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

基本信息

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
项目类别：
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

项目摘要

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.

抽象的大染色体区域的反复丢失是儿科和成人癌症基因组的一个标志，揭示这些缺失如何导致单体性 7 的恶性生长提出了特殊的挑战。 (-7) 和 del(7q) (-7/del(7q)) 是新发骨髓恶性肿瘤中反复出现的细胞遗传学异常，与骨髓增生异常综合征 (MDS) 和急性髓系白血病 (AML) 病例密切相关患有遗传性癌症倾向的儿童和青少年/青年 (AYA) 患者以及患有以下疾病的患者原发性癌症治疗后出现骨髓恶性肿瘤（t-MDS）。由于现代强化治疗，t-AML）与儿科和 AYA 人群特别相关许多实体癌症的治疗方案通常是可以治愈的，因此，存在大量且不断增长的治疗方案。不幸的是，t-MDS/t-AML 和其他骨髓细胞疾病的“高危”儿童和 AYA 癌症幸存者。 7 号染色体缺失的恶性肿瘤对目前的广泛细胞遗传学治疗非常无效。然而，全基因组分析研究表明 7q22 染色体带的缺失；测序研究和转录组分析没有揭示任何频繁的纯合失活骨髓恶性肿瘤中的候选 7q 肿瘤抑制基因这些数据表明其中一个基因存在单倍体不足。或更多 7q 基因参与白血病发生，这对阐明其潜在机制提出了巨大的挑战为了解决这个基本问题，我们部署了染色体工程。创建 5A3+/del 和 5G2+/del 小鼠，它们分别在小鼠染色体带 5A3 和 5A3 中缺失 5G2。这些缺失跨越约 4 MB 的基因组 DNA，与最常见的 7q22 缺失同线。在人类患者中发现 5A3+/del 造血干细胞和祖细胞 (HSPC) 表现出“白血病前期”。异常，但这些小鼠不会自发发展为 5G2+/del 小鼠的 MDS 或 AML。还发现 HSPC 异常，并将该菌株暴露于 N-乙基-N-亚硝基脲 (ENU) 加速了我们将利用这些 7q22 缺失的新模型来探索血液癌症的发展。以下具体目标：(1) 对 5G2+/del 和 5A3+/del/5G2+/del 小鼠的造血功能进行功能性询问，并观察小鼠群体的骨髓恶性肿瘤的发展 (2) 以研究 DNA 的影响； 5A3+/del/5G2+/del HSPC 的损伤剂；(3) 模拟骨髓恶性肿瘤的遗传复合物；通过将协同突变引入 5A3+/del/5G2+/del HSPC 并评估表型，使用 -7/del(7q) 以及精确模拟复发的基因工程小鼠的体内功能后果。在人类骨髓恶性肿瘤中发现的染色体带 7q22 缺失是一个多功能系统，用于执行功能研究和测试新的治疗策略。