Nov. 20 (Bloomberg) -- Ordinary skin cells from the face of a 36-year-old woman and the foreskin of a newborn were turned into stem cells and may have the power to become any cell in the body, according to reports in the journals Science and Cell.

The technique by U.S. and Japanese researchers may shift the ethics debate by ending use of embryos and leapfrog studies by hundreds of companies, including Geron Corp. and Advanced Cell Technology Inc. It may allow human tissue to be more easily created and help drugmakers test how compounds interact with diseased cells, said Ian Wilmut, who cloned Dolly the sheep.

The scientific teams each inserted four genes into the skin cells, switching on a process that converted them into a form equivalent to embryonic stem cells. The cells were then changed into heart, brain, muscle, fat and cartilage cells by one team using proven methods for growing tissue from embryonic cells.

``It will revolutionize the way in which we study and treat human disease,'' Wilmut, who was not involved in the research, said in a telephone interview from his home in Edinburgh, Scotland. The biologist, who ushered in a new era of exploration and ethical conflict with Dolly a decade ago, said he's shifting his research to work on reprogramming stem cells.

Scientists have grown embryonic stem cell colonies, called lines, from human embryos discarded by fertility clinics. The cells have the ability to grow almost limitlessly, and with chemical and genetic stimulation, can become virtually any cell in the body. Because embryos are killed to extract the cells, their use has been controversial and limited.

Lack of Donors

Scientific efforts to create embryonic stem cells by combining the genes of patients with egg cells donated by women have been slowed by the lack of donors.

The new method was first perfected in mice last year by Shinya Yamanaka of Kyoto University. He began years ago testing combinations of genes that are unusually active in embryonic stem cells. After mixing and matching, he found a combination of four genes that could bestow embryonic characteristics on stem cells.

Now that the technique has been established in human cells, it may eliminate the push for so-called therapeutic cloning of human embryos as a way to create stem cells that genetically match a person, said Wilmut, who predicted Yamanaka's work would earn him a Nobel Prize.

``We decided some weeks ago that we were not going to pursue'' human cloning, Wilmut said. ``It seems more likely that you'd get an effective or reliable source of stem cells from the Yamanaka procedure.''

Yamanaka, Thompson

The research teams were led by Yamanaka and James Thomson, the University of Wisconsin biologist credited as the first to isolate stem cells from human embryos and keep them alive.

Last week, an announcement by Oregon researchers that they had cloned a monkey embryo and extracted stem cells from it had drawn fresh excitement within the scientific community. Now that accomplishment has been overtaken, scientists said.

The transformed skin cells, or ``induced pluripotent cells,'' as Yamanaka calls them, showed they could turn into cardiac, brain, muscle, fat and cartilage cells, among other cell types, Yamanaka said. To get them to morph into cardiac cells, Yamanaka's team followed a paper recently published in the journal Nature Biotechnology that described how to make them from embryonic stem cells.

`It Works'

``We just applied the same protocol to human pluripotent cells and it works,'' Yamanaka said. ``It's amazing. Those cells were skin cells only two to three weeks ago and now they are beating cardiac cells in a dish.'' One of the properties of cardiac cells is that they rhythmically, and visibly, contract.

Because his procedure is relatively simple to perform --far easier than cloning -- it can be followed and replicated in thousands of labs around the world, Yamanaka said in a Nov. 16 telephone interview. That should dramatically speed the pace of research, he said.

``You don't need any special equipment and we don't need any special techniques,'' Yamanaka said. ``All we need is equipment for cell culture and for gene transfer. There may be many labs in the world that could make'' these cells.

President George W. Bush, who twice vetoed legislation that would have cleared the way for greater federal funding of human embryonic research, was ``very pleased'' by the announcement, a statement from White House press secretary Dana Perino said.

``The president believes medical problems can be solved without compromising either the high aims of science or the sanctity of human life,'' the statement said, noting that one of the studies was partially funded by the National Institutes of Health.

Federal Support

The lack of adequate federal support for embryonic stem cell research has left the field ``about four years behind where it should be,'' Thomson said. ``That's not a vindication, that will kill people.''

Both teams used viruses to shuttle the genes into the skin cells, and both lead scientists conceded that may create problems because the viruses could also carry diseases or other contaminating particles. While that wouldn't matter if the cell lines are used to test drugs, it may bar them from being given as therapy to a patient.

While Thomson and Yamanaka each used four genes to reprogram the cells, only two were the same. One of the genes used uniquely by Yamanaka's team, called c-Myc, is known to trigger cancer. Thomson said he doesn't think the choice of genes makes that much of a difference yet.

``I think we're probably in more or less the same place,'' he said in a telephone interview yesterday.

Jeanne Loring, director of the Center for Regenerative Medicine at the Scripps Institute in La Jolla, California, said scientists are seeking to trigger reprogramming without genes that may turn on a cancer process or other undesired event.

'Holy Grail'

``The new holy grail is to identify a way in which you could induce the same change in the cells without any permanent genetic change,'' she said in a telephone interview yesterday. ``The ideal is to just pulse a signal and then fade away.''

Yamanaka said he's concerned it may only be a matter of time until scientists figure out the right recipe for making egg cells and sperm cells from stem cells generated by his process.

That raises the prospect that a man's skin cells, for example, could be made into both egg and sperm and mate in a dish, Yamanaka said. The resulting embryo would not be an exact genetic clone of the man because when egg and sperm cells join, only half of the chromosomes in each find their way into the newly created embryo. Still, Yamanaka fears people may try this method and it could create defective embryos.

Clone Concerns

``I don't want someone trying to make human clones through our methods,'' he said. ``It would be very difficult to create completely normal sperm or eggs and we may end up having embryos with some kinds of defects. It's terrible. I'm very worried about that.''

He said he is already talking to Japanese government officials about this and believes there needs to be global ban on the use of such a process to create human births.

At the same time, company and academic scientists said work on stem cells taken from human embryos remains vital to advancing the field.

``These are early-stage studies,'' said Robert Lanza, chief scientific officer of Advanced Cell, in a telephone interview today. ``It is by no means certain that these cells can do all the same tricks as normal embryonic stem cells.''

Advanced Cell, based in Alameda, California, rose 1 cent to 25 cents in over-the-counter trading at 3:58 p.m. New York time. Geron, of Menlo Park, California, fell 41 cents, or 6.1 percent, to $6.34 in Nasdaq Stock Market composite trading.

Baltimore-based Osiris Therapeutics Inc., which is in the final stages of testing a product made from adult stem cells taken from tissues in mature humans, fell 79 cents, or 7 percent, to $10.56 in Nasdaq Stock Market trading.

``Cell reprogramming may take years to develop,'' said Randal Mills, Osiris's chief executive officer. ``It will be a long time before there's potential impact,'' he said.

To contact the reporter on this story: Rob Waters in San Francisco at rwaters5@bloomberg.net.

Last Updated: November 20, 2007 16:16 EST