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.

项目摘要/摘要全部或部分染色体7 [-7/del（7q）]的删除是最常见的核型髓样疾病的异常，尤其是高风险髓样疾病。骨髓增生综合征（MDS）是一系列以无效造血的特征的克隆疾病，导致周围细胞质和一个或多个血统中的发育异常，有转化为急性白血病的风险。 -7/del（7q）的发现为10％成年MDS病例，令人惊讶的是，在多达50％的小儿MDS病例中。 -7/del（7q）的存在是关联的核型较差，风险MD较高，并且预后较差，而二倍体染色体病例 7。-7/del（7q）通常是唯一的细胞遗传学发现，在小儿MDS病例的一部分中是唯一可检测到的分子异常，强烈表明染色体7在疾病发病机理中的驱动作用。十多年来，没有针对MD的新疗法，强调了迫切需要更好地理解 MD的复发遗传特征可能会导致新的治疗选择。人类和小鼠染色体之间缺乏同步是发展的主要障碍 -7/del的动物模型（7q）。在该领域的突破中，我们的实验室确定了Cux1，一个同源词的转录显示可调节细胞增殖和凋亡的因子，作为单倍损伤的髓样肿瘤基因位于通常删除的7Q区域。我们的实验室设计了强力霉素诱导的shRNA cux1- 敲除小鼠，而缺乏Cux1的小鼠患有髓样疾病，伴有三利肌发育不全和致命性贫血，MD的标志。这些数据强烈支持该7Q编码基因在MDS病因中的作用。但是，7染色体缺失通常很大，并且跨越了改变造血或导致造血的其他基因在小鼠模型中删除时髓样疾病。这些数据表明7Q可能是连续的基因综合征区域，其中多个相邻基因的损失导致疾病发展。我们的初步数据表明，人类K562白血病细胞中的CUX1损失降低了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的损失是H3K27甲基转移酶，在鼠造血祖细胞中，与任何一种单独的基因。这些数据为7Q是连续基因综合征区域的假设提供了支持。这提案的目的是：1）利用CRISPR-CAS9基因编辑来识别组合7Q基因缺失与CUX1损失合作，以驱动DEL（7Q）发病机理； 2）定义了7Q基因丢失的机制通过表征细胞缺乏的表观遗传和转录景观来驱动DEL（7Q）发病机理单独或单独使用EZH2损失的CUX1。该提议将提高我们对7号染色体的理解删除并为我提供髓样肿瘤和基因组学中的专业技能，这将推动我致力于独立调查员。