Discovery and development of Ku-targeted small molecule inhibitors: A novel mechanism of DNA-PK inhibition

Ku 靶向小分子抑制剂的发现和开发：DNA-PK 抑制的新机制

基本信息

批准号：
10581526
负责人：
Navnath S Gavande
金额：
$ 57.28万
依托单位：
INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-03-13 至 2025-02-28
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10581526
关键词：
Active Sites Address Advanced Development Antineoplastic Agents Automobile Driving BRCA1 gene BRCA2 gene Binding Biochemical Biological Availability Bleomycin Cancer Model Cells Characteristics Chemicals Chemistry Chemotherapy and/or radiation Cisplatin Clinical Combined Modality Therapy Coupled DNA DNA Binding DNA Damage DNA Double Strand Break DNA Repair DNA Sequence Alteration DNA-PKcs DNA-dependent protein kinase Data Development Dose Double Strand Break Repair Drug Design Drug Kinetics Etoposide Generations Genetic Genetic study Genome Stability Health Human In Vitro Ionizing radiation Knowledge Lung Maintenance Malignant Neoplasms Malignant neoplasm of lung Malignant neoplasm of ovary Mediating Modeling Modification Molecular Molecular Mechanisms of Action Nonhomologous DNA End Joining Outcome Ovarian Pathway interactions Patients Pharmaceutical Chemistry Pharmaceutical Preparations Pharmacology Study Phosphotransferases Play Property Publishing Radiation Radiation induced double strand break Reagent Regulation Reporting Research Roentgen Rays Role Series Signal Pathway Signal Transduction Stress Structure Structure-Activity Relationship Therapeutic Therapeutic Agents Toxic effect anti-cancer anti-cancer therapeutic cancer cell cancer genetics cancer therapy clinically relevant design drug-like compound early phase clinical trial genetic manipulation homologous recombination in vivo inhibitor innovation molecular targeted therapies nanomolar novel novel therapeutics pharmacologic protein kinase inhibitor recombinational repair repaired response small molecule small molecule inhibitor synthetic lethal interaction targeted agent uptake

项目摘要

The DNA-dependent protein kinase (DNA-PK) is a validated target for cancer therapeutics involved in the DNA-damage response (DDR) and non-homologous end joining (NHEJ) double strand break (DSB) repair pathways. Various anti-cancer therapeutic strategies, including ionizing radiation (IR) impart their efficacy by inducing DNA DSBs. Both genetic and pharmacologic studies have demonstrated that modulating the DDR and DSB repair pathways has a profound impact on the efficacy of DNA damaging therapeutic agents supporting the premise of targeting DNA-PK in cancer therapy. Development of DNA-PK inhibitors thus far has focused entirely on targeting the DNA-PKcs active site, three of which are currently in early phase clinical trials. We have exploited the requirement for DNA-PK activation of binding to DNA termini via the Ku 70/80 heterodimer to identify small molecule Ku inhibitors that inhibit DNA-PK via a novel mechanism. Preliminary data show that Ku-inhibitors abrogate DNA-PK catalytic activity at nanomolar concentrations and potentiate cellular sensitivity to DSB-inducing therapeutics. We have also proven that the observed cellular effects are a function of direct on-target Ku inhibition. Based on the rigorous published and preliminary data we hypothesize that DNA-PK inhibition mediated by targeting Ku-DNA binding, will inhibit the DDR and NHEJ pathways resulting in sensitization of cancer cells to DNA damaging anti-cancer agents. To address this hypothesis, we propose three specific aims. In Aim 1 we will develop highly potent and selective DNA-PK inhibitors by targeting the Ku-DNA interaction. Having established nanomolar inhibitors, chemistry efforts will focus on optimizing the physicochemical and pharmacokinetic properties to increase cellular uptake and bioavailability while retaining excellent potency and selectivity. In Aim 2 we will determine the molecular mechanism of action (MOA) of Ku inhibitors and elucidate how chemical inhibition of Ku impacts the cellular DDR and repair pathways. In Aim 3 we will interrogate how modulation of DSB repair via HRR and DDR signaling due to Ku inhibition impacts anticancer efficacy alone and in combination therapy in clinically relevant models of lung and ovarian cancer. We will also assess the impact of common cancer genetic mutations in genome stability and maintenance pathways (including BRCA1 and BRCA2) towards exploiting synthetic lethal interactions to enhance drug and radiation efficacy. Completion of these studies will provide essential information for the continued discovery and development of novel Ku-targeted DNA-PK inhibitors. The impact of this research thus extends beyond the generation of new knowledge, reagents and models to provide new molecularly targeted treatment options for a wide array of cancers that are currently difficult to treat effectively.

DNA依赖性蛋白激酶（DNA-PK）是涉及癌症治疗剂的验证靶标在DNA破坏响应（DDR）和非同源末端连接（NHEJ）双链断裂（DSB）中维修途径。各种抗癌治疗策略，包括电离辐射（IR）赋予他们通过诱导DNA DSB的功效。遗传学和药理学研究都表明调节 DDR和DSB修复途径对DNA破坏治疗剂的功效有深远的影响支持靶向DNA-PK在癌症治疗中的前提。到目前为止的DNA-PK抑制剂的开发已有完全专注于靶向DNA-PKCS活性位点，其中三个目前正在早期临床试验中。我们利用了通过KU 70/80的DNA-PK激活与DNA末端结合的要求杂化二聚体以鉴定通过新机制抑制DNA-PK的小分子KU抑制剂。初步的数据表明，KU抑制剂在纳摩尔浓度下消除DNA-PK催化活性并增强细胞对DSB诱导疗法的敏感性。我们还证明，观察到的细胞效应是直接靶向KU抑制的功能。根据严格发布和初步数据假设通过靶向KU-DNA结合介导的DNA-PK抑制作用将抑制DDR和 NHEJ途径导致癌细胞对DNA损害抗癌药的敏感性。到解决这一假设，我们提出了三个具体目标。在AIM 1中，我们将发展高度有力和选择性 DNA-PK抑制剂通过靶向KU-DNA相互作用。建立纳摩尔抑制剂后，化学努力将着重于优化物理化学和药代动力学特性以增加细胞摄取和生物利用度，同时保持出色的效力和选择性。在AIM 2中，我们将确定分子 KU抑制剂的作用机理（MOA），并阐明了KU化学抑制作用如何影响细胞 DDR和修复途径。在AIM 3中，我们将询问如何通过HRR和DDR调制DSB修复由于KU抑制作用而引起的信号会影响抗癌功效，并且在临床相关的联合治疗中肺癌和卵巢癌模型。我们还将评估常见癌症基因突变对基因组稳定性和维护途径（包括BRCA1和BRCA2）用于利用合成致死相互作用以增强药物和辐射功效。这些研究的完成将提供必不可少的持续发现和开发新型KU靶向DNA-PK抑制剂的信息。影响因此，这项研究超出了新知识，试剂和模型的产生，以提供新的知识和模型各种癌症的分子靶向治疗方案，这些癌症目前难以有效治疗。