Cediranib (recentin, AZD2171) reverses ABCB1-and ABCC1-mediated multidrug resistance by inhibition of their transport function

Cediranib (recentin, AZD2171) is an oral small-molecule multiple receptor tyrosine kinases inhibitor. Here we investigate the ability of cediranib to reverse tumor multidrug resistance (MDR) due to overexpression of ABCB1 (P-glycoprotein) and ABCC1 (MRP1) transporters. KBv200,MCF-7/adr, C-A120 and their parental sensitive cell lines KB, MCF-7 and KB-3-1 were used for reversal study. The intracellular accumulations of doxorubicin and rhodamine 123 were determined by flow cytometry. The expressions levels of ABCB1 and ABCC1 were investigated by Western blot and RT-PCR analyses. ATPase activity assay were performed by Luminescence. The functions of ERK in MCF-7/adr were investigated by RNA interference. Cediranib significantly enhanced the sensitivity of ABCB1 or ABCC1 substrates in MDR cells, with no effect found on sensitive cells. However, the expressions of these transporters were not affected and the reversal activity of cediranib was not related to the phosphorylation of AKT or ERK1/2. Further studies showed that cediranib inhibited ATPase activity of ABCB1 (P-glycoprotein) in a dose-dependent manner. Cediranib reverses ABCB1- and ABCC1-mediated MDR by directly inhibiting their drug efflux function. These findings may be useful for cancer combinational therapy with cediranib in the clinic.