Exosomal Transfer Of Cisplatin-Induced miR-425-3p Confers Cisplatin Resistance In NSCLC Through Activating Autophagy

Abstract

Yuzhu Ma,1,* Daolu Yuwen,2,* Jingwei Chen,1 Bingfeng Zheng,1 Jian Gao,1 Minmin Fan,1 Wenwen Xue,1 Yixuan Wang,1 Wuhao Li,1 Yongqian Shu,3 Qiang Xu,1 Yan Shen1 1State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210093, People’s Republic of China; 2Department of Oncology, Nanjing First Hospital, Nanjing Medical University, Nanjing 210006, People’s Republic of China; 3Department of Clinical Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, People’s Republic of China*These authors contributed equally to this workCorrespondence: Qiang Xu; Yan ShenState Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, 22 Han Kou Road, Nanjing 210093, People’s Republic of ChinaTel/Fax [phone]Email [email protected]; [email protected]: Exosomes are important mediators of intercellular communication. Previously, we characterized circulating exosomal miR-425-3p as a non-invasive prognostic marker for predicting clinical response to platinum-based chemotherapy in patients with non-small cell lung cancer (NSCLC).Methods: Circulating exosomal miR-425-3p was validated by qRT-PCR in paired serum samples from NSCLC patients during the course of platinum-based chemotherapy. Cell coculture was performed to examine the effects of exosomal miR-425-3p on the sensitivity of recipient A549 cells to cisplatin. Using bioinformatics, ChIP and luciferase reporter assays, the transcription factor essential for miR-425-3p expression was identified. Autophagic activity in the recipient cells was determined by Western blot and fluorescence microscopy.Results: Higher levels of exosomal miR-425-3p were found in serum samples from the patients in tolerance versus those at baseline. An upward trend in the expression of circulating exosomal miR-425-3p was revealed during chemotherapy. Furthermore, the expression of exosomal miR-425-3p could be induced by cisplatin in NSCLC cells. Exosomes isolated from either cisplatin-treated or cisplatin-resistant NSCLC cells conferred chemoresistance to sensitive A549 cells in a miR-425-3p-dependent manner. Cisplatin-induced c-Myc was found to directly bind the miR-425-3p promoter and transactivated its expression. Exosomal miR-425-3p facilitated autophagic activation in the recipient cells by targeting AKT1, eventually leading to chemoresistance.Discussion: Our results suggest that apart from a prognostic marker of treatment response, exosomal miR-425-3p might be a potential dynamic biomarker to tailor cisplatin resistance in NSCLC patients during the treatment and represent a promising therapeutic target for therapy-resistant NSCLC.Keywords: exosomes, miR-425-3p, NSCLC, chemoresistance, platinum-based chemotherapy, autophagy  

Keywords

• exosomes
• miR-425-3p
• NSCLC
• chemoresistance
• platinum-based chemotherapy
• autophagy