Control of Genomic Stability by Emil and Secruin

Emil 和 Secruin 对基因组稳定性的控制

• 批准号: 7101729
• 负责人: NORMAN LEHMAN
• 金额: $ 16.86万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2008-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7101729
• 关键词: antibody; cell cycle proteins; cell growth regulation; cell line; chromosome aberrations; chromosome movement; cyclins; cytogenetics; ligase; mitotic spindle apparatus; molecular oncology; neoplastic process; nervous system neoplasms; protein localization; protein protein interaction; protein structure function; transfection /expression vector; ubiquitin

DESCRIPTION (provided by applicant): Aneuploidy and chromosomal aberrations are common features of human neuroplasms. Genomic instability, or the tendency for mitotic errors to create chromosomal duplications, losses, and translocations has long been recognized as a major mechanism of tumorigenesis. The study of genomic instability promises new insights into cancer treatment. Recently, significant advances have been made in the understanding of the molecular details of the regulation of mitosis. Securin is a protein that functions to ensure accurate distribution of chromosomes to daughter cells by inhibiting anaphase progression until all chromosomes are properly aligned at metaphase. When cells are manipulated to over-or under-express securin they develop chromosomal abnormalities and micronuclei. Such micronuclei are frequently seen in neurological tumors, especially oligogendrogliomas. Another protein, Emi1, recently discovered by the Peter Jackson Laboratory, is involved in S phase activation and mitotic control. Emi1 blocks the degradation of securin by inhibiting its ubiquitination, but also directly binds to securin. Over-expression of Emi1 causes an abnormal prometaphase block and abnormal mitotic spindle formation. We hypothesize that the direct interaction of Emi1 and securin mediates this effect causing genomic instability. Hct116 colon carcinoma cells are a diploid cell line ideal for mitotic studies. I will use these cells as a tool to study the control of genomic stability by Emi1 and securin. I will also address the possible role of Emi1 and securin in the genesis of neurological tumors. The proposed research will specifically address the following questions. Do endogenous Emi1 and securing interact directly in cells, and if so, during which stage(s) of the cell cycle? Is the Emi1-securin interaction localized within the cell? Which functional domains of Emi1 and securin are important in determining their interaction? Does Emi1 misexpression cause spindle abnormalities or chromosomal missegregation, and is securin required for this effect? Does over- or under-expression of Emi1 produce chromosomal aberrations such as deletions or duplications? If so, do specific cytogenetic abnormalities occur? Does Emi1 over-expression induce cellular transformation, or cooperate with known oncogenes such as ras, myc, or securin, in inducing transformation? Does Emi1 misexpression occur in specific tumor types, including neurological tumors? Does Emi1 expression positively or negatively correlate with securin expression in tumors? Does Emi1 or securin expression correlate with activation of the cyclin D/Rb/E2F pathway in tumors? I will pursue an academic career in neuropathology and will apply the knowledge and experience gained from the proposed studies to translational neuro-oncology research.

描述（由申请人提供）：非整倍性和染色体畸变是人类神经系统的常见特征。基因组不稳定性，或有丝分裂错误导致染色体复制、丢失和易位的倾向，长期以来被认为是肿瘤发生的主要机制。基因组不稳定性的研究为癌症治疗提供了新的见解。最近，在理解有丝分裂调控的分子细节方面取得了重大进展。Securin是一种蛋白质，其功能是通过抑制后期进展直到所有染色体在中期正确对齐来确保染色体准确分布到子细胞。当细胞被操纵以过度或不足表达securin时，它们会发生染色体异常和微核。这种微核常见于神经系统肿瘤，尤其是少突神经胶质瘤。另一种蛋白质，PET 1，最近由彼得杰克逊实验室发现，参与S期激活和有丝分裂控制。BMP 1通过抑制其泛素化来阻断securin的降解，但也直接与securin结合。过表达的EST 1导致异常的前中期阻滞和异常的有丝分裂纺锤体形成。我们假设，直接相互作用的reflec 1和securin介导这种影响，导致基因组的不稳定性。hct 116结肠癌细胞是一种理想的二倍体细胞系，可用于有丝分裂研究。我将使用这些细胞作为工具来研究基因组稳定性的控制，由EST 1和securin。我还将讨论在神经系统肿瘤的发生中的可能的作用，BIP 1和securin。拟议的研究将具体解决以下问题。内源性的BMP 1和安全直接在细胞中相互作用，如果是这样，在细胞周期的哪个阶段（S）？是在细胞内定位的β 1-securin相互作用？在决定它们的相互作用中，哪些功能域是重要的？1的错误表达是否会导致纺锤体异常或染色体错误分离，以及这种效应是否需要securin？过表达或表达不足的p53 1是否会产生染色体畸变，如缺失或重复？如果是，是否发生了特定的细胞遗传学异常？过表达的p53 1是否诱导细胞转化，或与已知的癌基因如ras、myc或securin协同诱导转化？在包括神经系统肿瘤在内的特定肿瘤类型中是否会发生BMP 1的错误表达？肿瘤组织中securin表达与securin表达正相关还是负相关？肿瘤中CD 45 1或securin的表达是否与细胞周期蛋白D/Rb/E2 F通路的激活相关？我将从事神经病理学的学术生涯，并将从拟议的研究中获得的知识和经验应用于转化神经肿瘤学研究。