What will the US Senate actually do about therapeutic cloning--the procedure of using nuclear transfer to derive embryonic stem cells? The saga continues with the sudden plot changes, reversals of fortune, mischievous machinations, and the cliff-hanger ending worthy of a mystery thriller. The latest twist has not occurred in the Senate itself but in the laboratory. The journal Nature published two reports on stem cells in rodent models that are no less than thrilling to those of us who hope for--and wait for--cures. Ron McKay and his team at the National Institutes of Health have shown that stem-cell therapy actually works.1 In a rat model, mouse embryonic stem cells differentiated into neurons, secreting dopamine, and actually reversed the symptoms of Parkinson disease.
Research by Catherine Verfaillie and her team at the University of Minnesota demonstrates that a certain type of adult bone marrow cell, called MAPC, can differentiate into a wide range of cell types.2 Until now, it was believed that only embryonic stem cells had such an open biological future. MAPCs are remarkably malleable; they are also far less morally contentious.
Before this research became known, US Sen. Sam Brownback's (R-Kan.) bill to criminalize therapeutic cloning seemed virtually dead. His fallback position is said to be a moratorium rather than an outright ban. Indeed, in a 10-7 split vote, President George W. Bush's bioethics advisory council has just recommended a four-year moratorium on all forms of cloning. A competing bill--cosponsored by Sens. Dianne Feinstein (D-Calif.), Orrin Hatch (R-Utah), Arlen Specter (R-Pa.), and Ted Kennedy (D-Mass.)--that would allow and regulate therapeutic cloning was given an excellent chance of reaching the magic number of 60 votes. How should the Senate view the two Nature papers in the context of the emerging consensus for the Feinstein bill? Is it still important to leave this avenue open to scientists? Yes, more than ever.
Opponents of therapeutic cloning and stem cell research say that what is at stake is the very idea of what it means to be human. I would put it rather differently. At stake, right here, right now, is the sense that Americans have that we are masters of our fate. That we can face the future with confidence. That we can grow and change and thrive in a new world lying just beyond the horizon.
This was the belief that drew millions of immigrants to our shores to embrace lives they did not yet know. This same belief gave courage to those who headed west in covered wagons. And it is the core belief that has made Americans the people we are--the optimists and doers of the world, the people for whom the frontier is a challenge, not a barrier.
The 21st century will be the century of biology. With information from the human genome sequence and with stem cell technology, medicine will move from treatments that are often clumsy, toxic, and just not very effective to disease prevention, and to self-repair. Devastating illnesses that have blighted our lives could, one day, be stopped in their tracks. Such a paradigm shift is possible only if we face the future with confidence and humility. And with a commitment to plumb the depths of this new knowledge to extract the good and avoid the bad.
No society venerates the law as much as ours. How strange then that so many see the law as powerless in the face of biotechnology. How strange and how wrong. Powerful technologies need to be guided--to be reined in. We can do that. Therapeutic cloning unites two scientific discoveries that closed out the old millennium and promise to transform the new one. The cloning of Dolly the sheep3 was breathtaking biology. Scientists had taken a cell that only knew how to do and be one thing and tricked it into providing the instructions to reconstruct a new organism. Then, in 1998, John Gearhart at Johns Hopkins and Jamie Thomson at the University of Wisconsin published papers showing that they had derived human pluripotent stem cells4,5--cells that divided indefinitely in culture and had the potential to produce all the cell and tissue types in the human body.
Therapeutic cloning to derive embryonic stem cells--because it could circumvent the immune rejection elicited by therapies derived from generic stem cells--might give us our own body repair kit. And, even if it does not make it into the clinic as a practical and cost-effective tool, basic therapeutic-cloning research could elucidate the still mysterious biological mechanisms that turned one body cell into a sheep. We could then avoid the morally contentious embryo stage altogether and, say, transform a skin cell directly into a neural cell to cure our own Parkinson disease. The McKay research shows us that neurons derived from embryonic stem cells can alleviate Parkinson disease--perhaps permanently. An estimated 500,000 Americans have this terrible disease, and another 50,000 cases are diagnosed yearly. Is it really right to turn our backs on them? The moral case made by opponents of this research is based on the absolute sanctity of the very early embryo--a five-day-old ball of cells no larger than a grain of sand. But what of the moral case to be made for the sick and the dying?
Americans have always stepped lightly from the past. It has not shackled us. It has not prevented us from dreaming big dreams. For 18 months, I have been an expatriate in Britain. Especially now, in the year of Queen Elizabeth's Golden Jubilee, the irony of our disparate responses to therapeutic cloning has been striking. So much of Britain--its culture, its governmental institutions, its gentle way of life--is anchored in the past. Yet, Tony Blair recently gave a speech championing science as an engine for human progress. The United Kingdom will forge ahead in all three areas--adult and embryonic stem cells and therapeutic cloning--and is poised to lead the world.
The British have been pondering the moral and policy issues surrounding embryo research for almost 20 years. When Dolly came along, when human embryonic stem cells were derived in culture, when therapeutic cloning became a real possibility, they had a legal framework within which to situate it all.
We, alas, do not. And we have suddenly realized that we have been flying by the seats of our legal pants in areas that the British have tightly regulated for a dozen years. It is far easier to venture into morally complex territory--which therapeutic cloning certainly is--when there are clear rules, norms, and procedures. It is not only easier, it is smarter and safer. The best way forward is not criminalization of science out of fear. Nor is it a continuation of the unregulated status quo. The Feinstein bill would allow cloning for therapies (not reproduction), subject to strict scientific and ethical regulation. This is the environment of British science. Americans and American science deserve no less.
Scientists do not want to be our collective conscience; nor should they be. It is up to us as a society to decide on permissible uses of technology. Evidence of potential and of efficacy is coming thick and fast, but we are still a long way from knowing which kinds of therapies--those derived from embryonic or adult stem cells--will work for particular diseases. The widest range of options must be kept open. Cutting science off at the knees--throwing away the benefits because we have inchoate, science fiction-generated fears about sinister applications at the bottom of slippery slopes--is what is criminal, what should be criminal. Not therapeutic cloning. It should be allowed and regulated now.
Arlene Judith Klotzko, a lawyer and bioethicist, is writer in residence at the Science Museum, London, and adviser on science and society, Medical Research Council Clinical Sciences Centre. She is editor of The Cloning Sourcebook and author of the forthcoming A Clone of Your Own?, both published by Oxford University Press.
1. J.-H. Kim et al., "Dopamine neurons derived from embryonic stem cells function in an animal model of Parkinson's disease," Nature, 418:50-6, July 4, 2002.
2. Y. Jiang et al., "Pluripotency of mesenchymal stem cells derived from adult marrow," Nature, 418:41-9, July 4, 2002.
3. I. Wilmut et al., "Viable offspring derived from fetal and adult mammalian cells," Nature, 386:810-3, 1997.
4. J. Thomson et al., "Embryonic stem cell lines derived from human blastocysts," Science, 282:1145-7, 1998.
5. M.J. Shamblott et al., "Derivation of pluripotent stem cells from cultured human primordial germ cells," Proceedings of the National Academy of Sciences, 95:13726-31, 1998.