Prostate cancer could be caused by the aberrant activity of a newly identified stem cell type, a mouse study in this week’s Nature suggests. The finding has implications for therapeutic design.

The rare cells, identified by Michael Shen and colleagues, are found among the epithelial cells that line the inner cavity of the prostate gland. They can form copies of themselves, and also generate different, more mature cell types — the hallmarks of a true stem cell. Critically, the team show that when a particular tumour suppressor gene is deleted in the cells, they give rise to prostate cancer in mice.

Stem cells have been suggested to underlie other forms of cancer, for example some leukaemias. The find suggests that these putative prostate stem cells can, under certain circumstances, cause prostate cancer.

DOI: 10.1038/nature08361