The mechanical role of the glycocalyx in cancer cell adhesion

糖萼在癌细胞粘附中的机械作用

• 批准号: 10264931
• 负责人: Aaron Blanchard
• 金额: $ 9.18万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-16 至 2024-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10264931
• 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; Postdoctoral Fellow; Process; Property; Recurrence; Research; Role; Sampling; Screening for cancer; Series; Specificity; Structure; Techniques; Technology; Testing; Thick; Tissues; Vinculin; Work; anticancer research; cancer cell; cancer type; career; design; detection method; experience; experimental study; fluorophore; improved; mechanical device; mechanical properties; nano; nanosensors; overexpression; recruit; screening; simulation; skills; soft tissue; targeted cancer therapy; therapeutic target; tool

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.

项目概要 许多类型的癌症——例如总是致命的复发性多形性胶质母细胞瘤——过度表达 大糖蛋白形成厚厚的糖萼层，糖萼在物理上将细胞与其分离。 但最近的研究表明，糖萼可以反常地增加对软组织的粘附力 并因此促进癌细胞的转移。 糖萼迫使细胞表面的粘附分子（称为整合素）形成这些整合素簇。 具有协同效应，使它们能够比周围组织形成更强的粘附力 这些合作机制可以通过同等数量的非聚集整合素来实现。 近年来对糖萼的生物物理基础有了更细致的了解； 介导的粘附可以发现治疗靶点，加深我们对癌症转移的一般理解， 并阐明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是糖萼具有增加机械张力的附加作用 聚集的整合素经历了作为机械传感器的作用，经历了结构转换。 当受到机械张力时，会出现“活跃”构象，因此，如果我的假设成立，则表明存在一种“活跃”构象。 糖萼在粘附中的调节作用比以前意识到的更直接。 称为局部组织假说）通过研究文献中的间接观察得到了很好的支持 但由于与测量个体机械张力相关的挑战，尚未直接进行测试 然而，我职业生涯的大部分时间都致力于开发基于 DNA 的生物分子。 可用于直接测量活细胞中皮牛顿级整合素张力的机械传感器工具。 我建议利用这些工具来测试本地组织假设，并澄清这个快速增长的组织 我计划对细胞粘附早期阶段的整合素力进行成像并测试一组 同时，我计划利用支持或反驳当地组织假设的具体观察结果。 我的计算能力使用复杂的化学机械模拟方法来测试这个假设。 对于我的博士后（K00）工作，我将过渡到转化工作并开发利用 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的方法来检测循环 肿瘤细胞（CTC）使用软基质和不同硬度的基质，促进机械选择 这种基于机械选择的方法将能够对呈递糖萼的癌细胞进行机械分析。 CTC 可以确定哪些类型的组织最容易发生转移，并且还可以进行常规治疗 这项工作将大大增强对这些机制的理解。 转移的研究，以及可以将这种改进的理解应用于临床环境中诊断用途的工具。