Differential expression and response to arsenic stress of MRPs and ASAN1 determine sensitivity of classical multidrug-resistant leukemia cells to arsenic trioxide.

•The expression of arsenic transporters, MRP1, MRP2 and ASNA1, correlates negatively with leukemia MDR cells’ ATO-sensitivity.•ATO enhances and inhibits the transporters’ expression in arsenic-resistant and -sensitive leukemia MDR cells, respectively.•The transporters’ expression and response to arsenic stress determine leukemia MDR cells’ ATO-sensitivity.