Experts: Stem-cell breakthrough may not end short-term debate

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http://www.abpnews.com/2892.article

By Robert Marus
Published November 27, 2007


WASHINGTON (ABP) -- Although religious conservatives have cheered the Nov. 20 announcement of a breakthrough in stem-cell research, the moral controversy over the practice may not end any time soon.

The announcement -- made by independent teams of scientists working in Japan and Wisconsin -- holds the promise of cures for a host of debilitating and terminal diseases. Scientists have studied embryonic stem cells for more than a decade because of their potential to become any one of more than 200 types of tissues in the human body.

However, such stem-cell research has proven highly controversial because human embryos are destroyed in the process. In addition, some scientists have proposed cloning human embryos from patients with certain diseases. Such cloning would prevent rejection of any new tissues or organs grown from the stem cells and used for those patients.

Religious conservatives -- and many non-religious bioethicists -- find both prospects ethically troubling.

But the new research has the potential to render both moral quandaries moot because, for the first time, it reprograms adult cells to act in ways that are apparently identical to embryonic stem cells. The research was conducted by Shinya Yamanaka of Kyoto University and a team led by James Thomson at the University of Wisconsin. Yamanaka’s research was published online in the journal Cell, and Thomson’s was published in Science.

Both teams used four genes to “reprogram” human skin cells, which essentially reverted to the stem-cell format of their ancestors.

Religious conservatives who consider embryonic stem-cell research tantamount to abortion and who oppose cloning were ecstatic at the announcement.

Dubious “experiments involving embryo cloning and embryo destruction are being rendered obsolete. Scientists can now work with ‘embryonic-like’ stem cells without ethical concerns,” wrote Tony Perkins, president of the Family Research Council, in his Nov. 20 e-mail newsletter to supporters of the activist group.

The National Catholic Bioethics Center was more reserved in its praise for the study’s potential.

“Such strategies should continue to be pursued and strongly promoted, as they should help to steer the entire field of stem-cell research in a more explicitly ethical direction by circumventing the moral quagmire associated with destroying human embryos,” read a Nov. 20 statement from the Philadelphia-based group. “These strategies also circumvent a second series of moral objections by providing a method for obtaining patient-matched stem cells without cloning human embryos or using women's eggs.”

But scientists -- and some politicians -- have said the announcement doesn’t mean embryonic stem-cell research should cease immediately.

“Even though these announcements are momentous, until a reprogrammed panacea cell is used to make stem cells that actually function properly to repair a damaged nerve, spinal cord or heart, all avenues of research must be funded and pursued,” wrote Arthur Caplan, head of the Center for Bioethics at the University of Pennsylvania, in a column for MSNBC.com.

Caplan noted that the way the researchers reprogrammed the cells could make creating new tissues or injecting them into patients problematic. Yamanaka and Thomson’s gene-therapy technique, he wrote, “uses viruses to get the reprogramming done. Those who have worked with gene therapy know that retroviruses do not always put genetic material where it is supposed to go.”

Such misplaced genetic material can lead to unintended consequences. For instance, one study on mice with spinal-cord injuries noted that stem-cell therapy caused increased mobility but also significantly increased pain due to renewed and significant nerve growth.

Other such genetic misplacement can cause tumors to grow.

“This does not obviate the need for human embryonic stem-cell research,\" Story Landis, the head of the National Institutes of Health’s stem-cell task force, told the Los Angeles Times.

The researchers noted that they have yet to confirm whether the cells they created really are identical to embryonic stem cells. And Thomson cautioned that embryonic stem-cell research should continue.

Several members of Congress -- Republicans and Democrats alike -- who have supported federal funding for embryonic stem-cell research have announced that they would continue to push for such research. A bill to lift President Bush’s ban on embryonic research funding has passed Congress twice but failed to muster the necessary support to override Bush’s vetoes.

That’s the way it should stay, the Family Research Council’s Perkins said.

“Rather than accept the fact that these new reprogramming studies show tremendous promise for basic stem-cell research, politicians plan to push their embryo-killing legislation, even though they know they don't have the votes to override the president's veto,” he wrote in a Nov. 26 newsletter. “It would be a shame if ideology trumped the latest science.”