miR-449a targets Flot2 and inhibits gastric cancer invasion by inhibiting TGF-β-mediated EMT.
miR-449a targets Flot2 and inhibits gastric cancer invasion by inhibiting TGF-β-mediated EMT.
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miR-449a 靶向 Flot2 并通过抑制 TGF-β 介导的 EMT 来抑制胃癌侵袭
DOI：
10.1186/s13000-015-0435-5
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发表时间：
2015-11-14
影响因子：
2.6
通讯作者：
Liu T
中科院分区：
文献类型：
--
作者：
Li Q;Peng J;Li X;Leng A;Liu T
研究背景Flot2是SPFH结构域蛋白家族中高度保守的蛋白，最近被鉴定为癌基因，参与包括胃癌在内的多种癌症的肿瘤发生和转移。然而，Flot2在胃癌（GC）中的潜在分子机制尚不清楚。方法采用qRT-PCR和western blot检测GC细胞系和正常人胃上皮细胞中miR-449a和Flot2的表达。然后，使用荧光素酶报告基因测定来阐明Flot2是否是miR-449a的靶基因。最后进一步研究miR-449a在调控肿瘤侵袭中的作用和机制。结果本研究中,与GES-1相比,所有GC细胞系中miR-449a表达均下调,Flot2表达上调。荧光素酶报告基因测定将 Flot2 鉴定为 miR-449a 的新直接靶标。 miR-449a 通过抑制 Flot2 表达来调节 GC 细胞侵袭。一组上皮-间质转化（EMT）标记物的表达分析表明，miR-449a降低间充质标记物（波形蛋白和N-钙粘蛋白）的表达并诱导上皮标记物（E-钙粘蛋白）的表达，这与沉默的Flot2一致。此外，Flot2对于GC细胞中TGF-β诱导的EMT是必需的。结论我们的结果表明，miR-449a抑制Flot2表达导致通过抑制TGF-β介导的EMT减少细胞侵袭，并为进一步研究miR-449a调节的Flot2作为潜在的生物标志物和GC治疗的有前途的方法提供了新的理论基础。
BackgroundFlot2, a highly conserved protein of the SPFH domain containing proteins family, has recently been identified as oncogene to be involved in the tumorigenesis and metastasis of several cancers including gastric cancer. However, the underlying molecular mechanism of Flot2 in gastric cancer (GC) is largely unknown.MethodsqRT-PCR and western blot was performed to detect miR-449a and Flot2 expression in GC cell lines and Normal human gastric epithelial cells. Then, luciferase reporter assay was used to elucidate whether Flot2 is a target gene of miR-449a. Finally, the roles and mechanism of miR-449a in regulation of tumor invasion were further investigated.ResultsIn this study, miR-449a expression was downregulated and Flot2 was upregulated in all GC cell lines as compared with that in GES-1. luciferase reporter assay identified Flot2 as a novel direct target of miR-449a. miR-449a regulated GC cell invasion by suppressing Flot2 expression. Expression analysis of a set of epithelial-mesenchymal transition (EMT) markers showed that miR-449a reduced the expression of mesenchymal markers (vimentin and N-cadherin) and induced the expression of epithelial marker (E-cadherin), which was consistent with silenced Flot2. Moreover, Flot2 is necessary for TGF-β-induced EMT in GC cells.ConclusionsOur results demonstrated that miR-449a suppressed Flot2 expression results in decreased cell invasion through repressing TGF-β-mediated-EMT, and provides a new theoretical basis to further investigate miR-449a-regulated Flot2 as a potential biomarker and a promising approach for GC treatment.