VE-465 inhibits the Aurora kinases. (A) Immunoblot analysis of whole cell lysates from 1A9 and PTX10 cell lines probed for Aurora-A, Aurora-B and PP2A as a loading control. (B) Paclitaxel-resistant PTX10 and IA9 cells were treated for 48 hours with VE-465. Following treatment, mitotic cells were assessed by staining for Histone H3 phosphorylated on Ser10 (pH3S10), a marker of mitosis and an Aurora-B substrate (green). Nuclear chromatin was visualized with the To-Pro (blue) counter stain to indicate total number of cells. (C) Ten random fields were sampled for each concentration and percentage of pH3S10 positive cells calculated.