Figure 3.

Reversal of cross-resistance against Aurora kinase-targeting drugs in U-2OS/DX580 and Saos-2/DX580 cell lines. Columns represent the fold increase in VX-680 and ZM447439 sensitivity of cells transfected with scrambled oligonucleotide (SCR), with ABCB1 silencing siRNAs or in the presence of two different doses of the ABCB1 inhibitor CBT-1 (CBT-1 0.5 μM and CBT-1 1 μM). The fold increase in drug sensitivity was calculated by dividing the VX-680 and ZM447439 IC50 values of controls (cell treated with VX-680 or ZM447439 only) by the IC50 values of silenced- or CBT-1-treated cells.