Important differences between sources of embryonic stem cells

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Stem-cell research, including the use of human embryonic stem cells, has important implications for medical practice in the future, and the relief of suffering in many serious and intractable diseases. The European Commission's European Group on Ethics in Science and New Technologies (EGE) has recently issued an opinion on the ethical aspects of human stem-cell research. As one of the two rapporteurs of this opinion, I was disappointed by your report “European panel rejects creation of human embryos for research” (Nature 408, 277; 2000)

Human embryonic stem cells, which can give rise to many different cell types and tissues, are derived from early embryos in vitro. Your report makes little attempt to distinguish between (1) embryos donated for research by patients under-going in vitro fertilization (IVF) treatment ('spare embryos'); (2) embryos made for research by fertilizing donated oocytes in vitro ('research embryos') and (3) embryos made for research by transfer of somatic nuclei to donated oocytes ('nuclear-transfer embryos').

The first category, spare embryos, covers all the human embryonic stem-cell lines at present being studied in the United States and Australia. The EGE concludes that in those countries (including the United Kingdom) where human embryo research is allowed, it is hard to see any specific argument that would prohibit extending the scope of such research in order to develop new treatments to cure severe diseases. Further, the group sees no argument for excluding funding of such research from the European Union's Framework programme. Thus it takes the view that, in Europe, the derivation of stem cells from IVF embryos should be not only publicly controlled but also publicly funded — unlike the situation in the United States, where state funding is not permitted to be used for this research.

The second category, research embryos, is deemed ethically unacceptable when spare embryos, including tens of thousands of frozen embryos in Europe which may become available for donation, represent a ready alternative source. The headline on your report is misleading, since the present EGE opinion deals only with stem-cell research, and does not consider the possible use of research embryos for projects that cannot by their nature be carried out on spare embryos.

For the third category, nuclear-transfer embryos, the group concludes that making such embryos would be premature at present, in view of the extensive research still to be done on embryonic stem cells derived from spare human embryos, as well as on fetal and adult stem cells. It is this third conclusion that apparently has led you to refer to a “dramatic twist” to the debate.

Nature has an excellent reputation for clarity of presentation of scientific and social issues. It is unfortunate that in this instance, when Parliament is about to give its considered opinion on whether to extend the purposes of human embryo research in the United Kingdom in order to develop new treatments for severe diseases, an article has appeared that engenders confusion rather than clarity.

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