Understanding how variations in nuclear size after whole genome doubling affect tumorigenesis

项目摘要 癌症的特征是基因组、表观遗传和代谢变化，但也包括细胞/核大小的失败 控制然而，关于癌细胞的大小调节以及大小控制失败是否 有助于肿瘤发生。全基因组加倍（WGD），其导致四倍体并且是常见的染色体加倍。 肿瘤进展中中间事件是可以改变细胞和核大小的关键过程。虽然 在正常人类细胞中，倍性和核大小倾向于成比例缩放，DNA含量和核大小不成比例缩放。 在癌细胞中总是相关的。这表明，理解核大小是如何控制的， DNA含量的变化可能揭示肿瘤发生的重要机制。解决这一问题 需要一个合适的实验模型，例如将用于本项目的模型。该模型包括 一组通过在结肠直肠癌和乳腺癌中诱导WGD而衍生的四倍体（4 N）克隆细胞系 细胞，并可分为两组（小和大）的基础上核的大小。先前的研究显示 小的和大的4 N DLD 1克隆显示出不同的有丝分裂表型，这提出了关于 4 N细胞的大小控制机制以及核大小对其他细胞表型的影响。的确， 初步结果表明，小的4 N克隆在体外具有增加的肿瘤样行为， 大的4 N克隆和2N亲本细胞在软琼脂集落形成测定中。这些大小特异性表型 差异表明，小的4 N克隆也可能比大的4 N克隆在体内更具致瘤性， 它们在WGD之后限制核尺寸缩放的能力。这一假设将在第一个研究目标中得到检验 使用体外、体内和计算机模拟方法的组合和两种实验模型，包括新的 一组来自2N DLD 1细胞的小的和大的4 N克隆（总共运行16个细胞系）和基因组， 组织病理学和来自癌症基因组图谱（TCGA）的临床数据。第二个研究目标将测试 假设4 N克隆的核体积由基因组压实的程度决定， 确定结肠和乳腺WGD后调节细胞核大小的转录和表观遗传机制， 衍生细胞这些实验将解决一个基本但尚未探索的问题， 在核大小方面具有重要功能性后果，其有助于WGD后的肿瘤形成。的 该项目的研究结果可用于癌症诊断，并揭示新的癌症治疗靶点。这 该项目将提供充足的培训机会，使用动物模型，计算分析和质量 光谱从领先的研究人员的跨学科小组，以帮助申请人成为一个独立的 科学家为申请人提供的智力环境、资源和培训项目丰富， 补充拟议的研究项目。此外，集体制度环境是强有力的。 支持多学科研究，并有助于拟议研究的成功， 申请人的科学发展。

Project Summary Cancer is characterized by genomic, epigenetic, and metabolic changes, but also by a failure in cell/nuclear size control. Nevertheless, little is known about size regulation in cancer cells and whether failures in size control contribute to tumorigenesis. Whole genome doubling (WGD), which results in tetraploidy and is a frequent intermediate event in tumor progression, is a key process that can alter cell and nuclear size. However, while ploidy and nuclear size tend to scale proportionally in normal human cells, DNA content and nuclear size do not always correlate in cancer cells. This suggests that understanding how nuclear size is controlled following changes in DNA content may uncover important mechanisms underlying tumorigenesis. Addressing this issue requires a suitable experimental model, such as the one that will be used for this project. This model consists of a panel of tetraploid (4N) clonal cell lines that were derived by inducing WGD in colorectal and breast cancer cells and can be divided into two groups (small and large) based on nuclear size. Previous studies showed that the small and large 4N DLD1 clones display distinct mitotic phenotypes, which raised important questions about the mechanisms of size control in 4N cells and the impact of nuclear size on other cell phenotypes. Indeed, preliminary results indicate that the small 4N clones have increased tumor-like behavior in vitro, outperforming the large 4N clones and 2N parental cells in soft agar colony formation assays. These size-specific phenotypic differences suggest that the small 4N clones may also be more tumorigenic in vivo than the large 4N clones due to their ability to restrict nuclear size scaling after WGD. This hypothesis will be tested in a first research aim using a combination of in vitro, in vivo, and in silico methods and two experimental models, including the novel panel of small and large 4N clones derived from 2N DLD1 cells (for a running total of 16 cell lines) and genomic, histopathology, and clinical data from The Cancer Genome Atlas (TCGA). A second research aim will test the hypothesis that the nuclear volumes of the 4N clones are dictated by the degree of genomic compaction and will identify the transcriptional and epigenetic mechanisms that regulate nuclear size after WGD in colon- and breast- derived cells. These experiments will address a fundamental yet underexplored question of whether variations in nuclear size have important functional consequences that contribute to tumor formation following WGD. The findings of this project could be leveraged for cancer diagnostics and unveil new cancer therapeutic targets. This project will provide ample training opportunities in the use of animal models, computational analysis, and mass spectrometry from an interdisciplinary group of leading researchers to help the applicant become an independent scientist. The intellectual environment, resources, and training programs provided to the applicant are rich and complementary to the proposed research project. Moreover, the collective institutional environment is strongly supportive of multidisciplinary research, and it is instrumental to the success of the proposed studies and scientific development of the applicant.