Development of Cell-Derived Matrices for Three-DimensionalIn VitroCancer Cell Models

Most morphogenetic and pathological processes are driven by cells responding to the surrounding matrix, such as its composition, architecture, and mechanical properties. Despite increasing evidence for the role of extracellular matrix (ECM) in tissue and disease development, many in vitro substitutes still fail to effectively mimic the native microenvironment. We established a novel method to produce macroscale (>1 cm) mesenchymal cell-derived matrices (CDMs) aimed to mimic the fibrotic tumor microenvironment surrounding epithelial cancer cells. CDMs are produced by human adipose mesenchymal stem cells cultured in sacrificial 3D scaffold templates of fibronectin-coated poly-lactic acid microcarriers (MCs) in the presence of macromolecular crowders. We showed that decellularized CDMs closely mimic the fibrillar protein composition, architecture, and mechanical properties of human fibrotic ECM from cancer masses. CDMs had highly reproducible composition made of collagen types I and III and fibronectin ECM with tunable mechanical properties. Moreover, decellularized and MC-free CDMs were successfully repopulated with cancer cells throughout their 3D structure, and following chemotherapeutic treatment, cancer cells showed greater doxorubicin resistance compared to 3D culture in collagen hydrogels. Collectively, these results support the use of CDMs as a reproducible and tunable tool for developing 3D in vitro cancer models.The researchers thank MICIU (BES-2016-077182, MAT2015-68906-R, RTI2018-096320-B-C21, PGC2018-097323-A-I00, DPI2017-83721-P) and the Spanish network of cell therapy (TERCEL) for financial support. Finally, the researchers also thank Programme/Generalitat de Catalunya (2017-SGR-359) and the Severo Ochoa program of the Spanish Ministry of Science and Competitiveness (grant SEV-2014-0425, 2015-2019)