Cell migration is central to the process of angiogenesis, which involves the formation of new blood vessels from pre-existing vasculature. This is a vital process in normal growth and development, as well as in wound healing. During the reorganization phase of angiogenesis, endothelial cells assemble to form capillary-like structures (tube formation). This process is associated with several pathological conditions, such as cardiovascular diseases, tumor growth and cancer metastasis. For example, tumors stimulate blood vessel formation to receive sufficient nutrients and oxygen, allowing them to grow into larger and more dangerous malignant cancers.
The tube formation assay has been developed to model the reorganization stage of angiogenesis in vitro. This typically involves plating endothelial cells onto Basement Membrane Extract (BME), enabling them to grow into branching tube-like structures typical of tube formation during angiogenesis in vivo (after 12-24 hours). This assay has allowed researchers to understand how tube formation underlies certain pathologies, as well as to start developing novel therapeutics by identifying compounds that inhibit tube formation.