Characterizing TP53 and PPM1D mutations as resistance drivers to radiation therapy in Diffuse Intrinsic Pontine Gliomas

描述 TP53 和 PPM1D 突变作为弥漫性内源性桥脑胶质瘤放射治疗耐药驱动因素

• 批准号: 10245071
• 负责人: RAMEEN BEROUKHIM
• 金额: $ 52.33万
• 依托单位: BROAD INSTITUTE, INC.
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2023-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10245071
• 关键词: Address; Aftercare; Autopsy; Biopsy; Brain; CRISPR screen; Cancer Etiology; Cell Line; Child; Child Care; Childhood Brain Neoplasm; Clinical; Clinical Data; Clinical Trials; Collaborations; DNA Sequence Alteration; Data; Diagnosis; Diffuse intrinsic pontine glioma; Disease; Enrollment; Evaluation; Event; Excision; Exhibits; Fright; Genes; Genetic; Genome; Genomics; Genotype; Glioma; Goals; In Vitro; Lead; MDM2 gene; Methods; Modeling; Mutation; Neurologic; Neurosurgeon; Newly Diagnosed; PPM1D gene; Patients; Pharmacology; Pontine structure; Positioning Attribute; Protein phosphatase; Publishing; Radiation; Radiation Tolerance; Radiation therapy; Relapse; Resistance; Role; Safety; Scientist; Signal Transduction; Structure; TP53 gene; Testing; Therapeutic; Time; Tissue Sample; Tissues; Translating; Treatment Efficacy; Tumor Tissue; Work; base; childhood cancer mortality; clinical candidate; effective therapy; experimental study; gain of function; genome sequencing; genome-wide; improved; in vitro Model; in vivo; inhibitor/antagonist; mortality; mutant; new therapeutic target; precision medicine; prevent; radiation resistance; radiation response; response; standard of care; therapeutic candidate; therapeutic target; therapy resistant; treatment response; treatment strategy; trial design; tumor; whole genome

Abstract Children diagnosed with Diffuse Intrinsic Pontine Gliomas (DIPGs) are faced with a mortality rate of 100%. The current standard of care is radiation therapy. Despite achieving initial responses, tumors quickly exhibit resistance and start to grow again. We have taken leading positions in a national trial, DIPG-BATs, that has evaluated routine biopsy of DIPGs in children. We seek to take advantage of the tissue obtained through the DIPG-BATs trial to understand the genetic underpinnings of DIPG and their impact on therapeutic response. We also seek to identify therapeutic combinations that are sufficient to prevent the acquisition of radiation resistance. In Aim 1, we propose to analyze the largest set of DIPG whole genomes to date. We will combine sequencing data collected on the DIPG-BATs trial with those from newly diagnosed patients, in addition to previously published genomes. In Aim 2, we will evaluate the role of PPM1D mutations in generating resistance to radiation therapy. Our initial analysis of BAT biopsies has revealed that over 50% of DIPG genomes contain mutations in either PPM1D or TP53, and that these mutations are mutually exclusive. PPM1D has been characterized as a negative regulator of TP53, a critical facilitator of radiation sensitivity. In Aim 3, we will use both hypothesis- based and unbiased approaches to identify therapeutic combinations with radiation that increase efficacy. We will utilize genetic and pharmacological methods of inhibiting PPM1D and MDM2 in combination with radiation in patient-derived DIPG lines with TP53 mutations. We will also perform a genome-wide CRISPR-cas9 screen to identify genes whose suppression selectively increase radiation response in DIPG-relevant cell lines. These experiments will address at least three central questions regarding resistance to radiation therapy in DIPG: characterization of driver genomic alterations and identification of those that confer resistance to radiation therapy, determination of how alterations in p53 signaling confer resistance to radiation, and evaluation of PPM1D as a novel therapeutic target.

抽象的 被诊断患有弥漫性内源性脑桥胶质瘤 (DIPG) 的儿童面临着 100% 的死亡率。这 目前的标准护理是放射治疗。尽管取得了初步反应，但肿瘤很快就表现出 抵抗力并开始再次增长。我们在国家试验 DIPG-BAT 中处于领先地位，该试验已 评估儿童 DIPG 的常规活检。我们寻求利用通过以下方式获得的组织： DIPG-BAT 尝试了解 DIPG 的遗传基础及其对治疗反应的影响。我们 还寻求确定足以防止获得辐射抗性的治疗组合。 在目标 1 中，我们建议分析迄今为止最大的 DIPG 全基因组集。我们将结合测序 DIPG-BATs 试验中收集的数据来自新诊断的患者以及之前的患者 已发表的基因组。在目标 2 中，我们将评估 PPM1D 突变在产生辐射抗性中的作用 治疗。我们对 BAT 活检的初步分析表明，超过 50% 的 DIPG 基因组含有突变 在 PPM1D 或 TP53 中，并且这些突变是相互排斥的。 PPM1D 的特征为 TP53 的负调节因子，TP53 是辐射敏感性的关键促进因子。在目标 3 中，我们将使用两个假设 - 基于且公正的方法来确定可提高疗效的放射治疗组合。我们 将利用遗传和药理学方法结合放射抑制 PPM1D 和 MDM2 在具有 TP53 突变的患者来源的 DIPG 系中。我们还将进行全基因组 CRISPR-cas9 筛选 鉴定其抑制选择性增加 DIPG 相关细胞系辐射反应的基因。这些 实验将解决至少三个关于 DIPG 放射治疗耐药性的核心问题： 驱动基因组改变的表征和赋予抗辐射性的基因组改变的鉴定 治疗、确定 p53 信号传导的改变如何赋予对辐射的抵抗力以及评估 PPM1D作为一个新的治疗靶点。