Identification of small molecule inhibitors to exonuclease 1 for breast cancer treatment

鉴定用于乳腺癌治疗的核酸外切酶 1 小分子抑制剂

基本信息

批准号：
10735307
负责人：
DAVID A. HORNE
金额：
$ 57.54万
依托单位：
BECKMAN RESEARCH INSTITUTE/CITY OF HOPE
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-08-02 至 2026-07-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10735307
关键词：
BRCA1 gene Benchmarking Binding Biochemical Biological Biological Assay Biological Process Breast Breast Cancer Cell Breast Cancer Treatment Cancer Etiology Cancerous Catalogs Cell Death Cell physiology Cells Chemicals Clinical Collaborations Core Facility Critical Pathways DNA DNA Damage DNA Repair DNA Repair Enzymes DNA biosynthesis DNA redundancy DNA replication fork Dedications Development Dose Drug Kinetics EXO1 gene Enzyme Inhibition Enzymes Excision Exclusion Excretory function Exonuclease Failure Family member Fluorescence Fluorescence Resonance Energy Transfer Genes Genetic Goals Growth Human Human Cloning In Vitro Invaded Kinetics Knock-out Label Lead Length Libraries Literature Malignant Neoplasms Measures Medical Medicine Metabolism Mutate Mutation Normal Cell Pathway interactions Pharmaceutical Chemistry Pharmaceutical Preparations Poly(ADP-ribose) Polymerase Inhibitor Poly(ADP-ribose) Polymerases Positioning Attribute Powder dose form Predisposition Process Property Proteins Qualifying RNA primers Reaction Research Rodent Signal Pathway Single-Stranded DNA Specificity Structure-Activity Relationship Testing Therapeutic Toxic effect Validation Work absorption analog anti-cancer therapeutic brca gene cancer cell cheminformatics counterscreen cytotoxic cytotoxicity druggable target exodeoxyribonuclease gene repair high throughput screening hormone related cancer improved inhibitor insight lead optimization malignant breast neoplasm meter novel novel therapeutics nuclease pre-clinical prototype repaired replication stress response scaffold scale up small molecule small molecule inhibitor synergism tool

项目摘要

ABSTRACT Our overall goal, which is fully responsive to PAR-20-271, is to develop a selective and effective inhibitor of the multi-functional DNA repair enzyme exonuclease 1 (EXO1) that can be used both as a research tool (chemical probe) and as a pre-clinical starting point toward the development of a potential cancer therapeutic drug. There is no EXO1-specific small molecule inhibitor listed in the Chemical Probe Portal or other literature. We will achieve our goal through discovery research, from implementing a primary high-throughput screen (HTS) that we have already developed, to validating hits via a well-developed “critical path” of secondary assays, to performing early hit-to-lead optimization via purchase of commercially available analogs of validated chemical scaffolds and limited focused medicinal chemistry. EXO1 represents a druggable target, as it contains functionally essential exonuclease activity for double-strand break response and repair (DSBRR) for processing of stalled replication forks, which are critical pathways by which cells counteract endogenous DNA damage and replication stress. Compared to normal cells, cancer cells carry a significantly higher burden of double-strand breaks and replication stress, which generates a therapeutic window for treating cancer. To exploit this, current therapeutic approaches primarily target proteins acting in repair pathways or in checkpoint signaling pathways controlling repair. Many cancer cells are already defective in DSBRR; thus, EXO1 inhibition will cause cancer cell-specific cell death through a synthetic lethality mechanism. Furthermore, EXO1is will display greater specificity than currently used PARP inhibitors, because PARPs participate in a wide array of other cellular processes, whereas EXO1 does not. Our group was the first to clone the human EXO1 gene and to characterize its biochemical properties. We have expressed and purified the full-length and active EXO1 enzyme at scale, developed a robust fluorescence-based enzyme inhibition assay, and performed a pilot HTS in our own core facility. Thus, in collaboration with the Prebys Center of Sanford Burnham Prebys Medical Discovery Institute, we are well positioned to 1) identify inhibitors of EXO1 exonuclease by performing HTS of a well-curated ~320,000 compound library; 2) validate hits for potency and selectivity; 3) perform “structure-activity relationship (SAR)-by-catalog” and limited focused medicinal chemistry and benchmark absorption, distribution, metabolism, and excretion (ADME)/pharmacokinetic (PK) characterization of best probes; and 4) determine the mode of action (MOA) and biological effects of validated EXO1i candidate probes. All of our Aims are responsive to and within the scope of PAR-20-271. The development of novel EXO1is will not only allow us to provide a critical tool (i. e. chemical probe) to test mechanistic insights into the replication-repair interface but will also support development of a novel chemotherapeutic drug that blocks both upstream DNA replication steps and the downstream DSBRR pathway, with the potential to induce clinical synthetic lethality in breast cancer and other DSBRR-deficient cancers.

摘要我们的总体目标完全响应 PAR-20-271，是开发一种选择性且有效的多功能 DNA 修复酶核酸外切酶 1 (EXO1) 的抑制剂，可用作研究工具（化学探针）并作为开发潜在癌症治疗方法的临床前起点化学探针门户或其他文献中没有列出 EXO1 特异性小分子抑制剂。我们将通过发现研究实现我们的目标，从实施初级高通量筛选（HTS）开始我们已经开发出通过二次分析的完善“关键路径”来验证命中，通过购买经过验证的化学物质的市售类似物来执行早期的先导化合物优化支架和有限的集中药物化学代表了一个可成药的靶点，因为它含有。用于加工的双链断裂响应和修复 (DSBRR) 的功能必需的核酸外切酶活性停滞的复制叉，这是细胞抵抗内源性 DNA 损伤的关键途径与正常细胞相比，癌细胞携带明显更高的双链负担。断裂和复制压力，这产生了治疗癌症的治疗窗口。方法主要针对修复治疗途径或检查点信号传导途径中起作用的蛋白质许多癌细胞的 DSBRR 已经存在缺陷，因此抑制 EXO1 会导致癌症。此外，EXO1is 将通过合成致死机制表现出更大的细胞特异性细胞死亡。特异性高于目前使用的 PARP 抑制剂，因为 PARP 参与多种其他细胞过程，而 EXO1 则不然，我们的团队是第一个克隆人类 EXO1 基因并对其进行表征的团队。我们已经大规模表达和纯化了全长的活性 EXO1 酶，开发了一种强大的基于荧光的酶抑制测定，并在我们自己的核心中进行了试点 HTS 因此，与桑福德伯纳姆普雷比斯医学发现研究所的普雷比斯中心合作，我们有能力 1) 通过对精心策划的 HTS 来识别 EXO1 核酸外切酶的抑制剂约 320,000 个化合物库；2) 验证命中的效力和选择性；3) 执行“结构-活性关系” （SAR）按目录”和有限的重点药物化学和基准吸收、分布、代谢、和最佳探针的排泄（ADME）/药代动力学（PK）表征；以及4）确定模式；经验证的 EXO1i 候选探针的作用 (MOA) 和生物效应我们所有的目标都是响应和。在 PAR-20-271 的范围内，新型 EXO1is 的开发不仅使我们能够提供一个关键工具。（即化学探针）来测试复制修复界面的机制见解，但也支持开发一种新型化疗药物，可阻断上游 DNA 复制步骤和下游 DSBRR 通路，有可能诱导乳腺癌和其他癌症的临床合成致死率 DSBRR 缺乏的癌症。