Reversal of Multi-Drug Resistance by Vector-Based-ShRNA-Mdr1 In Vitro and In Vivo

摘要

In order to investigate the effects of vector-based hairpin small interference RNA(shRNA) on the reversal of multi-drug resistance(mdr) of A2780/Taxol cells,a novel vector pEGFP-H1/mdr1 containing mdr1-shRNA targeting at position 2943-2963 of mdr1 was designed and synthesized.Subsequently,A2780/Taxol cells were transfected with pEGFP-H1/mdr1,and the expression of mdr1 mRNA and P-gp was detected by using RT-PCR and Western blot respectively.MTT was used to measure the 50% inhibition concentration(IC50) of Taxol to A2780/Taxol cells.The results showed that at the 24th and 48th h after transfection,the expression of mdr1 mRNA was decreased to(52.1±1.0)% and(0.01±1.7)%,and that of P-gp decreased to(88.3±2.1)% and 0%,respectively.At the 48th h after transfection,the relative reversal rate of A2780/Taxol cells to Taxol was 69.54%.In vivo,the nude mice xenografts were injected with pEGFP-H1/mdr1,and then administrated Taxol.The tumor volume in pEGFP-H1/mdr1-transfected group was significantly reduced as compared with that in blank control group or pEGFP-H1-transfected group(807.20±103.16 vs 1563.78±210.54 or 1480.78±241.24 mm3,both P<0.01).These results suggested that transfection of pEGFP-H1/mdr1 could efficiently down-regulate the expression of mdr1 mRNA and P-gp in A2780/Taxol cells,and effectively restore the sensitivity of A2780/Taxol cells to Taxol both in vitro and in vivo.