Sensitization to Chemoradiation by Therapeutic Targeting of the DNA Damage Response

通过 DNA 损伤反应的治疗靶向来提高放化疗敏感性

• 批准号: 9901492
• 负责人: THEODORE S LAWRENCE
• 金额: $ 58.21万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-01 至 2022-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9901492
• 关键词: Apoptotic; Biological Assay; Biological Markers; Body Weight decreased; CASP3 gene; Cancer Therapy Evaluation Program; Cell Cycle Checkpoint; Cell Death; Cell Line; Cell Survival; Cell model; Cells; Cellular Assay; Characteristics; Clinical Trials; Collection; Combined Modality Therapy; Comet Assay; DNA Damage; DNA Double Strand Break; DNA Repair; DNA Repair Pathway; DNA biosynthesis; Data; Defect; Dependence; Dominant Genetic Conditions; Dose; Dose-Limiting; Double Strand Break Repair; Drug Targeting; Future; Germ Cells; Goals; Gold; Image; Immune system; Immunocompetent; Investigation; Magnetic Resonance Imaging; Malignant neoplasm of pancreas; Measures; Mutation; Nonhomologous DNA End Joining; Normal Cell; Normal tissue morphology; Organ; PRKDC gene; Pancreatic Ductal Adenocarcinoma; Pathway interactions; Patients; Phosphotransferases; Radiation; Radiation Tolerance; Reporter; Safety; Schedule; Small Intestines; Surrogate Markers; TP53 gene; Therapeutic Index; Time; Toxic effect; Translating; Treatment Efficacy; Tumor Markers; Validation; Xenograft procedure; advanced pancreatic cancer; base; cellular targeting; chemoradiation; chemotherapy; clinical development; design; diffusion weighted; efficacy study; gastrointestinal; gemcitabine; high throughput screening; human model; imaging biomarker; improved; improved outcome; in vivo; inhibitor/antagonist; intestinal crypt; mouse model; neoplastic cell; pancreatic cancer cells; pancreatic neoplasm; pharmacodynamic biomarker; pre-clinical; predictive marker; prevent; response; response biomarker; standard of care; targeted agent; targeted biomarker; targeted sequencing; therapeutic target; tissue injury; treatment response; tumor; tumor growth

ABSTRACT There is an urgent need to improve the efficacy of chemoradiation therapy for patients with locally advanced pancreatic cancer (LAPC). Since unrepaired DNA double-strand breaks (DSB) are responsible for the majority of cell death in response to chemoradiation, targeting cellular DNA damage response (DDR) pathways is a promising approach to enhance the efficacy of chemoradiation therapy by preventing efficient repair of DNA damage, leading to loss of tumor cell viability. Since defects in the DDR such as P53 mutation occur in up to 70% of pancreatic ductal adenocarcinomas (PDAC), targeted inhibition of the DDR provides an opportunity to selectively enhance sensitivity to chemoradiation in tumor but not normal cells. The overall goal of our proposed study is to identify agents from the CTEP collection that modulate the cellular response to DNA damage and best sensitize tumor cells to standard of care chemoradiation therapy. To achieve this goal, we will in Aim 1 conduct an unbiased high throughput screen (HTS) in a panel of PDAC cell lines using a panel of agents from the CTEP collection that modulate the cellular DDR, including drugs that target ATR, DNAPK, PARP, and WEE1 (Aim 1A). An initial cell viability screen at various concentrations of single agents alone or in combination with chemoradiation will be conducted. In addition to concentration, optimal sequencing of targeted agents with chemoradiation will be investigated. A live cell assay for the DDR as well as apoptotic cell death will be utilized as orthogonal screens to assist in hit prioritization and validation. In Aim 1B, a group of agents selected by defined criteria will be further evaluated by conducting a “gold standard” clonogenic survival assay using a panel of PDAC cell lines. In Aim 1C we will conduct a normal cell counter screen using the above agents against normal cells to identify those which cause toxicity in combination with chemoradiation. The efficacy of these prioritized agents will be validated in Aim 1D using a panel of patient- derived xenograft (PDX) sphere explant cultures. Two agents with the optimal enhancement ratio (1B and 1D), and safety (1C) at the optimal concentration and schedule (1A and 1B) will be studied in Aim 2. We will compare the therapeutic efficacy of the nominated agents in combination with chemoradiation using both PDX and immune competent syngeneic mouse models of PDAC (Aim 2A). Normal tissue injury caused by these two agents (Aim 2B) will be evaluated, which together with tumor efficacy will lead to the choice of the agent to pursue in clinical trials. Aim 3 will delineate the mechanistic basis for the chemoradiation potentiating activity of the superior agent (Aim 3A) with the goal of selecting pharmacodynamic and imaging biomarkers (Aims 3B and 3C), using in vivo studies in mouse models, for the future clinical trial. Completion of these aims will provide the required preclinical data regarding efficacy, safety, and biomarkers of response (mechanistic- and imaging- based) for the rationale design of a future clinical trial for patients with LAPC.

摘要 目前迫切需要提高局部晚期乳腺癌患者放化疗的疗效 胰腺癌（LAPC）。由于未修复的DNA双链断裂（DSB）是导致大多数 针对细胞DNA损伤反应（DDR）途径， 通过阻止DNA的有效修复来提高放化疗疗效的有前途的方法 损伤，导致肿瘤细胞活力丧失。由于DDR中的缺陷如P53突变发生在多达 70%的胰腺导管腺癌（PDAC），靶向抑制DDR提供了一个机会， 选择性地增强肿瘤细胞而不是正常细胞对放化疗的敏感性。我们的总体目标是 拟议的研究是从CTEP收集中鉴定调节细胞反应的试剂， DNA损伤和肿瘤细胞对标准化放疗的最佳敏感性。实现这一 为了实现这一目标，我们将在目标1中使用一种新的筛选方法在一组PDAC细胞系中进行无偏倚的高通量筛选（HTS）。 来自CTEP集合的调节细胞DDR的试剂组，包括靶向ATR的药物， DNAPK、PARP和WEE 1（目标1A）。在不同浓度的单一试剂下进行初始细胞活力筛选 单独或与放化疗联合进行。除了浓度，最佳 将研究具有化学放射的靶向剂的测序。DDR的活细胞测定以及 因为凋亡细胞死亡将被用作正交筛选以帮助命中优先化和验证。在Aim中 1B，一组根据规定标准选出的代理人将通过执行“金标准”进行进一步评估 使用一组PDAC细胞系的克隆形成存活测定。在目标1C中，我们将进行正常细胞计数 使用上述试剂对正常细胞进行筛选，以鉴定与下列药物组合引起毒性的那些： 放化疗这些优先药物的疗效将在Aim 1D中使用一组患者进行验证- 衍生的异种移植物（PDX）球体外植体培养物。具有最佳增强比的两种药剂（1B和1D）， 将在目标2中研究最佳浓度和方案（1A和1B）下的安全性（1C）。我们将 比较指定药物与使用PDX和PDX的放化疗联合治疗的疗效。 和PDAC的免疫活性同系小鼠模型（Aim 2A）。这些造成的正常组织损伤 将评估两种药物（目标2B），这与肿瘤疗效一起将导致选择药物， 在临床试验中进行。目的3将描述的化学放射增强活性的机制基础， 上级药物（目的3A），目的是选择药效学和成像生物标志物（目的3B 和3C），使用小鼠模型中的体内研究，用于未来的临床试验。实现这些目标将 提供所需的关于疗效、安全性和反应生物标志物的临床前数据（机制和 基于影像学的）用于未来LAPC患者临床试验的基本原理设计。