Multiscale Imaging of Metastasis in Zebrafish.

Cancer progression to metastatic dissemination is responsible for ∼90% of deaths in patients. Tremendous efforts have been made to understand primary tumor growth, cancer genetics, and clonal evolution, but also secondary sites of colonization. Intravital imaging technologies are instrumental in understanding key steps of the metastasis cascade, which are believed to be therapeutically relevant targets. However, these remain cumbersome in mouse models. Recent work has demonstrated the zebrafish's unique ability as an experimental metastasis model for the dynamic study of cancer progression at the single-cell level. Its compatibility with state-of-the art imaging techniques and biophysical approaches allows probing of the interaction of tumor cells with their microenvironment and monitoring of fast and rare cellular events at high spatiotemporal resolution. In this review, we highlight the multiple benefits of the zebrafish as an alternative metastasis preclinical model from an imaging standpoint.