Reversal of Multidrug Resistance by Magnetic Fe3O4 Nanoparticle Copolymerizating Daunorubicin and mdr1-shRNA Expression Vetor in Leukemia Cells.

In many instances, Multidrug resistance (MDR) is mediated by increased expression at the cell surface of the MDR1 gene product, P-glycoprotein (P-gp), a 170-kD energy-dependent efflux pump. The aim of this study was to investigate the potential benefit of combination therapy with magnetic nanoparticle of Fe3O4 (MNP(Fe3O4)) and mdr1-shRNA Expression vetor.in K562/A02 leukemic cells.

To synthesis short hairpin RNA (shRNA)aiming divectly at the target sequence,we choice the 3491-3509,1539-1557and 3103-3121 nucleotide of mdr-1 mRNA as targets. Cloning in the plasmid vetor PGCSilencer-U6-neo-GFP, The recombinant plasmid vetors were called for PGY1-1,PGY1-2 and PGY1-3.The recombinant plasmid vetors were transfected into the cell 1ines K562/A02 by lipofection. After transfected 48 hours,the inhibition of mdr-1mRNA expression and the expression of P-gp was detected by realtime–PCR and Weston-blot, screening the recombinant plasmid vetor which has the most greatest mdr-1 gene inhibition ratio is PGY1-2.Analysis of the reveral ratio of multidrug resistance, the concentration of DNR and the content of mdr-1 gene and P-gp in K562/A02 cell line.

The combination of daunorubicin (DNR) with either MNP(Fe3O4) or PGY1-2 exerted a potent cytotoxic effect on K562/A02 cells, while MNP(Fe3O4) and PGY1-2 cotreatment can synergistically down regulation the expression of mdr-1 gene and the expression of P-gp(P<0.05). The transfection efficiency was 20%; the concentration of DNR in K562/A02 cell line was obviously elevated (P<0.05);the multidrug resistance index of K562/A02 cell line was obviously decreased (P<0.05).

MNP(Fe3O4) and PGY1-2 cotreatment can synergistically reveral multidrug resistance. Thus our in vitro data strongly suggests a potential clinical application of MNP(Fe3O4) and PGY1-2 combination on CML.

No relevant conflicts of interest to declare.