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

该奖项旨在研究个体健康和癌细胞生物力学特性的变化，并将这些特性与细胞重要结构，调节和侵入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为较软和较硬的组。预测细胞如何在体内扩散并产生新肿瘤的细胞的重要生物学特性将在较软和较硬的细胞组之间进行测量和比较。最后，该项目将开发一个细胞的计算机模型，以解释哪些基因是活跃的，这些基因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化可能会提高对癌症转移的理解，并创造一个新的癌症预测因子。s传播。这个项目将为研究生和本科生提供细胞力学、微细加工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外展活动促进招募和指导学生掌握尖端科学技术。细胞的机械完整性受到结构、交联和信号分子的动态网络的调节。因此，改变单个细胞的机械特性可以揭示这些分子网络变化的重要见解。例如，侵袭性肿瘤细胞通常机械软化，从而增强其从原发性肿瘤中逃逸的能力。然而，给定细胞类型内的机械变化可能是实质性的，这不仅限制了细胞机械测量的特异性，而且还提出了一个有趣且未回答的问题：为什么相似细胞之间的细胞机械特性不同？本研究的目的是了解基因表达的变化如何导致细胞群体之间以及细胞群体内的细胞力学变化。这项研究将检查细胞的机械性能（模量，粘性松弛，和大小）和基因表达之间的相关性，在细胞的基础上。将进行两项独特的实验测量。首先，用原子力显微镜测量单个细胞的生物力学，随后分析先前从卵巢健康细胞和癌细胞的群体研究中鉴定为差异表达的机械相关基因的基因表达。其次，生物物理细胞分选装置将用于获得较硬和较软表型的细胞。将检查每个分选的细胞组的功能和基因表达差异。最后，实验结果将用于通知细胞的多尺度计算模型，以解释生物变异（例如交联密度）如何导致生物物理变异。该研究将描述活细胞的机械特性的基本方面，特别是细胞骨架交联，核膜，以及由于短时间尺度（例如细胞周期）和较长时间尺度（例如上皮间充质转化）的动态过程引起的微机械变化。该项目将回答一些问题，例如非侵入性细胞的较软亚型是否仍然可以显示转移样迁移。卵巢癌细胞转移的生物物理学知识可能会导致新的诊断和治疗方法的基础上检测和抑制特定的细胞生物物理表型。该项目将继续开展教育和外联工作，以增加攻读科学和工程的学生人数。该项目将培训研究生和本科生通过使用最先进的实验和计算方法解决跨学科问题。

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.