The role of fusion protein, OTT-MKL1, in acute megakaryoblastic leukemia

融合蛋白OTT-MKL1在急性巨核细胞白血病中的作用

• 批准号: 8254784
• 负责人: Yeun Hee Kim
• 金额: $ 3.37万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-06-21 至 2013-01-20
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8254784
• 关键词: 1p13; 22q13; Acute Megakaryocytic Leukemias; Acute Myelocytic Leukemia; Affect; Apoptosis; Blood Platelets; Bone Marrow; CBFB gene; Candidate Disease Gene; Cell Death; Cell Death Induction; Cell Line; Cell Survival; Cells; Child; Chimeric Proteins; Chromosomal translocation; Chromosome abnormality; Chromosomes; Chromosomes, Human, Pair 1; Complement; DNA; Data; Development; Diagnostic; Disease; Disease remission; Doxycycline; Engineering; Fetal Liver; Fusion Protein Expression; Gene Expression; Genes; Genomics; Germ Cells; Hematopoietic; Human; Infant; Knockout Mice; Laboratories; Lesion; Leukemic Cell; Libraries; MYH11 gene; Megakaryoblast; Megakaryocytes; Megakaryocytopoieses; Molecular; Mus; Mutation; Mutation Analysis; Normal Cell; Patients; Pattern; Process; Production; Publishing; RUNX1 gene; Recurrence; Reporting; Role; Sampling; Screening procedure; Signal Pathway; Signal Transduction; Testing; Transgenes; base; bcr-abl Fusion Proteins; cancer cell; exome; fusion gene; knock-down; leukemia; leukemogenesis; mouse model; outcome forecast; prevent; small hairpin RNA; small molecule; small molecule libraries; stable cell line; transgene expression; tumorigenesis

DESCRIPTION (provided by applicant): Acute megakaryoblastic leukemia (AMKL) is a subtype of acute myeloid leukemia characterized by increased megakaryoblasts in the fetal liver and/or bone marrow. The leukemia usually presents in infants, and has a very poor prognosis. One of the main cytogenetic abnormalities associated with AMKL is a translocation between chromosomes 1 and 22, resulting in the fusion protein, OTT-MKL1 (OM). In our laboratory, we discovered that OTT and MKL1 are differentially regulated in normal megakaryopoiesis as OTT expression is downregulated whereas MKL1 expression is upregulated during the differentiation, and we have begun to elucidate the functions of OTT and MKL1. However, the molecular function of OM in megakaryocyte differentiation and/or in leukemogenesis is largely unknown. We have observed a rapid induction of cell death upon OM expression in various cell lines and primary cells. Furthermore, in a previously published mouse model expressing the OM fusion transgene, development of AMKL in these mice is slow and rare. These results suggest that OM induced leukemia is a multistep process that requires acquisition of additional mutations in cancer cells for survival of the initial cell death induced by OM and for subsequent proliferation. Therefore, I hypothesize that additional collaborating genomic lesions promote OM- induced AMKL and these mutations define a network of factors that promote AMKL. I propose to elucidate the mechanisms by which OM disrupts normal megakaryocytic differentiation and induces leukemia. I will identify potential OM-collaborating mutations based on deep sequencing data from an AMKL patient sample and validate these mutations using primary murine and human hematopoietic cells with engineered inducible OM transgene expression. I will complement my mutation analysis using shRNA and small molecule screening approaches to functionally define genes and signal networks affect by the OM fusion gene. These studies will provide critical molecular details of OM and its leukemogenic role in AMKL to understand the disease and for development of targeted therapies for this disease. ) PUBLIC HEALTH RELEVANCE: Chromosome translocation is a common structural abnormality in cancer cells that results from joining of two separate chromosomes at a specific breakpoint to generate a fusion gene whose product promotes oncogenesis. Acute megakaryoblastic leukemia is associated with a recurrent translocation that results in a fusion protein. My project aims to determine molecular mechanisms responsible for the fusion protein to induce acute megakaryoblastic leukemia. )

描述（由申请人提供）：急性巨核细胞白血病（AMKL）是急性髓性白血病的一种亚型，其特征是胎儿肝脏和/或骨髓中的巨核细胞增加。白血病通常出现在婴儿中，并且具有非常差的预后。与AMKL相关的主要细胞遗传学异常之一是染色体1和22之间的易位，导致融合蛋白OTT-MKL 1（OM）。在我们的实验室中，我们发现OTT和MKL 1在正常巨核细胞中受到差异调节，因为在分化过程中OTT表达下调，而MKL 1表达上调，并且我们已经开始阐明OTT和MKL 1的功能。然而，OM在巨核细胞分化和/或白血病发生中的分子功能在很大程度上是未知的。我们已经观察到OM在各种细胞系和原代细胞中表达后快速诱导细胞死亡。此外，在先前发表的表达OM融合转基因的小鼠模型中，AMKL在这些小鼠中的发展缓慢且罕见。这些结果表明，OM诱导的白血病是一个多步骤的过程，需要在癌细胞中获得额外的突变，以存活OM诱导的初始细胞死亡和随后的增殖。因此，我假设额外的协作基因组病变促进OM诱导的AMKL，并且这些突变定义了促进AMKL的因子网络。我建议阐明OM破坏正常巨核细胞分化和诱导白血病的机制。我将根据AMKL患者样本的深度测序数据确定潜在的OM协作突变，并使用具有工程诱导OM转基因表达的原代鼠和人造血细胞验证这些突变。我将使用shRNA和小分子筛选方法来补充我的突变分析，以功能性地定义受OM融合基因影响的基因和信号网络。这些研究将提供OM及其在AMKL中致白血病作用的关键分子细节，以了解该疾病并开发针对该疾病的靶向治疗。) 公共卫生关系：染色体易位是癌细胞中常见的结构异常，其由两个单独的染色体在特定断点处连接以产生融合基因而引起，该融合基因的产物促进肿瘤发生。急性巨核细胞白血病与导致融合蛋白的复发性易位有关。我的项目旨在确定融合蛋白诱导急性巨核细胞白血病的分子机制。)