Evaluating the mechanism by which the DYNLL1-MRE11 complex regulates DNA end resection and genome stability.

评估 DYNLL1-MRE11 复合物调节 DNA 末端切除和基因组稳定性的机制。

• 批准号: 10606076
• 负责人: Michelle Swift
• 金额: $ 6.91万
• 依托单位: DANA-FARBER CANCER INST
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-02-01 至 2025-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10606076
• 关键词: Attenuated; BARD1 gene; BRCA deficient; BRCA1 Protein; BRCA1 gene; Binding; Blood Cells; CRISPR screen; Cancer Biology; Cancer Patient; Carcinoma; Cell Cycle; Cells; Clinical; Complex; DNA; DNA Damage; DNA Double Strand Break; DNA Repair; DNA Repair Gene; DNA-PKcs; Development; Equilibrium; Excision; Frequencies; G1 Phase; G2 Phase; Genes; Genome Stability; Genomic DNA; Genomic Instability; Germ-Line Mutation; Impairment; Malignant Neoplasms; Malignant neoplasm of ovary; Malignant neoplasm of pancreas; Malignant neoplasm of prostate; Mediating; Methodology; Modeling; Modification; Molecular; Mutation; Nonhomologous DNA End Joining; Ovarian Serous Adenocarcinoma; Pathway interactions; Patients; Phase; Phosphoric Monoester Hydrolases; Phosphorylation; Phosphotransferases; Poly(ADP-ribose) Polymerase Inhibitor; Poly(ADP-ribose) Polymerases; Primary Neoplasm; Proteins; Regulation; Resected; Resistance; Resistance development; Role; S phase; Sampling; Serine; Serous; Sister Chromatid; Therapeutic; Ubiquitination; brca gene; burden of illness; cancer cell; clinically relevant; combat; genome-wide; genomic profiles; homologous recombination; in vivo; inhibitor; inhibitor therapy; malignant breast neoplasm; member; mutant; next generation sequencing; novel; nuclease; p53-binding protein 1; patient derived xenograft model; prevent; recruit; refractory cancer; repaired; response; restoration; synthetic lethal interaction; therapeutic target; tumor; tumorigenesis

PROJECT SUMMARY The synthetic lethal interaction of BRCA deficiency with PARPi is being exploited therapeutically in diverse clinical contexts, including ovarian, pancreatic, and prostate cancers). However, PARPi resistance has emerged as a vexing clinical problem for the treatment of BRCA1/2-deficient ovarian cancer carcinomas. Analyses of PARPi resistance in BRCA1-mutant tumors across independent studies suggest that loss of genes involved in either promoting NHEJ or suppressing HR leads to the partial restoration of HR in the absence of BRCA1 activity. 53BP1 emerged as the master regulator that brings multiple complexes to the DSB. Loss of any of these factors causes PARPi resistance in BRCA1 mutant cells. Therefore, further understanding of factors that regulate the processing of DNA ends that are crucial for pathway choice have tremendous relevance in cancer biology. Our lab has previously identified that in ovarian cancer cells, loss of DYNLL1, a factor that is constitutively bound to 53BP1, also results in enhanced HR and PARPi resistance. We found that DYNLL1pS88 directly binds to and inhibits MRE11, thereby blocking the initiation of DNA end resection. However, how the interaction of DYNLL1 with MRE11 impairs its nuclease activity or its recruitment to foci remains unexplored. Furthermore, how this interaction is regulated in the context of the DNA damage response, for example, which kinase/phosphatase(s) regulates the phosphorylation of S88 residue of DYNLL1 to modulate its interaction with MRE11 needs to be investigated. Our overall objectives in this application are to identify the molecular mechanism(s) regulating repair pathway choice by further understanding how end resection proteins are regulated. Our central hypothesis is that cell cycle-specific regulation of DYNLL1 promotes BRCA1/BARD1 mediated ubiquitination of MRE11, thereby facilitating end resection at DSBs in S phase. We aim to understand the mechanism by which DYNLL1 mediates end resection and HR. We will first investigate the dynamics between BRCA1 and DNA-PKcs and how it regulates the DYNLL1 and MRE11 activity in the context of the cell cycle. Investigating the dynamics of these end resecting factors and their regulation in DSB repair bear significant clinical relevance in combating PARPi resistance in BRCA1-mutant tumors. Therefore, we propose to determine whether alterations in mechanisms involved in attenuated DNA end resection may drive development of PARPi resistance in the high grade serous ovarian cancer (HGSOC) using patient derived xenografts (PDXs) and primary tumors. We expect that these studies will further our understanding of how end resection machinery is regulated to ensure that the appropriate repair pathway is activated. Further understanding of these end resection factors and how they are dysregulated in cancer may lead us to a relevant therapeutic target to combat PARPi resistant cancers.

项目摘要 BRCA缺乏症与PARPI的合成致命相互作用正在治疗中以多种方式进行治疗 临床环境，包括卵巢，胰腺和前列腺癌）。但是，parpi抗性已经出现 作为治疗BRCA1/2缺陷卵巢癌癌的困扰临床问题。分析 跨独立研究的BRCA1突变肿瘤的PARPI耐药性表明，涉及的基因丧失 在没有BRCA1活性的情况下，促进NHEJ或抑制HR会导致人力资源的部分恢复。 53BP1作为主调节器出现，它为DSB带来了多个复合物。失去这些因素 在BRCA1突变细胞中引起PARPI抗性。因此，进一步了解调节的因素 对途径选择至关重要的DNA末端的处理在癌症生物学中具有很大的相关性。 我们的实验室先前已经确定，在卵巢癌细胞中，dynll1的丧失，这是一个组成型的因素 绑定到53BP1，还会导致HR和PARPI耐药性增强。我们发现dynll1ps88直接绑定 对并抑制MRE11，从而阻止DNA终端切除的开始。但是，如何相互作用 带有MRE11的Dynll1损害其核酸酶活性或对焦点的募集尚未探索。此外， 例如，在DNA损伤响应的背景下如何调节这种相互作用，例如 激酶/磷酸酶（S）调节Dynll1的S88残基的磷酸化，以调节其与其与其与其与其与其相互作用 需要研究MRE11。 我们在本应用中的总体目标是确定调节修复的分子机制 通过进一步了解如何调节终端切除蛋白来选择途径。我们的中心假设是 Dynll1的细胞周期特异性调节促进了BRCA1/BARD1介导的MRE11的泛素化， 从而促进DSB的最终切除术。 我们旨在了解Dynll1介导最终切除和人力资源的机制。我们将首先 研究BRCA1和DNA-PKC之间的动力学以及如何调节Dynll1和Mre11活性 在细胞周期的背景下。调查这些最终切除因素的动态及其在 DSB修复在对抗BRCA1突变肿瘤中的PARPI耐药性方面具有显着的临床相关性。 因此，我们建议确定涉及减毒DNA端的机制的改变 切除可能推动使用高级浆液卵巢癌（HGSOC）的PARPI耐药性的发展 患者衍生的异种移植物（PDXS）和原发性肿瘤。我们希望这些研究将进一步 了解如何调节最终切除机械，以确保适当的维修途径是 活性。进一步了解这些最终切除因素及其在癌症中如何失调的可能 带领我们实现相关的治疗靶标，以对抗抗Parpi抗药性癌症。