Disrupting the AF4-AF9 protein complex in MLL leukemias.

破坏 MLL 白血病中的 AF4-AF9 蛋白复合物。

• 批准号: 7585321
• 负责人: Charles Stanley Hemenway
• 金额: $ 12.92万
• 依托单位: LOYOLA UNIVERSITY CHICAGO
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-03-12 至 2010-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7585321
• 关键词: 11q23; 4q21; AF-9 protein; Acute Lymphocytic Leukemia; Acute leukemia; Adult; Amino Acids; Anisotropy; Apoptosis; Binding; Biological Assay; Buffers; C-terminal; Cell Survival; Cells; Chemicals; Child; Chromosomal translocation; Collection; Complex; Cytotoxic Chemotherapy; Data; Differentiation and Growth; Dimethyl Sulfoxide; Disease; Dissociation; Drug usage; Dyes; Elements; Enzymes; Equilibrium; Fluorescence; Fluorescence Polarization; Goals; Hematopoietic; Hematopoietic stem cells; In Vitro; Label; Lead; MLL gene; MLLT2 gene; MLLT3 gene; Measurement; Measures; Molecular; Molecular Bank; New Agents; Peptide Library; Peptides; Performance; Pharmaceutical Preparations; Process; Protein Binding; Proteins; Reciprocal Translocation; Recombinants; Refractory; Reproducibility; Research; Resistance; Screening procedure; Series; Signal Transduction; Site; Solutions; Solvents; System; Techniques; Testing; Time; Toxic effect; Treatment outcome; United States National Institutes of Health; Validation; assay development; base; chemotherapy; combinatorial; drug candidate; drug development; effective therapy; high throughput screening; improved; in vivo; inhibitor/antagonist; leukemia; link protein; novel strategies; outcome forecast; pharmacophore; precursor cell; protein complex; protein protein interaction; small molecule; synthetic peptide; therapeutic target; therapy resistant

DESCRIPTION (provided by applicant): The ultimate goal of this project is to develop promising new agents for the treatment of acute lymphoblastic leukemia (ALL) characterized by a specific t(4;11) chromosome translocation. t(4;11) leukemia is a relatively common subtype of ALL and is unusually resistant to cytotoxic chemotherapy. The isolation, validation, and optimization of new compounds to treat t(4;11) leukemia is important given the limitations of currently available treatments. We have identified a protein:protein interaction that appears to be critical for the survival of t(4;11) leukemia. More important, small peptides that disrupt the interaction of these two proteins, AF4 and AF9, induce programmed cell death in t(4;11) leukemia cells. Additionally, these peptides do not inhibit the growth and differentiation of normal hematopoietic progenitor cells. These data indicate that the AF4-AF9 protein complex is a promising target for drug development. The NIH Molecular Libraries Screening Center Network offers a unique opportunity to screen an extensive molecular library to identify additional compounds that block AF4-AF9 binding. Here, we propose to develop an assay system that is well suited for high throughput screening of inhibitors of AF4-AF9 binding. Fluorescence polarization (FP) is a powerful technique to measure protein binding in a homogeneous solution. The technique is particularly well suited to measuring AF4-AF9 binding as the molecular complex can be mimicked by a peptide "probe" bound to the C-terminal domain of AF9. Furthermore, FP assays can be easily modified to analyze inhibitors of protein binding. FP competition assays have been used successfully for high throughput screening of inhibitors of other protein:protein interactions. Once optimized, the assay is simple, rapid, and inexpensive. In addition to a primary FP screening assay, we describe secondary assays to analyze "hits". These secondary assays include analyses of the anti-leukemic activity of lead compounds and have already been validated. It is anticipated that, following refinement, compounds identified and verified by this screening process will provide useful new anti-leukemic therapies. Despite improvements in the treatment of leukemia, some forms of the disease remain resistant to therapy. Here, we describe a system to rapidly identify chemicals that may serve as new drugs for the treatment of one of the most resistant forms of acute leukemia. We propose to develop and refine this testing system so that it may be used to isolate promising drug candidates from a large collection of chemicals developed by NIH.

描述(由申请人提供)：该项目的最终目标是开发有前景的新药物来治疗以特殊t(4；11)染色体易位为特征的急性淋巴细胞白血病(ALL)。T(4；11)白血病是ALL中比较常见的一种亚型，对细胞毒化疗具有异常的耐药性。考虑到现有治疗方法的局限性，分离、验证和优化治疗t(4；11)白血病的新化合物是很重要的。我们已经确定了一种蛋白质：蛋白质相互作用，它似乎对t(4；11)白血病的生存至关重要。更重要的是，破坏AF4和AF9这两种蛋白质相互作用的小肽可以诱导t(4；11)白血病细胞的程序性死亡。此外，这些多肽不抑制正常造血祖细胞的生长和分化。这些数据表明AF4-AF9蛋白复合体是一个很有前途的药物开发靶点。美国国立卫生研究院分子文库筛选中心网络提供了一个独特的机会来筛选广泛的分子文库，以识别阻止AF4-AF9结合的其他化合物。在这里，我们建议开发一种适合于高通量筛选AF4-AF9结合抑制剂的检测系统。荧光偏振(FP)是测量蛋白质在均相溶液中结合的一种强有力的技术。这项技术特别适合于测量AF4-AF9的结合，因为分子复合体可以通过与AF9的C-末端结构域结合的肽“探针”来模拟。此外，FP分析方法可以很容易地修改以分析蛋白质结合的抑制剂。FP竞争分析已经成功地用于高通量筛选其他蛋白质的抑制物：蛋白质相互作用。一旦进行了优化，该检测方法简单、快速、廉价。除了初级FP筛查试验外，我们还描述了分析“HITS”的次级试验。这些二次分析包括对先导化合物的抗白血病活性的分析，并已得到验证。预计，经过改进后，通过这一筛选过程确定和验证的化合物将提供有用的新的抗白血病疗法。尽管白血病的治疗方法有所改进，但某些形式的疾病仍然对治疗产生抗药性。在这里，我们描述了一种快速识别化学物质的系统，这些化学物质可能作为治疗最具耐药性的急性白血病之一的新药。我们建议开发和改进这个测试系统，以便它可以用于从NIH开发的大量化学物质中分离出有前途的候选药物。