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The mechanical role of the glycocalyx in cancer cell adhesion

糖萼在癌细胞粘附中的机械作用

基本信息

批准号：
10247898
负责人：
Aaron Blanchard
金额：
$ 9.36万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-09-16 至 2021-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10247898
关键词：
3-Dimensional Adaptor Signaling Protein Adhesions Biochemical Biological Assay Biophysical Process Biophysics Blood Blood Circulation Blood specimen Brain Breast Cancer Diagnostics Cell Adhesion Cell Adhesion Molecules Cell surface Cells Clinical Coagulation Process Cytoskeleton DNA Detection Development Diagnostic Doctor of Philosophy Early Diagnosis Elements Fibrinogen Fluorescence Microscopy Fluorescence Polarization Glioblastoma Glycocalyx Glycoproteins Human Image Image Analysis Immobilization Individual Integrins Invaded Letters Literature Lung Maps Measures Mechanics Mediating Methods Modeling Molecular Molecular Conformation Motor Nature Neoplasm Circulating Cells Neoplasm Metastasis Observation in research Outcomes Research Phase Platelet Activation Process Property Recurrence Research Role Sampling Screening for cancer Series Specificity Structure Techniques Technology Testing Thick Tissues Vinculin Work anticancer research base cancer cell cancer type career design experience experimental study fluorophore improved mechanical device mechanical properties nano nanosensors overexpression recruit screening simulation skills soft tissue targeted cancer therapy therapeutic target tool

项目摘要

Project Summary Many types of cancer – such as recurrent glioblastoma multiform, which is invariably lethal – overexpress bulky glycoproteins to form a thick glycocalyx layer. The glycocalyx physically separates the cell from its surroundings, but recent work has shown that the glycocalyx can paradoxically increase adhesion to soft tissues and therefore promote the metastasis of cancer cells. This surprising phenomenon occurs because the glycocalyx forces adhesion molecules (called integrins) on the cell's surface into clusters. These integrin clusters have cooperative effects that allow them to form stronger adhesions to surrounding tissues than would be possible with equivalent numbers of un-clustered integrins. These cooperative mechanisms have been intensely scrutinized in recent years; a more nuanced understanding of the biophysical underpinnings of glycocalyx- mediated adhesion could uncover therapeutic targets, deepen our general understanding of cancer metastasis, and elucidate general biophysical processes that extend far beyond the realm of cancer research. Here I present the hypothesis that the glycocalyx has the additional effect of increasing mechanical tension experienced by clustered integrins. Integrins function as mechanosensors that undergo structure-switching into “active” conformations when subjected to mechanical tension. As such, my hypothesis would, if true, suggest a more immediate regulatory role of the glycocalyx in adhesion than previously realized. This hypothesis (which I call the local organization hypothesis) is well-supported through indirect observation in the research literature but has not been directly tested due to challenges associated with measuring mechanical tension on individual biomolecules in live cells. However, I have devoted much of my career to developing DNA-based mechanosensor tools that can be used to directly measure piconewton-scale integrin tension in live cells. Here I propose to utilize these tools to test the local organization hypothesis and bring clarity to this rapidly-growing research field. I plan to image integrin forces during the early stages of cellular adhesion and test for a set of specific observations that would support or refute the local organization hypothesis. In parallel, I plan to leverage my computational skills to test this hypothesis using a sophisticated chemomechanical simulation method. For my postdoctoral (K00) work, I will transition into translational work and develop tools that leverage the principles of glycocalyx-mediated adhesion for cancer diagnostic purposes. Because glycocalyx-presenting cancer cells adhere more readily to soft substrates, I will develop a flow-based method for detecting circulating tumor cells (CTCs) using soft substrates and substrates of varying stiffness that facilitate mechanoselection of glycocalyx-presenting cancer cells. This mechanoselection-based method will enable mechanical profiling of CTCs to determine what types of tissues are most vulnerable to metastasis and will also allow for conventional biochemical profiling in parallel. This work will deliver a substantially enhanced understanding of the mechanisms of metastasis, as well as tools that can put this improved understanding to diagnostic use in clinical settings.

项目摘要许多类型的癌症--如复发性多形性胶质母细胞瘤，它总是致命的--过度表达，庞大的糖蛋白形成厚的糖萼层。糖萼在物理上将细胞与其周围环境，但最近的工作表明，糖萼可以矛盾地增加粘附到软组织从而促进癌细胞的转移。这一令人惊讶的现象之所以发生，是因为糖萼迫使细胞表面的粘附分子（称为整联蛋白）成簇。这些整合素簇具有协同作用，使它们与周围组织形成比可能具有相等数量的未成簇的整联蛋白。这些合作机制一直受到近年来，人们对糖萼的生物物理基础有了更细致的了解，介导的粘附可以揭示治疗靶点，加深我们对癌症转移的一般理解，并阐明了远远超出癌症研究领域的一般生物物理过程。在这里我提出的假设，即糖萼有增加机械张力的额外作用由聚集的整合素引起。整合素作为机械传感器，其经历结构转换， “活性”构象时，受到机械张力。因此，我的假设如果是真的，糖萼在粘附中比以前认识到的更直接的调节作用。这个假设（我所谓的地方组织假说）是很好的支持，通过间接观察的研究文献但是由于与测量个体上的机械张力相关的挑战，活细胞中的生物分子。然而，我把我职业生涯的大部分时间都花在了开发基于DNA的机械传感器工具，可用于直接测量活细胞中的皮牛顿级整联蛋白张力。这里我建议利用这些工具来测试本地组织假设，并澄清这一快速增长的研究领域。我计划在细胞粘附的早期阶段成像整合素的力量，并测试一组支持或反驳局部组织假说的具体观察结果。与此同时，我计划利用我的计算能力来测试这个假设使用复杂的化学力学模拟方法。对于我的博士后（K 00）工作，我将过渡到翻译工作，并开发利用用于癌症诊断目的的糖萼介导的粘附原理。因为糖萼呈递癌细胞更容易粘附在软基质上，我将开发一种基于流动的方法来检测循环肿瘤细胞（CTC），其使用软基质和不同硬度的基质，糖萼递呈癌细胞。这种基于机械选择的方法将使得能够机械地分析 CTCs来确定什么类型的组织最容易发生转移，并且还将允许常规的生化分析并行。这项工作将大大提高对这些机制的理解以及可以将这种改进的理解用于临床诊断的工具。