Novel DNA Repair Inhibitors for Cancer Therapy

用于癌症治疗的新型 DNA 修复抑制剂

• 批准号: 10456727
• 负责人: PETER M GLAZER
• 金额: $ 98.49万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10456727
• 关键词: Affinity; Animals; Anti-Idiotype Vaccine; Antibodies; Autoantibodies; BRCA2 gene; Binding; Biological Markers; Cancer cell line; Cell membrane; Cells; Chemotherapy and/or radiation; Clinic; DNA; DNA Damage; DNA Repair; DNA Repair Pathway; DNA-dependent protein kinase; Development; Dropout; Glioma; Human; Isocitrate Dehydrogenase; Lupus; Malignant Neoplasms; Mus; Mutation; Nature; Nonhomologous DNA End Joining; Normal tissue morphology; PTEN gene; Pathway interactions; Patients; Penetration; Peptides; Phase I Clinical Trials; Phenotype; Positioning Attribute; Publishing; RNA; Radiation; Testing; Therapeutic; Therapeutic Agents; Toxic effect; Tumor Tissue; Work; base; cancer cell; cancer therapy; chemotherapy; in vivo; inhibitor; leukemia; neoplastic cell; next generation; novel; novel therapeutics; pre-clinical; repaired; response; small hairpin RNA; small molecule; synergism; tumor; tumor microenvironment

Project Summary/Abstract. We seek to identify novel therapeutic agents that are selectively toxic to cancer cells and that specifically sensitize tumors to radiation or chemotherapy. We have discovered that a cell-penetrating, lupus-derived autoantibody (3E10) increases the sensitivity of cancer cells to radiation and to DNA-targeted chemotherapy. Importantly, 3E10, by itself, is synthetically lethal to BRCA2- and PTEN-deficient cancer cells, but is otherwise non-toxic to cells in culture or to mice. The antibody also showed no detectable toxicity in humans when tested in a phase I clinical trial in lupus patients as a putative anti-idiotype vaccine. We previously determined 3E10 to be a potent inhibitor of homology-dependent repair (HDR), and we have now identified RAD51 as the functional target. We have also found that 3E10 is preferentially taken up in tumor tissue in vivo based on its mechanism of cell penetration, providing a further basis to pursue its development for cancer therapy. These new results provide the basis to enhance the potency of 3E10 (by directed mutation, affinity maturation, and multi-valent constructs) and to rationally develop therapeutic strategies by identifying synthetic lethal interactions (via unbiased shRNA dropout screen and interrogation of curated cancer cell lines) and determining synergies with other agents, as a prelude to pre-clinical animal tumor studies. We expect that 3E10 will be synthetic lethal to cancers deficient in DNA repair and damage response pathways. We also have developed a strategy to selectively target DNA repair inhibitors to tumors by exploiting the acidic tumor microenvironment. We will use a pH low insertion peptide (pHLIP) that inserts directionally across cell membranes at low pH and delivers cargoes selectively into tumor cells in vivo. Focusing on DNA-PK in the non-homologous end-joining pathway (NHEJ) of DNA repair, we will build on advances made in collaborative work to develop tumor-targeted antisense and small molecule inhibition of DNA-PK. We will incorporate next generation γPNAs modified at the γ position to increase binding to RNA for potent antisense activity. This is based on our promising proof-of-concept studies published in Nature demonstrating the in vivo anti-tumor activity of pHLIP-PNA conjugates. We will also conjugate small molecule DNA-PK inhibitors to pHLIP, leveraging potent molecules that have not advanced to the clinic because of normal tissue toxicity, and conferring tumor selectivity. This work will provide a versatile platform to apply to other DNA repair targets. We have recently identified the oncometabolite, 2-hydroxyglutarate (2HG), as a new biomarker of deficient DNA repair in human malignancies. We found that elevated levels of 2HG confer a BRCAness phenotype of deficient HDR that renders cancer cells sensitive to synthetic lethal killing by PARP inhibitors and by 3E10. 2HG is produced by the neomorphic activity of isocitrate dehydrogenase-1 and -2 (IDH1/2) mutations found in gliomas, leukemia, and other cancers. We will investigate the mechanism by which 2HG suppresses DNA repair and identify vulnerabilities that can be exploited for therapeutic gain in human tumors.

项目摘要/摘要。 我们试图鉴定出对癌细胞有选择性毒性的新型治疗剂，特别是 对放射或化学疗法的敏感肿瘤。我们发现一种细胞渗透的，狼疮的衍生 自身抗体（3E10）提高了癌细胞对放射线的敏感性和对DNA靶向化疗的敏感性。 重要的是，3E10本身在BRCA2和PTEN缺陷癌细胞中是致命的，但否则是 对培养物或小鼠中细胞无毒。测试后，抗体在人类中也没有可检测到的毒性 在狼疮患者的I期临床试验中，作为推定的抗IDiotype疫苗。我们以前确定了3E10 成为同源依赖性修复（HDR）的潜在抑制剂，现在我们已经确定RAD51为 功能目标。我们还发现，根据其体内肿瘤组织，最好在体内服用3E10 细胞渗透机制，为追求其开发癌症治疗提供了进一步的基础。这些 新结果为提高3E10的效力提供了基础（通过定向突变，亲和力成熟和 多价构建体）并通过识别合成致死性来合理地制定治疗策略 相互作用（通过无偏的shRNA辍学筛查和策划的癌细胞系的询问）和 确定与其他药物的协同作用，是临床前动物肿瘤研究的前奏。我们期望这一点 3E10将对缺乏DNA修复和损伤响应途径的癌症是合成的致命性。 我们还制定了一种策略，通过利用该策略，以选择性地靶向DNA修复抑制剂。 酸性肿瘤微环境。我们将使用pH低插入肽（phlip），该肽可以在 低pH值的细胞膜并在体内选择性地将货物选择性地输送到肿瘤细胞中。专注于DNA-PK DNA维修的非同源最终结合途径（NHEJ），我们将基于协作的进步 努力发展为肿瘤的反义和小分子抑制DNA-PK。我们将结合下一步 γPNA的一代在γ位置改变，以增加与RNA的结合，以进行潜在的反义活性。这是 基于我们在自然界发表的概念验证研究，证明了体内抗肿瘤 phlip-pNA结合物的活性。我们还将连接小分子DNA-PK抑制剂以phlip， 利用由于组织正常而尚未到临床的潜在分子，并且 会议肿瘤的选择性。这项工作将为应用于其他DNA维修目标的多功能平台。 我们最近确定了oncometabolite 2-羟基戊二酸（2HG），是一种不足的新生物标志物 人类恶性肿瘤中的DNA修复。我们发现2HG会议的水平升高 不足的HDR会使癌细胞对PARP抑制剂杀死的合成致死性和3E10敏感。 2Hg是由异戊二酸脱氢酶1和-2（IDH1/2）突变的新形态活性产生的 神经胶质瘤，白血病和其他癌症。我们将研究2HG抑制DNA的机制 修复和确定可以探索的漏洞，以供人类肿瘤的治疗增加。