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Manipulating chromosome structure to suppress genome instability

操纵染色体结构以抑制基因组不稳定

基本信息

批准号：
8700803
负责人：
Amity Manning
金额：
$ 13.52万
依托单位：
MASSACHUSETTS GENERAL HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-08-01 至 2015-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8700803
关键词：
Address Agar Aneuploid Cells Aneuploidy Antimitotic Agents Area Award Bioinformatics Biological Biological Assay Candidate Disease Gene Cell Death Cell Survival Cells Centromere Cessation of life Characteristics Chromatin Chromatin Structure Chromosomal Instability Chromosome Segregation Chromosome Structures Chromosomes DNA Damage Data Defect Development Drug resistance Enhancers Environment Enzymes Epigenetic Process Evolution Exhibits Faculty Fostering Future Gene-Modified Generations Genetic Heterogeneity Genetic Screening Genome Genome Stability Genomic Instability Genomics Goals Grant Growth Health Histones Human Institutes Malignant Neoplasms Mediating Medical Mentors Mentorship Methylation Mitotic Modification Molecular Neoplasm Metastasis Numerical Chromosomal Abnormality Outcome Pathway interactions Patients Phase Phenotype Physical condensation Positioning Attribute Publications Regulation Relapse Research Resistance Resources Retinoblastoma Protein Role Solid Neoplasm Techniques Testing Therapeutic Time Training Transferase Tumor Suppressor Proteins Work Xenograft procedure cancer cell career cell growth cohesion drug sensitivity high throughput screening histone methyltransferase improved in vivo innovation insight mouse model neoplastic cell novel novel strategies outcome forecast research study response screening segregation skills stem success tumor tumor growth tumor initiation

项目摘要

DESCRIPTION (provided by applicant): The majority of solid tumors exhibit both structural and numerical chromosome aberrations characteristic of genomic instability. Chromosome instability (CIN), the frequent and persistent gains and losses of whole chromosomes results in the generation of aneuploid cells and has important implications. CIN has been proposed to facilitate the evolution of tumor cells by promoting genetic heterogeneity, thereby enabling changes that promote growth and metastasis. Furthermore, genomic diversity generated by CIN promotes the development of cancer cells that are resistant to therapeutics and are more prone to tumor relapse. Consequently, CIN correlates with poor patient prognosis. Limitations in identifying and treating cancers that exhibit CIN stem from a lack of understanding of the underlying molecular mechanisms that contribute to CIN and the inability to manipulate CIN in a therapeutically relevant manner. I have recently demonstrated that pRB, a tumor suppressor whose function is compromised in many human cancers, promotes genome stability. I have shown that pRB loss leads to defects in chromatin structure, and that these abnormalities promote increased DNA damage and corruption of mitotic fidelity. However, corruption of the pRB pathway is not the only mechanism by which chromatin structure is compromised, and other regulators of chromatin structure are likely to similarly impact genome stability. One manner in which chromatin structure is impacted is through regulation of chromatin and histone methylation status. Indeed, a growing body of evidence has suggested that modification of epigenetic characteristics of cells correlates with aneuploidy. In addition, my preliminary studies have shown that modulation of levels of a subset of methyl-transferases can compromise chromatin structure and genome integrity. Together, these data suggest that general deregulation of chromatin structure is broadly relevant to the genesis of genomic instability. However, this has not been analyzed in a systematic manner, and the mechanisms by which chromatin structure are deregulated and contributes to genome instability remain unknown. Significantly, I have shown that by restoring chromosomal structure, I can suppress both DNA damage and promote accurate chromosome segregation in tumor cells. In doing so, I have identified Wapl, a negative regulator of cohesion as a novel regulator of CIN. In the following proposal, this novel strategy will enable me to test, for the first time, whether suppression of CI renders tumor cells less capable of developing chemotherapeutic resistance in vivo, and thus less likely to relapse following traditional treatments. In addition, using a combination of bioinformatics and cell biological approaches, I will examine whether structural defects associated with CIN can be exploited to increase sensitivity to DNA damaging agents and decrease cell survival. Finally, I will identify regulators of chromatin structure whose deregulation impacts genome stability using a novel screening approach I have developed. The successful completion of the aims described in this proposal will not only provide new and valuable insights into the genesis of CIN in human cancers, but also reveal the therapeutic ramifications of manipulating this common feature in tumors. My career goal is to obtain a research faculty position at a leading institute where I will define the tumor suppressive mechanisms that maintain normal chromosome structure and genomic integrity. However, my successful transition to independence in this field would be significantly bolstered by augmenting my expertise in cell biological techniques with new training opportunities in mouse models of cancer, bioinformatics and high throughput screening approaches. It is with these acquired skills that I will be able to identify cancer-relevant regulators of chromatin structure tat impact genome stability and assess their roles as novel tumor suppressors. The success of this project will be greatly enhanced by the outstanding training committee that I have assembled to mentor and advise me as I progress towards independence. This committee includes my co-mentors Dr. Nicholas Dyson and Dr. Jeffrey Engelman, as well as Dr. Daniel Haber, Dr. Cyril Benes, and Dr. David Pellman, all of whom are experts in their respective fields. In addition, the exceptional research environment available at MGH and the Harvard Medical Area has all of the necessary physical resources required for the completion of the proposed training and research studies. The K99/R00 award would afford me the protected time needed for this advanced training and allow me to continue to foster my growth under the mentorship of Dr. Dyson and Dr. Engelman. I expect that the mentored phase of this proposal, which includes using mouse models to investigate the therapeutic relevance of manipulating CIN in solid tumors, and the initiation of a novel screening approach, will take 1-2 years and result in at least one major publication. The following independent phase of the award will allow me to identify and characterize additional, cancer-relevant, regulators of chromosome structure and genome stability. Together these data will be used to justify future studies proposed in an R01 grant that I plan to submit at the start of the third year of the independent phase.

