Dual Targeting of DNA Repair and p53 pathways for treatment of brain cancer

DNA 修复和 p53 通路双重靶向治疗脑癌

• 批准号: 8110715
• 负责人: Karen Elizabeth Pollok
• 金额: $ 31.23万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-15 至 2015-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8110715
• 关键词: Address; Adult; Affect; Aftercare; Alkylating Agents; Apoptosis; Bioluminescence; Brain; Brain Neoplasms; Cancer Patient; Caring; Cell Cycle Arrest; Cell Death; Cell Line; Cell Survival; Cells; Chemosensitization; Childhood; Chimeric Proteins; Clinical; Combined Modality Therapy; Cytotoxic agent; DNA Damage; DNA Repair; DNA Repair Pathway; DNA repair protein; Data; Development; Drug Combinations; Drug Kinetics; Drug toxicity; E2F1 gene; EGFR Gene Amplification; Exposure to; Frequencies; Genotoxic Stress; Glioblastoma; Goals; Growth; Human; Image; Imaging technology; Implant; In Vitro; Investigation; Kinetics; Laboratories; Lead; Lentivirus Vector; Luciferases; MDM2 gene; Malignant Neoplasms; Malignant neoplasm of brain; Mediating; Modeling; Molecular Profiling; Monitor; Mus; Normal Cell; Normal tissue morphology; O(6)-Methylguanine-DNA Methyltransferase; Operative Surgical Procedures; Outcome; Pathway interactions; Patients; Pharmaceutical Preparations; Pharmacodynamics; Population; Positioning Attribute; Production; Quality of life; Radiation; Radiation Induced DNA Damage; Radiation Oncology; Radiation-Sensitizing Agents; Refractory; Regimen; Regulation; Research; Resistance; Signal Pathway; Signal Transduction; Signal Transduction Pathway; Signaling Molecule; Testing; Therapeutic; Time; Tissues; Toxic effect; Toxicology; Treatment Efficacy; Treatment Protocols; Treatment outcome; Vascular Endothelial Growth Factors; Xenograft Model; angiogenesis; attenuation; base; cancer therapy; cancer type; cell killing; cell type; clinically relevant; combinatorial; conventional therapy; cytotoxicity; drug efficacy; effective therapy; experience; hypoxia inducible factor 1; improved; in vivo; in vivo Model; inhibitor/antagonist; irradiation; killings; migration; mutant; neoplastic cell; novel; outcome forecast; public health relevance; response; senescence; small molecule; stem; success; temozolomide; treatment response; treatment strategy; tumor; tumor progression; tumor xenograft; ubiquitin-protein ligase

DESCRIPTION (provided by applicant): Development of efficacious strategies for treatment of glioblastoma multiforme (GBM) remains a significant challenge in both pediatric and adult patients. Some improvements, such as treatment with radiation and temozolomide (TMZ), have led to increased survival. However, the prognosis for brain tumor patients remains poor, and is largely due to the ability of these malignancies to acquire chemoresistance by modulation of p53-regulated signaling pathways that control cell survival. Our long-term goal is to develop therapeutic strategies that sensitize drug- and radiation-resistant brain tumors to therapy. In this proposal, we will investigate the efficacy of a novel combination therapy that targets the HDM2/p53 network and DNA repair. Inhibition of HDM2 interactions with key signaling molecules-p53, p73a, and HIF1a-by the small molecule inhibitor, nutlin3, can modulate their downstream effector function. Depending on the cell type studied, exposure to the HDM2 antagonist can lead to cell cycle arrest, senescence, apoptosis, decreased migration, and attenuation of VEGF production. To what extent TMZ and radiation in combination with nutlin3 can modulate these critical intracellular targets has not been studied. Our data indicate that nutlin3 can significantly potentiate TMZ- and radiation-mediated cytotoxicity in glioblastoma cells in vitro. In addition, nutlin3 also enhanced TMZ-mediated glioblastoma cell kill in an ectopic xenograft model. Our overall objective is to develop efficacious treatment strategies that kill brain tumor cells but not normal cells. For drug efficacy studies, ectopic and orthotopic glioblastomas will be established in NOD/SCID/IL2Rnull mice. A panel of established glioblastoma cell lines and early passaged glioblastoma primary cultures that differ in EGFR gene amplification, p53 status (wild-type or mutant), HDM2 status, MGMT expression, and sensitivities to TMZ and irradiation will be utilized. Real-time bioluminescence imaging will be utilized to serially monitor glioblastoma progression over time. Our central hypothesis is that nutlin3 potentiates the TMZ- and/or radiation-induced DNA damage response by perturbing HDM2-mediated regulation of key signaling molecules, and leads to increased glioblastoma cell death in vivo. To test this hypothesis, the following specific aims are proposed: 1) Develop therapeutic regimens and validate intracellular target modulation mediated by inhibition of HDM2-protein interactions during exposure to DNA-damaging agents 2) Assess in vivo the outcome of modulating HDM2-dependent signaling to increase therapeutic efficacy of TMZ- and/or radiation- mediated DNA damage. 3) Employ intracranial GBM xenograft models in combination with serial real- time bioluminescence imaging to monitor therapeutic impact of modulating HDM2-dependent signaling in combination with TMZ- and/or radiation-mediated DNA damage. The treatment strategies investigated here will use clinically relevant in vivo models and novel multi-targeting approaches and have the potential to improve treatment efficacy and quality of life for patients with GBM. PUBLIC HEALTH RELEVANCE: The central hypothesis is that the HDM2 antagonist, nutlin3, potentiates TMZ and/or radiation-induced DNA damage response by perturbing HDM2-mediated regulation of key signaling molecules and leads to increased glioblastoma cell death in vivo. The underlying mechanisms of glioblastoma cell kill will be determined and ectopic and orthotopic brain tumor models will be used to evaluate in vivo efficacy.

