Figure 4. Sensitivity of UKF-NB-3 and its ABCB1-expressing sub-lines with acquired resistance to SNS-032 (UKF-NB-3^rSNS-032^300nM), doxorubicin (UKF-NB-3^rDOX²⁰), etoposide (UKF-NB-3^rETO¹⁰⁰), and vincristine (UKF-NB-3^rVCR¹⁰) to the non-ABCB1 substrate cisplatin, and sensitivity of the non ABCB1-expressing cisplatin-resistant UKF-NB-3 sub-line UKF-NB-3^rCDDP¹⁰⁰⁰ to the ABCB1 substrates SNS-032, doxorubicin, etoposide, and vincristine.

(A) Cisplatin concentrations that reduce cell viability by 50% (IC₅₀) and relative cisplatin sensitivity in drug-resistant UKF-NB-3 sub-lines relative to UKF-NB-3, numerical values are presented in Supplementary Table S1D. *P < 0.05 relative to UKF-NB-3; (B) IC₅₀ values for SNS-032, doxorubicin, etoposide, or vincristine in UKF-NB-3 or UKF-NB-3^rCDDP¹⁰⁰⁰ cells, numerical values are presented in Supplementary Table S1E. *P < 0.05 relative to UKF-NB-3