[Stitcher]

Concerns of Dashed Hopes From Promised Miracles

New York Times
January 12, 2007
News Analysis
By NICHOLAS WADE
http://www.nytimes.com/2007/01/12/wa...=1&oref=slogin

It was a day of promised miracles in the House of Representatives. Almost every other lawmaker who spoke during the debate on the stem cell bill told of a close relative with a deadly affliction whose cure depended on generating new human embryonic stem cell lines.

But the bill that was passed, on a 253-to-174 vote, had a more modest goal than the oratory implied. It would merely allow scientists supported by the federal government to derive new cultures of stem cells from the early embryos discarded by clinics using in-vitro fertilization.

That would overturn President Bush’s decision of Aug. 9, 2001, which restricted the scientists’ research to the cell lines already derived by that date. But even with the faster pace of research and discovery that new cell lines might allow, many scientists believe it will be years before any cures for disease could be developed.

The striking hopes that stem cell advocates have raised in order to overturn Mr. Bush’s decision may generate public disenchantment with such research if its promise is not quickly fulfilled.

“In those places like California where the public has been sold the Golden Gate Bridge for stem cell research and it doesn’t pay off, there might be some difficulty,” said Dr. Leon Kass, former chairman of the President’s Council on Bioethics.

Even scientists who believe that the restrictions on embryonic stem cell research have been harmful are concerned about the overstatements.

“We don’t know yet how valuable this technology is going to be,” said Thomas Cech, president of the Howard Hughes Medical Institute. “All of a sudden, the content increases in value just because you can’t have it,” Dr. Cech said.

Wild overpromise was not confined to supporters of the House bill, which was identical to one passed by the House and Senate last year and then vetoed by President Bush.

Opponents of the measure, and a White House report issued on Wednesday, made much of the idea that alternatives to embryonic stem cells were close at hand. Several House members on Thursday cited a report published last week by Anthony Atala of the Wake Forest University School of Medicine that said embryoniclike stem cells could be obtained from amniotic fluid.

But scientific literature is several stages removed from accepted truth. It is more like an arena in which most novel claims are shot down by fellow scientists, making it rash to bet on the longevity of any new claim.

Dr. Atala reported that amniotic stem cells could generate six kinds of mature cells, implying they were versatile enough to substitute for embryonic stem cells. But leading scientists were skeptical.

“The evidence that they can make neurons is extremely poor,” said Dr. Arnold Kriegstein of the University of California, San Francisco, an expert on neural stem cells.

John Gearhart, an embryonic stem cell specialist at Johns Hopkins University, said that the amniotic cells were “certainly not in the category of embryonic stem cells.”

Many biologists believe that the most promising immediate use of embryonic stem cells is in the study of disease-specific cells, an idea long advocated by Dr. Irving Weissman of Stanford University. If scientists could generate embryonic cells from patients’ adult cells, they could study Parkinson’s or diabetes, for example, from its earliest moments, laying the groundwork for rebuilding a patient’s diseased tissues.

But this approach requires generating stem cell lines to order, from adult cells, and the House bill does not address this issue. It only permits the creation of more lines from surplus fertility clinic embryos, similar to those already available.

For that reason Dr. Kass, who opposes the generation of new embryonic stem cell lines, sees the House bill as lacking in substance.

“From the point of view of science, I don’t see the current legislation as being terribly important,” he said. “I see it as being symbolically important to the scientists who wish to say, ‘Get your moral views off our backs.’ ”

The president’s August 2001 decision can be seen as an artful compromise. It appeased opponents of research, but removed the roadblocks that existed in the Clinton administration, and at least allowed scientists to get started. Had they produced dramatic results in the last five years, they would have provided the president political ground to shift his position. But research, as is often the case, has been slow, and dramatic therapies with embryonic stem cells have not yet emerged.

But Dr. Kass believes Mr. Bush’s decision was made more on moral than political grounds.

“He’s not going to change his mind,” Dr. Kass said. “This was fundamentally decided as a matter of complicated moral principle: not to incentivize or reward any future destruction of nascent human life. And if you understood that, you wouldn’t expect anything different from him.”

Thus Congress’s expected passage of the bill, and Mr. Bush’s probable veto, will not address the looming issue of whether to permit generations of disease-specific lines.

As before, it is legal for privately financed researchers to do so. But if the vast body of federally financed researchers is sidelined, the pace of advance will be much slower.