Many of the body's cell types enter a state in which they do not divide and, or so scientists thought, reduce their metabolic rates. But Hilary Coller and her colleagues at Princeton University in New Jersey show that quiescent human fibroblast cells — common in connective tissues — have similar metabolic activity to their proliferating counterparts.

The team measured and analysed the levels of 62 metabolites extracted from the cells, as well as levels of secreted proteins. They found that quiescent cells were busy breaking down and resynthesizing proteins and lipids, as well as secreting proteins that help to maintain tissues. Moreover, inhibiting a metabolic pathway in these cells led to increased programmed cell death, leading the authors to suggest that certain dormant cells, such as cancer stem cells, can be selectively killed.

PLoS Biol. 8, e1000514 (2010)