DNA repair dysfunction in cancer induced by altered BRCA2 localization

BRCA2 定位改变引起的癌症 DNA 修复功能障碍

• 批准号: 10739521
• 负责人: Judit Jimenez Sainz
• 金额: $ 20.58万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-12 至 2026-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10739521
• 关键词: Affect; Antibodies; Award; Biochemistry; Biological; Biology; Breast Cancer Detection; Breast Cancer gene; C-terminal; Cancer Biology; Cancer Diagnostics; Cancer Etiology; Cancer Patient; Cancer-Predisposing Gene; Cell Nucleus; Cell model; Cellular biology; Centrosome; Chromosome Mapping; Clinical Management; Cytoplasm; Cytosol; DNA; DNA Binding Domain; DNA Damage; DNA Double Strand Break; DNA Repair; DNA Repair Gene; DNA Repair Pathway; DNA replication fork; Defect; Development; Double Strand Break Repair; Ensure; Family member; Frameshift Mutation; Functional disorder; Gene Expression; Gene Mutation; Genome Stability; Genomic Instability; Goals; Hereditary Breast and Ovarian Cancer Syndrome; Human; Institution; Knowledge; Lead; Malignant Neoplasms; Mass Spectrum Analysis; Measures; Missense Mutation; Molecular; Mutation; Nonsense Mutation; Normal Cell; Nuclear; Nuclear Import; Nuclear Localization Signal; Nuclear Protein; Oncogenes; Pancreas; Pathogenicity; Pathway interactions; Patients; Pharmaceutical Preparations; Platinum; Poly(ADP-ribose) Polymerase Inhibitor; Positioning Attribute; Postdoctoral Fellow; Prevention; Principal Investigator; Process; Proteins; Proteomics; Reporting; Research; Risk Assessment; Testing; Therapeutic Intervention; Time; Tissue Microarray; Tissue Sample; Treatment outcome; Tumor Tissue; Uncertainty; Variant; cancer cell; cancer genetics; cancer risk; carcinogenesis; career; clinical application; diagnostic tool; driver mutation; genetic testing; genetic variant; genome integrity; hereditary risk; human tissue; malignant breast neoplasm; melanoma; neoplastic cell; novel; nucleocytoplasmic transport; patient stratification; prevent; prostate cancer risk; protein folding; protein misfolding; reconstitution; repair function; repaired; response; risk stratification; skill acquisition; success; targeted cancer therapy; targeted treatment; therapy resistant; tool; trafficking; tumor; variant of unknown significance; virulence gene

PROJECT SUMMARY/ABSTRACT BRCA2, as part of the DNA repair pathway, is a key regulator in homology-directed repair (HDR) and fork protection mechanism, which ensures genome instability. For full activity, BRCA2 must be transported into the nucleus to repair DNA double-strand breaks (DSBs). In normal cells, loss of nuclear BRCA2 can lead to genome instability and cancer but, in tumor cells, BRCA2 cytosolic mislocalization can lead to sensitivity to targeted therapies. I identified a paradoxical relationship between BRCA2 nuclear import and treatment. Pathogenic missense mutations in the DNA binding domain of BRCA2 direct the protein to the cytosol which increase sensitivity to PARP inhibitors (PARPi) and platinum drugs. Therefore, although BRCA2 mislocalization might be a cause of cancer, keeping it out of the nucleus allows for much better treatment outcomes. This has opened an avenue of research that I am perfectly aligned to study. In this K22 proposal I will address the nuclear transport of BRCA2, how cancer-driver mutations lead to cytosolic mislocalization and how BRCA2 localization can be used as a diagnostic tool. To test this, I will define the molecular mechanism(s) regulating nuclear/cytoplasmic shuttling of BRCA2 pathogenic missense variants (Aim 1), determine the impact of BRCA2 cellular localization on HDR, fork protection and cytosolic processes (Aim 2) and exploit BRCA2 localization as a cancer diagnostic tool (Aim 3). My priority will be to focus on missense variants identified during my postdoctoral career to decipher the underlying molecular mechanism of nuclear/cytosolic BRCA2 trafficking. At the successful completion of this K22 proposal, I will reveal novel pathways and factors that ensure proper localization of BRCA2 and how pathogenic BRCA2 missense variants have altered localization and functionality. This knowledge will give us a better understanding of the pathogenicity of BRCA2 missense variants and how we can modulate the functionality of BRCA2. My career goal is to obtain an independent position at a leading institution where I will dissect the functionality of missense variants in DNA repair proteins and how their cellular localization is important for genome stability as a tool to predict cancer risk and to treat cancer patients. My successful transition will be supported by advancing my expertise in cell biology, biochemistry, mass spectrometry and human cellular models. I will use these acquired skills to define why and how certain pathogenic BRCA2 missense variants are mislocalized to the cytosol. Importantly, the protected time that this award provides me will allow me to elucidate the factors and pathways by which BRCA2 is transported from the cytosol to the nucleus, how this might be altered in BRCA2 missense variants and how this could be used for targeted therapies. Furthermore, the success of this project will be greatly enhanced by the outstanding advisors and collaborators that advise me through the K22 period. The receipt of this award will allow me to expand my research plan and establish myself as a principal investigator in the field of cancer biology.

