ABSTRACT
Snake venoms consist of a complex mixture of many bioactive molecules. Among them are disintegrins, which are peptides without enzymatic activity, but with high binding affinity for integrins, transmembrane receptors that function to connect cells with components of the extracellular matrix. Integrin-mediated cell attachment is critical for cell migration and dissemination, as well as for signal transduction pathways involved in cell growth. During tumor development, integrins play key roles by supporting cancer cell proliferation, angiogenesis, and metastasis. The recognition that snake venom disintegrins can block integrin functions has spawned a number of studies to explore their cancer therapeutic potential. While dozens of different disintegrins have been isolated, none of them as yet has undergone clinical evaluation in cancer patients. Among the best-characterized and preclinically most advanced disintegrins is vicrostatin (VCN), a recombinant disintegrin that was rationally designed by fusing 62 N-terminal amino acids derived from the disintegrin contortrostatin with 6 C-terminal amino acids from echistatin, the disintegrins from another snake species. Bacterially produced VCN was shown to target multiple tumor-associated integrins, achieving potent anti-tumor and anti-angiogenic effects in in vitro and in vivo models in the absence of noticeable toxicity. This review will introduce the field of snake venom disintegrins as potential anticancer agents and illustrate the translational development and cancer-therapeutic potential of VCN as an example.