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细胞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、调节和侵袭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两组。这些细胞的重要生物学特性预测了它们如何在体内扩散并产生新的肿瘤，这些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，以解释哪些基因活跃的差异如何导致它们变硬或变软。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，并创造一种新的癌症预测因子。年代蔓延。该项目将为研究生和本科生提供细胞力学、微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，促进学生在尖端科学技术方面的招聘和指导。细胞的机械完整性是由结构、交联和信号分子的动态网络调节的。因此，单个细胞力学性质的改变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会机械地软化，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变化可能是实质性的，这不仅限制了细胞力学测量的特异性，而且还提出了一个有趣且未解决的问题：为什么相似细胞之间的细胞力学特性会有所不同？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。本研究将以细胞为基础，研究细胞力学特性（模量、粘性松弛和大小）与基因表达之间的关系。将进行两个独特的实验测量。首先，将使用原子力显微镜对单个细胞进行生物力学测量，随后分析先前在卵巢健康细胞和癌细胞群体研究中发现的机械相关基因的基因表达差异。其次，将使用生物物理细胞分选装置获得更硬和更软表型的细胞。将检查每一组细胞的功能和基因表达差异。最后，实验结果将用于为细胞的多尺度计算模型提供信息，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力学特性的基本方面，特别是细胞骨架交联，核膜，以及由于短时间尺度（如细胞周期）和长时间尺度（如上皮向间质转化）的动态过程而引起的微力学变化。这个项目将回答一些问题，如软亚型非侵入性细胞是否仍然可以表现出转移样迁移。卵巢癌细胞转移的生物物理知识可能会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推广工作，以增加攻读理工科的学生人数。该项目将培养研究生和本科生利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.