Down-regulation of miR-223 reverses epithelial-mesenchymal transition in gemcitabine-resistant pancreatic cancer cells

Abstract

// Jia Ma 1, 2 , Binbin Fang 3 , Fanpeng Zeng 3 , Cong Ma 3 , Haijie Pang 3 , Long Cheng 4 , Ying Shi 2 , Hui Wang 3 , Bin Yin 1 , Jun Xia 2 , Zhiwei Wang 1 1 The Cyrus Tang Hematology Center and Collaborative Innovation Center of Hematology, Jiangsu Institute of Hematology, The First Affiliated Hospital, Soochow University, Suzhou 215123, China 2 Department of Biochemistry and Molecular Biology, Bengbu Medical College, Anhui 233030, China 3 Research Center of Clinical Laboratory Science, Bengbu Medical College, Anhui 233030, China 4 Department of Clinical Laboratory, Yijishan Hospital, Wannan Medical College, Wuhu 241000, Anhui, China Correspondence to: Zhiwei Wang, e-mail: zwang6@bidmc.harvard.edu Jun Xia, e-mail: xiajunbbmc@126.com Bin Yin, e-mail: yinbin@suda.edu.cn Keywords: Gemcitabine, miR-223, EMT, invasion, pancreatic cancer Received: October 01, 2014      Accepted: November 08, 2014      Published: December 31, 2014 ABSTRACT Recent studies have demonstrated that acquisition of epithelial-to-mesenchymal transition (EMT) is associated with drug resistance in pancreatic cancer cells; however, the underlying mechanisms are not fully elucidated. Emerging evidence suggests that microRNAs play a crucial role in controlling EMT. The aims of this study were to explore the potential role of miR-223 in governing EMT in gemcitabine-resistant (GR) pancreatic cancer cells. To achieve this goal, real-time reverse transcription-PCR and western blot analysis were used to validate whether GR cells acquired EMT in AsPC-1 and PANC-1 cells. Invasion, migration, and detachment assays were performed to further identify the EMT characteristics in GR cells. The miR-223 inhibitor was used to determine its role in GR-induced EMT. We found that GR cells acquired EMT features, which obtained elongated fibroblastoid morphology, decreased expression of epithelial marker E-cadherin, and up-regulation of mesenchymal markers. Furthermore, we observed that GR cells are associated with high expression of miR-223. Notably, inhibition of miR-223 led to the reversal of EMT phenotype. More importantly, miR-223 governs GR-induced EMT in part due to down-regulation of its target Fbw7 and subsequent upregulation of Notch-1 in pancreatic cancer. Our study implied that down-regulation of miR-223 could be a novel therapy for pancreatic cancer.