Author: Becerra E, Berumen L, Soto-Ontiveros V, García-Alcocer G.
Multidrug resistance protein 4 (MRP4) has been related to leukemia, and its overexpression is one of the main causes of chemoresistance. 6-mercaptopurine (6-MP) is a chemotherapeutic drug, but being a substrate of MRP4 decreases its chemotherapeutic efficacy. Using the CytoSMART Exact (formerly known as the Corning Cell Counter), Becerra et al. determined that MRP4 inhibitor ceefourin-1 enhanced the antiproliferative and apoptotic effect of 6-MP in leukemic Jurkat cells, but not in normal lymphoblasts. Altogether, ceefourin-1 and 6-MP cooperate to trigger apoptosis in leukemic cells, thereby counteracting 6-MP’s chemoresistance activity.