Polyploid cell cycle regulation and genome instability

多倍体细胞周期调控和基因组不稳定性

基本信息

批准号：
9276715
负责人：
BRIAN R CALVI
金额：
$ 31.08万
依托单位：
TRUSTEES OF INDIANA UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-08-12 至 2019-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9276715
关键词：
Ablation Alpha Cell Aneuploid Cells Aneuploidy Apoptosis Apoptotic Biological Assay Cell Cycle Cell Cycle Regulation Cell Survival Cell division Cells Centrosome Chromatin Chromosome Fragile Sites Chromosome Segregation Collection Competence Complex Cytokinesis DNA DNA Damage DNA Sequence Alteration DNA biosynthesis Data Defect Development Disease Progression Drosophila genus Gap Junctions Gene Targeting Genes Genetic Genetic Screening Genome Stability Genomic Instability Genotoxic Stress Goals Human Image Investigation Kinetochores Knowledge Lead Link Malignant Neoplasms Mammals Mediating Methods Mitosis Mitotic Molecular Molecular Genetics Mus One-Step dentin bonding system Outcome Pathway interactions Polyploid Cells Polyploidy Process Proteins Publishing Recruitment Activity Regulation Repression Research Resolution S Phase Stress TP53 gene Testing Tissues Variant cancer cell cancer therapy cell type cellular imaging daughter cell experimental study fly gene product genome integrity insight live cell imaging novel programs public health relevance therapy resistant transcription factor transcriptome tumor

项目摘要

DESCRIPTION (provided by applicant): Cell division cycles and checkpoints are altered during both development and cancer. In this proposal, we focus on a developmental cell cycle variation called the endocycle (G/S cycle), which results in polyploid cells. Evidence suggests that an inappropriate switch into an endocycle contributes to genome instability and cancer. There is a large knowledge gap, however, in understanding how this alternative cell cycle is regulated and how it compromises genome integrity. Our overall objective is to define mechanisms in endocycling cells that repress apoptosis and contribute to aneuploidy when these cells return to mitosis. To achieve this goal, our proposal leverages the complementary expertise of the Calvi and Walczak labs in Drosophila endocycles and human cell mitosis respectively. Our central hypothesis is that a specific remodeling of the cell cycle transcriptome promotes endocycles, represses apoptosis, and causes genome instability. This hypothesis emanates from our discovery that endocycling cells in Drosophila development repress apoptosis by blocking the p53 genotoxic stress pathway. Experimental ablation of mitosis in Drosophila creates induced endocycling cells (iECs), and is sufficient to repress apoptosis. This suggests that there is an unsuspected link between cell cycle programs and apoptotic pathways. iECs can later resume mitotic divisions that are error prone, resulting in proliferative aneuploid daughter cells. We are also evaluating conservation to humans. Ablation of mitosis also creates human polyploid iECs, which can return to a mitosis that is severely error prone. Our transcriptome analysis has provided crucial insights into mechanism and leads to a unifying hypothesis for how endocycle regulation is linked to the repression of apoptosis and genome instability. Our central hypothesis will be tested in three specific aims: In Aim 1, we will define the molecular mechanisms by which the cell cycle and apoptotic pathways are linked in Drosophila. A novel unbiased genetic screen also exploits the power of Drosophila to discover new players in this process. Aim 2 uses molecular and genetic methods to test the hypothesis that persistent replication stress in Drosophila iECs compromises genome integrity. Aim 3 takes advantage of our expertise in human cell mitosis and advanced cellular imaging to define the mechanisms of chromosome segregation errors when human iECs return to mitosis. We also test the hypothesis that a specific remodeling of the cell cycle contributes to these errors, spawning proliferative, aneuploid daughter cells. The outcome of these integrated aims will show how endocycling cells avoid apoptosis despite persistent replication stress, and how this stress, with errors in mitosis, generates aneuploid cells. A transient switch to an endocycle may contribute to therapy resistance of the cancer cell, with a return to mitosis generating high rates of aneuploidy that contributes to disease progression. This research is significant because the outcomes will define new mechanisms for cell survival and aneuploidy, and will ultimately lead to more effective cancer therapies.

描述（由适用提供）：在发育和癌症期间都改变了细胞分裂周期和检查点。在此提案中，我们专注于一种称为内猫（g/s周期）的发育细胞周期变化，该变化导致多倍体细胞。有证据表明，转向内猫的不适当切换会导致基因组不稳定性和癌症。但是，在了解如何调节这种替代细胞周期以及如何损害基因组完整性时，存在很大的知识差距。我们的总体目的是定义内吞细胞中反映凋亡的机制，当这些细胞恢复有丝分裂时会导致非整倍性。为了实现这一目标，我们的提议分别利用了果蝇内吞和人类细胞有丝分裂的Calvi和Walczak实验室的完整专业知识。我们的中心假设是，对细胞周期转录组的特定重塑促进了内鼠，抑制细胞凋亡并导致基因组不稳定性。这一假设源于我们发现果蝇发育复制凋亡中的内吞细胞通过阻止p53遗传毒性应激途径。果蝇中有丝分裂的实验消融会产生诱导的内鼠细胞（IEC），并且足以复制细胞凋亡。这表明细胞周期程序与凋亡途径之间存在一个未经规模的联系。 IEC随后可以恢复容易出错的有丝分裂分裂，从而导致非整倍性子细胞增殖。我们还在评估对人类的保护。有丝分裂的消融还会产生人类多倍体IEC，这可能会恢复到易于误差的有丝分裂。我们的转录组分析提供了对机制的关键见解，并导致了统一的假设，即对于凋亡和基因组不稳定性的表达如何联系在一起。我们的中心假设将以三个特定的目的进行检验：在AIM 1中，我们将定义细胞周期和凋亡途径在果蝇中连接的分子机制。一个新颖的公正遗传屏幕还探讨了果蝇在此过程中发现新玩家的力量。 AIM 2使用分子和遗传学方法来检验果蝇IEC中持续的复制应激损害基因组完整性的假设。 AIM 3利用我们在人类细胞有丝分裂和晚期细胞成像方面的专业知识来定义当人IEC返回有丝分裂时染色体隔离误差的机制。我们还测试了一个假设，即细胞周期的特定重塑有助于这些误差，产卵剂，非整倍性子细胞。这些综合目的的结果将表明内环细胞如何避免凋亡持续的复制应力，以及这种压力如何与有丝分裂的误差产生非整倍性细胞。瞬时转移到内吞可能会导致癌细胞的治疗耐药性，并恢复有丝分裂的速率促进疾病进展的非整倍性。这项研究很重要，因为结果将定义细胞存活和非整倍性的新机制，并最终导致更有效的癌症疗法。