The real scientists seem to be losing the argument. The National Institutes of Health canceled the first meeting of the committee set up to review applications seeking federal funds for human embryonic stem cell research. For some time, there have been ominous signs. Shortly after taking office, President George W. Bush asked Tommy Thompson, his Secretary of Health and Human Services, to review the legal basis for the NIH stem cell guidelines. (See "On the Brink") With this latest development, the future of stem cell research--and with it the prospect of finding treatments for hitherto intractable chronic disease and disability--is clearly at grave risk.
Embryonic stem cells have the potential to develop into all basic tissue types--but not into a human being. They could provide a virtually limitless source of tissue for transplantation. Adult stem cells are more problematic. While their destinies are not as limited as we had once believed, they tend to occur in low numbers and to be hard to access and isolate.
There have been promising advances in redirecting adult stem cells to become something Mother Nature never intended--blood into nerve, for example. Recently, scientists working with fat sucked out of patients during liposuction were able to isolate stem cells that, in a laboratory dish, gave rise to cells that make muscle, bone, and cartilage and also to cells that made more of themselves.1
However, some remarkable feats of adult stem cells seem more like party tricks than the predictable, controllable metamorphoses that would be required before actual human therapies could be undertaken. It would be very convenient if the spare tire around our waists could be sucked out and turned into replacement patches for failing hearts, but we are not there yet. Not even close.
The overwhelming consensus among real scientists about the state of real science is that no avenue of stem cell research can be safely ignored. We simply don't know what types of cells would work best for particular diseases. Those seeking to exploit exciting and potentially life-saving adult stem cell breakthroughs to advance their religious views and political goals are not just misusing science; they are perverting it.
And if all goes as the opponents hope--and federal funding for embryonic stem cell research is stopped in its tracks--science's most unlikely cheerleaders may well be responsible for ceding leadership of this major area of research to Great Britain. In January, after a surprisingly contentious debate lasting more than eight hours, the British House of Lords voted overwhelmingly to allow research on embryonic stem cells, this following an equally lopsided victory in the House of Commons one month before.
Differences Across the Atlantic
Under the new legislation, drafted as an amendment, embryo research related to cell and tissue therapies would also be allowed. This includes so-called therapeutic cloning or--as it has been termed by the policymakers keen to avoid any association with reproductive cloning--cell nuclear replacement. What they have made legal is something akin to a Woody Allen script run backward. In Allen's 1973 film Sleeper, attempts are made to clone Hitler from his preserved nose. Instead of cloning people from spare parts--or spare cells, as is the case with the animal and human reproductive cloning--British scientists hope to grow those parts by cloning people.
This procedure is the same as the one used to create Dolly the sheep.2 Up to a point. The nucleus from a human cell is inserted into an egg that had its own nucleus removed. An embryo is formed. But the embryo will not be implanted in a uterus. Instead, embryonic stem cells will be derived from its inner cell mass. Because cloning is done first, there will be no problem with immunological compatibility.
Because of pervasive disquiet about any form of cloning--and a very real threat that the amendment would be scuttled by a behind-the-scenes move to refer the entire question to a House of Lords Select Committee, thereby killing this research for at least two years--a compromise was cobbled together at the last minute: The legislation would be passed immediately and the Select Committee review would start later. The Select Committee was then formed, and it has recently held its first meeting.
As further reassurance for anxious peers, the health minister, Lord Hunt, promised that the government would introduce primary legislation to ban reproductive cloning, the legal status of which is somewhat ambiguous. It probably is technically legal, at least for the moment. To add to the legal murkiness, a court challenge to the new regulations was filed at the end of January, less than a week after the Lords' vote. The crux of the legal argument is that the Human Fertilisation and Embryology Act (including the amendment to it just passed) is not applicable at all to therapeutic cloning because the act defines the word embryo as the product of fertilization. Not somatic cell nuclear transfer.
Meanwhile, back on our side of the Atlantic, the proposal to use federal funds for embryonic stem cell research now under consideration is far more modest in scope than the British scheme. Two of the steps described above would be left out. There is no plan to use federal funds to support therapeutic cloning, and the embryo will not be created specifically for cell therapies.
Under the current NIH Guidelines, embryo stem cells can be derived from surplus embryos donated for research by the couple who created them. The derivation of the stem cells cannot be funded, only research using those cells. In vitro fertilization is a highly inefficient technology. More embryos must be created than are ever used, and tens of thousands of such embryos are in frozen limbo in this country. They will never be implanted in anyone's uterus; they will never become a baby.
In Britain, public policy on cloning and stem cells is linked. In the United States, discussion of these technologies is proceeding on two separate tracks. Legislation that would ban both reproductive and therapeutic cloning has been introduced in Congress, and President Bush has voiced support. His stand on federal funding for embryonic stem cell research is still not clear, although the signs are certainly not encouraging.
Of course, even without federal government involvement, embryonic stem cell research will go forward in the United States. But it won't be the full-scale effort that we all deserve--an effort that could exploit the vast intellectual potential of U.S. science. Federal funding is imperative because of the resources it would provide and the ethical and scientific oversight it would mandate.
No one is exempt from the scourge of the chronic diseases for which stem cell-derived therapies hold the promise of cure. Patients, future patients, and loved ones of patients--we all have a stake in the president's decision.
1. P.A. Zuk et al., "Multilineage cells from human adipose tissue: Implications for cell-based therapies," Tissue Engineering, 7:211-8, April 2001.
2. I. Wilmut et al., "Viable offspring derived from fetal and adult mammalian cells," Nature, 385:810-3, 1997.