Decellularized colorectal cancer matrix as bioactive microenvironment for in vitro 3D cancer research

Three-dimensional (3D) cancer models are overlooking the scientific landscape with the primary goal of bridging the gaps between two-dimensional (2D) cell cultures, animal models and clinical research. In this thesis, we describe an innovative tissue engineering approach applied to colorectal cancer (CRC) starting from decellularized human biopsies in order to generate an organotypic 3D bioactive model. This in vitro 3D system recapitulates the ultrastructural environment of native tissue as demonstrated by histology, immunohistochemistry, immunofluorescence and scanning electron microscopy analyses. Mass spectrometry of proteome and secretome confirmed a different stromal composition between decellularized healthy mucosa and CRC in terms of structural proteins (COL1A1, COL1A2, and COL3A1) and secreted proteins such as DEFA3. Importantly, we proved that our 3D acellular matrices retained their biological properties: using CAM assay, we observed a decreased angiogenic potential in decellularized CRC compared with healthy colon mucosa, caused by direct effect of DEFA3. In addition, we demonstrated that following a 5 days of recellularization with HT-29 cell line, the 3D tumor matrices induced an over-expression of IL-8, a DEFA3-mediated pathway and a mandatory chemokine in cancer growth and proliferation, compared with recellularized healthy mucosa and 2D conventional culture model. Given the biological activity maintained by the scaffolds after decellularization, we believe this approach is a powerful tool for future pre-clinical research and screenings