Effect of magnetic nanoparticles of Fe(3)O(4) and 5-bromotetrandrine on reversal of multidrug resistance in K562/A02 leukemic cells

This study aims to evaluate the multidrug resistance (MDR) reversal activity by magnetic nanoparticles of Fe(3)O(4) (MNPs-Fe(3)O(4)) and 5-bromotetrandrine (BrTet) MDR cell line K562/A02 solitarily or symphysially. The proliferation of K562 and K562/A02 cells and the cytotoxicity on peripheral blood mononuclear cells (PMBCs) were evaluated by MTT assay. Cellular accumulation of daunorubicin (DNR) was analyzed by flow cytometry. Real-time polymerase chain reaction and Western blotting analyses were performed to examine the mRNA and protein levels of mdr1, respectively. The results showed that the combination of MNPs-Fe(3)O(4) and BrTet with effective concentrations significantly increased cytotoxicity against MDR cell line K562/A02. Both BrTet and MNPs-Fe(3)O(4) increased the intracellular DNR accumulation in the K562/A02 cell line, and downregulated the level of mdr1 gene and expression of P-glycoprotein. Furthermore, the combination did not have significant cytotoxicity in PMBCs. We propose that MNPs-Fe(3)O(4) conjugated with DNR and BrTet probably have synergetic effects on MDR reversal.