Stem Cells, Redux

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Science  12 Mar 2004:
Vol. 303, Issue 5664, pp. 1581
DOI: 10.1126/science.303.5664.1581

On p. 1669 of this issue of Science appears the in-print version of a paper published online in Science Express on 12 February 2004. That report, “Evidence of a Pluripotent Human Embryonic Stem Cell Line Derived from a Cloned Blastocyst,” was a collaboration led by Woo Suk Hwang and a team of more than a dozen collaborators. The work was done at Seoul National University in South Korea. When the results were announced at a press briefing at the AAAS Annual Meeting in Seattle, well over a hundred reporters and over 20 television cameras were on hand, and the subsequent coverage in the media has been intense.

This is an opportune moment for review: The 3-week interval has provided a good gestation time for reactions. These reactions, some hasty and others thoughtful, form an interesting study of how new scientific findings may become incorporated into a policy framework that is developing under intense political pressure. To begin with the science itself, what the researchers did is to inject enucleated ova, derived from financially uncompensated women who volunteered, with somatic cell nuclei taken from the same donor. Blastocysts were produced by this procedure, and from one of them a stem cell line was produced and propagated through 70 divisions. The pluripotency of these cells was established in ways that left little doubt that they were true embryonic stem cells, although the investigators concede that their experiments have not quite eliminated the possibility of a parthenogenetic origin.


On the science front, praise has been forthcoming from most researchers who work with stem cells. The Massachusetts Institute of Technology's Rudolf Jaenisch called the work “elegant” but emphasized, as did others, that applications to transplantation medicine are still far away. Other intriguing possibilities await future research. For example, the investigators could not yet say whether success is affected if the somatic cell nucleus is taken from a person other than the egg donor. We also now know that oocytes can be produced from mouse stem cell lines. If that could be done with human stem cells, wouldn't it mitigate concerns about using women as “egg factories”?

The Korean experiment illustrates some important international differences with respect to the legal status of this kind of research. It could have been performed in Israel, Sweden, or the United Kingdom, but not in the United States using federal funds or in Germany. The future status of such research in the United States is clouded by statutory uncertainty. Bills passed or under consideration would not only prohibit reproductive cloning but would criminalize somatic cell nuclear transfer experiments of this kind. In the United States, some states outlaw reproductive cloning but allow therapeutic cloning; indeed, a proposed ballot initiative in California would raise $3 billion to support research that cannot now be done with federal funds. The potential benefits are significant: Stanford's Irving Weissman notes that a somatic cell nucleus carrying a genetic defect could be transferred into an ovum in order to create stem cell lines that could tell us much about the disease. The Korean technical achievement is good news in that respect; the bad news, Weissman points out, is that we can't use it here.

Plainly, these findings may affect the U.S. ethical debate. Leon Kass, the chairman of the President's Council of Bioethics, sees them as a downward step on a slippery moral slope: “tomorrow,” he predicts, “cloned blastocysts for baby-making.” After the recent purge of two pro-stem cell members, Kass has his commission under control. But science is, after all, an international activity. The Korean success reminds us that stem cell research, along with its therapeutic promise, is under way in countries with various cultural and religious traditions. Our domestic moral terrain is not readily exportable: U.S. politicians can't make the rules for everyone, and they don't have a special claim to the ethical high ground.

And of course, political decisions in the United States may carry real penalties for its own scientific enterprise. Harvard's Doug Melton, a leader in stem cell biology whose institution has just made a major commitment to it, says it this way: “Look, life is short. I don't want spend the rest of mine reading about exciting advances in my field that can only be achieved in another country.”

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