Figure 4

Cytotoxic effect of specific ABCB1 inhibitor verapamil. The AMO-1 cell line and its derivatives adapted to bortezomib (AMO-BTZ) and carfilzomib (AMO-CFZ) have been cultured in the presence of 5 μm verapamil and bortezomib/carfilzomib (Btz/Cfz) for 5 days and viability was assessed by MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) test. Absorbance values of treated cells were normalized to the controls without specific inhibitors. Data are presented as a mean±s.d. of three independent replicates.