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Analysis: Stem cells without the embryo

By STEVE MITCHELL, UPI Senior Medical Correspondent

WASHINGTON, June 6 (UPI) -- Scientists say they have developed a method in mice for creating the equivalent of embryonic stem cells without using eggs or destroying an embryo, a finding that could help circumvent the controversy surrounding the promising research.

The finding, which was published online by Nature, comes as the U.S. House of Representatives is set to vote on a bill relaxing restrictions on federal funding of embryonic stem cell research and a separate bill that would authorize cloning for therapeutic purposes.

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Sean Tipton, president of the Coalition for the Advancement of Medical Research, an organization that supports embryonic stem cell research, said the new research, while important, probably won't have a significant impact on the current political debate.

"It will change the talking points a little, but I don't think it's going to change any votes," Tipton told United Press International.

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He predicted Congress would pass the stem cell bill, setting up a repeat of last year's situation in which President Bush used his first veto to reject the legislation.

Bush opposes the research because it requires destroying an embryo, but the consensus of biomedical researchers is that it has the potential to lead to disease treatments, and at least two companies -- Advanced Cell Technology and Geron -- have said they plan to file investigational new drug applications this year to take their stem cell-based therapies into the clinic.

Whether Bush will once again block efforts to relax limits on federal funding he put in place in 2001 remains uncertain because the new legislation contains provisions the president said he would require in order to endorse it.

"He has changed his mind a little bit on at least one scientific issue," Tipton said, referring to Bush's recent switch on dealing with global warming. "Maybe there's somebody giving some science advice over at 1600 Pennsylvania Avenue."

As it is, Tipton said, Bush's current policy may be inhibiting research, such as the current study, that would enable scientists to develop ways of obtaining human embryonic stem cells without embryos.

"If people really want to allow the research to develop, we need to lift the restrictions on embryonic stem cells," he said.

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In the new research, two teams of scientists -- one led by the Whitehead Institute for Biomedical Research and the other by Japan's Kyoto University -- used viruses and genetic engineering to reprogram mice skin cells to an earlier stage where they appeared to have the capability of giving rise to all the different cell types of the body.

Genetic tests showed the cells to be indistinguishable from embryonic stem cells, and further research showed they could give rise to a live mouse when injected into an embryo and implanted into a uterus.

"The work shows that you can take any specialized cell and turn it back into a cell that can generate all the different cell types," Alex Meissner, a scientist involved in the research at the Whitehead Institute, told UPI.

The technique still has to be modified to work in human cells, and there are several challenges to doing that, such as the fact that the viruses used to reprogram the mice cells cause cancer, but researchers agree the technique holds promise for treating human illness.

George Daley, a stem cell researcher at Children's Hospital Boston, said the work is "incredibly exciting" and scientists may be close to finding a way to make it work with human cells because his lab and other groups have previously been looking at that aspect.

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"There are many labs worldwide attempting this strategy in human cells," Daley said. "I would be surprised if this doesn't lead fairly rapidly to a similar breakthrough in human cells."

Still, Daley said the new technique does not negate the need to pursue other embryonic stem cell research.

"I think it's going to be seized upon by opponents of embryonic stem cell research to say we don't need to go forward with work already under way," he said. "That would be a real mistake."

For one reason, it could take some time to figure out how to apply this technique to human cells and get it to the current state of embryonic stem cell research.

Noting that there are more than 200 embryonic stem cell lines, Daley said, "It would take a number of years before the equivalent number of lines is ever developed from this alternative procedure, so I wouldn't put the other research on hold."

Another reason for continuing embryonic stem cell research is there are lots of phenomena that can be studied with embryonic stem cells, such as understanding development, birth defects or chromosomal abnormalities, that can't be done with cells generated by the new technique, he said.

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