Biomimetic 3D Clusters Using Human Adipose Derived Mesenchymal Stem Cells and Breast Cancer Cells: A Study on Migration and Invasion of Breast Cancer Cells

Invasion and metastasis of cancer directly related to human death have been associated with interactions among many different types of cells and three-dimensional (3D) tissue matrices. Precise mechanisms related to cancer invasion and metastasis still remain unknown due to their complexities. Development of tumor microenvironment (TME)-mimicking system could play a key role in understanding cancer environments and in elucidating the relating phenomena and their driving forces. Here we report a facile and novel platform of 3D cancer cell-clusters using human adipose-derived mesenchymal stem cells (hASCs) and breast cancer cells (MDA-MB-231) within a collagen gel matrix to show cancer invasion in the cell and extracellular matrix (ECM). Both clusters A (hASC only) and AC (hASC and MDA-MB-231) exhibited different behaviors and expressions of migration and invasion, as observed by the relating markers such as fibronectin, α-SMA, and CXCR4. hASCs showed a protrusive migration from a cluster center, whereas MDA-MB-231 spread out radially followed by hASC migration. Finally, the effect of matrix was further discussed by varying collagen gel densities. The new biomimetic system of 3D cancer clusters developed here has the potential to be utilized for research on migration and invasion of cancer cells in extracellular matrices.直接危及人类生命的癌症侵袭与转移，与多种不同类型细胞及三维（3D）组织基质间的相互作用密切相关。由于癌症侵袭与转移的复杂性，其背后的精确机制至今仍未阐明。构建模拟肿瘤微环境（TME）的实验体系，对于解析癌症微环境、阐明相关癌变现象及其驱动因素具有关键意义。本研究报道了一种简便新颖的三维癌细胞团平台：以胶原凝胶基质为载体，搭载人脂肪来源间充质干细胞（hASCs）与乳腺癌细胞（MDA-MB-231），用于模拟细胞与细胞外基质（ECM）中的癌症侵袭过程。通过纤连蛋白（fibronectin）、α-平滑肌肌动蛋白（α-SMA）及CXCR4等相关标志物检测发现，仅含hASCs的A团簇与共含hASCs和MDA-MB-231细胞的AC团簇，在迁移侵袭行为及相关分子表达层面均存在显著差异。hASCs呈现出从团簇中心向外突出迁移的表型，而MDA-MB-231细胞则先呈放射状铺展，随后伴随hASCs的迁移过程。最后，本研究通过调整胶原凝胶密度，进一步探讨了基质的作用效应。本研究构建的新型三维癌细胞团仿生体系，有望用于细胞外基质中癌细胞迁移与侵袭的相关研究。