MicroRNA-137, an HMGA1 Target, Suppresses Colorectal Cancer Cell Invasion and Metastasis in Mice by Directly Targeting FMNL2
MicroRNA-137, an HMGA1 Target, Suppresses Colorectal Cancer Cell Invasion and Metastasis in Mice by Directly Targeting FMNL2
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HMGA1 靶标 MicroRNA-137 通过直接靶向 FMNL2 抑制小鼠结直肠癌细胞侵袭和转移
DOI：
10.1053/j.gastro.2012.11.033
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发表时间：
2013-03-01
期刊：
影响因子：
29.4
通讯作者：
Ding, Yanqing
中科院分区：
文献类型：
--
作者：
Liang, Li;Li, Xianzheng;Ding, Yanqing
背景与目的：Formin-like（FMNL）2在结直肠肿瘤中上调，并与肿瘤进展相关，但对其调控机制知之甚少。我们研究了microRNA是否调节结直肠癌（CRC）细胞中FMNL 2的水平。方法：我们使用实时聚合酶链反应和免疫印迹分析来测量来自患者（n = 50）的CRC细胞和组织样本中miR-137、高迁移率族AT-钩（HMGA）1和FMNL 2的水平。我们使用荧光素酶报告基因测定来确定miR-137与FMNL 2 3'非翻译区以及HMGA 1与miR-137启动子之间的关联。染色质免疫沉淀试验用于评估HMGA 1与miR-137启动子的直接结合。结果：基于生物信息学数据预测miR-137和miR-142- 3 p与FMNL 2结合。在结直肠癌细胞系和组织中，只有miR-137水平与FMNL 2蛋白水平呈显著负相关。miR-137靶向FMNL 2信使RNA; miR-137的表达在体外抑制CRC细胞的增殖和侵袭，以及在裸鼠中抑制CRC异种移植物向肝和肠的转移。HMGA 1与miR-137的启动子结合并激活其转录，从而降低CRC细胞中FMNL 2的水平。miR-137在CRC细胞中的异位表达抑制了丝裂原活化蛋白激酶（MAPK）和Akt的磷酸化，从而降低了基质金属蛋白酶2、基质金属蛋白酶9和血管内皮生长因子的水平;它还降低了CRC细胞的侵袭性，抑制了通过磷脂酰肌醇-4，5-二磷酸3-激酶、Akt和MAPK的信号传导。结论：与邻近正常粘膜相比，CRC样本中miR-137和HMGA 1的水平降低，FMNL 2的水平升高。在CRC细胞中，miR-137靶向FMNL 2信使RNA，并受转录因子HMGA 1调控。miR-137的表达降低了CRC细胞的体外侵袭和小鼠肿瘤异种移植物的转移。FMNL 2似乎激活磷脂酰肌醇-4，5-二磷酸3-激酶、蛋白激酶B（Akt）和MAPK信号通路。
BACKGROUND & AIMS: Formin-like (FMNL) 2 is up-regulated in colorectal tumors and has been associated with tumor progression, but little is known about regulatory mechanisms. We investigated whether microRNAs regulate levels of FMNL2 in colorectal cancer (CRC) cells. METHODS: We used real-time polymerase chain reaction and immunoblot analyses to measure levels of miR-137, high-mobility group AT-hook (HMGA)1, and FMNL2 in CRC cells and tissue samples from patients (n = 50). We used luciferase reporter assays to determine the association between miR-137 and the FMNL2 3' untranslated region, and HMGA1 and the miR-137 promoter. Chromatin immunoprecipitation assays were used to assess direct binding of HMGA1 to the miR-137 promoter. RESULTS: miR-137 and miR-142-3p were predicted to bind FMNL2 based on bioinformatic data. Only the level of miR-137 had a significant inverse correlation with the level of FMNL2 protein in CRC cell lines and tissues. FMNL2 messenger RNA was targeted by miR-137; expression of miR-137 inhibited proliferation and invasion by CRC cells in vitro, and metastasis to liver and intestine by CRC xenografts in nude mice. HMGA1 bound to the promoter of miR-137 and activated its transcription, which reduced levels of FMNL2 in CRC cells. Ectopic expression of miR-137 in CRC cells inhibited phosphorylation of mitogen-activated protein kinase (MAPK) and Akt, which reduced levels of matrix metalloproteinase 2, matrix metalloproteinase 9, and vascular endothelial growth factor; it also reduced invasiveness of CRC cells, inhibiting signaling via phosphatidylinositol-4,5-bisphosphate 3-kinase, Akt, and MAPK. CONCLUSIONS: Levels of miR-137 and HMGA1 are reduced, and levels of FMNL2 are increased, in CRC samples compared with adjacent normal mucosa. In CRC cells, miR-137 targets FMNL2 messenger RNA and is regulated by the transcription factor HMGA1. Expression of miR-137 reduces CRC cell invasion in vitro and metastasis of tumor xenografts in mice. FMNL2 appears to activate phosphatidylinositol-4,5-bisphosphate 3-kinase, protein kinase B (Akt), and MAPK signaling pathways.