Research has confirmed, the long suspected theory, arisen from the low prevalence of cancer in Down syndrome patients, that the genes on chromosome 21 could be beneficial in treating cancer. Cancer research Sandra Ryeom and her collegues have shown that an extra copy of the Dscr1 gene, located on the 21st chromosome and therefore affected by trisomy, is significant enough to suppress tumour growth in mice, and angiogenesis (blood vessel formation) in humans.
Ryeome found that the protein expressed by this gene, DSCR1, elevated in the tissues of Down syndrome patients due to the extra gene, suppresses signals from the vascular endothelial growth factor (VAGF) which promotes angiogenesis. VAGF is a protein, secreted by cancerous cells, which attaches to specific receptors on nearby blood vessels, encouraging new blood vessels to form. Studies conducted on mice showed that endothelial cells showed a decreased growth response to VEGF when they had an extra copy of Dscr1. It was also found that DSCR1 suppresses VEGF signalling via the calcineurin pathway, a specific signalling pathway contained within the cells which make blood vessel walls.
By working with induced pluriptent stem cells (iPS cells), which are known to induce tumours when inserted into mice, Ryeome validated that the tumours with reduced number of blood vessels found in mice with an extra chromosome 21 is viable to work in humans. But it is highly likely that more than one gene located on chromosome 21 is responsible for angiogenesis, so more study needs to be done.
Original article : Why Do People with Down Syndrome have less Cancer ? Research in Mice and Human Stem Cells suggests New therapeutic targets.
http://www.sciencedaily.com/releases/2009/05/090520140359.htm
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