Short hairpin RNA-mediated MDR1 gene silencing increases apoptosis of human ovarian cancer cell line A2780/taxol

Abstract

Recurrent ovarian cancer is often resistant to drugs such as paclitaxel. Short hairpin RNA (shRNA) targeting MDR1, a gene involved in the process of drug resistance, may be a promising strategy to overcome drug resistance. Construction and identification of eukaryotic expression plasmid of shRNA targeting on MDR1 gene. The plasmid was transiently transfected into human ovarian cancer cell line A2780/Taxol. Apoptosis was determined by flow cytometry using annexin V-FITC/PI double labeling. Expression of MDR1 mRNA was detected by quantitative polymerase chain reaction (qPCR) and P-glycoprotein expression was detected using Western blot. The IC50 of paclitaxel in MDR1shRNA-transfected group was significantly reduced (1.986±0.153) μmol/ml as compared with that in negative control (5.246±0.107) μmol/ml and empty vector-transfected group (5.212±0.075) μmol/ml (P<0.05). The percent of the relative reverse sensitivity to paclitaxel on A2780/Taxol cells was 67.1%, and the apoptotic rate was significantly increased [(6.977±0.333)%] compared with control [(1.637±0.111)%] and empty vector-transfected group [(1.663±0.114)%] (P<0.05). Expressions of MDR1 mRNA and P-glycoprotein were significantly reduced compared with control (P<0.05). The present study demonstrated that the eukaryotic expression plasmid of shRNA targeting on MDR1 inhibited the expression of MDR1 effectively, thus enhance the sensitivity of A2780/Taxol cells to paclitaxel.