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The Politics of Stem Cells
Legislative uncertainties hinder research in the U.S.
  
By Bruce Agnew


Featured Article.

Some of the most exciting biomedical research of the 21st century isn't getting done. Research on stem cells from human embryos has become so entangled in politics and public misunderstanding that researchers are worried about serious delays in understanding life-threatening diseases.



Particularly in the United States, research involving human embryonic stem cells has slowed because of philosophical qualms, political opposition and confusion about the science. What's more, the field now seems treacherous for scientists, largely due to legislative uncertainties and restrictions on research from the White House.

"There are a lot of experiments that are obvious and would be extremely valuable for scientists to do," says Keith Yamamoto, vice dean for research at the University of California, San Francisco School of Medicine. "But it's too much work to put together a research proposal only to find out it's going to be made illegal—or that there will be a four-year moratorium proposed."

President Bush declared in 2001 that scientists who receive federal research funds—by far the majority—could work only with a handful of stem cell lines (those that were in existence before August 9, 2001). The White House said that more than 60 usable embryonic stem cell lines were available. But in reality the number is closer to nine.

To compound the problem, Congress has threatened to make it illegal to use cloning to create new stem cell lines for biomedical research. The possibility that Congress will outlaw the use of cloning technology to derive new cell lines is scaring researchers away, according to Yamamoto and other scientists.

Prospects seem dim that the controversies—and the uncertainties—will be resolved anytime soon. However, one "research friendly" bill has been introduced in the Senate and has attracted support from an odd but important coalition of influential people. One of them is Nancy Reagan, whose husband, the former President, is in a late stage of Alzheimer's disease.


Nancy Reagan

"I am determined to do what I can to save other families from this pain," she said in a letter, arguing in favor of stem-cell research with appropriate safeguards.

The opening days of the new Congress saw a virtual rerun of last year's fights. Over just the past few weeks:

-President Bush in his State of the Union address urged Congress to prohibit "all" human cloning "because no human life should be started or ended as the object of an experiment."

-Legislation was introduced in both House and Senate to ban the use of "somatic cell nuclear transfer"—the cloning technique by which Dolly the sheep was produced—to create a living human organism "at any stage of development." Within a few days of its introduction, the House bill had attracted more than 100 co-sponsors.

-A competing bill that would prohibit human reproductive cloning but would permit nuclear transfer to create embryonic stem cell lines for research was introduced in the Senate.

This latter, pro-research measure is cosponsored by an ideologically broad coalition, ranging from Diane Feinstein (D-CA) and Ted Kennedy (D-MA) to Zell Miller (D-GA) and Orrin Hatch (R-UT), whose right-to-life credentials are unassailable.

Essentially the same alignment of forces in the previous Congress produced a stalemate. The House passed a broad anti-cloning bill by a 265-162 vote in July 2001, but neither the broad prohibition nor a pro-research version came to a vote in the Senate because neither side could muster the 60 votes needed to shut down a Senate filibuster.

The most likely outcome now seems to be a continuing standoff unless members of Congress can learn the difference between using stem cells for research and using them for human reproduction.

Even if the Senate passed a pro-research bill, the House would be unlikely to agree. And even if such a bill made it through Congress, President Bush would likely veto it. The question of using somatic cell nuclear transfer to derive human embryonic stem cells involves an uncomfortable mix of science (including cell cloning), ethics and theology. It has not yet resulted in any useful compromise.


Dolly

One of the stumbling blocks is a broad, deep lack of understanding of what the word "cloning" means. The word is widely used in our society and has been given a number of meanings, most of them wrong.

To scientists, cloning means making a copy of something—anything, a stretch of DNA, a virus, a cell. To most laypeople, including many members of Congress, cloning means creating a carbon-copy organism, like Dolly the sheep or the army of clones in a recent "Star Wars" movie. It means making an exact copy of a living adult and the imagination often focuses on evil ones at that.

"We have to do a better job of educating the public that the word 'clone' is not synonymous with movies such as 'The Boys from Brazil' or 'The March of the Clones' or whatever else Hollywood has manufactured," says Nobel Laureate Paul Berg of Stanford University in California.

