An essential role of RNF187 in Notch1 mediated metastasis of hepatocellular carcinoma
An essential role of RNF187 in Notch1 mediated metastasis of hepatocellular carcinoma
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RNF187在Notch1介导的肝细胞癌转移中的重要作用
DOI：
10.1186/s13046-019-1382-x
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发表时间：
2019-09-02
影响因子：
11.3
通讯作者：
Liu, Chao
中科院分区：
文献类型：
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作者：
Zhang, Lei;Chen, Jiewei;Liu, Chao
研究背景Notch信号通路的异常激活与肝细胞癌的转移密切相关，但其潜在的分子机制尚不清楚。最近发现环指蛋白187(RNF187)是多种肿瘤的驱动因子，但其在肝癌中的表达模式和生物学功能尚不清楚。方法检测Notch1和RNF187在两个独立的肝癌组织中的表达水平，并通过Notch1在肝癌细胞中的调控作用来探讨Notch1在肝癌转移中的调控作用。采用RNA序列分析、生物信息学分析、荧光素酶报告分析和染色质免疫沉淀分析等方法研究Notch1信号与其潜在靶标Ring inger Protein 187(RNF187)之间的关系。功能获得和功能丧失研究被用来分析Notch1-RNF187信号在促进肝细胞癌转移中的作用。结果通过RNA-seq、荧光素酶报告基因分析和芯片分析，证实RNF187是Notch1的直接转录靶点，因为Notch1可以激活RNF187启动子，而Notch1的亲迁移和亲侵袭作用被RNF187敲除后显著减弱。同时，RNF187沉默可减弱Notch1依赖的上皮-间充质转化(EMT)。此外，RNF187的过表达抵消了Notch1基因敲除对癌症进展的抑制作用。重要的是，肝Notch1高表达的肝细胞癌患者的无病生存期(DFS)比低表达的患者短。此外，Notch1和RNF187高水平共表达的患者显示出最短的DFS。Notch1和RNF187的表达水平是影响肝癌预后的独立因素。结论首次证实RNF187是Notch1促进肝癌侵袭转移的重要因子。具有高度的临床相关性，我们发现Notch1-RNF187的激活与肝细胞癌患者的预后不良相关。这些发现为开发应对肝癌转移的新策略提供了坚实的基础。
BackgroundAberrant activation of Notch signaling has been causally linked to the metastasis of hepatocellular carcinoma (HCC), however the underlying molecular mechanisms are still poorly understood. RING finger protein 187 (RNF187) was recently revealed to be a driver of several cancers, but its expression pattern and biological function in HCC are unknown.MethodsThe expression levels of Notch1 and RNF187 were assessed in two independent cohorts of HCC tissues, and modulation of Notch1 in HCC cells was performed to explore the regulatory role of Notch1 in HCC metastasis. RNA-sequencing (RNA-seq), bioinformatics analysis, luciferase reporter analysis, and chromatin immunoprecipitation assay (ChIP) were used to clarify the relationship between Notch1 signaling and its potential target Ring finger protein 187 (RNF187). Gain- and loss-of-function studies were used to dissect the role of Notch1-RNF187 signaling in promoting HCC metastasis. The impact of Notch1-RNF187 activity in determining clinical prognosis for HCC patients was evaluated by multivariate Cox regression.ResultsBy RNA-seq, luciferase reporter analysis, and ChIP assay, RNF187 was confirmed to be a direct transcriptional target of Notch1, as Notch1 could activate RNF187 promoter whereas the pro-migratory and pro-invasive effects of Notch1 were significantly attenuated by RNF187 knockdown. Meanwhile, RNF187 silencing could attenuate the Notch1-dependent epithelial-mesenchymal transition (EMT). Moreover, overexpression of RNF187 counteracted the inhibitory effect of Notch1 knockdown on cancer progression. Importantly, HCC patients with high level of hepatic Notch1 expression had shorter disease-free survival (DFS) than those with low level of hepatic Notch1 expression. Furthermore, patients with high level of Notch1 and RNF187 co-expression showed the shortest DFS. The expression level of Notch1 and RNF187 was an independent prognostic factor for HCC.ConclusionsFor the first time we identified that RNF187 is an essential factor for Notch1 to promote invasion and metastasis of HCC. Of highly clinical relevance, we found that activation of Notch1-RNF187 correlates with a worse prognosis of HCC patients. These findings provide a solid foundation for developing novel strategies to tackle HCC metastasis.