Abstract
OBJECTIVE: 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. METHODS: 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. RESULTS: 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). CONCLUSION: 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.