Proc. Natl Acad. Sci. USA doi:10.1073/pnas.0900351106 (2009)

The blood-pressure drug losartan could fight some breast cancers, studies in mice suggest.

Arul Chinnaiyan of the University of Michigan in Ann Arbor and his colleagues analysed 3,200 experiments that characterized gene-expression patterns in breast cancer tumours. The search revealed that a gene called AGTR1 was expressed at higher than normal levels in 10–20% of the cancers.

Human mammary cells that express AGTR1 at abnormally high levels became more invasive when stimulated with angiotensin II, which activates the AGTR1 protein. Meanwhile, losartan, a treatment for high blood pressure that inhibits AGTR1, reduced this response. It also reduced tumour growth by 30% in mice implanted with AGTR1-overexpressing breast cancer cells.