The COMPASS family of H3K4 methylases in development and cancer

H3K4 甲基化酶 COMPASS 家族在发育和癌症中的作用

• 批准号: 8759914
• 负责人: Ali Shilatifard
• 金额: $ 26.18万
• 依托单位: STOWERS INSTITUTE FOR MEDICAL RESEARCH
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-03-09 至 2014-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8759914
• 关键词: Address; Biochemical; Biochemistry; Biological Models; Cataloging; Catalogs; Cell Culture Techniques; Cells; Childhood Leukemia; Chimera organism; Chromatin; Chromosomal Rearrangement; Complex; DNA Sequence Rearrangement; Development; Drosophila genus; Enhancers; Enzymes; Family; Family member; Funding; Gene Expression; Gene Expression Regulation; Gene Targeting; Genes; Genetic; Goals; Grant; Growth; Hematologic Neoplasms; Histones; Homologous Gene; Human; Laboratories; Learning; MLL2 gene; Macromolecular Complexes; Malignant Neoplasms; Mammalian Cell; Methylation; Methyltransferase; Molecular; Molecular Genetics; Mutate; Mutation; Names; Pathogenesis; Pattern; Positioning Attribute; Property; Protein Family; Proteins; Reagent; Regulation; Research Personnel; Role; Sequence Homology; Solid Neoplasm; Somatic Mutation; Ursidae Family; Yeasts; base; cancer therapy; design; leukemia; protein B; protein complex; public health relevance; therapeutic target; tool

DESCRIPTION (provided by applicant): Project Summary Studies from my laboratory during the past seventeen years have focused on the characterization of the molecular functions and biochemical properties of the Set1/MLL family of proteins. Their chimeras and mutations are associated with childhood leukemia and other forms of cancers. Our hope is that our molecular studies will advance our understanding of the molecular mechanisms of rearrangement and mutation-based cancer through this family of proteins. During the current funding cycle of this grant, my laboratory has employed genetics and biochemistry in multiple model systems including Drosophila and mammalian cell cultures. We demonstrated that Drosophila cells possess three Set1-related proteins: dSet1, Trithorax (Trx), and Trithorax-related (Trr), all found within COMPASS-like compositions capable of methylating histone H3K4. Mammalian cells possess two representatives for each of the three subclasses found in Drosophila for a total of six COMPASS family members: SET1A/SET1B (related to dSet1); MLL1 and MLL2 (related to Trx); and MLL3 and MLL4 (related to Trr). Furthermore, given that there is almost no sequence homology between many of the MLL translocation partners, for many years, it was unclear why MLL translocations into so many unrelated genes result in the pathogenesis of leukemia. Our biochemical studies on the purification of the MLL-chimeras demonstrated that many of the MLL translocation partners are part of the same macromolecular complex we named the Super Elongation Complex (SEC). We demonstrated that the translocations of MLL within any of the subunits of SEC result in the misrecruitment of SEC to the MLL target genes and in the perturbation of the transcriptional checkpoint control of these genes, triggering leukemic growth. Additionally, what we have learned is that recent cataloging of somatic mutations in cancer have identified a large number of mutations in the components of the MLL1-4 and Set1A/B complexes in both hematological malignancies and solid tumors. As a matter of fact, collectively MLL1-4 and Set1A/B appear to bear more mutations in different forms of cancers than p53. However, we know very little about the MLL1-4 and Set1A/B families in development and why their mutations are associated with cancer. Given that we have developed a fantastic set of reagents and tools within the past seventeen years towards these factors and their associated proteins in multiple model systems, my laboratory is in a very unique position to define the molecular bases of these factors' involvement in cancer pathogenesis for the purpose of targeted therapeutics. Therefore, the goals of this renewal application are the full molecular and biochemical characterization of MLL1-4 and Set1A-B and their complexes in the regulation of gene expression and development and how their mutations contribute to the pathogenesis of human cancer. The goals of this renewal application will be aggressively pursued via three specific aims. Specific Aim 1 is focused on the characterization of the molecular properties of the Trx/COMPASS family members (MLL1 and MLL2); identification of their molecular properties and specific recruitment to chromatin; and how their translocations contribute to leukemic pathogenesis. Specific Aim 2 will be focused in defining the role of the Trr/COMPASS family (MLL3 and MLL4) in enhancer monomethylation and how enhancer malfunction through specific mutations of the components of this family result cancer in pathogenesis. Specific Aim 3 is focused on the molecular characterization and structural studies of the Set1/COMPASS family (Set1A and Set1B) and how histone H3K4 trimethylation implemented by this class of enzymes is involved in the regulation of gene expression throughout development. We will take advantage of a variety of biochemical, molecular, and genetic tools in multiple model systems to address the proposed aims. These studies should (i) be instrumental for our understanding of the diverse roles of the COMPASS family in the regulation of the pattern of H3K4 methylation and how they regulate development and differentiation; and (ii) have a fundamental impact on our understanding of how mutations within the COMPASS family result in cancer. This information has the potential of proving helpful to investigators attempting to design rational approaches for the treatment of cancer.

