Understanding the Relationship Between Cell Mechanical Variability and Gene Expression Through Single Cell Experiments and Modeling

通过单细胞实验和建模了解细胞机械变异与基因表达之间的关系

• 批准号: 1538161
• 负责人: Todd Sulchek
• 金额: $ 39.59万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1538161&HistoricalAwards=false
• 关键词: Understanding; Relationship; Between; Cell; Mechanical

This award is to study the variation in biomechanical properties of individual healthy and cancerous cells and to relate these properties to the underlying gene expression of important structural, regulatory, and invasive features of the cell. The project will use a new cell sorting device to divide healthy and cancerous cells into softer and stiffer groups. Important biological properties of the cells that predict how they could spread in the body and make new tumors will be measured and compared between the softer and stiffer cell groups. Finally the project will develop a computer model of the cell to explain how differences in which genes are active cause them to be stiff or soft. Knowledge of the biomechanical variation of cancer cells may improve the understanding of cancer metastasis and create a new predictor of a cancer?s spread. This project will provide training opportunities to graduate and undergraduate students on cell mechanics, microfabrication, and cancer biology. The research activities will also promote the recruitment and mentoring of students in cutting-edge scientific techniques through outreach in the Atlanta public high schools.The mechanical integrity of cells is regulated by a dynamic network of structural, cross-linking, and signaling molecules. Therefore, alterations of the mechanical properties of individual cells can reveal important insights into changes in these molecular networks. For example, invasive tumor cells typically soften mechanically, which thereby enhance their capacity to escape from a primary tumor. However, the mechanical variation within a given cell type can be substantial, which not only limits the specificity of cell mechanical measurements, but also poses an intriguing and unanswered question: why do cell mechanical properties vary between similar cells? The objective of this research is to understand how variations in gene expression can lead to variations of cellular mechanics between populations of cells as well as within populations of cells. This study will examine the correlation between cellular mechanical properties (modulus, viscous relaxation, and size) and gene expression, on a cell by cell basis. Two unique experimental measurements will be conducted. First, individual cells will be measured biomechanically with atomic force microscopy and subsequently analyzed for gene expression of mechanically relevant genes previously identified to be differentially expressed from population studies of ovarian healthy and cancer cells. Second, a biophysical cell sorting device will be used to obtain cells of stiffer and softer phenotypes. Each sorted group of cells will be examined for functional and gene expression differences. Finally, the experimental results will be used to inform a multiscale computational model of the cell to explain how biological variation (e.g. crosslinking density) can lead to biophysical variation. The study will delineate the fundamental aspects of the mechanical properties of living cells, particularly cytoskeleton crosslinking, nuclear membrane, and micromechanical changes due to dynamical processes on short time scales (e.g. cell cycle) and longer time scales (e.g. epithelial to mesenchymal transition). This project will answer questions such as whether softer subtypes of noninvasive cells can nonetheless show metastatic-like migration. Knowledge of the biophysics of metastasis of ovarian cancer cells may lead to new diagnostic and treatment approaches based upon detecting and inhibiting specific cell biophysical phenotypes. The project will continue the educational and outreach efforts to increase the number of students pursuing science and engineering. The project will train graduate and undergraduate students in solving interdisciplinary problems by using state-of-the-art experimental and computational methods.

该奖项旨在研究单个健康和癌细胞的生物力学特性的变化，并将这些特性与细胞的重要结构、调节和侵袭性特征的潜在基因表达联系起来。该项目将使用一种新的细胞分选设备，将健康细胞和癌细胞分成更软和更硬的组。预测细胞如何在体内扩散并形成新的肿瘤的细胞的重要生物学特性将被测量，并在较软和较硬的细胞组之间进行比较。最后，该项目将开发细胞的计算机模型，以解释哪些基因活跃的差异是如何导致它们变硬或变软的。了解癌细胞的生物力学变异可能会提高对癌症转移的理解，并创造一个新的癌症预测指标--S扩散。该项目将为研究生和本科生提供细胞力学、微制造和癌症生物学方面的培训机会。研究活动还将通过在亚特兰大公立高中的推广，促进尖端科学技术学生的招募和指导。细胞的机械完整性由结构、交联和信号分子的动态网络调节。因此，单个细胞的机械性质的改变可以揭示这些分子网络的变化。例如，侵袭性肿瘤细胞通常会机械软化，从而增强它们逃离原发肿瘤的能力。然而，给定细胞类型内的力学差异可能是巨大的，这不仅限制了细胞力学测量的特异性，而且提出了一个有趣而又未解的问题：为什么相似细胞之间的细胞力学特性不同？这项研究的目的是了解基因表达的差异如何导致细胞群体之间以及细胞群体内的细胞力学变化。这项研究将在一个细胞一个细胞的基础上，研究细胞机械性能(模数、粘滞松弛和大小)和基因表达之间的相关性。将进行两项独特的实验测量。首先，将用原子力显微镜对单个细胞进行生物力学测量，然后分析以前在卵巢健康细胞和癌细胞群体研究中确定的差异表达的机械相关基因的基因表达。其次，将使用生物物理细胞分选装置来获得更坚硬和更柔软的表型细胞。每一组分类的细胞都将被检查功能和基因表达的差异。最后，实验结果将被用来为细胞的多尺度计算模型提供信息，以解释生物变化(例如，交联密度)如何导致生物物理变化。这项研究将描述活细胞力学性质的基本方面，特别是细胞骨架的交联、核膜，以及由于短时间尺度(例如细胞周期)和长时间尺度(例如上皮向间充质转变)上的动态过程而引起的微观力学变化。这个项目将回答一些问题，比如较软的非侵入性细胞亚型是否仍然可以表现出类似转移的迁移。了解卵巢癌细胞转移的生物物理学知识可能导致基于检测和抑制特定细胞生物物理表型的新的诊断和治疗方法。该项目将继续开展教育和宣传工作，以增加攻读理工科的学生人数。该项目将培训研究生和本科生使用最先进的实验和计算方法解决跨学科问题。