Investigating the role of OTULIN and the regulation of linear ubiquitination in the pathogenesis of Activated B-Cell-like Diffuse Large B-Cell Lymphoma

研究 OTULIN 的作用和线性泛素化在活化 B 细胞样弥漫性大 B 细胞淋巴瘤发病机制中的调节

• 批准号: 494877499
• 负责人: Privatdozent Dr. Sjoerd van Wijk
• 金额: --
• 依托单位: Institut für Experimentelle Pädiatrische Hämatologie und Onkologie (EPHO)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/494877499?language=en
• 关键词: Investigating; role; OTULIN; regulation; linear

Dysregulation of NF-ĸB signalling underlies many forms of cancer. Activated B-cell Diffuse Large B-Cell Lymphoma (ABC-DLBCL), a heterogeneous form of non-Hodgkin lymphoma, is characterised by chronic active NF-ĸB signalling, rendering ABC-DLBCL addictive to NF-ĸB. This dependency often originates from gain-of-function mutations in critical regulators of B-cell receptor (BCR)-mediated NF-ĸB signalling, like BCR subunits, MALT1, MyD88, CARD11 and LUBAC, the linear ubiquitin-specific E3 ligase. Chronic BCR and NF-ĸB activation trigger non-degradative linear ubiquitination of several substrates, among them LUBAC itself affecting LUBAC function in a context-dependent manner. Inhibition of LUBAC selectively kills ABC-DLBCL cells, suggesting that LUBAC and linear ubiquitin are central oncogenic nodes in ABC-DLBCL and that modulating the linear ubiquitin axis could potentially serve as therapeutic target. This is of special interest, since ABC-DLBCL is generally associated with a poor prognosis and the success of standard chemotherapy strongly depends on the mutational background. Although linear ubiquitination and LUBAC function are counteracted by two deubiquitinating enzymes, CYLD and OTULIN, CYLD is proteolytically inactivated by MALT1 in ABC-DLBCL, supporting LUBAC-mediated linear ubiquitination as oncogenic driver. In contrast, the role of OTULIN in regulating linear ubiquitination, LUBAC function, oncogenic NF-ĸB signalling and tumorigenesis in ABC-DLBCL remains unknown and elusive. Therefore, this proposal aims to unravel the role of OTULIN in controlling LUBAC E3 ligase function, cellular linear ubiquitination, chronic NF-ĸB signalling and ABC-DLBCL tumorigenesis. Using systematic multidisciplinary and state-of-the-art approaches, including CRISPR/Cas9-mediated genetic knock-out and knock-in, mass-spectrometry combined with classical biochemistry and in vivo evaluation of ABC-DLBCL tumorigenesis in preclinical mouse models, this proposal will reveal the precise roles of OTULIN in oncogenic linear ubiquitination and NF-ĸB in ABC-DLBCL tumour cell fate control.The outcomes of this proposal are expected to provide crucial novel insights in how OTULIN controls linear ubiquitin and LUBAC in ABC-DLBCL tumorigenesis and will contribute to novel therapeutic approaches to selectively target ABC-DLBCL. Understanding OTULIN function will also lead to a better understanding of other tumour entities, like certain subtypes of acute myeloid leukaemia, chronic myeloid leukaemia and multiple myeloma, that rely on linear ubiquitination and LUBAC. Finally, the proposed research project will also have fundamental implications for OTULIN function in innate immunity and inflammation.

NF-κ B信号的失调是许多癌症的基础.活化的B细胞弥漫性大B细胞淋巴瘤（ABC-DLBCL）是一种异质形式的非霍奇金淋巴瘤，其特征在于慢性活性NF-KB信号传导，使得ABC-DLBCL对NF-KB成瘾。这种依赖性通常源于B细胞受体（BCR）介导的NF-κ B信号传导的关键调节因子中的功能获得性突变，如BCR亚基、MALT 1、MyD 88、CARD 11和LUBAC（线性泛素特异性E3连接酶）。慢性BCR和NF-κ B激活触发几种底物的非降解线性泛素化，其中LUBAC本身以上下文依赖性方式影响LUBAC功能。LUBAC的抑制选择性地杀死ABC-DLBCL细胞，这表明LUBAC和线性泛素是ABC-DLBCL中的中心致癌节点，并且调节线性泛素轴可以潜在地用作治疗靶点。这是特别令人感兴趣的，因为ABC-DLBCL通常与不良预后相关，并且标准化疗的成功在很大程度上取决于突变背景。虽然线性泛素化和LUBAC功能被两种去泛素化酶CYLD和OTULIN抵消，但CYLD在ABC-DLBCL中被MALT 1蛋白水解失活，支持LUBAC介导的线性泛素化作为致癌驱动因子。相比之下，OTULIN在调节线性泛素化、LUBAC功能、致癌NF-KB信号传导和ABC-DLBCL中的肿瘤发生中的作用仍然未知且难以捉摸。因此，该提议旨在阐明OTULIN在控制LUBAC E3连接酶功能、细胞线性泛素化、慢性NF-κ B信号传导和ABC-DLBCL肿瘤发生中的作用。使用系统的多学科和最先进的方法，包括CRISPR/Cas9介导的基因敲除和敲入，质谱结合经典生物化学和临床前小鼠模型中ABC-DLBCL肿瘤发生的体内评价，这一提议将揭示OTULIN在致癌线性泛素化中的确切作用，以及NF-APB在ABC中的确切作用。DLBCL肿瘤细胞命运控制：预期该提议的结果将提供关于OTULIN如何控制ABC-DLBCL肿瘤发生中的线性泛素和LUBAC的关键新见解，并将有助于选择性靶向ABC-DLBCL的新治疗方法。了解OTULIN功能也将有助于更好地了解其他肿瘤实体，如急性髓性白血病，慢性髓性白血病和多发性骨髓瘤的某些亚型，这些肿瘤依赖于线性泛素化和LUBAC。最后，拟议的研究项目也将对天然免疫和炎症中的OTULIN功能产生根本性影响。