MicroRNA-708 Suppresses Cell Proliferation and Enhances Chemosensitivity of Cervical Cancer Cells to cDDP by Negatively Targeting Timeless

Abstract

Xinwei Zou,1–3,* Chenjie Zhu,1–3,* Lin Zhang,1 Yi Zhang,1 Fengqing Fu,2,3 Youguo Chen,1–3 Jinhua Zhou1–3 1Department of Obstetrics and Gynecology, The First Affiliated Hospital of Soochow University, Suzhou, People’s Republic of China; 2Clinical Research Center of Obstetrics and Gynecology, Jiangsu Key Laboratory of Clinical Immunology, Soochow University, Suzhou, People’s Republic of China; 3Jiangsu Institute of Clinical Immunology, The First Affiliated Hospital of Soochow University, Suzhou, People’s Republic of China*These authors contributed equally to this workCorrespondence: Jinhua Zhou; Youguo ChenDepartment of Obstetrics and Gynecology, The First Affiliated Hospital of Soochow University, 188 Shizi Road, Suzhou 215006, People’s Republic of ChinaTel [phone]Fax [phone]Email [email protected]; [email protected]: Cervical cancer is the fourth most common cause of cancer-associated mortality in women worldwide. Previous studies have reported that microRNAs (miRNAs) are involved in multiple biological aspects of cancer progression by regulating gene expression. Here, we investigated the role of microRNA-708 (miR-708) in cervical cancer.Methods: The expression levels of miR-708 in cervical cancer tissues and paired-normal cervical tissues were tested by quantitative polymerase chain reaction (qPCR). The interaction between miR-708 and Timeless was identified by bioinformatics method, dual-luciferase reporter assay, and Western blotting. The effects of over-expression of miR-708 on cell proliferation and cisplatin sensitivity were determined by Cell Counting Kit-8 (CCK-8) and colony formation assay. Cell cycle and apoptosis were analyzed by flow cytometry. DNA damage induced by over-expression of miR-708 was determined by comet assay. Expression levels of the genes involved in repair of DNA damage were analyzed by Western blotting.Results: MiR-708 was down-regulated in cervical cancer tissues compared with paired-normal cervical tissues. By bioinformatics method, Western blotting, and dual-luciferase reporter assay, we found that Timeless was a direct target of miR-708. Furthermore, miR-708 suppressed cellular viability, colony formation, promoted apoptosis, and induced DNA damage levels. MiR-708 also enhanced chemosensitivity of cervical cancer cells to cDDP via impairing the ATR/CHK1 signaling pathway.Conclusion: We conclude that miR-708 suppresses cell proliferation, facilitates cisplatin efficacy, and impairs DNA repair pathway in cervical cancer cells. These results demonstrate that miR-708 might be a candidate therapeutic target for future cervical cancer therapy.Keywords: cervical cancer, miR-708, Timeless, repair of DNA damage, chemotherapy

Keywords

• cervical cancer
• mir-708
• timeless
• repair of dna damage
• chemotherapy