The Molecular Basis of Chromosome Periphery Function, Structure and Composition

背景：有丝分裂的目的是在两个新的子细胞中平均分配我们的DNA，这是一个对生命至关重要的事件。如果拆开，只有一个细胞的DNA含量超过两米长。这给需要分裂的细胞带来了挑战。为了使有丝分裂尽可能有效，我们的DNA被浓缩成46个紧凑的结构，称为染色体(带有著名的‘X’形状)。然而，在有丝分裂过程中，即使组装成染色体，DNA分离也可能出错，一些细胞收到的DNA数量不正常。这被称为非整倍体，可能会导致癌症和出生缺陷。至关重要的是，我们必须充分了解导致非整倍体的每一个机制，以便我们能够预防或治疗它。我的研究重点是有丝分裂染色体外围(MCP)，这是一种覆盖有丝分裂染色体整个外表面的鞘，就像手(染色体)上的厚厚的冬季手套(MCP)。MCP是在100多年前被发现的，然而直到最近还没有人能够将其移除，从而测试MCP是否或如何可能是染色体的重要组成部分。我最近发现了有史以来第一种通过一种名为Ki67(鞘的关键成分)的蛋白质去除MCP的方法。我接着证明了MCP对于有丝分裂染色体的正常运作是重要的，最近，它可能在非整倍体中也起到了作用。尽管取得了这些进展，我们仍然不知道鞘是由什么组成的，它的全部功能是什么，它看起来是什么样子(它的结构)，最后是它对疾病的贡献。Ki67在每个未知因素中的作用也不清楚，但很重要，因为Ki67与一些癌症的进展有关，目前正在作为药物靶点进行测试。目的：该提案的目标是以我未发表的数据为基础，调查MCP(和Ki67)如何促进非整倍体。这一点很重要，因为更好地了解这一鞘可能会揭示新的癌症预防措施或治疗方法。Aim 1-Function)使用显微镜实验，包括我最近开发的先进成像工具3D相关光电子显微镜(3DCLEM)，来确定MCP如何以及为什么会导致非整倍体。Aim 2-Structure)研究MCP在纳米尺度上的外观(人的头发直径约50,000 nm，MCP厚约100 nm)，并确定其结构对其功能的重要性。这将使用CryoCLEM进行，这是世界上最强大的成像工具之一，很少有人可以执行。目标3-组成)调查MCP是由什么组成的，并探索其他组件是否也具有重要功能，如Ki67，可能在未来的研究中用作药物靶点。主办研究所和合作者：我的实验室将设在诺丁汉大学生物发现研究所III。这座全新的GB 2500万GB的建筑包含最先进的设备和数百名疾病专家，包括内科医生、癌症研究人员和药物发现专家。这种专业知识的组合旨在最大限度地发挥研究的影响，使从基础研究(使用培养皿中的细胞)到治疗(为患者)的过程尽可能高效。我很幸运地拥有一个由国际知名合作者组成的现有网络。自从我来到UON以来，这个网络已经扩大到包括安娜·格拉博夫斯卡(Anna Grabowska)和艾伦·麦金太尔(Alan McIntyre)等癌症生物学家，以及肯顿·阿尔基尔(Kenton Arkill)和罗伯特·勃兰特(Robert Brandt)等技术专家(与ThermoFisher进行了工业合作)。自从我发现如何去除MCP以来，这个领域重新焕发了活力，几个实验室也证实了MCP是有丝分裂染色体的关键组成部分。我对这一兴趣的复兴做出了重大贡献，利用我的技能、MCP的全面知识和重要的合作，我处于一个独特的位置来推动这项研究，并成为该领域的世界领导者。

Background: The purpose of mitosis is to divide our DNA equally between two new daughter cells, an event that is essential for life. The DNA content of just one cell extends over two metres in length, if unravelled. This presents a challenge for cells that need to divide. To make mitosis as efficient as possible our DNA is condensed into 46 compact structures known as chromosomes (with a famous 'X' shape). However, even assembled into chromosomes DNA separation during mitosis can go wrong, with some cells receiving an abnormal amount of DNA. This is known as aneuploidy, and can lead to cancer and birth defects. It is critical that we fully understand each and all of the mechanisms that lead to aneuploidy, so that we can prevent or treat it. My research focuses on the mitotic chromosome periphery (MCP) a sheath that covers the entire outer surface of mitotic chromosomes, like a thick winter glove (the MCP) on a hand (the chromosome). The MCP was discovered over 100 years ago, however until recently no one has been able to remove it and therefore test if or how the MCP might be an important component of chromosomes. I recently discovered the first ever way to remove the MCP through a protein called Ki67 (a key component of the sheath). I went on to show that the MCP is important for mitotic chromosomes to function correctly and, most recently, that it may also have a role in aneuploidy. Despite these advances we still do not know; what the sheath is made of, what its full functions are, what it looks like (its structure) and finally its contribution to diseases. The role of Ki67 in each of these 'unknowns' is also unclear, but is important as Ki67 has been implicated in the progression of some cancers and is currently being tested as a drug target.Aims: The goal of this proposal is to build on my unpublished data and investigate how the MCP (and Ki67) contributes to aneuploidy. This is important, because a better understanding of this sheath may reveal new preventative measure or treatments for cancer.Aim 1 - Function) Use microscopy experiments, including 3D correlative light electron microscopy (3DCLEM), an advanced imaging tool that I recently developed, to determine how and why the MCP can cause aneuploidy.Aim 2 - Structure) Investigate what the MCP looks like on a nanometre scale (a human hair is ~50,000nm in diameter, the MCP is ~100nm thick) and determine how its structure is important for its function. This will be performed using CryoCLEM, one of the most powerful imaging tools in the world and that few people can perform.Aim 3 - Composition) Investigate what the MCP is made of and explore if other components also have important functions, like Ki67, that might be used as a drug target during future studies.Host Institute and Collaborators: My lab will be based at the University of Nottingham Biodiscovery Institute III. This brand new £25million building contains state of the art equipment and hundreds of disease experts, including; medical doctors, cancer researchers and drug discovery specialists. This mix of expertise is designing to maximise research impact, making the progression from basic research (using cells in a dish) to treatments (for patients), as efficient as possible. I am fortunate to have an existing network of internationally renowned collaborators. Since my arrival at UoN this network has expanded to include cancer biologists such as Anna Grabowska and Alan McIntyre and technical experts such as Kenton Arkill and Robert Brandt (industrial collaboration with ThermoFisher). Since I discovered how to remove the MCP this field has been revitalised, with several labs also confirming that the MCP is a critical component of mitotic chromosomes. My contribution to this revival of interest has been significant and using my skills, comprehensive knowledge of the MCP and important collaborations, I am in a unique position to drive this research and become a world leader in this field.