Figure 5.

Inhibition of transporter-dependent fluorescent reporter dye extrusion from K562/ABCB1 and K562/ABCG2 cells by nilotinib, dasatinib and bosutinib. Concentration-dependent inhibitory potential of tyrosine kinase inhibitors (TKIs) on the ABCB1-dependent extrusion of calcein-AM (A) and ABCG2-dependent extrusion of Hoechst 33342 (B) was tested using K562/ABCB1 and K562/ABCG2 intact cells respectively. Cellular fluorescence was measured by using a spectrofluorometer, and TKI-mediated relative inhibition of dye extrusion was calculated as described in Methods. Data represent the mean of at least three independent experiments; bars represent SD.