Emodin Enhances the Chemosensitivity of Endometrial Cancer by Inhibiting ROS-Mediated Cisplatin-resistance

Background: Endometrial cancer is a common cause of death in gynecological malignancies. Cisplatin is a clinically chemotherapeutic agent. However, drug-resistance is the primary cause of treatment failure. Objective: Emodin is commonly used clinically to increase the sensitivity of chemotherapeutic agents, yet whether Emodin promotes the role of Cisplatin in the treatment of endometrial cancer has not been studied. Method: CCK-8 kit was utilized to determine the growth of two endometrial cancer cell lines, Ishikawa and HEC-IB. The apoptosis level of Ishikawa and HEC-IB cells was detected by Annexin V / propidium iodide double-staining assay. ROS level was detected by DCFH-DA and NADPH oxidase expression. Expressions of drug-resistant genes were examined by real-time PCR and Western blotting. Results: Emodin combined with Cisplatin reduced cell growth and increased the apoptosis of endometrial cancer cells. Co-treatment of Emodin and Cisplatin increased chemosensitivity by inhibiting the expression of drugresistant genes through reducing the ROS levels in endometrial cancer cells. In an endometrial cancer xenograft murine model, the tumor size was reduced and animal survival time was increased by co-treatment of Emodin and Cisplatin. Conclusion: This study demonstrates that Emodin enhances the chemosensitivity of Cisplatin on endometrial cancer by inhibiting ROS-mediated expression of drug-resistance genes.