Non-apoptotic functions of caspase-2 in cell division and genomic stability

Caspase-2 在细胞分裂和基因组稳定性中的非凋亡功能

• 批准号: 9923704
• 负责人: Lisa Bouchier-Hayes
• 金额: $ 32.53万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-05-01 至 2023-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9923704
• 关键词: Aging; Aneuploidy; Apoptosis; Apoptotic; CASP2 gene; Caspase; Cell Cycle; Cell Cycle Checkpoint; Cell Cycle Progression; Cell Cycle Regulation; Cell Death; Cell Line; Cell Nucleolus; Cell Proliferation; Cell Survival; Cell division; Cell physiology; Cells; Chromosome abnormality; Co-Immunoprecipitations; Complement; Complex; Cytoplasm; Cytosol; DNA; DNA Damage; DNA Repair; DNA replication fork; Data; Defect; Disease; Engineering; Ensure; Exposure to; Fluorescence; Foundations; Fractionation; Frequencies; GOLGA3 gene; Genes; Genome; Genome Stability; Genomic Instability; Human; Image; Impairment; Kinetics; Knowledge; Laboratories; Lesion; Life; Lymphoma; MDM2 gene; Malignant Neoplasms; Malignant neoplasm of liver; Malignant neoplasm of lung; Measurable; Measures; Mission; Molecular; Mutate; NPM1 gene; National Institute of General Medical Sciences; Nucleolar Proteins; Pathway interactions; Peptide Hydrolases; Phenotype; Phosphoproteins; Physiological; Play; Prevention; Process; Proliferating; Proteins; Public Health; Publishing; Regulation; Research; Role; Site; Stimulus; TP53 gene; Techniques; Testing; Tumor Suppression; Tumor Suppressor Proteins; Visualization; base; cell type; design; disease diagnosis; experimental study; functional outcomes; homologous recombination; imaging modality; innovation; insight; irradiation; malignant breast neoplasm; mouse model; novel; nucleophosmin; outcome forecast; prevent; recruit; repaired; replication stress; response; tumorigenesis

PROJECT SUMMARY/ABSTRACT Several groups have shown a strong association between caspase-2 deficiency and accelerated tumorigenesis in murine models of lymphoma, breast, and lung cancer. Such phenotypes are often accompanied by enhanced cell proliferation and increased genomic instability with minimal measurable apoptotic defects. Therefore caspase-2 appears to play a crucial role in maintaining genomic stability and may do so independent of its role in apoptosis. To test this, this proposal will study the mechanisms of caspase-2 is activation during the DNA damage response with a focus on the upstream caspase-2 regulator PIDD. The central hypothesis is that DNA damage induces two distinct caspase-2 activation platforms – a cytoplasmic platform that is PIDD independent and a nucleolar platform that requires PIDD – each providing access to distinct substrates that regulate genomic instability by both pro-apoptotic and non-apoptotic mechanisms. This hypothesis has been formulated based on published and preliminary data produced in the applicant’s laboratory showing that caspase-2 is activated in the cytoplasm and in the nucleolus and that the nucleolar activation is dependent on the nucleolar phosphoprotein nucleophosmin (NPM1) for both assembly and function. This hypothesis will be tested by pursuing two specific aims: 1) Determine the mechanisms of caspase-2 activation in the nucleolus versus the cytosol; and 2) Identify the relative contributions of the nucleolar and cytoplasmic complexes to downstream caspase-2 functions and how these protect from genomic instability. Under the first aim, an already proven imaging-based method for measuring caspase-2 activation, will be used to investigate the distinct mechanisms of differential caspase-2 activation in the nucleolus and in the cytosol. These experiments will specifically probe the roles of PIDD and NPM1. Under the second aim, based on preliminary data that shows that caspase-2-deficient cells, proliferate faster and accumulate more DNA damage following replication stress, the requirement of the nucleolar and cytoplasmic complexes for apoptotic and non-apoptotic caspase-2 functions will be explored in the context of apoptosis, cell cycle regulation, substrate cleavage and DNA repair mechanisms. The approach is innovative because it utilizes novel imaging-based techniques that are designed to assess caspase-2 activation in single cells so that the relationship between the localization of caspase-2 activation with apoptosis, DNA damage, and cell division will be directly explored on a per cell basis. It also provides a new paradigm of caspase activation in the nucleolus. The proposed research is significant because it is proposed that site-specific activation of caspase-2 in the cytosol and nucleolus governs distinct functions of this protease that cooperate to protect from genomic instability. These mechanisms may underlie the known physiological roles of caspase-2 in tumor suppression and in protecting against accelerated aging. Ultimately, such knowledge has the potential to inform how diseases where caspase pathways are disrupted can be treated or prevented.

项目摘要/摘要 几个组显示caspase-2缺乏症与加速肿瘤发生之间有很强的关联 在淋巴瘤，乳腺癌和肺癌的鼠模型中。这种表型通常伴随着增强 细胞增殖和基因组不稳定性增加，而最小可测量的凋亡缺陷。所以 caspase-2似乎在维持基因组稳定性方面起着至关重要的作用，并且可能与其作用无关 在凋亡中。为了测试这一点，该建议将研究caspase-2的机制是在DNA期间激活 损坏响应，重点是上游caspase-2调节器PIDD。中心假设是DNA 损害引起两个不同的caspase-2激活平台 - 一个独立的细胞质平台 以及一个需要PIDD的核平台 - 每个人都可以访问调节基因组的不同底物 促凋亡和非凋亡机制的不稳定性。该假设已根据 申请人实验室中生成的已发布和初步数据，表明Caspase-2在 细胞质和核仁中，核仁激活取决于核仁磷蛋白 用于组装和功能的核素（NPM1）。该假设将通过追求两个特定 目的：1）确定核仁与细胞质中caspase-2激活的机制； 2）确定 核和细胞质复合物对下游caspase-2功能的相对贡献以及 这些如何保护基因组不稳定性。在第一个目标下，已经是基于成像的一种方法 测量caspase-2激活将用于研究差异cas​​pase-2的不同机制 核仁和细胞质中的激活。这些实验将专门探究PIDD和 NPM1。在第二个目标下，基于初步数据，该数据表明caspase-2缺陷细胞增殖 更快并在复制应力后会累积更多的DNA损伤，核仁的需求和 凋亡和非凋亡caspase-2功能的细胞质复合物将在以下背景下探索 凋亡，细胞周期调节，底物裂解和DNA修复机制。这种方法是创新的 因为它利用了新型基于成像的技术，这些技术旨在评估单个中的caspase-2激活 细胞使得caspase-2激活与凋亡，DNA损伤和 细胞分裂将以每个细胞为基础直接探索。它还提供了新的caspase激活范式 核仁。拟议的研究很重要，因为提出了特定地点的激活 caspase-2在细胞质和核仁中控制该保护酶的不同功能，以保护该保护酶 基因组不稳定性。这些机制可能是caspase-2在肿瘤中的已知物理作用的基础 抑制和防止加速衰老。最终，这种知识有可能告知 如何治疗或预防如何处理胱天蛋白酶途径的疾病。