The family of mammalian enzymes called phosphoinositide-3-OH kinases (PI(3)K) are fundamental cell signalling molecules whose exact roles have been difficult to pin down. Bart Vanhaesebroeck and colleagues show in a paper published online by Nature that one form of this enzyme, p110-alpha PI(3)K, is vital for cell growth and metabolism, findings that may help to explain why it is mutated in a variety of cancers.
The team tested the role of p110-alpha by genetically engineering mice so that the enzyme was still manufactured at normal levels but no longer active. Mice carrying one copy of the defective gene did not respond normally to the hormones insulin, insulin-like growth factor-1 and leptin, and exhibited a range of growth and metabolic disorders as a result.
The study suggests that cancer cells may hijack cell growth pathways by increasing activation of p110-alpha, and supports the idea that blocking p110-alpha could block cancer growth.
Bart Vanhaesebroeck (Ludwig Institute for Cancer Research, London, UK)
Abstract available online.
(C) Nature press release.
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