Understanding the impact of DNA ADP-ribosylation on telomere function in cancer cells

了解 DNA ADP-核糖基化对癌细胞端粒功能的影响

• 批准号: 10751121
• 负责人: Anne Wondisford
• 金额: $ 5万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10751121
• 关键词: ADP ribosylation; ATRX gene; Adenosine Diphosphate Ribose; Biological Assay; Cancer Patient; Cancer cell line; Cell Death; Cell Death Induction; Cell Survival; Cell physiology; Cells; Chromatin; Chromatin Remodeling Factor; Chromosomes; Clinical; Complement; Complex; DAXX gene; DNA; DNA Damage; DNA Modification Process; DNA Repair; DNA Sequence; Data; Defect; Deposition; Development; Ensure; Enzyme Inhibition; Enzymes; Excision; Exposure to; Functional disorder; Genes; Genetic Transcription; Glycoside Hydrolases; Histones; Hydrolase; Hydrolysis; Impairment; In Vitro; Investigation; Knowledge; Laboratories; Malignant Neoplasms; Malignant neoplasm of ovary; Malignant neoplasm of prostate; Mammalian Cell; Mediating; Mediator; Metabolism; Modification; Monitor; Mutate; Mutation; Nucleic Acids; Outcome; Pathway interactions; Physiological; Poly Adenosine Diphosphate Ribose; Poly(ADP-ribose) Polymerase Inhibitor; Poly(ADP-ribose) Polymerases; Post-Translational Protein Processing; Proliferating; Proteins; RNA; RNA-Directed DNA Polymerase; Recurrence; Research; Role; Source; Stress; Structure; TERF1 gene; Telomerase; Telomere Length Maintenance; Telomere Pathway; cancer cell; cancer therapy; cellular targeting; chromatin remodeling; homologous recombination; improved; innovation; insight; malignant breast neoplasm; mutant; novel; pharmacologic; poly ADP-ribose glycohydrolase; recruit; repaired; sensor; targeted treatment; telomere; therapy development; tool

RESEARCH SUMMARY/ABSTRACT Cancer cells must employ a telomere lengthening mechanism to ensure replicative immortality. 15% of cancer cells utilize Alternative Lengthening of Telomeres (ALT), a homologous recombination-mediated pathway. Perturbation of the ALT mechanism can be achieved by disruption of enzymes involved in ADP-ribosylation, a post-translational modification that regulates several cellular processes including transcription, metabolism, and DNA repair. The pharmacological inhibition of enzymes involved in ADP-ribosylation has proven to be of immense biomedical value in cancer therapy. Over the last 30 years, studies have primarily built on intensive investigation of ADP-ribosylation as a modification that is exclusively found on proteins. Yet, new evidence is emerging that nucleic acids, DNA and RNA, are direct and perhaps even the predominant sources of ADP- ribosylation, especially in the aftermath of DNA damage. This paradigm shift has major implications for our understanding of the physiological function of ADP-ribosylation in ALT. Thus, improving our knowledge of the cellular targets and mechanisms of this new DNA modification will be vital for the development of enhanced ADP-ribose-targeting therapeutics that achieve better clinical outcomes for ALT cancer patients. I found that telomeres, specialized structures at the ends of the chromosomes, are targets of the major ADP-ribosylation enzymes; Poly ADP-ribose Polymerase (PARP1), Poly ADP-ribose Glycohydrolase (PARG), and a newly identified factor known as Terminal ADP-ribose Hydrolase (TARG1). I uncovered that PARP1 coordinates the ADP-ribosylation of telomeric DNA sequences and that TARG1, acting in conjunction with PARG, is responsible for the removal ADP-ribose from telomeric DNA. Furthermore, I show that the disruption of TARG1 expression provokes replicative complications at ALT telomeres that may have catastrophic consequences for cancer cell viability. In Aim 1, I will further assess the impact of DNA ADP-ribosylation and defects in factors that regulate its removal on telomere function and ALT. In Aim 2, I will dissect the impact of co-suppression of TARG1 and PARG, factors that regulate DNA ADP-ribosylation, on cancer cell viability, and the contribution of telomere dysfunction therein. This study will provide new and crucial knowledge on the novel and fundamental role of ADP-ribosylation in ALT. By exploring the impact that its deregulation has on ALT, this study will contribute new insights into how the deregulation of ADP-ribosylation contributes to cancer treatment.

研究摘要/摘要 癌细胞必须采用端粒延长机制，以确保复制不朽。 15％的癌症 细胞利用端粒（ALT）的替代性延长，这是一种同源重组介导的途径。 ALT机制的扰动可以通过破坏参与ADP-核糖基化的酶，A 翻译后修饰，调节几个细胞过程，包括转录，代谢和 DNA修复。事实证明，参与ADP-核糖基化的酶的药理抑制作用已 癌症治疗中的巨大生物医学价值。在过去的30年中，研究主要基于密集型 对ADP-核糖基化的研究作为一种仅在蛋白质上发现的修饰。但是，新的证据是 核酸，DNA和RNA是直接的，甚至可能是ADP-的主要来源 核糖基化，尤其是在DNA损伤后发生的。这种范式转变对我们的主要影响 理解ALT中ADP-核糖基化的生理功能。因此，提高我们对 这种新DNA修饰的细胞靶标和机制对于增强的发展至关重要 ADP-ribose靶向疗法，可为ALT癌症患者获得更好的临床结果。 我发现端粒（染色体末端的专门结构）是主要目标 ADP-核糖基化酶；多ADP-核糖聚合酶（PARP1），聚ADP-核糖糖醇（PARG），， 以及新鉴定的被称为末端ADP-核糖水解酶（TARG1）的因子。我发现了那个parp1 协调端粒DNA序列的ADP-核糖基化和TARG1，作用于 PARG负责从端粒DNA中去除ADP-核糖。此外，我证明了破坏 targ1表达的挑衅会在Alt端粒上的复制并发症，这些并发症可能具有灾难性的 癌细胞生存能力的后果。在AIM 1中，我将进一步评估DNA ADP-核糖基化和 调节其在端粒功能和ALT上去除的因素的缺陷。在AIM 2中，我将剖析 TARG1和PARG的共抑制，调节DNA ADP-核糖基化，癌细胞活力和 其中端粒功能障碍的贡献。这项研究将为小说提供新的至关重要的知识 ADP-核糖基化在ALT中的基本作用。通过探索其放松管制对ALT的影响， 研究将为ADP-核糖基化放松管制如何促进癌症治疗的新见解。