Silencing multidrug resistance-associated proteins 2 gene by siRNA reversed multidrug resistance in hepatocellular carcinoma cells HepG2

Objective To investigate the suppression of multidrug resistance-associated proteins 2 (MRP2) and the protein product induced by small interfering RNA (siRNA) in the multidrug-resistant (MDR) hepatocellular carcinoma (HCC) cell line HepG2/adriamycin (ADM) and the effect on MDR.Methods MDR HepG2/ADM cells were developed by exposing parental cells to stepwise increasing concentrations of ADM from 0.1 to 2.0 mg/L.MRP2 targeted small interfering RNA fragments were designed and synthesized,and transfected into MDR HepG2/ADM cells.The suppression of MRP2 and the protein product were detected by using real-time reverse transcription quantitative poiymerase chain reaction (RT-qPCR) and Western blotting at 24 h after transfection.Methyl thiazol tetrazolium (MTT) assay was used to determine drug sensitivity of HepG2/ADM cells before and after transfection based on the results of IC50.Results MTT assay showed that the IC50 values of HepG2/ADM against ADM,5-fluorouracil,vincristine,and oxaliplatin were 0.3204,3.8002,0.2014 and 0.1221 respectively.siRNA transfection significantly inhibited the expressiou of MRP2 mRNA and protein in HepG2/ADM cells ( P ＜ 0.05).After MRP2-siRNA transfection,the IC50 values of HepG2/ADM against ADM,5-fluorouracil,vincristine,and oxaliplatin were decreased significantly (0.1023,1.4417,0.0452 and 0.0268,respectively).Conclusion Silencing MRP2 genes by siRNA can reverse MDR of HepG2/ADM cells.MRP2 is closely related to MDR of HepG2/ADM HCC cells and silencing MRP2 might improve the sensitivity of resistant cells to chemotherapeutic drugs. Key words: Carcinoma, hepatocellular; Multidrug resistance; Multidrug resistance-associated proteins 2; Small interfering RNA