Scientists Use Skin To Create Stem Cells
Thursday, June 7, 2007
Three teams of scientists said yesterday they had coaxed ordinary mouse skin cells to become what are effectively embryonic stem cells without creating or destroying embryos in the process -- an advance that, if it works with human cells, could revolutionize stem cell research and quench one of the hottest bioethical controversies of the decade.
In work being published today, the scientists describe a method for turning back the biological clocks of skin cells growing in laboratory dishes. Thus rejuvenated, the cells give rise to daughter cells that are able to become all the parts needed to make a new mouse.
If the process also works with human cells, as scientists suspect it will with some modifications, it would mean that a person's own skin cells could be converted directly into stem cells without having to collect healthy human eggs or destroy human embryos -- steps that until now have been required to obtain embryonic stem cells.
Those stem cells could then be used to make a wide variety of personalized replacement tissues.
The findings have generated tumult on Capitol Hill, where the House is set to vote today on a bill that would loosen President Bush's 2001 restrictions on the use of human embryos in stem cell research.
Acutely aware that their new work could undermine that key political goal, the scientists cautioned that their success with mouse cells does not guarantee quick success with human cells. They called for Congress to pass the bill, which would give federally funded researchers access to embryos slated for destruction at fertility clinics.
"A human is not a mouse, so a lot more work has to be done," said Marius Wernig, who led one team with Rudolf Jaenisch of the Whitehead Institute for Biomedical Research in Cambridge, Mass.
But opponents of human embryo research said the findings bolster their argument that stem cell science can progress apace without harming human embryos.
"Morally and practically, this new approach appears to be far superior," said Richard Doerflinger of the U.S. Conference of Catholic Bishops.
The new experiments reveal the remarkable degree of control that scientists have recently gained over the highly complex inner workings of living cells, and they generated intense excitement in the scientific community earlier this week as word leaked out.
"Clearly the work offers hope that similar methods can be applied [to develop] cell-based therapies," Robin Lovell-Badge, chief of developmental genetics at Britain's National Institute for Medical Research, said in a statement.
In nature, human embryonic stem cells are found nestled inside five-day-old embryos, which are about the size of the period at the end of this sentence. Since the cells can make every kind of human tissue, scientists want to use them to study development and to grow replacement parts for ailing patients.