The mechanism behind why people with Down syndrome are less likely to develop cancer has been unraveled by a new study.
The research team from Children's Hospital Boston has showed that since the patients have an extra copy of chromosome 21, it appears that people with Down syndrome may be getting an extra dose of one or more cancer-protective genes.
Lead researcher Dr Sandra Ryeom discovered that a single extra copy of Dscr1 is capable to suppress angiogenesis, the development of blood vessels essential for cancer's growth and tumour growth in mice.
The gene has also been found to inhibit angiogenesis in human cells.
The researchers showed that DSCR1 acts by suppressing signalling by the angiogenesis-promoting protein vascular endothelial growth factor (VEGF).
With an extra copy of Dscr1, the cells, which make up blood vessel walls showed a decreased growth response to VEGF in mouse model.
An extra copy of another chromosome 21 gene, Dyrk1A, also appeared to decrease cells' response to VEGF.
"I think there may be four or five genes on chromosome 21 that are necessary for angiogenesis suppression," Nature quoted Ryeom as saying.
"In huge databases of cancer patients with solid tumors, there are very few with Down syndrome. This suggests that protection from chromosome 21 genes is pretty complete," she added.