Tumor-selective inhibition of DNA repair using pHLIP

使用 pHLIP 肿瘤选择性抑制 DNA 修复

• 批准号: 9977999
• 负责人: Alanna Kaplan
• 金额: $ 4.63万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-01 至 2021-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9977999
• 关键词: Acidity; Aftercare; Biological Assay; Biological Availability; Biological Markers; Biology; Blood Vessels; Cell Death; Cell Line; Cell Proliferation; Cell Survival; Cell membrane; Cells; Clinical; Comet Assay; Cytotoxic Chemotherapy; DNA Damage; DNA Repair; DNA Repair Inhibition; DNA Repair Pathway; Dangerousness; Development; Dose; Double Strand Break Repair; Exposure to; Fibrosis; Gamma-H2AX; Genetic; Glycolysis; Goals; Immunofluorescence Immunologic; Impairment; Inflammation; Ionizing radiation; Label; Lactic acid; Lymphoma; Malignant Neoplasms; Measures; MicroRNAs; Mus; Nature; Nonhomologous DNA End Joining; Normal tissue morphology; Oncogenic; Organ; Pathway interactions; Peptide Nucleic Acids; Peptides; Pharmacology; Production; Publishing; Radiation; Radiation exposure; Radiation therapy; Radiosensitization; Reporter; System; Technology; Testing; Therapeutic Index; Therapeutic Uses; Tissues; Toxic effect; Western Blotting; Work; XRCC5 gene; antisense nucleic acid; antitumor effect; base; cancer cell; cancer therapy; cell type; curative treatments; extracellular; genome integrity; homologous recombination; improved; in vivo; inhibitor/antagonist; interest; laboratory experience; mouse model; neoplastic cell; new technology; novel; repaired; side effect; small molecule; small molecule inhibitor; systemic toxicity; therapeutic development; tool; tumor; tumor growth; tumor microenvironment; uptake

PROJECT SUMMARY The development of therapeutic agents that specifically target cancer cells while sparing healthy tissue would represent an important advance in cancer therapy by reducing toxicity to healthy tissue. Acidity is a hallmark of the tumor microenvironment that can be targeted using pH-low insertion peptides (pHLIPs). Cargo attached to pHLIP can be selectively delivered to tumor cells in vivo based on the acidity of the tumor microenvironment. The objective of this proposal is to develop a tool to inhibit DNA repair specifically within the tumor microenvironment while sparing normal tissue, with a long-term goal of developing novel cancer treatments with wider therapeutic indices. DNA repair is crucial for tumor cell survival after exposure to ionizing radiation (IR), and thus inhibiting DNA repair causes increased cell death after IR exposure (radiosensitization). Furthermore, in susceptible genetic backgrounds, inhibition of DNA repair causes cell death in the absence of radiation through a mechanism known as synthetic lethality. Small molecule inhibitors of non-homologous end joining (NHEJ), a critically important pathway in DNA repair, cause exquisite radiosensitization. However, the clinical use of these inhibitors has been hindered by in vivo toxicity and poor bioavailability. This proposal aims to use new technologies to overcome the current limitations in targeting NHEJ by developing peptide nucleic acid (PNA) based oligomers to reduce expression of the essential NHEJ factor Ku80 and using pHLIPs to selectively deliver these PNA molecules to tumors (pHLIP-αKu80(γ)), with the hypothesis that this approach will allow for the selective radiosensitization of tumor cells. This hypothesis will be tested through the following aims. To evaluate the activity of pHLIP-αKu80(γ) against cancer cells in culture (Aim 1), pHLIP-conjugated PNAs with antisense activity against Ku80 will be tested for pH-dependent activity against cancer cells in culture. Specifically, effects on DNA repair and cell survival after IR will be determined. Efforts will also be made to identify genetic backgrounds that demonstrate synthetic lethality with pHLIP-αKu80(γ) treatment. To evaluate and optimize the tumor radiosensitizing effects of pHLIP-αKu80(γ) in vivo (Aim 2), the pharmacology and toxicity of pHLIP-αKu80(γ) treatment will be assessed, and tumor growth delay and clonogenic survival assays will be used to measure radiosensitization and synthetic lethal interactions. The development of pHLIP-αKu80(γ) would provide a means of selectively radiosensitizing tumors cells regardless of tumor type, biomarker expression, and genetic background. By inhibiting DNA repair selectively in tumors, this approach spares healthy tissue and is thus expected to reduce toxicity. Therefore, pHLIP-αKu80(γ) could be used to improve the efficacy of radiation therapy without causing additional toxicity, marking an important clinical advancement. !

项目摘要 开发特异性靶向癌细胞而不影响健康组织的治疗剂将有助于 通过减少对健康组织的毒性，代表了癌症治疗的重要进展。酸度是一个标志 的肿瘤微环境，可以使用pH低插入肽（pHLIPs）的目标。货物附加 基于肿瘤微环境的酸度，pHLIP可以选择性地递送到体内肿瘤细胞。 该提案的目的是开发一种工具，专门抑制肿瘤内的DNA修复 微环境，同时保留正常组织，长期目标是开发新的癌症治疗方法 具有更宽的治疗指数。DNA修复对于电离辐射后肿瘤细胞的生存至关重要 (IR)因此抑制DNA修复导致IR暴露后细胞死亡增加（放射增敏）。 此外，在易感的遗传背景中，DNA修复的抑制导致细胞死亡， 辐射通过一种叫做合成致死的机制。非同源末端小分子抑制剂 NHEJ是DNA修复中的一个重要途径，可引起强烈的放射增敏作用。但 这些抑制剂的临床应用受到体内毒性和差的生物利用度的阻碍。这项建议旨在 使用新技术，通过开发肽核酸， 酸（PNA）基寡聚物以减少必需NHEJ因子Ku80的表达，并使用pHLIPs 选择性地将这些PNA分子递送到肿瘤（pHLIP-α Ku80（γ）），假设这种方法 将允许肿瘤细胞的选择性放射增敏。这一假设将通过以下方式进行检验： 目标。为了评价pHLIP-α Ku80（γ）对培养的癌细胞的活性（目的1）， 将测试具有针对Ku80的反义活性的PNA针对癌细胞的pH依赖性活性， 文化具体而言，将确定IR后对DNA修复和细胞存活的影响。还将努力 以鉴定证明pHLIP-α Ku80（γ）处理的合成致死性的遗传背景。到 评价和优化pHLIP-α Ku80（γ）的体内放射增敏作用（目的2）， 将评估pHLIP-α Ku80（γ）治疗的毒性， 测定将用于测量放射增敏和合成致死相互作用。的发展 pHLIP-α Ku80（γ）将提供一种选择性放射增敏肿瘤细胞的方法， 生物标志物表达和遗传背景。通过选择性地抑制肿瘤中的DNA修复， 不损伤健康组织，因此有望降低毒性。因此，pHLIP-α Ku80（γ）可用于 提高放射治疗的疗效，而不引起额外的毒性，标志着一个重要的临床 进步。 !