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：
9067257
负责人：
Antonio Iavarone
金额：
$ 38.97万
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/9067257
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 Health Hereditary Disease Human 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 Sampling Set protein Sleeping Beauty Specificity Stem cells Substrate Domain System Technology Time Tumor Suppressor Genes Tumor Suppressor Proteins Ubiquitin Validation Work actionable mutation base cancer cell cancer initiation cancer stem cell 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 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（应用程序提供）：在人类癌症的遗传分析中，焦点基因拷贝数变异（CNV）和点突变通过确定其确切位置提供了有关候选驱动器基因的独家信息。最近，我们进行了大规模分析，其中我们将体细胞点突变和局灶性CNV信息整合在单个框架中，以提名在胶质母细胞瘤多形制（GBM）中实施的新驱动基因，这是最具侵略性的人类癌症之一。从该分析中出现的顶级基因是LZTR1，该基因编码为Cullin-3（Cul3）泛素蛋白连接酶复合物的底物适配器编码，底物仍在等待发现。在GBM中，LZTR1的目标是功能丧失突变和局灶性缺失，因此表现为一种新的肿瘤抑制基因，最近在其他肿瘤中证实了这一概念。从机械的角度来看，我们发现LZTR1的意外能力损害了人类GBM（GBM）干细胞（GSC）中最具侵略性的细胞亚群的自我更新和生长。该提案的核心目的是识别并在功能上表征LZTR1泛素连接酶复合酶复合物的底物，并破译机械LZTR1如何操作以防止正常神经细胞中的肿瘤发育。我们的总体假设是，LZTR1-CUL3蛋白复合物通过调节的一组底物的调节蛋白水解抑制肿瘤的生长。我们的初步数据已经确定并验证了一组具有公认的线粒体活性为新LZTR1底物的蛋白质。加上我们最近的观察到LZTR1定位在线粒体中，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放松管制联系起来。在AIM 1中，LZTR1底物总体上是总体上，我们将确定LZTR1在大脑中的正常活性，并模拟人类GBM在一个新的遗传小鼠模型中携带LZTR1灭活突变的人类GBM，其中LZTR1基因在神经系统中有条件地敲定了LZTR1基因。我们还将使用“睡美人”插入诱变系统来识别与脑肿瘤发生的LZTR1丧失协调的遗传变化。