The role of the LZTR1 ubiquitin ligase in stem cells and cancer

LZTR1 泛素连接酶在干细胞和癌症中的作用

基本信息

批准号：
9262886
负责人：
Antonio Iavarone
金额：
$ 38.31万
依托单位：
COLUMBIA UNIVERSITY HEALTH SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-05-15 至 2020-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9262886
关键词：
Adopted Applications Grants BTB/POZ Domain Biochemical Biological Biological Process Biology Brain Brain Neoplasms Cell model Cells Chromosomal translocation Code Complex Copy Number Polymorphism Cullin Proteins Data Data Set Development Dissection Ensure Event Foundations Gene Dosage Genes Genetic Glioblastoma Glioma Goals Growth Hereditary Disease Human Impairment In Vitro Individual Insertional Mutagenesis Knock-out Knockout Mice Ligase Link Location Maintenance Malignant Neoplasms Malignant neoplasm of brain Mass Spectrum Analysis Mediating Mitochondria Modeling Molecular Mouse Strains Mus Mutation Nervous system structure Neurons Normal Cell Orphan Pathogenesis Play Point Mutation Proteins Proteolysis Recruitment Activity Reporting Role Salvelinus Sampling Set protein Sleeping Beauty Specificity Stem cells Substrate Domain Suppressor Genes System Technology Tertiary Protein Structure Time Tumor Initiators Tumor Suppressor Genes Tumor Suppressor Proteins Ubiquitin Validation Variant Work actionable mutation base cancer cell cancer initiation cullin-3 follow-up genetic analysis genetic regulatory protein in vivo innovation loss of function loss of function mutation mouse model multicatalytic endopeptidase complex nerve stem cell neurodevelopment next generation sequencing novel novel therapeutic intervention prevent protein complex protein function public health relevance scaffold self-renewal teration tumor tumor growth tumorigenesis ubiquitin ligase

项目摘要

DESCRIPTION (provided by applicant): In the genetic analysis of human cancer, focal gene copy number variation (CNV) and point mutations provide exquisite information on candidate driver genes by pinpointing their exact location. Recently, we conducted a large-scale analysis in which we integrated somatic point mutations and focal CNV information in a single framework to nominate new driver genes implicated in glioblastoma multiforme (GBM), one of the most aggressive types of human cancer. The top-ranking gene that emerged from this analysis is LZTR1, which codes for the substrate adaptor of a Cullin-3 (Cul3) ubiquitin ligase complex for which the substrates still await discovery. In GBM, LZTR1 is targeted by loss-of-function mutations and focal deletions, thus behaving as a new tumor suppressor gene, a notion recently confirmed in other tumors. From a mechanistic standpoint, we have discovered the unexpected capacity of LZTR1 to impair self-renewal and growth of the most aggressive cellular subpopulation in human GBM, the glioma stem cells (GSCs). The central objective of this proposal is to identify and functionally characterize the substrates of the LZTR1 ubiquitin ligase complex and decipher how mechanistically LZTR1 operates to prevent tumor development in normal neural cells. Our overarching hypothesis is that the LZTR1-Cul3 protein complex suppresses tumor growth through the regulated proteolysis of a particular set of substrates. Our preliminary data have already identified and validated a set of proteins with recognized mitochondrial activities as new LZTR1 substrates. Together with our recent observation that LZTR1 localizes at mitochondria, these results are exciting new findings that link alterations of LZTR1 to deregulation of mitochondrial functions in cancer. In Aim 1, the LZTR1 substrates will be comprehensively identified from a novel mass spectrometry-based technology that has already successfully recognized exciting, new substrate candidates of LZTR1. The functional validation of the substrates will be pursued in highly relevant cellular models directly generated from primary human GBM and will be related to the landscape of mutations of LZTR1 discovered in human cancer. In Aim 2, we will determine the normal activity of LZTR1 in the brain and model human GBM harboring inactivating mutations of LZTR1 in a new genetic mouse model in which the LZTR1 gene is conditionally knocked out in the nervous system. We will also use the Sleeping Beauty insertional mutagenesis system to identify the genetic alterations that cooperate with loss of LZTR1 for brain tumorigenesis.

描述（申请人提供）：在人类癌症的遗传分析中，焦点基因拷贝数变异（CNV）和点突变通过精确定位候选驱动基因的确切位置，提供了关于它们的精确信息。我们将体细胞点突变和局灶性 CNV 信息整合到一个框架中，以提名与多形性胶质母细胞瘤 (GBM) 相关的新驱动基因，GBM 是人类癌症中最具侵袭性的类型之一。分析的结果是 LZTR1，它编码 Cullin-3 (Cul3) 泛素连接酶复合物的底物接头，该复合物的底物仍有待发现。在 GBM 中，LZTR1 是功能缺失突变和局灶性缺失的靶标，因此表现为新的肿瘤抑制基因，这一概念最近在其他肿瘤中得到证实，从机制的角度来看，我们发现 LZTR1 具有意想不到的能力，可以损害最具攻击性的细胞亚群的自我更新和生长。在人类 GBM 中，神经胶质瘤干细胞 (GSC) 的中心目标是鉴定 LZTR1 泛素连接酶复合物的底物并对其进行功能表征，并破译 LZTR1 如何在机制上阻止正常神经细胞中的肿瘤发展。 LZTR1-Cul3 蛋白复合物通过调节一组特定底物的蛋白水解作用来抑制肿瘤生长，我们的初步数据已经鉴定并验证了这一点。一组具有公认的线粒体活性的蛋白质作为新的 LZTR1 底物，加上我们最近观察到 LZTR1 定位于线粒体，这些结果是令人兴奋的新发现，将 LZTR1 的改变与癌症中线粒体功能的失调联系起来。通过基于质谱的新型技术进行全面鉴定，该技术已成功识别出令人兴奋的 LZTR1 新底物候选物。底物的功能验证将直接在高度相关的细胞模型中进行。目标 2 中，我们将确定 LZTR1 在大脑中的正常活性，并在新的基因小鼠中建立含有 LZTR1 失活突变的人类 GBM 模型。我们还将使用睡美人插入诱变系统来识别与大脑 LZTR1 缺失相配合的基因改变。肿瘤发生。