Novel mechanism for p53 tumour suppression

The tumour suppressor activity of the transcription factor p53 is typically thought to reflect its ability to induce cell cycle arrest, apoptosis or senescence in response to cellular stress, but there is emerging evidence for other activities of p53. Here Wei Gu and colleagues show that a metabolic target of p53 can also contribute to its tumour suppressor activity. In particular, they find that p53 suppresses expression of SLC7A11, a key component of the cystine/glutamate amino acid transport machinery. This leads to inhibition of cystine uptake and promotes ferroptosis, an iron-dependent form of cell death. This previously unrecognized function of p53 seems to be important in tumour suppression, particularly when other pathways are inoperative.