In Vivo Functional Analysis of Chromosome 7q22 Deletions in Myeloid Malignancies

骨髓恶性肿瘤中染色体 7q22 缺失的体内功能分析

• 批准号: 9924474
• 负责人: KEVIN M. SHANNON
• 金额: $ 33.87万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-05-22 至 2022-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9924474
• 关键词: 1 year old; Abnormal Cell; Acute Myelocytic Leukemia; Address; Adolescent; Adult; Aftercare; Alkylating Agents; Blood; CHEK2 gene; CRISPR/Cas technology; Cancer Survivor; Cells; Child; Childhood; Chromosome 7; Chromosome Arm; Chromosome Band; Chromosome Deletion; Chromosome abnormality; Chromosomes; Complex; Cytogenetic Analysis; Cytogenetics; DNA; DNA Damage; DNA sequencing; Data; Defect; Development; Drug resistance; Dysmyelopoietic Syndromes; Engineering; Ethylnitrosourea; Exhibits; Exposure to; Fluorescent in Situ Hybridization; Genes; Genetic; Genetic Transcription; Genetically Engineered Mouse; Genomic DNA; Germ Lines; Growth; Hematologic Neoplasms; Hematological Disease; Hematopoiesis; Hematopoietic; Hematopoietic stem cells; Human; Impairment; Inherited; Lymphoid; Malignant - descriptor; Malignant Childhood Neoplasm; Malignant Neoplasms; Modeling; Modernization; Molecular; Monosomy 7; Mouse Strains; Mus; Mutagens; Mutation; Myelogenous; Myeloproliferative disease; Output; Pathogenesis; Patients; Phenotype; Population; Populations at Risk; Predisposition; Radiation therapy; Reagent; Recurrence; Refractory; Resources; Second Primary Cancers; Solid; Specimen; System; Testing; Therapeutic; Treatment Protocols; Tumor Suppressor Genes; Work; aged; cancer genome; cell behavior; chromosome 7 loss; chromosome 7q loss; clinical risk; cohort; genetic analysis; genome-wide; genome-wide analysis; high risk; in vivo; leukemia; leukemic transformation; leukemogenesis; mouse development; mutant; novel; novel therapeutic intervention; reconstitution; response; self-renewal; transcriptome; young adult

ABSTRACT Recurring losses of large chromosomal regions are a hallmark of pediatric and adult cancer genomes that pose exceptional challenges for uncovering how these deletions contribute to malignant growth. Monosomy 7 (-7) and del(7q) (-7/del(7q)) are recurring cytogenetic abnormalities in de novo myeloid malignancies that are strongly associated with cases of myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) arising in children and in adolescent/young adult (AYA) patients with inherited cancer predispositions and in those who develop myeloid malignancies after treatment for a primary cancer. Therapy-induced MDS and AML (t-MDS and t-AML) are particularly relevant to the pediatric and AYA population due to modern intensive treatment protocols for many solid cancers, which are frequently curative. As a result, there is a large and growing population of “at risk” pediatric and AYA cancer survivors. Unfortunately, t-MDS/t-AML and other myeloid malignancies with chromosome 7 deletions are highly refractory to current therapies. Extensive cytogenetic and genome wide analysis studies implicate deletions of chromosome band 7q22 in leukemogenesis; however, sequencing studies and transcriptome analysis did not reveal frequent homozygous inactivation of any candidate 7q tumor suppressor gene in myeloid malignancies. These data implicate haploinsufficiency for one or more 7q genes in leukemogenesis, which pose formidable challenges for elucidating the underlying molecular mechanisms. To address this fundamental problem, we deployed chromosome engineering to create 5A3+/del and 5G2+/del mice, which respectively harbor deletions in mouse chromosome bands 5A3 and 5G2. These deletions span ~4 MB of genomic DNA that is syntenic to the most common 7q22 deletions identified in human patients. 5A3+/del hematopoietic stem and progenitor cells (HSPC) exhibit “preleukemic” abnormalities, but these mice do not spontaneously develop MDS or AML. Preliminary studies of 5G2+/del mice also revealed HSPC abnormalities and exposing this strain to N-ethyl-N-nitrosourea (ENU) accelerated the development of hematologic cancer. We will utilize these novel models of 7q22 deletions to pursue the following specific aims: (1) to functionally interrogate hematopoiesis in 5G2+/del and 5A3+/del/5G2+/del mice and to observe cohorts of mice for the development of myeloid malignancies; (2) to investigate the effects of DNA damaging agents on 5A3+/del/5G2+/del HSPC; and, (3) to model the complex genetics of myeloid malignancies with -7/del(7q) by introducing cooperating mutations into 5A3+/del/5G2+/del HSPC and assessing the phenotypic and functional consequences in vivo. Genetically engineered mice that accurately model recurrent chromosome band 7q22 deletions found in human myeloid malignancies are a versatile system for performing functional studies and testing new therapeutic strategies.

抽象的 大型染色体区域的反复损失是小儿和成人癌症基因组的标志 在发现这些缺失如何导致恶性增长的情况下构成出色的挑战。单肌7 （-7）和DEL（7Q）（-7/del（7q））是从头髓样恶性肿瘤中的经常性细胞遗传学异常 与骨髓增生综合征（MDS）和急性髓样白血病（AML）的病例密切相关 在儿童和青少年/年轻成人（AYA）遗传性癌症易感性的患者中 治疗原发性癌症后，患有髓样恶性肿瘤。治疗引起的MDS和AML（T-MD） 由于现代强化治疗 许多固体癌症的方案，这些癌症经常是治愈性的。结果，有一个大而增长 “处于危险”的小儿和AYA癌症存活的人群。不幸的是，T-MDS/T-AML和其他髓样 染色体7缺失的损害对当前疗法具有高度难治性。广泛的细胞遗传学 基因组广泛的分析研究暗示了染色体带7q22在白血病中的缺失。然而， 测序研究和转录组分析并未揭示任何纯合的灭活 念珠菌恶性肿瘤中候选7Q肿瘤抑制基因。这些数据暗示了一个单倍度不足 或更多的7Q基因在白血病中，这对阐明潜在的挑战构成了巨大的挑战 分子机制。为了解决这个基本问题，我们将染色体工程部署到 创建5A3+/DEL和5G2+/DEL MICE，它们在鼠标染色体带5A3和 5G2。这些缺失涵盖了与最常见的7q22缺失同步的基因组DNA的〜4 Mb 在人类患者中确定。 5A3+/DEL造血茎和祖细胞（HSPC）暴露了“ pReleukemic” 异常，但是这些小鼠不会在赞助的情况下发展MD或AML。 5G2+/DEL小鼠的初步研究 还揭示了HSPC异常，并将这种菌株暴露于N-乙基n-硝酸（ENU）加速了 血液学癌症的发展。我们将利用这些7q22删除的新型模型来追求 以下特定目的：（1）在5G2+/DEL和5A3+/DEL/DEL/5G2+/DEL MICE中询问造血的功能。 观察小鼠的骨髓发育； （2）研究DNA的影响 5A3+/DEL/5G2+/DEL HSPC上的破坏代理； （3）建模髓样恶性菌的复杂遗传学 使用-7/del（7q）通过将合作突变引入5A3+/DEL/5G2+/DEL HSPC并评估表型 体内功能后果。精确模拟复发的基因工程小鼠 在人髓样恶性肿瘤中发现的染色体带7q22缺失是一种用于执行的多功能系统 功能研究和测试新的治疗策略。