Defining the Pathogenesis of Del(7q) in Hematopoietic Stem Cells

定义造血干细胞中 Del(7q) 的发病机制

基本信息

批准号：
10647633
负责人：
Matthew Jotte
金额：
$ 5.27万
依托单位：
UNIVERSITY OF CHICAGO
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：
2022-04-01 至 2026-03-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10647633
关键词：
Abnormal Karyotype Acceleration Acute leukemia Adult Anemia Apoptosis Automobile Driving Bioinformatics Blood CD34 gene CRISPR/Cas technology Cell Proliferation Cells Chromatin Chromosome 7 Chromosome abnormality Clonal Expansion Cytogenetics Data Development Diploidy Disease Dose Doxycycline Dysmyelopoietic Syndromes Dysplasia EZH2 gene Electroporation Engineering Environment Epigenetic Process Erythropoiesis Etiology Gene Combinations Gene Deletion Gene Dosage Genes Genetic Genetic Transcription Genomics Hematopoiesis Hematopoietic stem cells Histones Homeobox Human In Vitro Ineffective Hematopoiesis K-562 K562 Cells Karyotype Knock-out Knowledge Lead Leukemic Cell Maintenance Malignant Neoplasms Methodology Methyltransferase Modeling Molecular Molecular Abnormality Monosomy 7 Mus Mutation Myelogenous Myeloid Cells Myelopoiesis Myeloproliferative disease Neoplasms Onset of illness Outcome Pathogenesis Pathogenicity Peripheral Physicians Population Prognosis Recurrence Research Personnel Risk Role Scientist Series Syndrome Synteny Technical Expertise Techniques Training Transcription Alteration Transplantation Treatment Efficacy Tumor Suppressor Genes Work animal model development career cell growth chromosome 7q loss combinatorial cytopenia data integration derepression dosage druggable target experimental study high risk in vivo knock-down knockout gene mouse model new therapeutic target novel therapeutics nuclease pediatric myelodysplastic syndrome skills small hairpin RNA stemness transcription factor transcriptome sequencing

项目摘要

PROJECT SUMMARY/ABSTRACT Deletions of all or part of chromosome 7 [-7/del(7q)] are among the most common karyotypic abnormalities in myeloid diseases, particularly high-risk myeloid diseases. Myelodysplastic syndrome (MDS) is a series of clonal disorders characterized by ineffective hematopoiesis, leading to peripheral cytopenias and dysplasia in one or more blood lineages with risk of transformation to acute leukemia. -7/del(7q) is found in 10% of adult MDS cases and, strikingly, in up to 50% of pediatric MDS cases. The presence of -7/del(7q) is associated with a poor karyotype and higher risk MDS, and carries a worse prognosis than cases with diploid chromosome 7. -7/del(7q) is often the only cytogenetic finding, and in a subset of pediatric MDS cases is the sole detectable molecular abnormality, strongly suggesting a driving role for chromosome 7 deletions in disease pathogenesis. There have been no new therapies for MDS in over a decade, highlighting an urgent need to better understand the recurrent genetic features of MDS that may lead to new treatment options. The lack of synteny between human and mouse chromosome 7 is a major barrier in the development of animal models of -7/del(7q). In a breakthrough in the field, our lab identified CUX1, a homeobox transcription factor shown to regulate cell proliferation and apoptosis, as a haploinsufficient myeloid tumor suppressor gene located in a commonly deleted region of 7q. Our lab engineered a doxycycline-inducible shRNA CUX1- knockdown mouse, and mice deficient in Cux1 develop a myeloid disease with trilineage dysplasia and lethal anemia, hallmarks of MDS. These data strongly support a role for this 7q-encoded gene in MDS etiology. However, chromosome 7 deletions are often large and span additional genes that alter hematopoiesis or lead to myeloid disease when deleted in mouse models. These data suggest 7q may be a contiguous gene syndrome region, in which loss of multiple neighboring genes en bloc contributes to disease development. Our preliminary data show CUX1 loss in human K562 leukemia cells decreases the repressive epigenetic histone mark H3K27me3. We further show that combined loss of Cux1 and the 7q gene Ezh2, an H3K27 methyltransferase, in murine hematopoietic progenitors synergistically increases myeloid cell expansion in vitro, compared to either gene alone. These data provide support for the hypothesis that 7q is a contiguous gene syndrome region. This proposal aims to: 1) leverage CRISPR-Cas9 gene editing to identify combinatorial 7q gene deletions that cooperate with Cux1 loss to drive del(7q) pathogenesis; and 2) define mechanisms by which loss of 7q genes drives del(7q) pathogenesis by characterizing the epigenetic and transcriptional landscape of cells deficient in Cux1 alone or with combined Ezh2 loss. This proposal will advance our understanding of chromosome 7 deletions and provide me with a specialized skill set in myeloid neoplasia and genomics that will propel me toward a career as an independent investigator.

