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

基本信息

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
项目类别：
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

项目摘要

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。我们将结合测序除了之前收集的数据外，还收集了 DIPG-BAT 试验中新诊断患者的数据已发表的基因组。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 PPM1D 或 TP53 中都有突变，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抗辐射性以及评估 PPM1D作为一个新的治疗靶点。