Determining the Role of BCOR Mutations in Myeloid Malignancies

确定 BCOR 突变在骨髓恶性肿瘤中的作用

• 批准号: 9254536
• 负责人: Robert Coleman Lindsley
• 金额: $ 17.7万
• 依托单位: DANA-FARBER CANCER INST
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-04-15 至 2021-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9254536
• 关键词: Acute Myelocytic Leukemia; Acute leukemia; Adult; Advisory Committees; Affect; Attenuated; Automobile Driving; Biological; Biology; Biometry; Blood; Bone Marrow; CRISPR/Cas technology; Cell Line; Cell physiology; Cells; ChIP-seq; Chemicals; Chromatin; Clinical; Collaborations; Communities; Complex; Couples; DNA Methylation; DNA sequencing; Dana-Farber Cancer Institute; Data; Dependence; Development; Development Plans; Differentiation and Growth; Disease; Disease Progression; Dysmyelopoietic Syndromes; EZH2 gene; Environment; Epigenetic Process; Failure; Gene Expression; Gene Mutation; Genes; Genetic; Genetic Transcription; Genetically Engineered Mouse; Genomics; Goals; Growth Factor; Hematopoiesis; Hematopoietic; Hematopoietic stem cells; Histone H3; Histones; Human; Immunoprecipitation; In Vitro; Individual; International; Knockout Mice; Lead; Lysine; Malignant Neoplasms; Mediating; Mentorship; Modeling; Modification; Molecular; Morbidity - disease rate; Mus; Mutate; Mutation; Myelogenous; Myeloproliferative disease; Oncogenic; Outcome; PRC1 Protein; Pancytopenia; Pathogenesis; Pathway interactions; Patients; Physicians; Polycomb; Property; Proteins; RNA Splicing; Recruitment Activity; Recurrence; Reporting; Research; Research Personnel; Resistance; Role; Sampling; Scientist; Somatic Mutation; Stem cells; System; Technology; Testing; Time; Training; Transcriptional Regulation; Variant; Western Blotting; Xenograft procedure; career; career development; cohort; defined contribution; epigenome; genome editing; high risk; improved; in vitro Assay; in vivo; in vivo Model; innovation; insight; leukemia; leukemogenesis; loss of function mutation; mortality; mouse model; new therapeutic target; novel; older patient; public health relevance; self-renewal; therapy resistant; tool

 DESCRIPTION (provided by applicant): Acute myeloid leukemia (AML) is a genetically heterogeneous bone marrow cancer affecting at least 15,000 individuals per year in the US and causing significant morbidity and mortality. We identified BCOR loss of function mutations among a set of genes that is specifically mutated in AML that arises after myelodysplastic syndromes, is common among older patients, and is associated with poor clinical outcomes. The mechanisms by which BCOR mutations drive leukemogenesis are not understood. In preliminary studies, we showed that Bcor mutations promote increased hematopoietic stem cell self-renewal and sensitize primary cells to activating RAS mutations. These represent the first reported mouse models of Bcor-deficient myeloid disease. We also demonstrate for the first time that BCOR protein interacts in human AML cell lines with components of a variant polycomb repressive complex 1 (PRC1), suggesting a functional importance of ubiquinated histone 2A lysine 119 (H2AK119ub) in AML development. Our hypothesis is that somatic mutations affecting BCOR cause failure to recruit PRC2 to polycomb repressive targets via reduction of H2AK119ub. To define the molecular basis of BCOR function during initiation and progression of myeloid malignancies, we propose the following Specific Aims 1) Define the contribution of Bcor deletion to myeloid transformation in primary Tet2-/- hematopoietic cells. We will use CRISPR/Cas9 gene editing in primary mouse Tet2-/- cells in vitro and in vivo to define the functional impact of Bcor loss of function mutations on hematopoietic stem cell self-renewal and lineage-specific differentiation. 2) Identify the role of RAS mutations in promoting transformation of Bcor- deficient cells. We will take advantage of novel in vitro and in vivo models to identify the cooperative effects of activating RAS mutations during transformation of Bcor-deficient cells. 3) Define the impact of BCOR deficiency on histone epigenetic modifications during myeloid leukemogenesis. We will define the global and locus-specific effects of BCOR deletion on histone H3 epigenetic marks in a human AML cell line and assess whether genetic and chemical targeting of EZH2 attenuates BCOR-associated transformation. Collectively, the information learned in these studies will provide new insights into the biology o AML and lay the groundwork for developing novel targeted therapies. The applicant, Dr. Coleman Lindsley, has outlined a five-year career development plan to meet his goal of becoming an independent investigator in translational leukemia research. Dr. Lindsley has assembled an Advisory Committee of internationally recognized experts to provide scientific and career mentorship. He has established collaborations with experts in cancer epigenetics, leukemia genetics, and applied biostatistics to provide experimental advice and specific training in the field. Dana-Farber Cancer Institute is an optimal environment for completion of Dr. Lindsley's scientific and career goals, given its outstanding research community and long-standing record for training independent physician-scientist.

 描述（由申请人提供）：急性髓性白血病（AML）是一种遗传异质性骨髓癌，在美国每年至少影响15，000例患者，并导致显著的发病率和死亡率。我们在一组基因中发现了BCOR功能缺失突变，这些基因在骨髓增生异常综合征后出现的AML中特异性突变，在老年患者中很常见，并与不良临床结局相关。BCOR突变驱动白血病发生的机制尚不清楚。在初步研究中，我们发现Bcor突变促进造血干细胞自我更新增加，并使原代细胞对激活RAS突变敏感。这些代表了第一次报道的Bcor缺陷型骨髓疾病的小鼠模型。我们还首次证明了BCOR蛋白在人AML细胞系中与变体polycomb抑制复合物1（PRC 1）的组分相互作用，表明泛素化组蛋白2A赖氨酸119（H2 AK 119 ub）在AML发展中的功能重要性。我们的假设是，影响BCOR的体细胞突变导致PRC 2无法通过减少H2 AK 119 ub募集到多梳抑制靶点。为了确定BCOR功能在骨髓恶性肿瘤的起始和进展期间的分子基础，我们提出了以下具体目的：1）确定Bcor缺失对原代Tet 2-/-造血细胞中骨髓转化的贡献。我们将在体外和体内的原代小鼠Tet 2-/-细胞中使用CRISPR/Cas9基因编辑，以确定Bcor功能丧失突变对造血干细胞自我更新和谱系特异性分化的功能影响。2)确定RAS突变在促进Bcor缺陷细胞转化中的作用。我们将利用新的体外和体内模型，以确定在Bcor缺陷细胞转化过程中激活RAS突变的协同作用。3)明确骨髓性白血病发生过程中BCOR缺乏对组蛋白表观遗传修饰的影响。我们将确定BCOR缺失对人类AML细胞系中组蛋白H3表观遗传标记的全局和位点特异性影响，并评估EZH 2的遗传和化学靶向是否减弱BCOR相关转化。总的来说，这些研究中获得的信息将为AML生物学提供新的见解，并为开发新的靶向治疗奠定基础。申请人科尔曼林斯利博士概述了五年职业发展计划，以实现他成为转化白血病研究独立研究者的目标。Lindsley博士组建了一个由国际知名专家组成的咨询委员会，提供科学和职业指导。他与癌症表观遗传学、白血病遗传学和应用生物统计学方面的专家建立了合作关系，为该领域提供实验建议和具体培训。Dana-Farber癌症研究所是Lindsley博士完成科学和职业目标的最佳环境，因为其杰出的研究社区和长期以来培养独立医生科学家的记录。