Tumour incidence: When three is better than two

People with Down’s syndrome seem to be less susceptible to cancers - an observation that may at least partly derive from their having an extra copy of the chromosome responsible for the syndrome, chromosome 21. This idea to the test in mouse models of Down’s syndrome and finds that the animals are indeed less likely to develop colon cancer.

Roger Reeves and colleagues pinpoint a gene, known as Ets2, on chromosome 21 that seems to confer protection in these mice. The authors explain their finding as a ‘dosage’ effect: having three copies of chromosome 21 instead of the normal two means that more Ets2 protein is produced. This came as a surprise, because Ets2 is generally thought to encourage tumours to grow.

The discovery could be exploited in developing a drug to promote cancer resistance, suggest the authors.

CONTACT
Roger Reeves (The Johns Hopkins University, Baltimore, MD, USA)
Tel: +1 410 955 6621; E-mail: rreeves@jhmi.edu

David Threadgill (University of North Carolina, Chapel Hill, NC, USA) N&V Author
Tel: +1 919 843 6472; E-mail: dwt@med.unc.edu