MicroRNA expression profiles of drug-resistance breast cancer cells and their exosomes

// Shanliang Zhong 1 , Xiu Chen 2 , Dandan Wang 2 , Xiaohui Zhang 1 , Hongyu Shen 2 , Sujin Yang 2 , Mengmeng Lv 2 , Jinhai Tang 2 , Jianhua Zhao 1 1 Center of Clinical Laboratory Science, Jiangsu Cancer Hospital Affiliated to Nanjing Medical University, Nanjing 210009, China 2 Department of General Surgery, Jiangsu Cancer Hospital Affiliated to Nanjing Medical University, Nanjing 210009, China Correspondence to: Jianhua Zhao, e-mail: seuzsl@163.com , jhzhao2838@sina.com Keywords: microvesicles, breast, cancer, chemoresistance, microRNA Received: December 02, 2015 Accepted: February 11, 2016 Published: February 18, 2016 ABSTRACT Exosomes have been shown to transmit drug resistance through delivering miRNAs. We aimed to explore their roles in breast cancer. Three resistant sublines were established by exposing parental MDA-MB-231 cell line to docetaxel, epirubicin and vinorelbine, respectively. Preneoadjuvant chemotherapy biopsies and paired surgically-resected specimens embedded in paraffin from 23 breast cancer patients were collected. MiRNA expression profiles of the cell lines and their exosomes were evaluated using microarray. The result showed that most miRNAs in exosomes had a lower expression level than that in cells, however, some miRNAs expressed higher in exosomes than in cells, suggesting a number of miRNAs is concentrated in exosomes. Among the dysregulated miRNAs, 22 miRNAs were consistently up-regulated in exosomes and their cells of origin. We further found that 12 of the 22 miRNAs were significantly up-regulated after preneoadjuvant chemotherapy. Further study of the role of these 12 miRNAs in acquisition of drug resistance is needed to clarify their contribution to chemoresistance.