GENETICS OF MYELODYSPLASTIC SYNDROMES

骨髓增生异常综合征的遗传学

基本信息

批准号：
8841404
负责人：
Matthew J Walter
金额：
$ 37.43万
依托单位：
WASHINGTON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-08-01 至 2017-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8841404
关键词：
Acute Myelocytic Leukemia Age Apoptosis Biological Assay Blood Bone Marrow Cells Bone Marrow Transplantation CD34 gene Candidate Disease Gene Cell Cycle Cell Cycle Kinetics Cells Chromosome abnormality Chromosomes Chromosomes, Human, Pair 5 Complication Data Defect Development Disease Distal Dominant Genes Dose Dysmyelopoietic Syndromes Engineering Erythroid Progenitor Cells Event Gene Mutation Gene Targeting Genes Genetic Goals Hematopoiesis Hematopoietic Human Individual Ineffective Hematopoiesis Insertional Mutagenesis Knock-out Knockout Mice Laboratories Macrocytic Anemia Measures Modeling Molecular Chaperones Moloney Leukemia Virus Monitor Mus Mutate Newborn Infant Outcome Patients Penetrance Phenotype Population Prevalence Proteins RNA Interference Recurrence Reporter Retroviridae Risk S Phase Site Stem cells Syndrome Testing Viral Wild Type Mouse Work arm chromosome 5q loss defined contribution effective therapy erythroid differentiation improved integration site interstitial leukemia mouse development mouse model outcome forecast overexpression progenitor stem

项目摘要

DESCRIPTION (provided by applicant): The long-term goal of this project is to identify and characterize genes that contribute to the development and progression of myelodysplastic syndromes (MDS). A better understanding of these genes may allow us to create effective therapies for patients with MDS and improve outcomes. An interstitial deletion involving one copy of the long arm of chromosome 5 (5q) is among the most common cytogenetic abnormalities in de novo and therapy-related MDS (25-40% of patients). We identified HSPA9 as a candidate gene located on the chromosome 5q31.2 commonly deleted region that contributes to altered hematopoiesis. We propose to define the mechanism of altered hematopoiesis caused by reduced levels of HSPA9 and to test whether Hspa9 haploinsufficiency contributes to MDS initiation and progression using primary human hematopoietic cells and heterozygous Hspa9 knock-out mice (Hspa9+/-), respectively, in the following specific aims: Specific Aim 1: We will determine whether the accelerated apoptosis and altered cell cycle kinetics observed following HSPA9 knockdown are p53-dependent. Because HSPA9 is known to physically interact with p53 in several models, we will determine whether they interact in primary human CD34+ cells. We will measure p53 activation in CD34+ cells following HSPA9 knockdown using a reporter assay and identify candidate p53-target genes responsible for the phenotype. We will validate the importance of p53 and the candidate genes using murine knockout models and RNA interference in primary human CD34+ cells. Specific Aim 2: We will establish whether haploinsufficiency of Hspa9 cooperates with Rps14 haploinsufficiency in mice. Mice lacking one copy of Rps14, a del(5q) gene, develop a macrocytic anemia and reduced progenitor cells. Most chromosome 5q deletions produce haploinsufficiency of both Hspa9 and Rps14 genes, suggesting that loss of both genes may cooperate in MDS. To directly test whether haploinsufficiency of Hspa9 and Rps14 cooperate during MDS initiation, we will intercross Hspa9+/- mice with mice lacking one copy of Rps14 and comprehensively characterize the hematopoiesis of singly or doubly heterozygous mice. Specific Aim 3: We will determine whether Hspa9 haploinsufficiency predisposes mice to develop leukemia. A devastating complication of MDS is the development of leukemia, which is highly-associated with deletions spanning chromosome 5q31.2. Identifying genes that contribute to del(5q31.2)-associated leukemia is vital to our understanding of this disease. To directly test whether haploinsufficiency of Hspa9 contributes to leukemia development, we will infect Hspa9+/- or wild-type littermate mice with a modified Moloney murine leukemia virus (MOL4070LTR retrovirus, a well established AML model) and monitor mice for the development of AML. We will identify and study candidate cooperating genes using mouse models.

描述（由申请人提供）：该项目的长期目标是识别和表征有助于骨髓增生异常综合征（MDS）发生和进展的基因。更好地了解这些基因可能使我们能够为 MDS 患者创造有效的疗法并改善预后。涉及 5 号染色体长臂 (5q) 一份副本的间质缺失是新发 MDS 和治疗相关 MDS（25-40% 的患者）中最常见的细胞遗传学异常之一。我们将 HSPA9 确定为位于染色体 5q31.2 常缺失区域的候选基因，该区域有助于改变造血功能。我们建议分别使用原代人类造血细胞和杂合 Hspa9 敲除小鼠 (Hspa9+/-) 来定义 HSPA9 水平降低引起的造血改变的机制，并测试 Hspa9 单倍体不足是否会导致 MDS 的发生和进展。具体目标：具体目标 1：我们将确定 HSPA9 敲除后观察到的加速细胞凋亡和细胞周期动力学改变是否依赖于 p53。由于已知 HSPA9 在多种模型中与 p53 发生物理相互作用，因此我们将确定它们是否在原代人 CD34+ 细胞中相互作用。我们将使用报告基因检测来测量 HSPA9 敲低后 CD34+ 细胞中 p53 的激活，并鉴定负责表型的候选 p53 靶基因。我们将使用小鼠敲除模型和原代人 CD34+ 细胞中的 RNA 干扰来验证 p53 和候选基因的重要性。具体目标 2：我们将确定小鼠中 Hspa9 的单倍体不足是否与 Rps14 单倍体不足协同作用。缺乏一份 Rps14（一种 del(5q) 基因）的小鼠会出现大细胞性贫血，祖细胞数量减少。大多数染色体 5q 缺失都会导致 Hspa9 和 Rps14 基因的单倍体不足，表明这两个基因的缺失可能在 MDS 中协同作用。为了直接测试 Hspa9 和 Rps14 单倍体不足是否在 MDS 启动过程中协同作用，我们将 Hspa9+/- 小鼠与缺乏一份 Rps14 的小鼠杂交，并全面表征单杂合子或双杂合子小鼠的造血功能。具体目标 3：我们将确定 Hspa9 单倍体不足是否会使小鼠易患白血病。 MDS 的一个毁灭性并发症是白血病的发展，这与跨越染色体 5q31.2 的缺失高度相关。识别导致 del(5q31.2) 相关白血病的基因对于我们了解这种疾病至关重要。为了直接测试 Hspa9 单倍体不足是否会导致白血病的发展，我们将用改良的莫洛尼鼠白血病病毒（MOL4070LTR 逆转录病毒，一种成熟的 AML 模型）感染 Hspa9+/- 或野生型同窝小鼠，并监测小鼠 AML 的发展。我们将使用小鼠模型来识别和研究候选合作基因。