Figure 1. Quizartinib enhances uptake of substrates of ABCG2 and ABCB1 in a concentration-dependent manner in cells overexpressing these proteins.

(A) ABCB1 and ABCG2 expression measured by immunoblotting in resistant and parental cell lines. (B) Quizartinib chemical structure. (C) Quizartinib effect on substrate transport by ABCB1 and ABCG2 was measured by comparing cellular fluorescence measured by flow cytometry after uptake of fluorescent substrates of these proteins, DiOC₂(3) and pheophorbide A (PhA), respectively, in the presence and absence of quizartinib in HL60/VCR, K562/ABCB1 cells overexpressing ABCB1 and 8226/MR20 and K562/ABCG2 cells overexpressing ABCG2, with the ABCB1 modulator PSC-833 and ABCG2 modulator fumitremorgin C (FTC) as positive controls. Each bar represents the mean ± SEM of triplicate experiments. D-value is the Kolmogorov-Smirnov statistic and values ≥0.2 are considered significant.