Models for assessing anti-angiogenesis agents: Appraisal of current techniques

Abstract

A number of reproducible, technically satisfactory methods are available for experimentally measuring the anti- and proangiogenic activities of vascular growth factors, hormones, peptides, and pharmaceuticals. A group of widely used in vitro and in vivo assays for angiogenesis are reviewed here. The in vitro assays are the aortic ring, sprouting, and tube formation systems and the in vivo assays are the chick chorioallantoic membrane (CAM), the zebrafish, tumor xenografts in the immunocompromised mouse, and the Matrigel plug models. Human angiogenesis cannot be entirely reproduced in a single assay system. Thus, satisfactory preclinical anti- and proangiogenesis assay results do not assure clinical efficacy. Most of the assays discussed here, however, respond predictably to standard angiogenesis inhibitors and proangiogenesis factors and are cost effective.