Modeling Colorectal Cancer Progression Through Orthotopic Implantation of Organoids.

Colorectal cancer (CRC) related death has often been attributed to the presence of metastatic disseminated disease. A concise understanding of the molecular mechanism(s) that drive metastatic progression is therefore needed but has thus far been hampered by the limited number of CRC mouse models that progress toward this disease stage. In addition, preclinical evaluation of therapeutic modalities aimed at managing metastatic disease also rests on the availability of relevant in vivo models that faithfully recapitulate the key molecular features of metastatic human CRC. To overcome these limitations, we have recently developed methodologies that enable the study of CRC progression at relevant orthotopic sites. Here, we provide a detailed methodology that describes the injection of CRC derived cell lines and organoids directly into the colorectal mucosa. This results in the growth of a single tumor mass within the colon, that can spontaneously metastasize to the liver. Furthermore, we also present a surgical procedure to directly inject cells into the portal venous circulation to induce CRC tumor growth in the liver without the requirement of a primary tumor.