Thursday, 25 September 2008

Step towards safer stem cells

Researchers have turned adult cells into stem cells using a virus that doesn't fuse with the cell's genome, providing a potentially safer way to generate stem cells, Konrad Hochedlinger and colleagues reported in Science.

Scientists have made huge advances in stem cell biology of late, and can reprogramme adult human cells into induced so-called pluripotent stem (iPS) cells by overexpressing a set of proteins. Although these reprogrammed cells provide great promise for stem cell therapy — they can alleviate symptoms of Parkinson's and sickle cell anemia in mouse models, for example — there are still many barriers to their safe therapeutic use. For one thing, scientists have had to reprogramme target cells with a virus that fuses with the host genome, and this fusion process increases the risk of tumour development.

To address this considerable limitation, Hochedlinger and colleagues used adenoviruses, which don't fuse with the host genome, to reprogramme adult mouse cells. These so-called adeno-iPS cells are similar to conventional iPS cells — they can differentiate into various tissue, including lung, brain and heart — but do not increase the risk of tumour formation or fuse with the host's genome.

If these findings can be replicated in human cells, adeno-iPS cells may represent a source of safe stem cells, that can be tailored to individual patients' needs, with broad implications for stem-cell therapy.