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（由申请方提供）：治疗相关骨髓肿瘤（t-MN）是细胞毒性治疗的晚期并发症，通常用于原发性恶性疾病。5号染色体长臂del（5 q）的杂合缺失经常在使用烷化剂进行细胞毒性治疗后的t-MN中观察到，并且与TP 53的缺失或突变相关。为了鉴定5号染色体上的白血病相关基因，我们先前描绘了5q31.2的970 kb常见缺失片段（CDS），并鉴定了该CDS内的第一个单倍不足髓样抑制基因EGR 1。我们还确定APC是5 q上的另一个单倍性不足的髓系抑制基因。我们开发了Mx 1-Cre+ Apcfl/+诱导模型，并表明Apc对造血干细胞和祖细胞（HSPCs）的维持和存活至关重要。Apcdel/+小鼠发生严重的大红细胞性贫血，重现了具有del（5 q）的t-MN的特征。值得注意的是，Egr 1和Apc的一致性单倍不足合作加速贫血发作。我们发现，在Egr 1和Apc单倍型不足的HSPC中，细胞内在的Tp 53缺失导致小鼠发生侵袭性AML，这代表了人类del（5 q）AML的第一个小鼠模型。我们假设5 q含有一个或多个额外的髓系抑制基因（顺式突变），与EGFR 1和APC单倍不足，以及额外的合作突变（反式突变）白血病的发生所需的。该项目的总体目标是确定导致烷化剂诱导的具有del（5 q）的t-MN的协同突变和遗传途径。通过合作，我们将比较通过t-MN患者和del（5 q）小鼠模型的基因组分析确定的遗传途径，以及涉及-7/del（7 q）和17 p丢失的单倍不足基因的小鼠模型，通常与del（5 q）一起出现在t-MN中。在目的1中，我们将通过表征EGFR 1在造血中的作用来确定EGFR 1转化的分子机制。具体来说，我们将确定EGR 1在HSPC和具有del（5 q）的t-MN中的转录靶点，并研究5 q和7 q上的病变合作的机制。在目标2中，我们将通过表征Egr 1、Apc和Tp 53单倍不足小鼠或ENU处理的Egr 1 +/-小鼠中产生的骨髓肿瘤的基因组模式，来鉴定在骨髓肿瘤发病机制中与EGFR 1和/或APC单倍不足协同作用的基因突变（一种烷化剂诱导的髓样肿瘤），并通过评估5 q上候选髓样抑制基因的协同作用，例如，CSNK 1A 1、SPRY 4和赖氨酸特异性脱氨酶KDM 3B。在进行这项工作时，我们将为临床前研究产生遗传上准确和易于处理的体内模型，为研究药物代谢的基本问题提供关键资源。 t-MN中的电阻。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。