Project 2: Elucidating Mechanisms of Chromatin Dysregulation by Oncohistones

项目 2：阐明肿瘤组蛋白染色质失调的机制

基本信息

批准号：
10269905
负责人：
CHARLES DAVID ALLIS
金额：
$ 26.7万
依托单位：
ROCKEFELLER UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-09-09 至 2025-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10269905
关键词：
ATAC-seq Affect Alleles Allografting Animal Model Bar Codes Biological Assay Biology Cancer Biology Cancer cell line Cell Differentiation process Cell Fate Control Cell Line Cell physiology Cells Cellular Structures ChIP-seq Characteristics Charge Chemicals Childhood Glioma Chondroblastoma Chromatin Chromatin Structure Collaborations Complementary DNA Cues DNA DNA Damage DNA Modification Process DNA Repair DNA methylation profiling Data Defect Development Epigenetic Process Frequencies Gene Expression Genetic Genetic Screening Genetic Transcription Genome Goals Grant Growth H3 K27M mutation Histone H3 Histones Human Knock-in Laboratories Lead Libraries Light Link Lysine Malignant Childhood Neoplasm Malignant Neoplasms Mass Spectrum Analysis Mediating Mesenchymal Stem Cells Methionine Missense Mutation Modeling Modification Molecular Mus Mutate Mutation N-terminal Nucleosomes Oncogenic Pathologic Pathway interactions Patients Pharmacology Phenotype Play Positioning Attribute Post-Translational Protein Processing Pre-Clinical Model Process Property Proteins Reader Recurrence Research Research Personnel Role Site Somatic Mutation Structure Tail Technology Testing Therapeutic Translating Transplantation Tumor Subtype Undifferentiated Variant Work Writing Xenograft procedure cancer cell cancer type cell type cellular transduction design driver mutation epigenome gain of function genome-wide histone methyltransferase histone modification in vivo insight interdisciplinary approach mouse model multidisciplinary novel oncohistone prevent programs response sarcoma self-renewal small molecule small molecule inhibitor success transcriptome sequencing transcriptomics translational approach tumor tumorigenesis tumorigenic

项目摘要

PROJECT SUMMARY (ALLIS) Genome-wide sequencing technologies have allowed an unprecedented discovery of somatic mutations in chromatin and epigenetic modifiers in human cancers, providing mechanistic links between cancer epigenomes and genetic alterations. The collective number of oncogenic mutations in epigenetic regulators has led to the emerging view of “driver mutations” underlying cancer epigenomes. Nowhere is this better illustrated than with the now classical findings of high-frequency (50-95%) missense mutations in core histones, such as histone H3 lysine 27 to methionine (H3K27M) mutation in pediatric gliomas, and H3 lysine 36 to methionine (H3K36M) mutations in chondroblastomas and undifferentiated sarcomas. During the prior grant period, we have shown that these mutations directly prevent the ‘writing’ of some critical regulatory histone post-translational modifications (PTMs) to promote oncogenesis through altered chromatin organization, transcription, and in some cases cell fate and differentiation. More recently, we have extended our understanding of the landscape of histone mutations in cancers. We characterized an unexpectedly broad landscape of novel oncohistone mutations that occur in roughly 4% of all cancers. These mutations are found not only in the H3 N-terminal tail, which is the site of classical oncohistones, but also in the globular domain and in all four core histones. Our preliminary data suggest that a least a subset of these mutations affect one or more properties of chromatin and chromatin-dependent processes including nucleosome stability, histone PTMs, and cellular differentiation. We therefore hypothesize that novel oncohistone mutations will impact the landscape of histone PTMs and chromatin organization in a context dependent manner, leading to dysregulation of gene expression and effects on cell fate and tumorigenesis. The goal of this work is to rigorously test these hypotheses for a comprehensive set of cancer-associated histone mutations using a multidisciplinary approach that include genetics (barcoded oncohistone libraries, mouse models, barcoded-cell lines), epigenetics (ChIP-seq, ATAC-seq, DNA-methylation profiling), transcriptomics (RNA-seq), and chemical biology (“designer chromatin”, small molecule inhibitors). Specifically, we will 1) define molecular mechanisms by which novel oncohistones act and their impact on chromatin and gene expression; 2) determine how these molecular changes translate into phenotypes using cellular differentiation and tumor allograft models, and explore pharmacologic strategies to rescue differentiation blockade; and 3) extend our studies into animal models and diverse cellular contexts to test the roles of novel oncohistones in tumorigenesis and development. Together, these approaches will shed light on the function of newly discovered oncohistones and provide important insight into the role of histones and chromatin structure in tumorigenesis. Our findings are expected to pave new avenues towards intervening pharmacologically the aberrant epigenetic pathways for cancer therapeutics. To facilitate the success of this proposal, a world-class team of investigators, experts in cancer, chromatin and chemical biology, have been assembled.

项目概要（ALLIS）全基因组测序技术前所未有地发现了体细胞突变人类癌症中的染色质和表观遗传修饰因子，提供癌症表观基因组之间的机制联系表观遗传调节因子中致癌突变的集体数量导致了癌症表观基因组中“驱动突变”的新兴观点最能说明这一点。核心组蛋白（例如组蛋白 H3）中高频 (50-95%) 错义突变的经典发现儿童神经胶质瘤中赖氨酸 27 突变为蛋氨酸 (H3K27M)，以及 H3 赖氨酸 36 突变为蛋氨酸 (H3K36M) 在之前的资助期间，我们已经证明了软骨母细胞瘤和未分化肉瘤的突变。这些突变阻止了一些关键的翻译后调节组蛋白的直接“写入” 修饰（PTM）通过改变染色质组织、转录来促进肿瘤发生，并且在某些情况下最近，我们扩展了对细胞命运和分化的理解。我们对癌症中的组蛋白突变进行了意想不到的广泛研究。大约 4% 的癌症中出现这些突变，这些突变不仅存在于 H3 N 末端尾部，这是经典癌组蛋白的位点，但也在球状域和所有四个核心组蛋白中。初步数据表明，这些突变中至少有一部分会影响染色质的一种或多种特性，并且染色质依赖性过程，包括核小体稳定性、组蛋白 PTM 和细胞分化。因此，我们发现新的癌组蛋白突变将影响组蛋白 PTM 和染色质的景观以上下文相关的方式进行组织，导致基因表达失调并对细胞命运产生影响这项工作的目标是严格测试这些假设以获得全面的结果。使用包括遗传学（条形码）在内的多学科方法研究与癌症相关的组蛋白突变癌组蛋白文库、小鼠模型、条形码细胞系）、表观遗传学（ChIP-seq、ATAC-seq、DNA 甲基化分析）、转录组学（RNA-seq）和化学生物学（“设计染色质”、小分子抑制剂）。具体来说，我们将 1) 定义新型癌组蛋白作用的分子机制及其对染色质和基因表达；2) 确定这些分子变化如何转化为表型细胞分化和肿瘤同种异体移植模型，并探索挽救分化的药理学策略封锁；3）将我们的研究扩展到动物模型和不同的细胞环境中，以测试新颖的作用这些方法将共同揭示肿瘤组蛋白在肿瘤发生和发展中的功能。新发现的癌组蛋白，并为组蛋白和染色质结构的作用提供了重要的见解我们的研究结果有望为药物干预铺平新的途径。癌症治疗的异常表观遗传途径为了促进这一提案的成功，世界一流的研究。由癌症、染色质和化学生物学领域的专家组成的研究小组已经集结完毕。