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.

项目摘要/摘要 作为DNA修复途径的一部分，BRCA2是同源指导修复（HDR）和叉子保护的关键调节器 机制，可确保基因组不稳定性。为了进行全部活动，必须将BRCA2运输到核中以修复 DNA双链断裂（DSB）。在正常细胞中，核BRCA2的丧失会导致基因组不稳定性和癌症 但是，在肿瘤细胞中，BRCA2胞质错误定位会导致对靶向疗法的敏感性。 我确定了BRCA2核进口与治疗之间的悖论关系。致病错义突变 在BRCA2的DNA结合结构域中 （PARPI）和铂药。因此，尽管BRCA2错误定位可能是癌症的原因，但请保持 从细胞核中出来，可以取得更好的治疗结果。这为我开辟了一条研究途径 完全一致学习。在此K22提案中，我将解决BRCA2的核运输，即癌症驱动器的方式 突变导致胞质错误定位，以及如何将BRCA2定位用作诊断工具。为了测试这个，我 将定义调节BRCA2致病错过的核/细胞质穿梭的分子机制 变体（AIM 1），确定BRCA2细胞定位对HDR，叉保护和胞质过程的影响 （AIM 2）并利用BRCA2定位作为癌症诊断工具（AIM 3）。我的首要任务是专注于错过 在我的博士后职业中确定的变体破译了核/胞质的基本分子机制 BRCA2贩运。在成功完成此K22提案时，我将揭示新的途径和因素，以确保 BRCA2的适当定位以及致病性BRCA2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BRCA2错义变体的致病性以及如何 调节BRCA2的功能。 我的职业目标是在领先的机构中获得独立职位，我将剖析 DNA修复蛋白中的错义变体以及其细胞定位对于基因组稳定性作为一种工具的重要性 预测癌症风险并治疗癌症患者。通过提高我的专业知识，我的成功过渡将得到支持 细胞生物学，生物化学，质谱和人类细胞模型。我将使用这些获得的技能来定义为什么 以及某些致病性BRCA2错义变体如何将其定位在细胞质上。重要的是，受保护的时间 这个奖项为我提供的奖项将使我能够阐明BRCA2从 细胞核的细胞质，如何在BRCA2错义变体中改变这一点，以及如何将其用于 靶向疗法。此外，杰出顾问和 在K22时期为我提供建议的合作者。该奖项的收到将使我扩大我的研究计划 并确立自己是癌症生物学领域的主要研究者。