CELLS MIGRATING IN 3D MATRICES

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 细胞迁移是生物学中的一个基本过程，对于癌症转移、胚胎发育、伤口愈合和许多其他生物过程至关重要。总体目标是研究迁移和肿瘤细胞的侵袭使用新的显微镜技术。这是一个重要的生物学问题，在许多医学和临床领域具有潜在的后果。 具体而言，本研究将寻求建立如何使用“对相关方法”来研究三维组织组件中的细胞粘附。 我们研究了单个肿瘤细胞的迁移，这些肿瘤细胞来自于植入到I型胶原蛋白的3D凝胶基质中的人类胶质瘤细胞系ACBT。根据基质的密度，细胞可以在该3D组织模型中迁移。基质的性质对于细胞的迁移至关重要。使用共聚焦显微镜以反射模式对细胞和胶原纤维网络成像，使得可以长时间观察样品而不漂白。我们开发了一种基于图像相关光谱和局部测量的热波动，以确定胶原纤维的平均尺寸和局部刚度的方法。强度波动是由纤维反射的闪烁产生的。来自光纤中单个点的反射强度由于光纤位置波动而波动。我们发现了光纤直径和波动谱之间的相关性。使用连续采集几个小时，我们确定了在迁移过程中细胞在3D网络中强行移动时靠近细胞的纤维的位移。我们还观察到在特定位置的波动谱的变化，可能是由于细胞粘连的形成。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Cell migration is a fundamental process in biology, crucial for cancer metastasis, embryonic development, wound healing and many other biological processes. The overall aim is to study the migration and invasion of tumor cells using novel microscopy techniques. This is an important biological problem with potential consequences in many areas of medical and clinical interest. Specifically, this research will seek to establish how to use "pair correlation approaches" to study cellular adhesions in 3D tissue assemblies. We studied the migration of individual tumor cells, derived from the human glioma cell line ACBT that were implanted into a 3D gel matrix of collagen type I. Depending on the density of the matrix, cells can migrate in this 3D tissue model. The properties of the matrix are crucial for the migration of the cells. The cells and the collagen fiber network where imaged using a confocal microscope in the reflection mode so that the sample could be observed for a long period of time without bleaching. We developed a method based on image correlation spectroscopy and on local measurement of thermal fluctuations to determine the average size and the local stiffness of the collagen fibers. Intensity fluctuations were generated by the flickering of the reflections from the fibers. The reflected intensity from a single point in the fiber fluctuates due to fiber position fluctuations. We found a correlation between the fiber diameter and the fluctuation spectrum. Using continuous acquisition for several hours we determined the displacement of the fibers close to the cell as the cell forces its way in the 3D network during the migration process. We also observed changes in the fluctuation spectrum at specific locations probably due to the formation of cellular adhesions.