A, Cell lysates of NCI-H1693 cells were collected 48-hours after treating with combinations of MLN8237 and AZD1152 or B, MLN8237 and GSK1070916 and immunoblotted to detect phosphorylated histone H3 and phosphorylated Aurora A, B, C. Paclitaxel was used in both sets of immunoblots as a positive control and β-Actin was used as an internal immunoblotting control. C, NCI-H1693 cells were treated with combinations of MLN8237 and AZD1152 at concentrations selective for their primary targets for four days and cell viability was measured with a CellTiter-Glo assay. D, NCI-H1693 cells were treated with combinations of MLN8237 and AZD1152 at their selective for two days and cell death was measured with a CaspaseGlo 3/7 assay. E, F, Identical assays were repeated with GSK1070916 treatments. G, NCI-H1693 cells were treated with combinations of Aurora A and B/C selective inhibitors for seven days and cell growth was measured with a crystal violet staining assay. H, NCI-H1693 cells were treated with serial concentrations of MLN8237 in combination with serial dilutions of AZD1152 for four days and cell viability was measured with a CellTiter-Glo assay. I, J, Identical assays were repeated with GSK1070916 treatments. Data from CellTiter-Glo and CaspaseGlo 3/7 assays are presented as means of triplicate biological replicates with s.d. Some error bars are smaller than the data symbols. Statistical significance in the figures was assessed by one-way ANOVA and post hoc Dunnett’s multiple comparison tests. ** indicates statistical significance (P<0.01).