Reversal effect of MDR1 and MDR3 gene silencing on resistance of A2780/taxol cells to paclitaxel / 中华妇产科杂志

ABSTRACT

Objective To investigate the reversal effect of MDR1 and MDR3 gene silencing on resistance of A2780/taxol cells to paclitaxel.Methods shRNA plasmid vector specifically targeting MDR1 and MDR3 genes was transfected into A2780/taxol cells.The early stage cell apoptosis and the effect of intracellular rhodamine 123(Rh123)accumulation were detected by flow cytometry(FCM).The late stage cell apoptosis rate was detected by terminal deoxynucleotidyl transferase(TdT)-mediated deoxyuridine triphosphate(dUTP)nick end labeling(TUNEL).The 50% inhibition concentration(IC_(50))of paclitaxel on A2780/taxol cells was determined by methyl thiazolyl tetrazolium(MTT)assay.MDR1 and MDR3 mRNA were assessed by RT-PCR,and caspase-3 protein was detected by western blot.Results After treatment with MDR1 and MDR3 shRNA plasmid vector,early apoptosis rate of A2780/taxol cells was (20.21?0.56)% and(10.87?1.24)%,respectively.MDR1 and MDR3 shRNA could increase cellular Rh123 accumulation(116.6?8.1 and 98.4?3.8,respectively).The late stage apoptosis rates detected by TUNEL displayed the same tendency as FCM results did.The IC_(50)for paclitaxel of A2780/taxol cells was decreased significantly.The mRNA levels of MDR1 and MDR3 in A2780/taxol cells were decreased by (73.3?0.8)% and(51.6?0.4)% of control,and the reduction of MDR1 and MDR3 mRNA was in a time-dependent manner.The expression of caspase-3 protein of MDR1 and MDR3 shRNA vector transfected group in A2780/taxol cells was significantly increased [(80.8?2.6)% and(72.0?4.7)%, respectively ].Conclusion MDR1 and MDR3 gene silencing could recover sensitivity of A2780/taxol cells to paclitaxel and induce cell apoptosis,thus reversing cell resistance to paclitaxel.