Stem cell discovery hailed as milestone
— -- Teams of scientists reported Tuesday that they've succeeded in reprogramming human skin cells so they behave like highly coveted embryonic stem cells. If the work overcomes hurdles, the breakthrough could benefit science without the controversy that has dogged stem cell research.
While these cells don't have every attribute of the infinitely reprogrammable stem cells from embryos, they also don't carry the moral quandary of those cells. Until now, such versatile stem cells could be obtained only by destroying an embryo, which has bogged down the research in a nasty scientific and political quagmire.
The work appeared online in two prestigious journals, Cell and Science. The Cell paper comes from a group led by Shinya Yamanaka of Kyoto University in Japan. The Science paper comes from a group led by Junying Yu and James Thomson at the University of Wisconsin-Madison. Five months ago, the Yamanaka group reported similar success with mouse cells, setting the stage for a worldwide effort to get the technique to work in human cells.
"It's a huge deal," said Rudolf Jaenisch, a scientist at the Whitehead Institute in Cambridge, Mass. "You have the proof of principle that you can do it."
Embryonic stem cells can become virtually any kind of cell in the body, offering the promise of replacement tissues to treat ailments such as diabetes and spinal cord injuries. But both groups of scientists say they don't yet know how close to true embryonic stem cells these new cell lines are.
One of the problems with the new technique is the use of retroviruses to get the skin cells to act like stem cells. Retroviruses can insert genetic material into the chromosome of cells but have been linked to cancer.
While the work represents a tremendous scientific milestone and "a new era for stem cells," it doesn't mean that the technique is ready for prime time, said Robert Lanza, chief science officer of Advanced Cell Technology, a company working to derive stem cells from cloned human embryos. "Bottom line: There are very serious hurdles left to overcome," he said. "It could still take years to get this to work in humans in a way that could be used clinically."
