Published November 20, 2007
The news embargo now seems to have been broken on what is likely to rank as the most important development in stem cell science since the first derivation of human embryonic stem cells in 1998.
Two prominent scientific journals–Science and Cell–are each today publishing papers that demonstrate extraordinary success with a technique called “somatic cell reprogramming.” Working separately, and using slightly different methods, these two teams (one of which is led by James Thomson of the University of Wisconsin, the original innovator of human embryonic stem cells) have each successfully taken a regular human skin cell and transformed it into what appears to be the equivalent of an embryonic stem cell–all without the need for embryos, or eggs, or any other ethically controversial methods. The resulting cells (which they call induced pluripotent stem (iPS) cells) have passed all the tests for “pluripotency” and seem to function just like embryonic stem cells. Again, they’ve done this in humans, not just in animals. Thomson’s team puts the matter plainly in the usual scientific deadpan: “The human iPS cells described here meet the defining criteria we originally proposed for human ES [embryonic stem] cells, with the significant exception that the iPS cells are not derived from embryos.” In other words: embryonic stem cells not from embryos. A “significant exception” indeed.
This is first of all an extraordinary scientific discovery–quite apart from its connection with stem cell research. It suggests a previously unimagined level of plasticity at the cellular level in human beings that will have huge implications for medical research and future therapies, and not necessarily stem cell therapies. The ability to take one cell type, insert a few genetic factors, and end up with a completely different but functional cell type will revolutionize cell biology, and get a lot of PhD level textbooks thrown in the garbage today.
And for the stem cell debate, this really could mean the end, and the best possible end: a scientific way around the ethical problem, just as responsible people on both sides of the debate have long hoped might be possible. At first some folks in Washington and elsewhere will certainly be inclined to deny it or insist human cloning or embryo-destructive research remain essential, but as these findings sink in, that view is likely to sink too. It offers a path to a win-win conclusion to what seemed like an intractable argument–you get the cells scientists have said are so valuable, and you avoid the violation of human equality and dignity that so troubles some of us. It’s not only ethically preferable, it also seems to be scientifically superior in some ways, because it’s so much easier and more direct (as British scientist Ian Wilmut noted late last week (almost breaking the story), it offers genetically matched embryonic-like stem cells, as you’d get from human cloning, but without the need for cloning or embryos; all you need is a tiny bit of skin)
This kind of outcome has been the hope behind President Bush’s stem cell policy. In fact, the President spoke about this very same technique–reprogramming skin cells–in a speech back in July of 2006, and earlier this year signed an executive order to encourage this kind of work (Thomson’s team, in fact, was supported by the NIH). He should get credit for sticking to a crucial moral principle against immense and often quite irresponsible political pressure. But it has also been the hope of a great many stem cell scientists and advocates of research who did not share the President’s view of the ethical issues, but sought this for their own good reasons. It’s the scientists’ extraordinary work–and not the politicians–that really made this possible. This is not a win for one side or the other.
In the long run, if this turns out to be as big as it seems, the embryonic stem cell episode itself may turn out to have offered the country a model of how to govern ourselves responsibly in the age of biotechnology.