG | |||
| FK866 (nM ± SD) | TMZ (μM ± SD) | FK866 (nM ± SD) | TMZ (μM ± SD) | |
| sh | 8.3 ± 0.8 | 163.2 ± 2.2 | 22.3 ± 0.6 | 203.5 ± 4.8 |
| v | 5.2 ± 0.9 | 165.4 ± 1.9 | 20.7 ± 0.7 | 194.1 ± 3.4 |
| NAMPT | 2.8 ± 0.3 | 173.6 ± 2.1 | 15.3 ± 1.2 | 201.4 ± 5.3 |
| Tumorspehres - Monotherapy | ||||
|---|---|---|---|---|
| SF268 | U251MG | |||
| FK866 (nM ± SD) | TMZ (μM ± SD) | FK866 (nM ± SD) | TMZ (μM ± SD) | |
| sh | 9.5 ± 0.9 | 174.1 ± 3.6 | 27.3 ± 1.4 | 221.4 ± 3.2 |
| v | 6.1 ± 1.2 | 169.8 ± 2.1 | 18.6 ± 1.9 | 224.5 ± 1.7 |
| NAMPT | 2.5 ± 0.4 | 173.3 ± 3.2 | 11.3 ± 1.3 | 221.6 ± 4.7 |
| Monolayer - Combined | ||
|---|---|---|
| SF268 | U251MG | |
| FK866 + 100 μM TMZ (nM ± SD) | FK866 + 150 μM TMZ (nM ± SD) | |
| sh | 6.1 ± 0.2 | 19.4 ± 0.7 |
| v | 2.4 ± 0.4 | 14.3 ± 1.3 |
| NAMPT | 0.2 ± 0.4 | 5.1 ± 1.4 |
| Tumorspheres - Combined | ||
|---|---|---|
| SF268 | U251MG | |
| FK866 + 100 μM TMZ (nM ± SD) | FK866 + 150 μM TMZ (nM ± SD) | |
| sh | 7.3 ± 0.7 | 25.4 ± 1.8 |
| v | 4.2 ± 0.3 | 17.1 ± 0.9 |
| NAMPT | 0.5 ± 1.1 | 7.2 ± 0.7 |
For the assay, 5 × 103 cells were seeded and then treated with the different compound at 11 different concentrations at 1/3 dilutions after 24 hours. Then, 96 hours later, cell viability was measured via MTT assay and validated independently by crystal violet staining. IC50 was calculated as the concentration allowing 50% survival compared to day 0 controls. Combination experiments were performed testing 11 different concentrations at 1/3 dilutions of FK866 and maintaining same suboptimal concentration of TMZ (as indicated) in all tested points.