TRANSFERRING MECHANISMS AND BIOCHEMICAL REGULATION OF E2A-PBX1

E2A-PBX1的转移机制和生化调控

• 批准号: 6237091
• 负责人: MARK P KAMPS
• 金额: $ 8.37万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-02-01 至 1998-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6237091
• 关键词: 3T3 cells; acute myelogenous leukemia; cell differentiation; cell growth regulation; chimeric proteins; corticosteroid receptors; estrogen receptors; fibroblasts; fusion gene; gene induction /repression; gene mutation; genetic promoter element; genetic transcription; homeobox genes; laboratory mouse; molecular cloning; myeloid stem cell; neoplastic transformation; oncogenes; oncoproteins; pediatric neoplasm /cancer; transcription factor

This proposal examines how the altered transcription of cellular genes by the E2A-Pbx1 oncoprotein blocks myeloid differentiation and causes fibroblast transformation. It tests whether E2A-Pbx1 induces transcription of known genes that regulate normal growth or of a novel population of genes that regulate differentiation and growth by an alternate mechanism. It also uses E2A-Pbx1-responsive cellular promoters as model systems to investigate transcriptional regulation by E2A-Pbx1 and by the normal cellular Pbx1 protein. E2A-Pbx1 is expressed as a consequence of the t(1;19) chromosomal translocation in pediatric pre-B ALL. It is comprised of the transactivation domain of the transcription factor E2A, and the DNA-binding domain of the new homeobox protein, Pbx1. E2A-Pbx1 is a nuclear phosphoprotein, and exhibits unique oncogenic properties. In a mouse bone marrow transplantation model, it induces acute myeloid leukemia, and infection of mouse marrow with E2A-Pbx1 virus in vitro results in the rapid outgrowth of GM-CSF-dependent myeloblasts. Therefore, E2A-Pbx1 blocks myeloid differentiation without altering growth-factor requirements. E2A-Pbx1 also transforms NIH3T3 fibroblasts, indicating that it may activate transcription of primary response genes. Specific aims 1-3 focus on 1) developing conditional mutants of E2A-Pbx1, 2) using them to clone E2A-Pbx1-regulated genes, 3) determining whether E2A-Pbx1-regulated genes directly control cell division or differentiation, and 4) using promoters of E2A-Pbx1-inducible genes to investigate the biochemical mechanism of transcriptional activation by E2A-Pbx1 as well as indirect transcriptional repression. The fourth specific aim proposes to identify mutations that strongly enhance fibroblast transformation by E2A-Pbx1 and to determine the biochemical property of E2A-Pbx1 that is affected. This will help establish a biochemical basis for transformation by E2A-Pbx1. The last specific aim proposes to use conditionally-transformed myeloblast cell lines to construct a model system to identify human oncogenes in AML that block myeloid differentiation. Because our major focus is the completion of aims 1-4, aim 5 will be developed as time permits. Accomplishing these aims will reveal how the pediatric leukemia protein, E2A-Pbx1, interferes with both growth and differentiation and the mechanisms through which oncogenes interfere with this regulation.

该建议研究了细胞基因转录的改变 通过E2A-PBX1癌蛋白阻断髓样分化和原因 成纤维细胞转换。 它测试E2A-PBX1是否诱导 调节正常生长或新颖的已知基因的转录 通过 替代机制。 它还使用E2A-PBX1响应性细胞启动子 作为研究E2A-PBX1转录调控的模型系统 以及正常的细胞PBX1蛋白。 e2a-pbx1表示为 T（1; 19）小儿染色体易位的结果 全部。 它由转录的反式激活结构域组成 因子E2a和新同型蛋白质的DNA结合域PBX1。 E2A-PBX1是一种核磷蛋白，表现出独特的致癌性 特性。 在小鼠骨髓移植模型中，它诱导 急性髓细胞性白血病，以及用E2A-PBX1病毒感染小鼠骨髓 体外会导致GM-CSF依赖性骨髓细胞的快速生长。 因此，e2a-pbx1阻止髓样分化而不改变 生长因素要求。 e2a-pbx1还改变了NIH3T3成纤维细胞， 表明它可能激活一级反应基因的转录。 具体目的1-3专注于1）开发E2A-PBX1的条件突变体， 2）使用它们克隆E2A-PBX1调节的基因，3）确定是否确定是否是否 E2A-PBX1调节的基因直接控制细胞分裂或 分化，以及4）使用E2A-PBX1诱导基因的启动子 研究转录激活的生化机制 E2A-PBX1以及间接转录抑制。 第四 特定目的建议确定强烈增强的突变 E2A-PBX1的成纤维细胞转化并确定生化 受影响的E2A-PBX1的属性。 这将有助于建立 E2A-PBX1转化的生化基础。 最后的特定目标 建议使用有条件转换的肌细胞细胞系 构建一个模型系统，以识别AML中的人类发病蛋白 髓样分化。 因为我们的主要重点是完成 AIMS 1-4，AIM 5将随着时间的许可而开发。 完成这些 目标将揭示小儿白血病蛋白E2A-PBX1如何干扰 具有生长和分化以及通过的机制 癌基因干扰这种调节。