Abstract: Background and purpose: Ovarian cancer is the common gynecological cancer, and the drug resistance of anti-tumor drug was one of major reasons for therapy failure, some studies considered that there is a closed relationship between Gankyrin and drug resistance. In this study, we investigated the effects and mechanisms of Gankyrin silencing on reversing the cisplatin resistance of ovarian cancer drug-resistant SKOV3/DDP cell line. Methods: The expression of Gankyrin in SKOV3 and SKOV3/DDP cells was measured by real-time PCR assay, MTS assay was employed to determine the effect of Gankyrin on SKOV3/DDP sensitivity to cisplatin, apoptosis rate and intracellular concentration of rhodamine-123 (Rh-123) were determined by flow cytometry, the expression of multidrugs resistant protein MDR1, Caspase-3/8, Survivin and Bcl-2 were determined by Western blot and real-time PCR. The phosphorylation of AKT and expression of p53, NF-κB and PTEN were analyzed by Western blot assay. Results: The expression of Gankyrin was increased in SKOV3/DDP cells, Gankyrin silencing was able to increase the cisplatin sensitivity of SKOV3/DDP. Before and after gene silencing, the reverse folds (RF) to cisplatin were 1.81 and 2.45, respectively, the intracellular levels of Rh-123 were 1.73 and 2.42 fold, the apoptosis rates were 2.23 and 4.23 fold, the expressions of MDR1, Survivin and Bcl-2 were downregulated, the mRNA expressions of MDR1 were 62.8% and 21.6%, the mRNA expressions of Survivin were 24.5% and 10.3%, the mRNA expressions of Bcl-2 were 47.5% and 18.4%, the levels of Caspase-3/8, p53 and PTEN were elevated, phosphorylation of AKT and expression of NF-kB were downregulated compared with control group. Conclusion: Gankyrin silencing was able to reverse the cisplatin resistance of SKOV3/DDP cells by inhibiting the drug efflux and promoting cell apoptosis, the PTEN/AKT/NF-κB/p53 may be the key pathway.

Key words: Gankyrin gene, Ovarian cancer, Cisplatin resistant