Molecular mechanisms of myeloid suppressor genes on chromosome 5

5号染色体骨髓抑制基因的分子机制

• 批准号: 8997482
• 负责人: MICHELLE M LE BEAU
• 金额: $ 36.14万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-02-01 至 2020-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8997482
• 关键词: 17p; 5q32; Acute Myelocytic Leukemia; Alkylating Agents; Anemia; Apoptosis; Bone Marrow; Bone Marrow Cells; CSNK1A1 gene; Cell Therapy; Cells; Characteristics; Chromosome abnormality; Chromosomes, Human, Pair 5; Chromosomes, Human, Pair 7; Collaborations; Cytotoxic Chemotherapy; DNA Sequence Alteration; Deaminase; Development; Disease; Drug resistance; Dysmyelopoietic Syndromes; Erythropoiesis; Ethylnitrosourea; Event; Frequencies; Genes; Genetic; Genomics; Goals; Health; Hematopoiesis; Hematopoietic; Hematopoietic stem cells; Human; Induced Mutation; Lead; Lesion; Lysine; Macrocytic Anemia; Maintenance; Malignant - descriptor; Maps; Modeling; Molecular; Monocytosis; Mus; Mutation; Myelogenous; Myeloid Leukemia; Myeloproliferative disease; Pancytopenia; Pathogenesis; Pathway interactions; Patients; Pattern; Play; Pronormoblasts; Regulatory Pathway; Resources; Role; Staging; Stem cells; Suppressor Genes; TP53 gene; Tumor Suppressor Genes; Work; arm; base; cellular targeting; chromosome 5q loss; chromosome 7q loss; cytotoxic; in vivo Model; insight; leukemia; leukemogenesis; loss of function; mouse model; novel therapeutics; outcome forecast; preclinical study; stem; stem cell therapy; transcription factor; treatment strategy

DESCRIPTION (provided by applicant): Therapy-related myeloid neoplasms (t-MNs) are late complications of cytotoxic therapy typically for primary malignant diseases. Heterozygous deletions of the long arm of chromosome 5, del(5q), are frequently noted in t-MN following cytotoxic treatment with alkylating agents, and are associated with loss or mutations of TP53. To identify a leukemia-related gene on chromosome 5, we previously delineated a 970 kb commonly deleted segment (CDS) of 5q31.2, and identified the first haploinsufficient myeloid suppressor gene within this CDS, EGR1. We also identified APC as another haploinsufficient myeloid suppressor gene on 5q. We developed an Mx1-Cre+ Apcfl/+-inducible model, and showed that Apc is essential for the maintenance and survival of hematopoietic stem and progenitor cells (HSPCs). Apcdel/+ mice develop a severe macrocytic anemia, recapitulating characteristic features of t-MN with a del(5q). Notably, concordant haploinsufficiency for Egr1 and Apc cooperates to accelerate anemia onset. We showed that cell intrinsic loss of Tp53 in HSPCs haploinsufficient for Egr1 and Apc led to the development of an aggressive AML in mice, representing the first mouse model for human del(5q) AML. We hypothesize that 5q contains one or more additional myeloid suppressor genes (cis mutations) that cooperate with EGR1 and APC haploinsufficiency, and that additional cooperating mutations (trans mutations) are required for leukemogenesis. The overall goal of this project is to identify cooperating mutations and genetic pathways leading to alkylating agent-induced t-MN with a del(5q). Through collaborations, we will compare genetic pathways identified by genomic analysis of t-MN patients and mouse models for the del(5q), as well as mouse models for the haploinsufficient genes involved in the - 7/del(7q) and loss of 17p, commonly seen together with the del(5q) in t-MN. In Aim 1, we will identify the molecular mechanisms of transformation by EGR1 by characterizing the role of EGR1 in hematopoiesis. Specifically, we will identify the transcriptional targets of EGR1 in HSPCs, and t-MNs with a del(5q), and examine the mechanism by which lesions on 5q and 7q cooperate. In Aim 2, we will identify genetic mutations that cooperate with haploinsufficiency of EGR1 and/or APC in the pathogenesis of myeloid neoplasms by characterizing the genomic pattern of myeloid neoplasms arising in mice with haploinsufficiency for Egr1, Apc, and Tp53, or ENU-treated Egr1+/- mice (an alkylating agent-induced myeloid neoplasm), and by evaluating the cooperative role of candidate myeloid suppressor genes on 5q, e.g., CSNK1A1, SPRY4, and the lysine specific deaminase, KDM3B. In conducting this work, we will generate genetically accurate and tractable in vivo models for preclinical studies, providing critical resources for investigating the fundamental problem of drug resistance in t-MN. Establishing the genetic pathways leading to t-MN may inform the development of biologically-based treatment strategies.

描述（由申请人提供）：与治疗相关的髓样肿瘤（T-MNS）是主要恶性疾病的细胞毒性疗法的晚期并发症。用烷基化剂的细胞毒性治疗后，在T-MN中经常注意到5号染色体（5q）的长臂的杂合缺失，并且与TP53的损失或突变有关。为了在5号染色体上鉴定白血病相关的基因，我们先前以5q31.2的范围划定了970 KB通常删除的片段（CD）（CDS），并确定了该CDS中的第一个单倍髓样抑制基因，EGR1，EGR1，EGR1。我们还将APC鉴定为5Q上的另一个单倍抑制髓样抑制基因。我们开发了MX1-CRE+ APCFL/+ - 诱导模型，并表明APC对于造血茎和祖细胞（HSPC）的维持和存活至关重要。 APCDEL/+小鼠患有严重的大细胞性贫血，用DEL概括了T-MN的特征（5Q）。值得注意的是，EGR1和APC的一致性不足性可以加速贫血发作。我们表明，HSPC中TP53的细胞内在损失对EGR1和APC的含量充满了，导致小鼠侵袭性AML的发展，这代表了人类DEL（5Q）AML的第一个小鼠模型。我们假设5Q包含一个或多个与EGR1和APC单倍弥倍不足的额外的髓样抑制基因（CIS突变），以及其他合作突变（反式突变）是白血病发生所需的。该项目的总体目标是确定与DEL诱导烷基化剂诱导的T-MN的合作突变和遗传途径（5Q）。通过合作，我们将比较DEL（5Q）的T-MN患者和小鼠模型的基因组分析确定的遗传途径，以及与-7/DEL（7Q）涉及的单倍弹性基因的小鼠模型和17P的损失，通常与T-MN中的DEL（5Q）一起看到。在AIM 1中，我们将通过表征EGR1在造血中的作用来确定通过EGR1的分子机制。具体而言，我们将确定HSPC中EGR1的转录靶标，以及具有DEL（5Q）的T-MN，并检查5Q和7Q配合病变的机制。 In Aim 2, we will identify genetic mutations that cooperate with haploinsufficiency of EGR1 and/or APC in the pathogenesis of myeloid neoplasms by characterizing the genomic pattern of myeloid neoplasms arising in mice with haploinsufficiency for Egr1, Apc, and Tp53, or ENU-treated Egr1+/- mice (an alkylating agent-induced myeloid肿瘤），并通过评估候选髓样抑制基因在5q上的合作作用，例如CSNK1A1，SPRY4和赖氨酸特异性脱氨酶KDM3B。在进行这项工作时，我们将生成用于临床前研究的遗传准确且可拖延的体内模型，为研究药物的基本问题提供了关键的资源 T-MN的抗性。建立导致T-MN的遗传途径可能会为基于生物学的治疗策略的发展提供信息。