Cell invasion through extracellular matrix (ECM) is a critical step in tumor metastasis. To study cell invasion in vitro, the internal microenvironment can be simulated via the application of 3D models. This study presents a method for 3D invasion examination using microcarrier-based spheroids. Cell invasiveness can be evaluated by quantifying cell dispersion in matrices or tracking cell movement through time-lapse imaging. It allows measuring of cell invasion and monitoring of dynamic cell behavior in three dimensions. Here we show different invasive capacities of several cell types using this method. The content and concentration of matrices can influence cell invasion, which should be optimized before large scale experiments. We also introduce further analysis methods of this 3D invasion assay, including manual measurements and homemade semi-automatic quantification. Finally, our results indicate that the position of spheroids in a matrix has a strong impact on cell moving paths, which may be easily overlooked by researchers and may generate false invasion results. In all, the microcarrier-based spheroids 3D model allows exploration of adherent cell invasion in a fast and highly reproducible way, and provides informative results on dynamic cell behavior in vitro.

中文翻译：

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一种基于微载体的球体 3D 入侵测定，用于监测细胞外基质中的动态细胞运动。

通过细胞外基质 (ECM) 侵入细胞是肿瘤转移的关键步骤。为了研究体外细胞侵袭，可以通过应用 3D 模型来模拟内部微环境。本研究提出了一种使用基于微载体的球体进行 3D 入侵检查的方法。可以通过量化矩阵中的细胞分散或通过延时成像跟踪细胞运动来评估细胞侵袭性。它允许测量细胞侵袭和监测三个维度的动态细胞行为。在这里，我们展示了使用这种方法的几种细胞类型的不同侵袭能力。基质的含量和浓度会影响细胞侵袭，应在大规模实验前进行优化。我们还介绍了这种 3D 入侵检测的进一步分析方法，包括手动测量和自制的半自动量化。最后，我们的结果表明，球体在基质中的位置对细胞移动路径有很大影响，这可能很容易被研究人员忽视，并可能产生错误的入侵结果。总之，基于微载体的球体 3D 模型允许以快速且高度可重复的方式探索贴壁细胞的侵袭，并提供有关体外动态细胞行为的信息结果。