Molecular Basis of Aneuploidy

描述(由申请人提供)：本提案是对通知#NOT-OD-09-058的回应，标题：NIH宣布恢复法资金可用于竞争性修订申请。我们的父母GRANT(RO1 CA109330，“非整倍体的分子基础”)的广泛目标是了解姐妹染色单体分离中的异常如何导致染色体错配和非整倍体的产生。修订应用的目的是研究分离酶过表达及其错误定位在骨肉瘤中的作用，作为非整倍体发展的机制，以及在骨源性肉瘤的发生和发展中的作用。染色体数目不稳定，称为非整倍体，是儿童骨肉瘤的一个特征。目前还没有一种有效的方法来研究这种类型的癌症，很大程度上是因为还没有合适的动物模型来研究骨肉瘤染色体不稳定的机制。修改后的申请解决了骨肉瘤研究中的一个关键问题，并试图开发一种新的非整倍体骨肉瘤小鼠模型。虽然肿瘤抑制蛋白P53和类固醇激素如雄激素长期以来一直与青少年骨肉瘤的发展有关，但它们的确切作用机制尚不清楚。在这里，我们建议分离酶，一种在细胞分裂过程中染色体分离中必不可少的酶，与P53突变和雄激素共同作用，促进成骨细胞(形成骨的细胞)非整倍体和骨肉瘤。为了在活体环境中研究这一新想法，我们建议开发和表征基因工程小鼠模型。我们计划利用小鼠的基因杂交来设计控制小鼠基因表达的分子模型。结合遗传和生理操作的能力(例如激素水平)将使我们能够解决骨肉瘤肿瘤发生的复杂性质，这被认为是一个多步骤的过程。基因组技术的使用将使我们能够找到我们的小鼠模型(S)和人类骨肉瘤之间的共同点。我们相信，目前的项目不仅将阐明非整倍体导致骨肉瘤发生和发展的新机制，还将提供一个潜在的临床前模型，模拟人类骨肉瘤的几个方面。 公共卫生相关性：目前的项目解决了骨肉瘤研究中以前没有解决的一个关键问题，并试图开发一种新的非整倍体骨肉瘤小鼠模型。虽然肿瘤抑制蛋白P53和有丝分裂激素长期以来一直被认为在青少年骨肉瘤中发挥作用，但它们的确切作用机制尚不清楚。在这里，我们认为粘附素蛋白水解酶，分离酶，一种关键的细胞周期调节蛋白，与p53突变和有丝分裂激素一起工作，促进成骨细胞(形成骨生长的细胞)非整倍体，从而启动骨肉瘤并促进其发展。

DESCRIPTION (provided by applicant): This proposal is in response to the Notice# NOT-OD-09-058, title: NIH announces the availability of Recovery Act Funds for Competitive Revision Applications. The broad aim of our parent grant (RO1 CA109330, "Molecular Basis of Aneuploidy") is to understand how aberrations in sister chromatid separation contribute to chromosomal missagregation and generation of aneuploidy. The purpose of the revised application is to examine the role of Separase overexpression and its mislocalization in osteosarcoma as a mechanism of aneuploidy development, and in the initiation and progression of osteogenic sarcomas. Unstable chromosome number known as aneuploidy is a hallmark of pediatric osteosarcoma. There currently is not an effective way to study this type of cancer, largely because there is no suitable animal model to investigate the mechanism of chromosomal instability in osteosarcoma. The revised application addresses a key question in osteosarcoma research and attempts to develop a new mouse model for aneuploid osteosarcoma. While tumor suppressor protein p53 and steroid hormones such as androgens have long been implicated in the development of osteosarcoma in adolescents, the precise mechanisms of their contribution are not well understood. Here we propose that Separase, an enzyme that is essential in chromosomal separation during cell division, works in conjunction with both mutations in p53 and with androgens to promote osteoblast (the cell that make growing bone) aneuploidy and osteosarcoma. To investigate this novel idea in an in vivo setting, we propose to develop and characterize genetically engineered mouse models. We plan to use murine genetic crosses to engineer molecular models that control gene expression in the mouse. The ability to combine genetic and physiological manipulations (e.g. hormone levels) will allow us to address the complex nature of osteosarcoma tumorigenesis, which is thought to be a multi-step process. The use of genomic technology will allow us to find commonalities between our mouse model(s) and human osteosarcoma. We are confident the current project will not only shed light on new mechanisms of aneuploidy contributing to osteosarcoma initiation and progression but will also provide a potential pre-clinical model that emulates several aspects of the human osteosarcoma. PUBLIC HEALTH RELEVANCE: The current project addresses a key question in osteosarcoma research that has not been addressed before and attempts to develop a new mouse model for aneuploid osteosarcoma. While tumor suppressor protein p53 and mitogenic hormones have long been implicated to play a role in osteosarcoma in adolescents, the precise mechanisms of their contributions are not well understood. Here we propose that the cohesin protease, Separase, a critical cell cycle regulating protein, works in conjunction with mutations in p53 coupled with mitogenic hormones in promoting osteoblast (the cell that make growing bone) aneuploidy and thus initiating osteosarcoma and fuelling its progression.