The cancer-preventing reputation of antioxidants takes a hit with the discovery that they can sometimes promote the survival and proliferation of cancer cells. The finding, reported in this week's Nature, has implications for our understanding of cancer biology.

Normal epithelial cells die if they become detached from the structurally supportive extracellular matrix, but in breast cancer, cancer-causing genes such as erbB2 can provide survival signals to detached tumorigenic cells. Joan Brugge and colleagues show that cell detachment also causes metabolic defects that can be rescued by erbB2 and, unexpectedly, by antioxidants.

The antioxidants seem to work by boosting cellular energy levels via fatty acid oxidation. The findings are surprising but the work was done in cell culture and there is as yet no evidence that there are any implications for patients.

DOI: 10.1038/nature08268