The Long Intergenic Noncoding RNA UFC1, a Target of MicroRNA 34a, Interacts With the mRNA Stabilizing Protein HuR to Increase Levels of β-Catenin in HCC Cells
The Long Intergenic Noncoding RNA UFC1, a Target of MicroRNA 34a, Interacts With the mRNA Stabilizing Protein HuR to Increase Levels of β-Catenin in HCC Cells
复制标题
长基因间非编码 RNA UFC1（microRNA 34a 的靶标）与 mRNA 稳定蛋白 HuR 相互作用，增加 HCC 细胞中 β-连环蛋白的水平
DOI：
10.1053/j.gastro.2014.10.012
复制
发表时间：
2015-02-01
期刊：
影响因子：
29.4
通讯作者：
Liu, Li
中科院分区：
文献类型：
--
作者：
Cao, Chuanhui;Sun, Jingyuan;Liu, Li
背景与目的：长链非编码RNA（lncRNA）的活性改变与癌症的发生有关。我们研究了长基因间非编码RNA UFC 1（lincRNA-UFC 1）促进肝细胞癌（HCC）进展的机制，使用人类组织和细胞系。方法：我们使用微阵列比较7例患者HCC样本和邻近非肿瘤组织（对照）中lncRNA的表达谱。HCC和非肿瘤组织从2006年至2012年从中国广州的患者中收集。我们使用定量实时聚合酶链反应来测量49例患者组织中lincRNA-UFC 1的水平，并使用原位杂交来测量131例患者样本中的水平;从患者中收集了长达5年的临床数据。在BEL-7402、SK-Hep 1、Huh 7和MHCC-97 H HCC细胞系中，lincRNA-UFC 1被转基因表达或被短发夹RNA敲低;进行荧光素酶报告基因和RNA免疫沉淀和下拉测定。我们还分析了这些细胞在BALB/c裸鼠中的异种移植瘤的生长。研究结果：与对照组相比，HCC组织中lincRNA-UFC 1的水平增加，并且与肿瘤大小、巴塞罗那临床肝癌分期和患者结局相关。lincRNA-UFC 1在肝癌细胞中的转基因表达促进其增殖和细胞周期进程并抑制凋亡，而lincRNA-UFC 1的短发夹RNA敲低则具有相反的效果。与从对照细胞生长的肿瘤相比，从过表达lincRNA-UFC 1的细胞生长的异种移植肿瘤具有更大的平均体积和重量，并且形成更快。从lincRNA-UFC 1敲低生长的肿瘤小于对照。lincRNA-UFC 1直接与信使RNA（mRNA）稳定蛋白HuR（由ELAVL 1编码）相互作用，以增加β-连环蛋白mRNA（由CTNNB 1编码）和蛋白质的水平。肝癌组织中lincRNA-UFC 1水平与β-连环蛋白水平相关。相比之下，在HCC组织中microRNA 34 a和lincRNA-UFC 1的水平之间存在负相关性; microRNA 34 a降低了lincRNA-UFC 1的稳定性。结论：lincRNA-UFC 1是microRNA 34 a的靶点，可促进HCC细胞的增殖并减少细胞凋亡，从而促进小鼠异种移植肿瘤的生长。它直接与mRNA稳定蛋白HuR相互作用，以调节HCC细胞中β-连环蛋白的水平。
BACKGROUND & AIMS: Altered activities of long noncoding RNAs (lncRNAs) have been associated with cancer development. We investigated the mechanisms by which the long intergenic noncoding RNA UFC1 (lincRNA-UFC1) promotes progression of hepatocellular carcinoma (HCC), using human tissues and cell lines. METHODS: We used microarrays to compare expression profiles of lncRNAs in HCC samples and adjacent nontumor tissues (controls) from 7 patients. HCC and nontumor tissues were collected from 2006 through 2012 from patients in Guangzhou, China. We used quantitative real-time polymerase chain reaction to measure levels of lincRNA-UFC1 in tissues from 49 patients, and in situ hybridization to measure levels in samples from 131 patients; clinical data were collected from patients for up to 5 years. The lincRNA-UFC1 was expressed transgenically, or knocked down with short hairpin RNAs, in BEL-7402, SK-Hep1, Huh7, and MHCC-97H HCC cell lines; luciferase reporter and RNA immunoprecipitation and pull-down assays were performed. We also analyzed growth of xenograft tumors from these cells in BALB/c nude mice. RESULTS: Levels of the lincRNA-UFC1 were increased in HCC tissues compared with controls, and associated with tumor size, Barcelona Clinic Liver Cancer stage, and patient outcomes. Transgenic expression of the lincRNA-UFC1 in HCC cells promoted their proliferation and cell-cycle progression and inhibited apoptosis, whereas short hairpin RNA knockdown of lincRNA-UFC1 had opposite effects. Xenograft tumors grown from cells overexpressing lincRNA-UFC1 had larger mean volumes and weights, and formed more rapidly, than tumors grown from control cells. Tumors grown from lincRNA-UFC1 knockdown were smaller than controls. The lincRNA-UFC1 interacted directly with the messenger RNA (mRNA) stabilizing protein HuR (encoded by ELAVL1) to increase levels of beta-catenin mRNA (encoded by CTNNB1) and protein. Levels of lincRNA-UFC1 correlated with those of beta-catenin in HCC tissues. In contrast, there was a negative correlation between levels of microRNA 34a and lincRNA-UFC1 in HCC tissues; microRNA 34a reduced the stability of lincRNA-UFC1. CONCLUSIONS: The lincRNA-UFC1, a target of microRNA 34a, promotes proliferation and reduces apoptosis in HCC cells to promote growth of xenograft tumors in mice. It interacts directly with the mRNA stabilizing protein HuR to regulate levels of beta-catenin in HCC cells.