Stem cell holy grail

Scientists have discovered how to turn adult human skin cells into stem cells and then into heart, brain and bone tissue, and they have done it without using human eggs or embryos.

Researchers at Kyoto University and the University of Wisconsin announced the advance today, and it has breathtaking implications for the future of medical research and the bioethics debate. Robert Lanza, chief scientific officer of Advanced Cell Technologies, called the discovery "the holy grail. It's like turning lead into gold."

Shinya Yamanaka of Kyoto University first tested the technique - called somatic cell dedifferentiation - when he turned mice skin cells into stem cells last year. The same technique works with human cells. Scientists insert four genes into the skin cells, turning the cells into blank slates that they can then transform into other cell types like heart, brain and bone. Dr. James Thomson said in every test, the reprogrammed cells behaved just like human embryonic stem cells.

The technique has its drawbacks. As with embryonic stem cells, there is a risk that the cells will become cancerous, but scientists are optimistic that they can overcome this. The technique also has some marked advantages: Using a flake of skin is cheaper than using a fertilized human egg, the new cells are tailor-made for the donor, and the technique is not hampered by ethical controversy like human cloning or embryonic stem cell research. Wesley J. Smith, senior fellow of bioethics at Discovery Institute, told WoW the breakthrough undercuts the drive towards human cloning because it "gives scientists everything they said they wanted, without the moral baggage."

The news comes days after Professor Ian Wilmut, scientific daddy to cloned sheep Dolly, turned his back on therapeutic human cloning and announced that he was pursuing research in the new technique, calling it not only more practical but also more socially acceptable.