Reverse Paclitaxel Resistance by Silencing stathmin and mdr1 in Ovarian Cancer Cells

ObjectiveTo investigate the feasibility of reversing Paclitaxel resistance by RNA interference (RNAi)-mediated suppression of stathmin and mdr1 genes in ovarian cancer cells. MethodsTwo different plasmids with short hairpin RNAs(shRNAs) targeting stathmin and mdr1 were constructed respectively:pGU6-GFP-neo-STMN1 and pGU6-GFP-neo-MDR1.Then they were transfected into a Paclitaxel-resistant ovarian cancer cell line(SKOV3/TAX).The expression levels of mRNA and protein of stathmin and mdr1 were evaluated by Real-time RT-PCR and Western blot analysis.Cell apoptosis was detected in fluorescence microscopy.For assessing multidrug resistance against Paclitaxel,cell proliferation assays were performed by cell counting kit-8(CCK-8) and IC50 was calculated. Results The RNAi plasmid vectors were constructed successfully. Real-time RT-PCR and Western blot demonstrated that mRNAs and proteins of stathmin and mdr1 were markedly downregulated after transfection ( P<0.05). The cotransfected groups showed most cell apoptosis under fluorescence microscopy.CCK-8 results showed that the efficiency of reversing Paclitaxel resistance was best in the cotransfected group. Conclusion These studies indicated that targeted RNAi can inhibit stathmin and mdr1 effectively, and reverse Paclitaxel resistance in SKOV3/TAX cell in vitro.