Therapeutic angiogenesis: appropriate for clinical use?

The inhibition of angiogenesis is considered to be one of the most promising strategies that might lead to the development of novel antineoplastic therapies. This concept is supported by the dramatic results of gene inactivation experiments in mice that have identified several vascular endothelium related molecules as rate limiting for embryonic angiogenesis. Likewise, a number of recent animal studies have shown that angiogenesis inhibitors can prevent metastasis and shrink established experimental tumours to small dormant microtumours. In this review, Hellmut Augustin illustrates differences between developmental angiogenesis, physiological angiogenesis in the adult, and pathological angiogenesis in experimental animal tumours and natural human tumours. He then summarizes the experimental approaches to antiangiogenic therapies and finally discusses critical issues that need to be considered in translating these novel therapeutic strategies into clinical practice.