Orthotopic Xenografts of Colorectal Cancer Stem Cells.

Cancer stem cells (CSCs) are responsible for the initiation of primary tumors and for metastasis seeding at distant organs. Therefore, they represent crucial targets for the study and preclinical testing of new antimetastatic approaches. We recently generated a molecularly characterized biobank of colorectal CSCs, isolated from individual patients and cultured in serum-free medium as multicellular spheroids. Here, we describe in detail the generation of a metastatic model of colorectal cancer based on the orthotopic injection of CSCs into the cecum serosa of immunodeficient mice. Such a model represents an excellent experimental system to investigate the cellular and molecular mechanisms involved in colorectal cancer metastasis, to analyze rare premetastatic elements such as circulating and disseminated tumor cells, and for the preclinical testing of new agents with potential antimetastatic activity.