项目总结/摘要 BRCA 2作为DNA修复途径的一部分，是同源定向修复（HDR）和叉保护的关键调节因子 机制，这确保了基因组的不稳定性。为了充分发挥活性，BRCA 2必须被运送到细胞核中进行修复。 DNA双链断裂（DSB）。在正常细胞中，核BRCA 2的缺失可导致基因组不稳定和癌症 但是，在肿瘤细胞中，BRCA 2胞质定位错误可导致对靶向治疗的敏感性。 我发现了BRCA 2核输入和治疗之间的矛盾关系。致病性错义突变 在BRCA 2的DNA结合域中，将蛋白质引导至胞质溶胶，这增加了对PARP抑制剂的敏感性 （PARPi）和铂类药物。因此，尽管BRCA 2错误定位可能是癌症的一个原因， 可以获得更好的治疗效果。这开启了一条研究之路， 完美地与研究相结合。在这个K22提案中，我将讨论BRCA 2的核运输，即癌症驱动因素如何 突变导致胞质定位错误以及BRCA 2定位如何用作诊断工具。为了验证这个，我 将定义调节BRCA 2致病性错义的核/胞质穿梭的分子机制 变体（目的1），确定BRCA 2细胞定位对HDR、叉保护和胞质过程的影响 (Aim 2）并利用BRCA 2定位作为癌症诊断工具（目的3）。我的首要任务是集中在错误的 在我的博士后生涯中发现的变异，以破译核/胞质的潜在分子机制， BRCA 2基因非法交易。在这个K22提案的成功完成，我将揭示新的途径和因素，确保 BRCA 2的正确定位以及致病性BRCA 2错义变体如何改变定位和功能。 这些知识将使我们更好地了解BRCA 2错义变体的致病性，以及我们如何能够 调节BRCA 2的功能。 我的职业目标是在一家领先的机构获得一个独立的职位，在那里我将剖析 DNA修复蛋白中的错义变体以及它们的细胞定位如何对基因组稳定性很重要， 预测癌症风险和治疗癌症患者。我的成功过渡将通过提升我在以下方面的专业知识来支持 细胞生物学、生物化学、质谱和人类细胞模型。我将用这些习得的技能来解释为什么 以及某些致病性BRCA 2错义变异体是如何错误定位于细胞质的。重要的是，保护时间 这个奖项将使我能够阐明BRCA 2从细胞中运输的因素和途径。 细胞质到细胞核，这在BRCA 2错义变体中如何改变，以及如何用于 靶向治疗。此外，该项目的成功将大大提高了杰出的顾问和 在K22时期为我提供建议的合作者。获得这个奖项将使我能够扩大我的研究计划 让自己成为癌症生物学领域的首席研究员