描述（由申请人提供）：开发治疗多形性胶质母细胞瘤（GBM）的有效策略对于儿科和成人患者来说仍然是一个重大挑战。一些改进，例如放射治疗和替莫唑胺 (TMZ) 治疗，提高了生存率。然而，脑肿瘤患者的预后仍然很差，这在很大程度上是由于这些恶性肿瘤能够通过调节控制细胞存活的 p53 调节的信号通路来获得化疗耐药性。我们的长期目标是开发使抗药物和抗辐射脑肿瘤对治疗敏感的治疗策略。在本提案中，我们将研究一种针对 HDM2/p53 网络和 DNA 修复的新型联合疗法的功效。小分子抑制剂 nutlin3 抑制 HDM2 与关键信号分子（p53、p73a 和 HIF1a）的相互作用，可以调节其下游效应子功能。根据所研究的细胞类型，暴露于 HDM2 拮抗剂可能导致细胞周期停滞、衰老、凋亡、迁移减少和 VEGF 产生减弱。 TMZ 和辐射与 nutlin3 组合可以在多大程度上调节这些关键的细胞内靶标尚未得到研究。我们的数据表明，nutlin3 可以在体外显着增强 TMZ 和放射介导的胶质母细胞瘤细胞毒性。此外，nutlin3 还增强了异位异种移植模型中 TMZ 介导的胶质母细胞瘤细胞杀伤作用。我们的总体目标是开发有效的治疗策略，杀死脑肿瘤细胞而不是正常细胞。对于药物功效研究，将在 NOD/SCID/IL2Rnull 小鼠中建立异位和原位胶质母细胞瘤。将使用一组已建立的胶质母细胞瘤细胞系和早期传代的胶质母细胞瘤原代培养物，这些细胞系在 EGFR 基因扩增、p53 状态（野生型或突变型）、HDM2 状态、MGMT 表达以及对 TMZ 和辐射的敏感性方面存在差异。实时生物发光成像将用于连续监测胶质母细胞瘤随时间的进展。我们的中心假设是，nutlin3 通过扰乱 HDM2 介导的关键信号分子调节来增强 TMZ 和/或辐射诱导的 DNA 损伤反应，并导致体内胶质母细胞瘤细胞死亡增加。为了检验这一假设，提出了以下具体目标： 1) 开发治疗方案并验证暴露于 DNA 损伤剂期间通过抑制 HDM2-蛋白质相互作用介导的细胞内靶标调节 2) 评估体内调节 HDM2 依赖性信号传导的结果，以提高 TMZ 和/或辐射介导的 DNA 损伤的治疗效果。 3) 采用颅内 GBM 异种移植模型与连续实时生物发光成像相结合，监测调节 HDM2 依赖性信号传导与 TMZ 和/或辐射介导的 DNA 损伤相结合的治疗效果。这里研究的治疗策略将使用临床相关的体内模型和新颖的多靶点方法，并有可能提高 GBM 患者的治疗效果和生活质量。 公共健康相关性：核心假设是 HDM2 拮抗剂 nutlin3 通过扰乱 HDM2 介导的关键信号分子调节来增强 TMZ 和/或辐射诱导的 DNA 损伤反应，并导致体内胶质母细胞瘤细胞死亡增加。将确定胶质母细胞瘤细胞杀伤的潜在机制，并使用异位和原位脑肿瘤模型来评估体内功效。