Mouse models of colorectal cancer and liver metastases.

Colorectal cancer (CRC) is one of the most common malignancies in the western world. Its high mortality rates are particularly related to the occurrence of liver metastases. Many mouse models have been developed to evaluate the various features of CRC in human. Since none of the existing mouse models mimics all the characteristics of human CRC, it is of crucial importance that the optimal model is chosen for each experiment to resolve a specific experimental question. Currently used mouse models for CRC include chemically induced CRC models, genetically engineered mouse models and models in which colon tumors are implanted in recipient mice. Recently, conditional mouse models have been created in which a gene of interest can be (in)activated in a time- and tissue-specific manner. All models have their advantages and limitations. This review highlights the most commonly used mouse models for CRC and its liver metastases, their usefulness and shortcomings, as well as recent improvements, particularly regarding intravital (tumor) imaging.