Figure 1.

Drug toxicity. A. L540 cell growth inhibition measured by MTS assay after 72 hours treatment with vorinostat (vor) or two different aurora kinase inhibitors, MK-0457 and MK-5108. B. Apoptotic response of L540 cells at 48 and 72 hours, measured by Annexin-V assay. Drug treatments from left to right: 1) DMSO = control for left half of graph; 2) Vor = 1.5 μM vorinostat for left half of graph; 3) 0457 = 0.1 μM MK-0457; 4) Vor + 0457 = 1.5 μM vor + 0.1 μM MK-0457; 5) DMSO = control for right half of graph; 6) Vor = 1.5 μM vor for right half of graph; 7) 5108 = 0.1 μM MK-5108; 8) Vor + 5108 = 1.5 μM vor + 0.1 μM MK-5108. Experiments with MK-0457 (left of dotted line) were done separately from those with MK-5108 (right of dotted line), thus average apoptotic values with DMSO (1 and 5) and vorinostat (2 and 6) vary within the range of their standard deviations.

In all graphs, data are average of three experiments and error bars represent standard deviation. Dunnet’s t-test was used to compare all treatments to the corresponding vorinostat treatment (for panel B comparisons were made with vorinostat values on appropriate half of the graph). * = p < 0.05