描述（由申请人提供）： 在过去的十七年中，我的实验室的项目摘要研究集中在蛋白质的set1/mll家族的分子功能和生化特性的表征上。它们的嵌合体和突变与儿童白血病和其他形式的癌症有关。我们的希望是，我们的分子研究将通过这种蛋白质家族来提高我们对重排和基于突变的癌症的分子机制的理解。在该赠款的当前资助周期中，我的实验室在包括果蝇和哺乳动物细胞培养物在内的多种模型系统中采用了遗传学和生物化学。我们证明了果蝇细胞具有三种与Set1相关的蛋白：DSET1，Trithorax（TRX）和Trithorax相关（TRR），它们都在能够甲基化组蛋白H3K4的指南针样组合物中发现。哺乳动物细胞具有在果蝇中发现的三个亚类中的每个代表，共有六个指南针家族成员：set1a/set1b（与dset1有关）； MLL1和MLL2（与TRX相关）；以及MLL3和MLL4（与TRR有关）。此外，鉴于许多MLL转运伙伴之间几乎没有序列同源性，多年来，尚不清楚为什么MLL转移到如此多的无关基因导致白血病的发病机理。我们关于MLL-Chimeras纯化的生化研究表明，许多MLL易位伴侣是同一大分子复合物的一部分，我们将超级延伸复合物（SEC）命名为同一大分子。我们证明，在SEC的任何亚基中，MLL的易位导致SEC对MLL靶基因的错误侵犯以及对这些基因的转录检查点控制的扰动，从而触发了白血病的生长。此外，我们了解到的是，最近对癌症中体细胞突变的分类已经确定了血液恶性肿瘤和实体瘤的MLL1-4和SET1A/B复合物的大量突变。事实上，与p53相比，统称MLL1-4和SET1A/B的癌症似乎具有更多的突变。但是，我们对正在开发的MLL1-4和SET1A/B家族以及它们的突变与癌症相关的原因一无所知。鉴于我们在过去的十七年中开发了一套出色的试剂和工具，这些试剂和工具针对这些因素及其在多个模型系统中的相关蛋白质，我的实验室处于一个非常独特的位置，可以定义这些因素参与癌症发病机理的分子基础。出于靶向疗法的目的。因此，这种更新应用的目标是MLL1-4和SET1A-B的完整分子和生化表征及其在基因表达和发育调节中的复合物以及它们的突变如何促进人类癌症的发病机理。该更新申请的目标将通过三个特定目标积极实现。具体目标1的重点是TRX/Compass家族成员的分子特性的表征（MLL1和MLL2）；鉴定其分子特性和染色质的特定募集；以及它们的易位如何促进白血病发病机理。具体目标2将集中于定义TRR/Compass家族（MLL3和MLL4）在增强子单甲基化中的作用，以及如何通过该家族成分的特异性突变通过该家族的特定突变导致癌症导致发病机理中的功能。具体目标3的重点是SET1/Compass家族（SET1A和SET1B）的分子表征和结构研究，以及该类别酶实施的组蛋白H3K4三甲基化如何参与整个发育过程中基因表达的调节。我们将利用多种模型系统中的各种生化，分子和遗传工具来解决所提出的目标。这些研究应该（i）对我们对指南人家族在调节H3K4甲基化模式的多种作用以及它们如何调节发育和分化方面的多种作用； （ii）对我们对指南针家族中突变如何导致癌症的理解有根本的影响。该信息有可能证明对试图设计合理方法治疗癌症的研究人员有帮助。