Reversal of multidrug resistance of HepG2 by RNAi-mediated gene silence of MDR1 and MRP1

Objective To investigate the in vitro effect of silencing of gene MDR1 and MRP1 by siRNA on multidrug resistance reversal in hepatocellular carcinoma.Methods Plasmid vector of shRNA for gene MDR1 and MRP1 were constructed to transfect the multidrug resistance of hepatocellular carcinoma cell lines.Cells were grouped into control (HepG2),single gene silent (HepG2/MDR-1-si,HepG2/MRP-1-si),and combined gene silent (HepG2/mm-si).Cell cycle and apoptosis were measured by flowcytometry,and the resistance of transfected cells were measured by MTT.Cell activity and cell proliferation can be detected by CCK-8,activity of caspase-3 by A450,MDR1/mRNA and MRP1/mRNA by real-time PCR.Results Cell lines of pSUPER-HepG2/MDR-1-si and pSUPER-HepG2/MRP-1-si were constructed successfully.MRP-1-mRNA of HepG2/mm-si was equal to that of HepG2/MRP-1-si,and MDR-1-mRNA of HepG2/mm-si equals to that of HepG2/MRP-1-si (P ＞ 0.05).Activity of caspase-3 in HepG2/mm-si was higher than that of HepG2/MRP-1-si (14 623.7 ± 338.9 vs.13 215.7 ± 90.6,P ＜ 0.05).Cell activity and cell proliferation in HepG2/mm-si were lower than that of other groups (P ＜ 0.05).The sensitivity of HepG2/MDR-1-si and HepG2/MRP-1-si was higher than that of HepG2/mm-si (1.39-fold vs.1.0-fold,1.58-fold vs.1.0-fold,P ＜ 0.05).Cell count of apoptosis in HepG2/MDR-1-si and HepG2/MRP-1-si was larger than that of HepG2/mm-si (P ＜ 0.01).Conclusion In vitro silence of MDR1 and MRP1 gene by RNA interference can reverse the multidrug resistance of HepG2 cell line. Key words: Hepatocellular carcinoma;  Multidrug resistance;  RNA interference;  Gene silence