| Ovarian cancer is one of the most common malignant tumors of the female reproductive system.Cytoreductive surgery,followed by combination chemotherapy,was the most common management for ovarian cancer patients,but distant metastasis and drug-resistance are the major factors affecting prognosis.Therefore,studying the mechanisms of tumor cells distant metastasis and drug resistance may provide a new perspective for the treatment of ovarian cancer.NANOG is a key transcription factor that is overexpressed in various cancers,which plays an important role in the pathogenesis of them.NANOG overexpression is associated with highly tumorigenic,drug-resistant and poor prognosis.We determined whether NANOG was associated with EMT and chemoresistance in epithelial ovarian cancer cells.NANOG was high expressed in epithelial ovarian cancer.NANOG downregulation increased the expression of E-cadherin and decreased the expression of vimentin,β-catenin and Snail.Furthermore,cell migration and invasion abilities decreased.The multidrug resistant genes MDR-1 and GST-π were also downregulated after NANOG downregulation.The cells transfected with si-NANOG plasmid were more sensitive to cisplatin than cells transfected with empty vector.The data also demonstrated that Stat3 was correlated with NANOG mediated EMT and drug resistance.Silencing Stat3 expression with its inhibitor could abrogated NANOG mediated EMT changes and increased the cells’ sensitivity to chemotherapy.These results suggest that NANOG mediates EMT and drug resistance through activation of the Stat3 pathway in epithelial ovarian cancer.Thus,NANOG may be a new target for future therapeutic treatment in epithelial ovarian cancer. |