描述(申请人提供)：大多数实体肿瘤都表现出染色体结构和数目异常，其特征是基因组不稳定。染色体不稳定(CIN)是指整个染色体频繁而持久的得失，导致非整倍体细胞的产生，具有重要的意义。CIN已被提出通过促进遗传异质性来促进肿瘤细胞的进化，从而使促进生长和转移的变化成为可能。此外，CIN产生的基因组多样性促进了对治疗药物具有抵抗力且更容易肿瘤复发的癌细胞的发展。因此，CIN与患者预后不良相关。在识别和治疗表现为CIN的癌症方面的局限性源于缺乏对导致CIN的潜在分子机制的了解，以及无法以治疗相关的方式操纵CIN。我最近证明，pRb是一种肿瘤抑制因子，其功能在许多人类癌症中受到损害，它促进了基因组的稳定。我已经证明，pRb的丢失会导致染色质结构的缺陷，这些异常会导致DNA损伤增加，并破坏有丝分裂的保真度。然而，pRB途径的破坏并不是染色质结构受损的唯一机制，染色质结构的其他调节因素也可能类似地影响基因组的稳定性。影响染色质结构的一种方式是通过调节染色质和组蛋白甲基化状态。事实上，越来越多的证据表明，细胞表观遗传学特征的改变与非整倍体相关。另外，我的初步研究已经表明，调节甲基转移酶的一个子集的水平可以损害染色质结构和基因组完整性。综上所述，这些数据表明，染色质结构的普遍放松与基因组不稳定的发生广泛相关。然而，这还没有得到系统的分析，染色质结构被解除调控并导致基因组不稳定的机制仍不清楚。值得注意的是，我已经证明，通过恢复染色体结构，我可以抑制DNA损伤，并促进肿瘤细胞中准确的染色体分离。在这样做的过程中，我发现Wapl是一种新的CIN调节因子，它是一种凝聚力的负调控因子。在下面的提案中，这一新的策略将使我能够第一次测试抑制CI是否会降低肿瘤细胞在体内产生化疗耐药性的能力，从而降低传统治疗后复发的可能性。此外，我将结合生物信息学和细胞生物学的方法，研究是否可以利用与CIN相关的结构缺陷来增加对DNA损伤剂的敏感性，降低细胞存活率。最后，我将使用我开发的一种新的筛选方法来识别染色质结构的调节器，这些调节器的解除管制会影响基因组的稳定性。这项建议中描述的目标的成功完成不仅将为人类癌症中CIN的发生提供新的有价值的见解，而且还将揭示在肿瘤中操纵这一共同特征的治疗分支。我的职业目标是在一家领先的研究所获得一个研究人员的职位，在那里我将确定维持正常染色体结构和基因组完整性的肿瘤抑制机制。然而，通过在小鼠癌症模型、生物信息学和高通量筛查方法方面的新培训机会来增强我在细胞生物技术方面的专业知识，我将在这一领域成功地过渡到独立。正是凭借这些获得的技能，我将能够识别与癌症相关的染色质结构调节因子TAT，影响基因组稳定性，并评估它们作为新的肿瘤抑制因子的作用。在我走向独立的过程中，我组建了一个优秀的培训委员会来指导和建议我，这个项目的成功将大大增强。该委员会包括我的共同导师尼古拉斯·戴森博士和杰弗里·恩格尔曼博士，以及丹尼尔·哈伯博士、西里尔·贝内斯博士和大卫·佩尔曼博士，他们都是各自领域的专家。此外，麻省理工学院和哈佛医学区优越的研究环境具备完成拟议的培训和研究研究所需的一切必要的物质资源。K99/R00奖将为我提供进行这种高级培训所需的保护时间，并允许我在戴森博士和恩格尔曼博士的指导下继续促进我的成长。我预计这项建议的指导阶段，包括使用小鼠模型来研究操纵CIN在实体肿瘤中的治疗相关性，以及启动一种新的筛查方法，将需要1-2年的时间，并导致至少一篇主要论文发表。该奖项的下一个独立阶段将使我能够识别和描述其他与癌症相关的、染色体结构和基因组稳定性的调节器。这些数据加在一起将被用来证明R01拨款中提出的未来研究的合理性我计划在独立阶段的第三年开始时提交。