Harnessing E3 Ligases for Cancer Therapy

利用 E3 连接酶进行癌症治疗

• 批准号: 10442517
• 负责人: Thomas John Maimone
• 金额: $ 45.4万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10442517
• 关键词: Antineoplastic Agents; Azadirachta indica; Binding; Breast Cancer Cell; CDKN1A gene; Cells; Chemicals; Cysteine; Data; Disease; Glues; Human; Impairment; In Situ; In Vitro; Knock-out; Lead; Libraries; Ligands; Link; MDM2 gene; Malignant Neoplasms; Mediating; Modality; Modification; Molecular; Mus; N-terminal; Natural Products; Pathogenicity; Protac; Proteins; Proteome; Role; Technology; Testing; Thalidomide; Therapeutic; Tissues; Tumor Suppressor Proteins; Ubiquitination; activity-based protein profiling; anti-cancer; base; cancer therapy; cell type; chemoproteomics; drug discovery; in vivo; inhibitor; innovation; interest; malignant breast neoplasm; multicatalytic endopeptidase complex; novel; prevent; protein degradation; recruit; scaffold; small molecule; targeted cancer therapy; triple-negative invasive breast carcinoma; ubiquitin-protein ligase

Targeted protein degradation has arisen as a powerful drug discovery paradigm for targeting undruggable proteins for proteasomal degradation. This technology utilizes bifunctional degraders called proteolysis targeting chimeras (PROTACs) that consist of a protein-targeting ligand linked to an E3 ligase recruiter to ubiquitinate and proteasomally degrade proteins of interest. While targeted protein degradation can potentially be used to target any intracellular protein for degradation, a major challenge of this approach has been the dearth of E3 ligase recruiters. Using a chemoproteomic platform termed activity-based protein profiling (ABPP), which uses reactivity-based chemical probes to profile proteome-wide reactive, functional, and ligandable hotspots, we recently discovered that the anti-cancer natural product nimbolide, a triterpenoid isolated from Azadirachta indica or neem, covalently reacts with an N-terminal cysteine (C8) of the E3 ubiquitin ligase RNF114 in triple- negative breast cancer cells. Our preliminary data revealed that covalent modification of RNF114 by nimbolide leads to impaired ubiquitination of the tumor suppressor p21 through a nimbolide-dependent destabilization of the RNF114-substrate binding interaction, thus providing a potential mechanism for the anti-cancer effects of this natural product. This realization that nimbolide targeted a substrate recognition domain within RNF114 suggested that nimbolide could potentially be used as a novel recruiter for RNF114 for PROTAC applications. Consistent with this premise, we have shown that a PROTAC, XH2, linking nimbolide to a BRD4 inhibitor JQ1 led to proteasome-dependent degradation of BRD4 in breast cancer cells. This degradation was RNF114- dependent, as shown by BRD4 degradation in RNF114 wild-type cells, but not in RNF114 knockout cells. In this proposal, we will combine chemoproteomic and targeted protein degradation platforms to investigate the therapeutic potential of RNF114 modulators in cancer and exploit nimbolide and other covalent ligands targeting C8 of RNF114 as recruiters for PROTAC applications.

靶向蛋白质降解已成为一种强大的药物发现范式，用于靶向不可成药的药物 用于蛋白酶体降解的蛋白质。该技术利用称为蛋白水解靶向的双功能降解剂 嵌合体 (PROTAC) 由与 E3 连接酶募集剂连接的蛋白质靶向配体组成，可泛素化和 蛋白酶体降解感兴趣的蛋白质。虽然靶向蛋白质降解可潜在地用于靶向 对于任何细胞内蛋白质的降解，这种方法的一个主要挑战是缺乏 E3 连接酶 招聘人员。使用称为基于活性的蛋白质分析 (ABPP) 的化学蛋白质组学平台，该平台使用 基于反应性的化学探针来分析整个蛋白质组的反应性、功能性和可配体热点，我们 最近发现抗癌天然产物印苦内酯，一种从印楝中分离出来的三萜类化合物 indica 或印楝，与 E3 泛素连接酶 RNF114 的 N 末端半胱氨酸 (C8) 发生三重共价反应 阴性乳腺癌细胞。我们的初步数据表明，印楝内酯对 RNF114 进行共价修饰 通过印楝内酯依赖性不稳定，导致肿瘤抑制因子 p21 的泛素化受损 RNF114-底物结合相互作用，从而为 RNF114 的抗癌作用提供了潜在的机制 这种天然产品。印楝内酯靶向 RNF114 内的底物识别域 表明印楝内酯有可能用作 PROTAC 应用中 RNF114 的新型招募剂。 与这个前提一致，我们已经证明 PROTAC，XH2，将印楝内酯与 BRD4 抑制剂 JQ1 连接起来 导致乳腺癌细胞中 BRD4 的蛋白酶体依赖性降解。这种降解是RNF114- 依赖，如 RNF114 野生型细胞中 BRD4 降解所示，但 RNF114 敲除细胞中则不然。在这个 建议，我们将结合化学蛋白质组学和靶向蛋白质降解平台来研究 RNF114 调节剂在癌症中的治疗潜力并利用印苦内酯和其他共价键 靶向 RNF114 C8 的配体作为 PROTAC 应用的招募剂。