Investigating PolQ-mediated alternative NHEJ in breast cancer

研究乳腺癌中 PolQ 介导的替代 NHEJ

• 批准号: 10090458
• 负责人: Agnel Sfeir
• 金额: $ 21万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-02-01 至 2021-03-03
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10090458
• 关键词: Affect; BRCA1 gene; BRCA2 gene; Biochemical; Biotin; Breast Cancer Model; Cancer-Predisposing Gene; Cells; Characteristics; Chemotherapy and/or radiation; Chromosomal Rearrangement; Chromosome abnormality; Chromosomes; Cicatrix; Cisplatin; Clinical; DNA Damage; DNA Double Strand Break; DNA Repair; DNA Repair Pathway; Data; Defect; Development; Disease Progression; Double Strand Break Repair; Enzymes; Evolution; Genes; Genetic; Genetic Recombination; Genomic Instability; Genomics; Goals; Human; Ionizing radiation; Knockout Mice; Ligase; Malignant Neoplasms; Malignant neoplasm of ovary; Mammalian Cell; Mammary Neoplasms; Mediating; Molecular; Mus; Mutate; Mutation; Nonhomologous DNA End Joining; Outcome; Pathway interactions; Patients; Phenotype; Polymerase; Predisposition; Proteome; Proteomics; Radiation therapy; Relapse; Resistance; Role; Shapes; Signal Transduction; Site; Source; System; Testing; Therapeutic Agents; Treatment-Associated Neoplasms; Work; base; brca gene; breast cancer progression; cancer cell; cancer genome; cancer therapy; carcinogenesis; chemotherapy; cohort; effective therapy; established cell line; experimental study; genetic makeup; genome integrity; genome sequencing; genomic signature; homologous recombination; improved; in vivo; inhibitor/antagonist; insight; malignant breast neoplasm; mouse model; neoplastic cell; novel; novel therapeutics; ovarian neoplasm; recruit; repaired; treatment strategy; tumor; tumor behavior; tumor initiation; tumor progression; tumorigenesis; whole genome

Chromosomal rearrangements are a hallmark of cancer cells and constitute a major pathway by which genes that affect tumor initiation and progression become mutated. Such aberrancies can result from defects in double-stranded break (DSB) repair. There are three major pathways of DNA repair in mammalian cells – the well-studied homology recombination (HR) and non-homologous end joining (NHEJ) pathways, and the poorly characterized, yet highly error-prone alt-NHEJ (alternative-NHEJ) pathway. Genetic rearrangements consistent with alt-NHEJ have been noted both in spontaneous and therapy-related tumors. In this proposal we will focus on polymerase theta (Polθ), a low-fidelity enzyme that we recently identified as a key factor that mediates DSB repair by alt-NHEJ. Given that HR-defective tumors are “addicted” to repairing DSBs via the alt-NHEJ pathway, we hypothesize that the mutagenic activity of Polθ help establish a genomic landscape that is conducive for aggressive tumor behavior. Additionally, we predict that deleting Polθ in tumors with mutations in the breast cancer susceptibility (BRCA) genes will sensitize cells to DNA damage- inducing therapeutic agents, including radiation therapy, cisplatin and PARP inhibitors. In the second aim, we will investigate the impact of ATM and PARP1 on Polθ is recruited to break sites and how the polymerase modulates damage sites to promote erroneous repair. In addition, we will pursue a proteomic-based approach to highlight the full spectrum of molecular players involved in alt-NHEJ. Ultimately, a full understanding of the mechanistic basis of alt-NHEJ will provide a better understanding of the source of genomic instability during the course of malignancy and guide more effective treatment strategies for the increasing number of patients with HR mutated tumors.

染色体重排是癌细胞的一个标志，并构成了一个主要途径， 影响肿瘤发生和发展的基因发生突变。这种异常可以 由双链断裂（DSB）修复缺陷引起。DNA有三条主要的途径 哺乳动物细胞中的修复-研究充分的同源重组（HR）和非同源重组（HR）。 末端连接（NHEJ）途径，以及表征不佳但高度易错的alt-NHEJ （替代-NHEJ）途径。已经注意到与alt-NHEJ一致的遗传重排 无论是自发性肿瘤还是治疗相关的肿瘤。在这个建议中，我们将集中在聚合酶θ (Polθ），一种低保真度酶，我们最近发现它是介导DSB修复的关键因子， alt-NHEJ考虑到HR缺陷型肿瘤对通过alt-NHEJ修复DSB“上瘾”， 途径，我们假设Polθ的诱变活性有助于建立一个基因组景观 这有助于肿瘤的侵袭性行为。此外，我们预测，在肿瘤中删除Polθ 乳腺癌易感性（BRCA）基因突变会使细胞对DNA损伤敏感- 诱导治疗剂，包括放射疗法、顺铂和PARP抑制剂。在 第二个目的，我们将研究ATM和PARP 1对Polθ募集断裂位点的影响 以及聚合酶如何调节损伤位点以促进错误修复。此外，我们将 追求一种基于蛋白质组学的方法，以突出参与的分子参与者的全谱 alt-NHEJ最终，对alt-NHEJ的机理基础的充分理解将提供更好的 了解恶性肿瘤过程中基因组不稳定性的来源， 为越来越多的HR突变肿瘤患者提供有效的治疗策略。