项目概要/摘要 7 号染色体全部或部分缺失 [-7/del(7q)] 是最常见的核型缺失骨髓疾病异常，特别是高危骨髓疾病。骨髓增生异常综合征 (MDS) 是一系列以无效造血为特征的克隆性疾病，导致外周血细胞减少和一种或多种血统的发育异常，有转化为急性白血病的风险。 -7/del(7q) 见于 10% 成人 MDS 病例，令人惊讶的是，高达 50% 的儿童 MDS 病例。 -7/del(7q) 的存在是相关的核型较差，MDS 风险较高，预后比二倍体染色体病例差 7. -7/del(7q) 通常是唯一的细胞遗传学发现，并且在儿科 MDS 病例的子集中是唯一可检测到的分子异常，强烈表明 7 号染色体缺失在疾病发病机制中的驱动作用。十多年来，MDS 一直没有新的治疗方法，这凸显了迫切需要更好地了解 MDS MDS 的复发性遗传特征可能会带来新的治疗选择。人类和小鼠 7 号染色体之间缺乏同线性是发育的主要障碍 -7/del(7q)的动物模型。在该领域的一项突破中，我们的实验室鉴定出了 CUX1，一种同源盒转录作为单倍体不足的骨髓肿瘤抑制基因，可调节细胞增殖和凋亡的因子位于 7q 的常见删除区域。我们的实验室设计了强力霉素诱导的 shRNA CUX1- 基因敲除小鼠和 Cux1 缺陷小鼠会出现三系发育不良和致命的骨髓疾病贫血，MDS 的特征。这些数据有力地支持了该 7q 编码基因在 MDS 病因学中的作用。然而，7 号染色体缺失通常很大，并且跨越了改变造血功能或导致在小鼠模型中删除时发生骨髓疾病。这些数据表明 7q 可能是一种连续基因综合征区域，其中多个邻近基因的整体丢失导致疾病的发展。我们的初步数据显示人类 K562 白血病细胞中 CUX1 缺失会降低抑制性表观遗传组蛋白标记 H3K27me3。我们进一步表明，Cux1 和 7q 基因 Ezh2（一种 H3K27 甲基转移酶）的联合丢失，在小鼠造血祖细胞中，与任何一种相比，在体外可协同增加骨髓细胞的扩增单独基因。这些数据为 7q 是连续基因综合征区域的假设提供了支持。这该提案旨在：1) 利用 CRISPR-Cas9 基因编辑来识别组合 7q 基因缺失，与 Cux1 损失配合驱动 del(7q) 发病机制； 2) 定义 7q 基因丢失的机制通过表征缺陷细胞的表观遗传和转录景观来驱动 del(7q) 发病机制 Cux1 单独丢失或与 Ezh2 联合丢失。该提案将增进我们对 7 号染色体的理解缺失并为我提供了骨髓瘤和基因组学方面的专业技能，这将推动我前进走向独立调查员的职业生涯。