Effect of RNAi Silencing MDR1 Gene on the Sensitivity of Multidrug Resistant Actue Promyelocytic Leukemia Cells HT9 to Drugs

Abstract: The study investigated the effects of RNAi silencing MDR1 gene， increase the sensitivity of multidrug resistant actue promyelocytic leukemia cells HT9 to harringtonine and doxorubicin. One short hairpin RNA (small hairpin RNA， shRNA) was designed and constructed into pSilencer2.1-U6 neo plasmid. MDR1 shRNA expression plasmid pSilencer 2.1-U6 neo-MDR1 was constructed and introduced into HT9 cells. MDR1 mRNA was assayed by real-time fluorescent quantitative PCR. The P-gp protein was assayed by Western blot. The pump function of P-gp was assayed by FCM. The sensitivity of cells to drugs were assayed by MTT. The results suggested that pSilencer 2.1-U6 neo-MDR1 expression plasmid was constructed successfully. The results of PCR showed that the shRNA recombinant plasmid had integrated into genome. In HT9/sh-2.1-1 cells， MDR1 mRNA were decreased by 78.84% (P<0.01)， and P-gp protein were decreased by 48.27% (P<0.05); The Rho123 were increased from (10.80±0.58)% to (73.56±1.37)%; The sensitivity of transfected cells to harringtonine and doxorubicin were increased significantly， IC50 were decreased from (2.06±0.15) μmol/L to (0.57±0.01) μmol/L， (4.04±0.17) μmol/L to (1.56±0.05) μmol/L， respectively. So shRNA expression plasmid pSilencer 2.1-U6 neo-MDR1 can permanently inhibit the expression of MDR1 gene stability， and increase the sensitivity of HT9 cells to harringtonine and doxorubicin.

CSTR: 32200.14.cjcb.2012.10.0004