Inhibitors of integrins.

The inhibition of integrins--cell surface receptors with a crucial role in angiogenesis, tumour cell survival, invasion and metastases--has centred on the alpha(v)beta3 integrin. Work has culminated in two antagonists that are in clinical trials as cancer therapeutics. Other integrins appear to be candidate targets in the light of gene knockout studies. Surprisingly, genetic alpha(v)beta3 ablation did not confirm the pertinence of the use of alpha(v)beta3 antagonists. However, these apparent discrepancies could be explained by the new finding that this integrin has a role as a cell survival sensor, limiting rather than promoting angiogenesis. Accumulating data on the role of integrins and the mechanism of action of pharmacological antagonists will help to develop and apply an efficient anti-integrin therapy in cancer.