The role of ATRX and H3.3 mutations in pediatric glioblastoma

ATRX 和 H3.3 突变在儿童胶质母细胞瘤中的作用

• 批准号: 8784425
• 负责人: Jamie N. Anastas
• 金额: $ 3.33万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-15 至 2017-09-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8784425
• 关键词: Ablation; Adult; Alternative Therapies; Amino Acids; Brain; Brain Neoplasms; Breeding; Cancer Etiology; Cancer Patient; Cell Line; Cell Nucleolus; Cell Proliferation; Cells; Centromere; Cessation of life; Child; Childhood; Childhood Glioblastoma; Chromatin; Chromatin Remodeling Factor; Chromatin Structure; Clinical; Combined Modality Therapy; Communities; DNA; Defect; Development; Diagnosis; Employee Strikes; Enzymes; Epigenetic Process; Face; Future; Genes; Genomic Instability; Glioblastoma; Global Change; Goals; Heterochromatin; Histones; Hypersensitivity; In Vitro; Lead; Malignant - descriptor; Malignant Neoplasms; Malignant neoplasm of brain; Mediating; Methylation; Microscopy; Modification; Molecular; Mus; Mutate; Mutation; Neurodegenerative Disorders; Nucleosomes; Operative Surgical Procedures; Outcome; Patients; Pharmaceutical Preparations; Phenotype; Positioning Attribute; Pre-Clinical Model; Radiation; Relative (related person); Research Proposals; Role; Sampling; Structure; TP53 gene; Tail; Tamoxifen; Techniques; Testing; Tissues; Transgenic Mice; Transplantation; Tube; Variant; Work; X-Linked Mental Retardation; X-linked mental retardation 1; base; chemotherapy; chromatin remodeling; follow-up; gain of function; in vitro Assay; in vivo; mouse model; mutant; nerve stem cell; next generation sequencing; novel; outcome forecast; overexpression; public health relevance; research study; telomere; treatment strategy; tumor; tumor growth; tumorigenesis

DESCRIPTION (provided by applicant): Brain tumors are the leading cause of cancer-related deaths in children. Glioblastoma multiforme (GBM) is a deadly form of brain cancer that strikes both children and adults. Children diagnosed with GBM face dismal outcomes. Even aggressive treatment strategies are ineffective, as less than 20% of children will survive more than three years post-diagnosis. Sequencing of pediatric GBM has identified concurrent mutations in the genes encoding an ATP-dependent chromatin remodeling enzyme called ATRX, in p53, and in the histone variant, H3.3 (encoded by H3F3A and H3F3B). In cancer, ATRX mutations result in a loss of ATRX expression or activity and correlate with genome instability, aberrant telomere and centromere phenotypes, and with poor clinical prognosis. H3.3 mutations are found in the histone tail region that is subject to extensive covalent modification. Forced expression of mutant H3.3 has been recently shown to act in a dominant manner to induce global changes in the methylation of chromatin, yet the functional consequences of these mutations are still poorly understood. Based on these findings, we will test the overall hypothesis that ATRX and H3.3 mutations act in a cooperative manner leading to epigenetic instability, centromere and telomere abnormalities, and GBM tumorigenesis. First, we will generate novel mouse models of brain cancer to mimic the effects of patient ATRX and H3.3 mutations, which will be made available to the scientific community for future studies testing whether certain drugs can inhibit the growth of these tumors. In parallel, we will investigate the consequences of ATRX and H3.3 mutations on a mechanistic level. Using cutting edge microscopy and sequencing techniques we will analyze changes in DNA and chromatin organization after forcing normal neural progenitor cells to have ATRX and H3.3 mutations. We will also purify ATRX and both normal and mutant forms of H3.3 and study how these factors might work together to re-organize DNA into chromatin in a test tube. We hope that the detailed understanding of the functions of ATRX and H3.3 in mediating chromatin organization gained from these studies will enable the development of personalized therapies for cancer patients suffering from brain tumors with ATRX and H3.3 mutations.

描述（由申请人提供）：脑肿瘤是儿童癌症相关死亡的主要原因。多形性胶质母细胞瘤 (GBM) 是一种致命的脑癌，对儿童和成人都有影响。被诊断患有 GBM 的儿童面临着惨淡的结果。即使积极的治疗策略也无效，因为只有不到 20% 的儿童在诊断后能够存活三年以上。儿科 GBM 测序发现，p53 中编码 ATP 依赖性染色质重塑酶 ATRX 和组蛋白变体 H3.3（由 H3F3A 和 H3F3B 编码）的基因同时发生突变。在癌症中，ATRX 突变导致 ATRX 表达或活性丧失，并与基因组不稳定、异常端粒和着丝粒表型以及不良的临床预后相关。 H3.3 突变发现于经过广泛共价修饰的组蛋白尾区。最近已证明突变体 H3.3 的强制表达以显性方式作用，诱导染色质甲基化的整体变化，但这些突变的功能后果仍知之甚少。基于这些发现，我们将检验以下总体假设：ATRX 和 H3.3 突变以协同方式作用，导致表观遗传不稳定、着丝粒和端粒异常以及 GBM 肿瘤发生。首先，我们将生成新型脑癌小鼠模型来模拟患者 ATRX 和 H3.3 突变的影响，这些模型将提供给科学界用于未来的研究，测试某些药物是否可以抑制肿瘤的生长。 这些肿瘤。与此同时，我们将在机制水平上研究 ATRX 和 H3.3 突变的后果。使用尖端显微镜和测序技术，我们将分析强迫正常神经祖细胞发生 ATRX 和 H3.3 突变后 DNA 和染色质组织的变化。我们还将纯化 ATRX 以及 H3.3 的正常形式和突变形式，并研究这些因素如何共同作用，在试管中将 DNA 重新组织成染色质。我们希望从这些研究中获得的对 ATRX 和 H3.3 在介导染色质组织中的功能的详细了解将有助于为患有 ATRX 和 H3.3 突变的脑肿瘤患者开发个性化疗法。