11Q23 LEUKEMIA--ANALYSIS OF SECONDARY LEUKEMIAS AND AF-4

23 年 11 季度白血病——继发性白血病和 AF-4 的分析

• 批准号: 2109094
• 负责人: PETER H DOMER
• 金额: $ 6.24万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-02-01 至 1995-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2109094
• 关键词: DNA topoisomerases; acute leukemia; carcinogenesis; chromosome translocation; embryonic stem cell; enzyme inhibitors; gene conversion; genetic manipulation; genetically modified animals; hematopoiesis; human tissue; in situ hybridization; laboratory mouse; medical complication; molecular cloning; mutant; neoplasm /cancer genetics; nucleic acid sequence; open reading frames; protein structure function; recombinant DNA; transcription factor

The 11q23 cytogenetic locus is involved in a wide range of acute leukemia associated translocations. Numerous partner chromosomes form translocations with this locus producing three clinicopathologic syndromes. These are an acute lymphoblastic leukemia with mixed lineage features, acute myeloid leukemia with monocytic differentiation, and secondary acute leukemia in patients who have been treated with topoiomserase II inhibitors. The 11q23 gene involved, first named MLL (Mixed Lineage Leukemia), is a putative zinc finger transcription factor. The two fundamental goals of this proposal are to understand how topoiomserase II inhibitors induce secondary leukemia and what role an MLL fusion partner, AF-4, plays in development. In order to begin to understand the mechanism by which topoisomerase II inhibitors produce 11q23 translocations we will clone and sequence a number of secondary leukemia breakpoints. Their location will then be compared to the location of in vivo mapped MLL topoisomerase II binding sites. AF-4 (ALL- 1 fused to 4) is the 4q21 gene involved in the Acute Mixed Lineage Leukemia associated t(4;11)(q21;q23). Like all other characterized MLL translocations, the t(4;11) produces a fusion transcript encoding a putative chimeric protein. Although AF-4 has features such as a putative nuclear targeting sequence, basic regions, and proline-rich region which suggest it is a transcription factor its biochemical function is unknown. AF-4 is expressed in a wide range of tissues at varying levels including primitive hematopoietic cell lines. AF-4's wide range of expression suggests it has a prominent role in development. In order to understand AF-4's role in development and in so doing shed light on how AF-4 derived sequences contribute to leukemogenesis this proposal describes an analysis of the role AF-4 plays in murine development. Its goals are to clone the murine AF-4 ((mAF-4) gene, use mAF-4 probes in in situ hybridization experiments through murine development, and use the AF-4 genomic clones for gene targeting experiments in embryonic stem (ES) cells which will lead to the creation of mice lacking a functional mAF-4 gene. These mice will offer definitive information on AF-4's role in development. The ES cells will also be used in the in vitro "embryoid body" model of hematopoiesis. The completion of this work will provide the basis for two long term programs of research; one whose goal is to understand the mechanism by which secondary leukemia translocations occur and how to control that process and the other which will elucidate the fundamental biology of the AF-4 gene.

11q23细胞遗传学基因座与广泛的急性白血病有关 相关的易位。 许多伴侣染色体形式 该基因座的易位产生三个临床病理学 综合征。 这些是带有混合谱系的急性淋巴细胞白血病 特征，具有单核细胞分化的急性髓样白血病， 接受治疗的患者的继发性急性白血病 拓扑合酶II抑制剂。 涉及的11q23基因，首先命名为MLL （混合谱系白血病），是推定的锌指转录因子。 该提议的两个基本目标是了解如何 拓扑合酶II抑制剂诱导继发性白血病以及MLL的作用 Fusion合作伙伴AF-4正在开发中。 为了开始 了解拓扑异构酶II抑制剂产生的机制 11q23易位，我们将克隆并序列多个次级 白血病断裂点。 然后将他们的位置与 体内映射的MLL拓扑异构酶II结合位点的位置。 AF-4（all- 1融合到4）是参与急性混合谱系的4q21基因 白血病相关t（4; 11）（Q21; Q23）。 像所有其他特征MLL一样 易位，t（4; 11）产生编码A的融合转录本 推定的嵌合蛋白。 虽然AF-4具有诸如推定的功能 核靶向序列，基本区域和富含脯氨酸的区域 表明它是转录因子的生化功能尚不清楚。 AF-4在不同级别的多种组织中表达 原始造血细胞系。 AF-4的广泛表达 表明它在发展中具有重要作用。 为了理解 AF-4在开发中的作用，并因此阐明了AF-4的衍生方式 序列有助于白血病，该提案描述了一个分析 AF-4在鼠开发中的作用。 它的目标是克隆 鼠AF-4（（MAF-4）基因，在原位杂交中使用MAF-4探针 通过鼠开发进行实验，并使用AF-4基因组克隆 用于基因靶向胚胎（ES）细胞中的实验 导致创建缺乏功能性MAF-4基因的小鼠。 这些老鼠 将提供有关AF-4在开发中的作用的明确信息。 ES 细胞也将用于体外的“胚胎体”模型 造血。 这项工作的完成将为两个 长期研究计划；一个目标是了解 次要白血病易位的机制以及如何 控制该过程，另一个将阐明基本的过程 AF-4基因的生物学。