Targeting the molecular basis for tumour hypoxia.

Tumour hypoxia stems from impaired oxygen delivery as a result of a disorganised tumour vasculature and inadequate blood supply. Hypoxic tumours are highly resistant to chemotherapy and radiation therapy and correlate with a poor patient prognosis. Hypoxia is a powerful stimulus for the expression of genes involved in cell survival and angiogenesis. A key factor in this process is hypoxia-inducible factor (HIF), which regulates transcription of hypoxia-activated genes. Efforts are currently under way to develop targeted cancer therapeutics to hypoxia-activated pathways, and in particular to the transcription factor HIF.