Investigating multifactorial beta-catenin activation in hepatocellular cancers

研究肝细胞癌中的多因素 β-连环蛋白激活

基本信息

批准号：
10541171
负责人：
Xin Chen
金额：
$ 48.04万
依托单位：
UNIVERSITY OF HAWAII AT MANOA
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-03-01 至 2025-12-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10541171
关键词：
AXIN1 gene AXIN1 protein Address Adverse effects Biological CTNNB1 gene Cells Classification Collaborations Complement Development Disease Disparate Enterobacteria phage P1 Cre recombinase Event Exons FDA approved Gene Expression Genes Genetic Variation Glucose Glutamate-Ammonia Ligase Glutamine Hepatocarcinogenesis Human Immune checkpoint inhibitor Impairment In Vitro Injections Isotope Labeling Lead Ligands Liver LoxP-flanked allele Malignant Neoplasms Malignant neoplasm of liver Metabolic Metabolism Minor Modeling Molecular Mus Mutation Oncogenic Pathogenesis Pathway interactions Placebos Play Porcupines Pre-Clinical Model Primary carcinoma of the liver cells Productivity Role Sampling Scaffolding Protein Signal Pathway Signal Transduction Sleeping Beauty Tail Tankyrase Testing Therapeutic Transposase Universities Unresectable Veins beta catenin cancer therapy gain of function gain of function mutation hepatocellular carcinoma cell line inhibitor liver cancer model loss of function loss of function mutation molecular subtypes molecular targeted therapies mouse model mutant overexpression precision medicine receptor response tumor

项目摘要

Abstract Hepatocellular carcinoma (HCC) is a deadly malignancy with limited treatment options, and lacks molecular- targeted therapies. Activation of Wnt/β-catenin cascade has been shown to play a major role during HCC pathogenesis. Mutations in CTNNB1, the gene encoding for β-catenin, interfere with its degradation leading to its gain-of function (GOF) and activation, and are implicated in 20-35% of all HCCs. A mutually exclusive group of additional around 8% of HCCs is the one with the loss-of-function (LOF) mutations in AXIN1, which encodes for a scaffolding protein AXIN1, essential for β-catenin degradation. Our previous studies also showed that β- catenin activation alone is insufficient for HCC development. Based on the concomitant presence of CTNNB1 mutations and c-MET activation in ~11% of human HCC, and the presence of LOF mutations in AXIN1 and c- MET activation together in ~4% of human HCC, we established two murine HCC models, c-Met/β-catenin and c-Met/sgAxin1, using sleeping beauty transposon/transposase and hydrodynamic tail vein injection (SB-HDTVI). These models recapitulate the respective human HCC subsets based on gene expression studies. Intriguingly, using these mouse models and human HCC samples, we discovered that AXIN1 LOF mutant HCC does not show activation of canonical liver-specific β-catenin target genes such as glutamine synthetase (Gs) and Tbx3, which was evident in CTNNB1-mutant HCCs. In contrast, Hippo cascade is inactivated in LOF mutations in AXIN1 mutant, but not in CTNNB1-mutant HCCs. Based on the above observations, our overarching hypothesis is that despite β-catenin being the common downstream effector, mutations in CTNNB1 and AXIN1 lead to distinct molecular subtypes of HCC, and tumor development in these two classes requires participation of distinct signaling pathways. We propose the following three specific aims to address our highly relevant hypothesis. In Aim 1, we plan to define whether ligand dependent activation of Wnt/β-catenin is required for c-Met/sgAxin1 induced HCC formation in mice. In Aim 2, we will investigate Gs dependent and independent metabolic and signaling cascades in mouse HCC development. And in Aim 3, we will characterize the functional contribution of Hippo cascade in Ctnnb1 GOF and Axin1 LOF mutant HCCs. Altogether, our studies will elucidate the distinct signaling pathways induced by β-catenin activation due to two distinct mechanisms, and how we may effectively target these tumors based on genetic variations. The proposal represents an ongoing & productive collaboration between Dr. Xin Chen from UCSF and Dr. Paul Monga from University of Pittsburgh. The results may pave a way for precision medicine in HCC.

抽象的肝细胞癌 (HCC) 是一种致命的恶性肿瘤，治疗选择有限，并且缺乏分子治疗手段。 Wnt/β-连环蛋白级联的激活已被证明在 HCC 过程中发挥着重要作用。 CTNNB1（编码 β-连环蛋白的基因）的突变会干扰其降解，从而导致其功能获得 (GOF) 和激活，并且与所有 HCC 的 20-35% 相关。另外约 8% 的 HCC 中存在 AXIN1 功能丧失 (LOF) 突变，该突变编码我们之前的研究还表明，对于 β-连环蛋白降解至关重要的支架蛋白 AXIN1。由于 CTNNB1 的同时存在，仅连环蛋白激活不足以促进 HCC 的发展。约 11% 的人类 HCC 中存在突变和 c-MET 激活，AXIN1 和 c- 中存在 LOF 突变 MET 在约 4% 的人类 HCC 中同时激活，我们建立了两种小鼠 HCC 模型：c-Met/β-catenin 和 c-Met/sgAxin1，使用睡美人转座子/转座酶和流体动力尾静脉注射（SB-HDTVI）。有趣的是，这些模型根据基因表达研究概括了各自的人类 HCC 亚型。使用这些小鼠模型和人类 HCC 样本，我们发现 AXIN1 LOF 突变体 HCC 不会显示典型肝脏特异性 β-连环蛋白靶基因的激活，例如谷氨酰胺合成酶 (Gs) 和 Tbx3，这在 CTNNB1 突变的 HCC 中很明显，相反，Hippo 级联在 LOF 突变中失活。 AXIN1 突变体，但不存在于 CTNNB1 突变体 HCC 中根据上述观察，我们的总体假设是。尽管 β-catenin 是常见的下游效应子，但 CTNNB1 和 AXIN1 的突变会导致 HCC 具有不同的分子亚型，这两类肿瘤的发展需要不同的分子参与我们提出以下三个具体目标来解决我们高度相关的假设。目标 1，我们计划确定 c-Met/sgAxin1 是否需要 Wnt/β-catenin 的配体依赖性激活诱导小鼠 HCC 形成在目标 2 中，我们将研究 Gs 依赖性和非依赖性代谢和代谢。在目标 3 中，我们将描述小鼠 HCC 发展中的信号级联的功能贡献。 Ctnnb1 GOF 和 Axin1 LOF 突变型 HCC 中的 Hippo 级联反应总而言之，我们的研究将阐明不同的差异。由于两种不同的机制，β-连环蛋白激活诱导的信号通路，以及我们如何有效地该提案代表了一项持续且富有成效的合作。加州大学旧金山分校的 Xin Chen 博士和匹兹堡大学的 Paul Monga 博士之间的研究结果可能会铺平道路。 HCC 精准医疗的途径。