Zhu Yong, Yang Leiyan, Chong Qing-Yun, Yan Hong, Zhang Weijie, Qian Wenchang, Tan Sheng, Wu Zhengsheng, Lobie Peter E, Zhu Tao
Hefei National Laboratory for Physical Sciences at Microscale, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, People's Republic of China.
Cancer Science Institute of Singapore and Department of Pharmacology, National University of Singapore, Singapore, Singapore.
Cancer Manag Res. 2019 Jul 1;11:5983-6001. doi: 10.2147/CMAR.S207084. eCollection 2019.
Evidence indicates that long noncoding RNAs (lncRNA) possess important roles in various cellular processes and that dysregulation of lncRNAs promotes tumor progression. However, the expression patterns and biological functions of many specific lncRNAs in breast cancer remain to be determined. Quantitative real-time polymerase chain reaction was performed to detect Linc00460, miR-489-5p and FGF7 expression. Protein levels were determined using Western blot. MTT and colony formation assay were used to measure cell proliferation. Transwell assays were conducted to determine cell migration and invasion. Luciferase reporter assays were carried out to assess the interaction between miR-489-5p and Linc00460 or FGF7. Biotin pull-down assay was used to detect the direct interaction between miR-489-5p and Linc00460. In vivo experiments were performed to measure tumor formation and lung metastasis. We demonstrated that lncRNA Linc00460 was upregulated in breast cancer, and its expression level was positively associated with lymphatic metastasis and poor overall survival. Forced expression of Linc00460 increased, whereas Linc00460 silencing decreased, breast cancer cell viability, migration and invasion both in vitro and in vivo. Linc00460 was identified as a direct target of miR-489-5p, which further targeted FGF7 and exerted oncogenic functions in breast cancer. Mechanistically, Linc00460 served as a competing endogenous RNA of FGF-7 mRNA by sponging miR-489-5p, resulting in upregulated FGF7 expression and AKT activity. Notably, forced expression of miR-489-5p abrogated Linc00460-mediated oncogenic behavior and activation of the FGF7-AKT pathway in breast cancer cells. We have demonstrated that Linc00460 promotes breast cancer progression partly through the miR-489-5p/FGF7/AKT axis.
有证据表明，长链非编码RNA（lncRNA）在各种细胞过程中发挥着重要作用，lncRNAs的失调会促进肿瘤进展。然而，许多特定lncRNAs在乳腺癌中的表达模式和生物学功能仍有待确定。采用定量实时聚合酶链反应检测Linc00460、miR-489-5p和FGF7的表达。使用蛋白质印迹法测定蛋白质水平。采用MTT和集落形成试验检测细胞增殖。进行Transwell试验以确定细胞迁移和侵袭。进行荧光素酶报告基因试验以评估miR-489-5p与Linc00460或FGF7之间的相互作用。使用生物素下拉试验检测miR-489-5p与Linc00460之间的直接相互作用。进行体内实验以检测肿瘤形成和肺转移。我们证明lncRNA Linc00460在乳腺癌中上调，其表达水平与淋巴转移和总体生存率差呈正相关。Linc00460的过表达增加，而Linc00460沉默则降低乳腺癌细胞在体外和体内的活力、迁移和侵袭。Linc00460被确定为miR-489-5p的直接靶点，miR-489-5p进一步靶向FGF7并在乳腺癌中发挥致癌功能。机制上，Linc00460通过海绵化miR-489-5p作为FGF-7 mRNA的竞争性内源性RNA，导致FGF7表达上调和AKT活性增加。值得注意的是，miR-489-5p的过表达消除了Linc00460介导的乳腺癌细胞致癌行为和FGF7-AKT途径的激活。我们已经证明Linc00460部分通过miR-489-5p/FGF7/AKT轴促进乳腺癌进展。
