Ma Jia, Fang Binbin, Zeng Fanpeng, Ma Cong, Pang Haijie, Cheng Long, Shi Ying, Wang Hui, Yin Bin, Xia Jun, Wang Zhiwei
The Cyrus Tang Hematology Center and Collaborative Innovation Center of Hematology, Jiangsu Institute of Hematology, The First Affiliated Hospital, Soochow University, Suzhou 215123, China.
Department of Biochemistry and Molecular Biology, Bengbu Medical College, Anhui 233030, China.
Oncotarget. 2015 Jan 30;6(3):1740-9. doi: 10.18632/oncotarget.2714.
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.
近期研究表明，上皮-间质转化（EMT）的获得与胰腺癌细胞的耐药性相关；然而，其潜在机制尚未完全阐明。新出现的证据表明，微小RNA在控制EMT中起关键作用。本研究的目的是探讨miR-223在吉西他滨耐药（GR）胰腺癌细胞中调控EMT的潜在作用。为实现这一目标，采用实时逆转录PCR和蛋白质印迹分析来验证AsPC-1和PANC-1细胞中的GR细胞是否获得了EMT。进行侵袭、迁移和脱离实验以进一步确定GR细胞中的EMT特征。使用miR-223抑制剂来确定其在GR诱导的EMT中的作用。我们发现GR细胞获得了EMT特征，表现为成纤维细胞样形态拉长、上皮标志物E-钙黏蛋白表达降低以及间充质标志物上调。此外，我们观察到GR细胞与miR-223的高表达相关。值得注意的是，抑制miR-223导致EMT表型逆转。更重要的是，miR-223部分通过下调其靶标Fbw7并随后上调胰腺癌中的Notch-1来调控GR诱导的EMT。我们的研究表明，下调miR-223可能是一种治疗胰腺癌的新方法。
