Feng Xiaobin, Zhao Lifen, Gao Shuhang, Song Xiaobo, Dong Weijie, Zhao Yongfu, Zhou Huimin, Cheng Lei, Miao Xiaolong, Jia Li
College of Laboratory Medicine, Dalian Medical University, Dalian 116044, Liaoning Province, China.
Department of Oncology, The First Affiliated Hospital of Dalian Medical University, Dalian 116011, Liaoning Province, China.
Gene. 2016 Mar 10;578(2):232-41. doi: 10.1016/j.gene.2015.12.028. Epub 2015 Dec 14.
Fucosylation is the final step in the glycosylation machinery, which produces glycans involved in tumor multidrug resistance development. MicroRNAs (miRNAs) are endogenous negative regulators of gene expression and have been implicated in most cellular processes of tumors, including drug resistance. This study was undertaken to determine the roles of fucosylation and miR-224-3p in multidrug resistance of human breast cancer cell lines. Comparative analysis revealed differential modification patterns of fucosylation of the fucosylated N-glycans in drug-resistant T47D/ADR cells and sensitive line T47D cells. The expressional profiles of fucosyltransferase genes in two pairs of parental and chemoresistant human breast cancer cell lines showed that FUT4 was up-regulated highly in MDR cell lines. Altered level of FUT4 affected the drug-resistant phenotype of T47D and T47D/ADR cells both in vitro and in vivo. By bioinformatics analysis, we identified FUT4 as one of the miR-224-3p-targeted genes. Further studies showed an inverse relationship between of FUT4 and miR-224-3p in parental and ADR-resistant breast cancer cells, wherein miR-224-3p was downregulated in resistant cells. 3'-UTR dual-luciferase reporter assay confirmed that miR-224-3p directly targeted 3'-untranslation region (3'-UTR) of FUT4 mRNA. In addition, miR-224-3p overexpression sensitized T47D/ADR cells to chemotherapeutics and reduced the growth rate of breast cancer xenografts in vivo. Our results indicate that FUT4 and miR-224-3p are crucial regulators of cancer response to chemotherapy, and may serve as therapeutic targets to reverse chemotherapy resistance in breast cancer.
岩藻糖基化是糖基化机制的最后一步，该机制产生参与肿瘤多药耐药性发展的聚糖。微小RNA（miRNA）是基因表达的内源性负调控因子，并且已涉及肿瘤的大多数细胞过程，包括耐药性。本研究旨在确定岩藻糖基化和miR-224-3p在人乳腺癌细胞系多药耐药中的作用。比较分析揭示了耐药性T47D/ADR细胞和敏感细胞系T47D细胞中岩藻糖基化N-聚糖的岩藻糖基化修饰模式存在差异。两对亲本和化疗耐药的人乳腺癌细胞系中岩藻糖基转移酶基因的表达谱显示，FUT4在多药耐药细胞系中高度上调。FUT4水平的改变在体外和体内均影响T47D和T47D/ADR细胞的耐药表型。通过生物信息学分析，我们确定FUT4是miR-224-3p靶向的基因之一。进一步研究表明，在亲本和对阿霉素耐药的乳腺癌细胞中，FUT4与miR-224-3p呈负相关，其中miR-224-3p在耐药细胞中下调。3'-UTR双荧光素酶报告基因检测证实，miR-224-3p直接靶向FUT4 mRNA的3'-非翻译区（3'-UTR）。此外，miR-224-3p的过表达使T47D/ADR细胞对化疗药物敏感，并降低了体内乳腺癌异种移植物的生长速率。我们的结果表明，FUT4和miR-224-3p是癌症对化疗反应的关键调节因子，并且可能作为逆转乳腺癌化疗耐药性的治疗靶点。
