Axis inhibition protein 1 (Axin1) Deletion-Induced Hepatocarcinogenesis Requires Intact β-Catenin but Not Notch Cascade in Mice
Axis inhibition protein 1 (Axin1) Deletion-Induced Hepatocarcinogenesis Requires Intact β-Catenin but Not Notch Cascade in Mice
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DOI：
10.1002/hep.30556
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发表时间：
2019-12-01
期刊：
影响因子：
13.5
通讯作者：
Chen, Xin
中科院分区：
文献类型：
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作者：
Qiao, Yu;Wang, Jingxiao;Chen, Xin
轴抑制蛋白1（AXIN 1）的失活突变是Wnt/β-连环蛋白级联反应的负调节因子，是人类肝细胞癌（HCC）中常见的遗传事件之一，影响约10%的病例。在本论文中，我们试图确定Axin 1突变体和Wnt/β-catenin之间的遗传串扰以及Notch信号级联沿着肝癌发生。我们发现c-MET激活和AXIN 1突变在约3%-5%的人HCC样本中同时发生。随后，我们通过基于CRISPR/Cas9的Axin 1基因缺失（sgAxin 1）结合小鼠肝脏中基于转座子的c-Met表达（c-Met/sgAxin 1）产生了小鼠HCC模型。小鼠正常肝脏、c-Met/sgAxin 1诱导的HCC和c-Met/增量N90-β-连环蛋白诱导的HCC的整体基因表达分析揭示了c-Met/sgAxin 1 HCC中Wnt/β-连环蛋白和Notch信号传导的激活。然而，当与来自c-Met/增量N90-β-连环蛋白小鼠的相应病变相比时，在c-Met/sgAxin 1 HCC中仅诱导了少数典型Wnt/β-连环蛋白靶基因。为了研究内源性β-连环蛋白是否是c-Met/sgAxin 1驱动的HCC发展所必需的，我们在肝脏特异性Ctnnb 1敲除小鼠中表达了c-Met/sgAxin 1，这完全阻止了HCC的发展。一致地，在AXIN 1突变或缺失的人HCC细胞系中，β-连环蛋白的沉默强烈抑制细胞增殖。与此形成鲜明对比的是，通过表达免疫球蛋白κ J区（RBP-J）的重组信号结合蛋白的显性阴性形式或Notch 2的消融来阻断Notch级联反应并没有显著影响c-Met/sgAxin 1驱动的肝癌发生。结论：我们在这里证明了Axin 1的缺失与c-Met合作以β-连环蛋白信号依赖性但Notch级联非依赖性的方式在小鼠中诱导HCC。
Inactivating mutations of axis inhibition protein 1 (AXIN1), a negative regulator of the Wnt/beta-Catenin cascade, are among the common genetic events in human hepatocellular carcinoma (HCC), affecting approximately 10% of cases. In the present manuscript, we sought to define the genetic crosstalk between Axin1 mutants and Wnt/beta-catenin as well as Notch signaling cascades along hepatocarcinogenesis. We discovered that c-MET activation and AXIN1 mutations occur concomitantly in ~3%-5% of human HCC samples. Subsequently, we generated a murine HCC model by means of CRISPR/Cas9-based gene deletion of Axin1 (sgAxin1) in combination with transposon-based expression of c-Met in the mouse liver (c-Met/sgAxin1). Global gene expression analysis of mouse normal liver, HCCs induced by c-Met/sgAxin1, and HCCs induced by c-Met/ increment N90-beta-Catenin revealed activation of the Wnt/beta-Catenin and Notch signaling in c-Met/sgAxin1 HCCs. However, only a few of the canonical Wnt/beta-Catenin target genes were induced in c-Met/sgAxin1 HCC when compared with corresponding lesions from c-Met/ increment N90-beta-Catenin mice. To study whether endogenous beta-Catenin is required for c-Met/sgAxin1-driven HCC development, we expressed c-Met/sgAxin1 in liver-specific Ctnnb1 null mice, which completely prevented HCC development. Consistently, in AXIN1 mutant or null human HCC cell lines, silencing of beta-Catenin strongly inhibited cell proliferation. In striking contrast, blocking the Notch cascade through expression of either the dominant negative form of the recombinant signal-binding protein for immunoglobulin kappa J region (RBP-J) or the ablation of Notch2 did not significantly affect c-Met/sgAxin1-driven hepatocarcinogenesis. Conclusion: We demonstrated here that loss of Axin1 cooperates with c-Met to induce HCC in mice, in a beta-Catenin signaling-dependent but Notch cascade-independent way.