Opponents, such as President Bush and Leon Kass, chairman of the President's Council on Bioethics, believe that any use of somatic cell transfer could result in a human embryo, and thus a human life. "We find it disquieting, even somewhat ignoble, to treat what are in fact the seeds of the next generation as mere raw material for satisfying the needs of our own," a majority of Kass's council reported last July.

But proponents of this somatic cell technology deny that the technique produces the seeds of any generation. "I'm in favor of cloning nuclei in the form of stem cells," says Berg. "The product of that is not a human being." Some scientists and ethicists go so far as to argue that it is actually unethical not to do research that shows unusual promise for treating or preventing devastating disease.

Senator Hatch, whose influence as a conservative leader makes him an important player in the debate, argues that human life begins in the womb, not in a petri dish.

"Even those who believe that life begins at conception, even if the unison of sperm and egg takes place in the lab, need to consider carefully whether the joinder of an enucleated egg with a somatic cell nucleus, accompanied by chemical or electrical stimulation, should fairly be thought of as the same process as conception," Hatch told a Senate hearing in January.

Last July, Kass's bioethics council recommended a four-year moratorium on all research with somatic cell transfer if the intent is to produce human embryonic stem cells. Seven of the scientists on the Kass council voted against a moratorium; all of the ethicists voted in favor, as did one physician-scientist. Meanwhile, two separate committees of the National Academy of Sciences endorsed the research on grounds of its value to medicine.

Several states with ambitions to attract the biotechnology industry, including California and New Jersey, have tried to pass legislation of their own that would prohibit the use of cloning to make babies but would allow somatic cell nuclear transfer for scientific research.

In addition, some major research institutions, including Stanford and UCSF, have established satellite research centers that receive no federal funds to pursue such research. An outright federal prohibition would override these efforts.

A federal prohibition of all research to use this technology to create human embryonic stem cells also could erode one of the major potential benefits of stem cell science: the growth of replacement tissue such as cardiac muscle to repair heart damage, insulin-producing beta cells to cure type 1 diabetes, or dopamine-producing neurons to treat Parkinson's disease.


Microscopic view of a colony of undifferentiated human embryonic stem cells.

Theoretically, if a patient is his or her own donor of the somatic cell from which the embryonic stem cells would be grown, implanting the replacement tissue would raise no immunologic problems. This, clearly, has nothing to do with human reproduction.

The congressional standoff leaves would-be stem cell researchers with limited options. They can try to develop procedures with private industry or state funding—although that may eventually be prohibited. Or they can work with human embryonic stem cell lines derived from embryos originally created for in vitro fertilization (IVF) procedures.

This is where the president's moratorium of 2001 becomes an issue. A repertoire of nine cell lines with which to work is far different than 60 available cell lines. And because data suggest that none of those lines may be the best for use in medical experimentation, the need to develop new lines is imperative.

This amounts to a double whammy against stem cell research.

"At the present time, I don't think we have enough documented, usable cell lines to entice people into this field," says Berg.

James Battey, director of the National Institute on Deafness and Other Communication Disorders, who heads the National Institutes of Health's Stem Cell Task Force, contends that the restraints leave plenty of room for researchers.

"There's an enormous amount of basic research that can be done and needs to be done before anybody anticipates any clinical trials," Battey says.

Among the basic-research questions: How do you drive human embryonic stem cells to differentiate in a particular way—to be heart muscle or to produce dopamine in the brain, for instance? How do you then generate a pure population of the desired target cells? How do you assure that the cells will be long-lived? How do you prove, in animal models of disease, that they are effective therapies?

"All of these studies can be done right now, with human embryonic stem cell lines that you can order today on the NIH registry," Battey says.

Battey also challenges the contention that researchers are being scared away. At a meeting in London in January, however, he and research-funding officials from seven other nations agreed that a shortage of scientists trained to work with stem cells is a major problem. "That is probably the rate-limiting factor right now in moving the research agenda forwards," Battey says.

And political uncertainty is one of the reasons for the shortage. "These are careers," says Kevin Wilson, director of public policy for the American Society for Cell Biology, and vice president for legislative affairs of the Coalition for the Advancement of Medical Research. "Is a scientist going to get involved in a career field that could become against the law?"

As Wilson notes: "It's not a warm and fuzzy environment."

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