A signalling pathway that influences how sensitive cancer cells are to the beneficial effects of dietary restriction  is described in this week’s Nature.

Dietary restriction - eating less calories while maintaining essential vitamins and minerals - can extend lifespan, and reduce cancer incidence and growth. But some types of cancer cell are more sensitive to the anti-growth effects of dietary restriction than others, Nada Kalaany and David Sabatini report. The effect hinges on the activity of the phosphatidylinositol-3-kinase (PI3K) pathway. If the pathway is active, dietary restriction has no effect on cancer cells. However, if the pathway is inactive, tumours are sensitive to dietary restriction.

Therapies that mimic the effects of dietary restriction are currently being investigated as anti-cancer agents. But as several cancers carry alterations that lead to activation of the PI3K pathway, this study suggests that the approach will not work in many cases. The findings may help to predict which cancers will respond to dietary restriction.

Article DOI: 10.1038/nature07782