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

• 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
• 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

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.

项目总结/摘要 7号染色体的全部或部分缺失[-7/del（7 q）]是最常见的核型异常之一。 骨髓疾病，特别是高危骨髓疾病的异常。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， 在一个或多个具有转化为急性白血病风险的血液谱系中的发育不良。-7/del（7 q）在10%中被发现 在成人MDS病例中，并且惊人地，在高达50%的儿童MDS病例中。-7/del（7 q）的存在与 染色体核型差，MDS风险高，预后比二倍体染色体病例差 7. -7/del（7 q）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的 分子异常，强烈提示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，这突出表明迫切需要更好地了解 MDS的复发性遗传特征可能导致新的治疗选择。 人类和小鼠7号染色体之间缺乏同线性是发育中的主要障碍。 -7/del（7 q）动物模型。在该领域的一项突破中，我们的实验室发现了CUX 1，一种同源框转录， 作为一种单倍不足的髓系肿瘤抑制基因，一种调节细胞增殖和凋亡的因子 位于7 q的常见缺失区域。我们的实验室设计了一个强力霉素诱导的shRNA CUX 1- 敲除小鼠和Cux 1缺陷小鼠发生具有三系发育异常和致死性的骨髓疾病 贫血是骨髓增生异常综合征的标志这些数据有力地支持了这个7 q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，并且跨越改变造血或导致造血功能障碍的其他基因。 当在小鼠模型中删除时，骨髓疾病。这些数据表明，7 q可能是一个连续的基因综合征 区域，其中多个相邻基因的整体丢失有助于疾病的发展。我们的初步 数据显示，人类K562白血病细胞中的CUX 1缺失降低了抑制性表观遗传组蛋白标记， H3K27me3.我们进一步表明，Cux 1和7 q基因Ezh 2（一种H3 K27甲基转移酶）的联合缺失， 在小鼠造血祖细胞中协同增加骨髓细胞体外扩增， 吉恩独自一人这些数据为7 q是一个连续的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基因编辑来鉴定组合7 q基因缺失， 与Cux 1缺失协同驱动del（7 q）发病机制; 2）确定7 q基因缺失的机制 通过表征缺失的细胞的表观遗传和转录景观来驱动del（7 q）发病机制， Cux 1单独或合并Ezh 2缺失。这个提议将推进我们对7号染色体的理解 缺失，并为我提供了一个专门的技能，在骨髓瘤和基因组学，将推动我 成为一名独立调查员