Research reported this week by three different groups shows that normal skin cells can be reprogrammed to an embryonic state in mice. The race is now on to apply the surprisingly straightforward procedure to human cells.
If researchers succeed, it will make it relatively easy to produce cells that seem indistinguishable from embryonic stem cells, and that are genetically matched to individual patients. There are limits to how useful and safe these would be for therapeutic use in the near term, but they should quickly prove a boon in the lab.
This may be the most exciting news of the decade. These stories have a way of deflating after the first soundbites, but this one seems more promising than most.
About that word pluripotent...
Last year, Yamanaka introduced a system that uses mouse fibroblasts, a common cell type that can easily be harvested from skin, instead of eggs. Four genes, which code for four specific proteins known as transcription factors, are transferred into the cells using retroviruses. The proteins trigger the expression of other genes that lead the cells to become pluripotent, meaning that they could potentially become any of the body's cells. Yamanaka calls them induced pluripotent stem cells (iPS cells). "It's easy. There's no trick, no magic," says Yamanaka.