The stem cell spin
Posted: Monday, November 06, 2006 11:31 AM by Alan Boyle
Iraq will be the No. 1 topic for Election Day, but in key states, stem cells are also a big factor - and the outcome has the potential to change the course of embryonic stem cell research.
Missouri's Amendment 2 looms largest on the stem cell front: To its supporters, the measure would assure Missourians that they'll have access to the cures that embryonic stem cell research might bring, while criminalizing any attempt to create living, breathing human clones. In contrast, opponents say the measure would actually create "a constitutional right to clone."
Who's right? That all depends on what your definition of the word "clone" is.
Advanced Cell Technology / AP |
A single cell is extracted from an
embryo to create stem cells.
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Amendment 2's wording represents one of the most detailed legislative attempts yet to navigate the ethical mine field around reproductive vs. therapeutic cloning. Under the measure's definitions, the "cloning" concept would not apply to experiments that insert a person's genetic material into an egg cell, then push that cell to start dividing and produce stem cells.
That procedure has been called therapeutic cloning, but nowadays researchers tend to avoid the c-word and refer to it instead as somatic-cell nuclear transfer, SCNT.
Whether you call it therapeutic cloning or nuclear transfer, the process is aimed at producing embryonic stem cells - cells that are capable of transforming themselves into virtually any tissue in the body. Despite a
scandal-plagued false start in South Korea, researchers still hope the technique could someday lead to regenerative therapies that can cure maladies ranging from diabetes and spinal-cord injury to heart disease to Parkinson's disease.
That's why actor Michael J. Fox, a Parkinson's patient, has been talking up Amendment 2 as well as candidates who favor such research.
But the amendment is facing a conservative counteroffensive: Those who oppose embryonic stem cell research say the measure is nothing more than a "fake cloning ban."
Under Amendment 2, human cloning would refer only to efforts "to implant in a uterus anything other than the product of fertilization of an egg of a human female by a sperm of a human male for the purpose of initiating a pregnancy that could result in the creation of a human fetus, or the birth of a human being."
That's what's known as reproductive cloning - a procedure that virtually no one except for cult leaders and those on the scientific fringe would want to allow.
As stem cell pioneer James Thomson told me last year, the immediate result of both procedures would be an embryo - and it'd be well nigh impossible to tell the difference between one class and the other.
"If you create an embryo by nuclear transfer, and you give it to somebody who didn’t know where it came from, there would be no test you could do on that embryo to say where it came from. It is what it is," he said.
The distinction relates to the purpose for which the embryo is created. And that's what intrigues R. Alta Charo, a professor of law and bioethics at the University of Wisconsin at Madison (which is also where Thomson is based).
Charo told me that the Missouri measure would essentially give nuclear-transfer embryos a "different moral status" from that given to embryos implanted inside a woman's body. In Charo's view, that's not a bad thing.
"Our conventional way of describing the debate has not been nuanced enough," she said.
The "nuclear transfer vs. cloned baby" distinction isn't a new concept: In fact, it's reflected in the federal stem cell legislation that was drawn up by Sen. Orrin Hatch, R-Utah, but became stalled in the Senate. Amendment 2 has likewise attracted its share of support from pro-life Republicans - including Missourian John Danforth, who is a former U.S. senator as well as an Episcopal priest.
If the measure passes, it will likely add traction to this unconventional spin on the stem cell debate. But as of today, that's a big "if." The Missouri measure figures prominently in that state's senatorial contest between Republican incumbent Jim Talent (who's against it) and Democratic challenger Claire McCaskill (who's for it). Recent polls have shown Amendment 2 passing, but the Senate race is neck-and-neck, and the red-state turnout could have a big impact on the stem cell measure's fate.
Missouri isn't the only place where the stem cell debate is having an impact. It's also an issue in the Iowa and Michigan gubernatorial elections. And in Wisconsin - a hotbed for stem cell research, thanks in no small part to James Thomson's work - the stem cell question figures in a key race between Gov. Jim Doyle and his Republican challenger, Mark Green.
Doyle has been a strong supporter of embryonic stem cell research, and his veto was the only thing standing in the way of a ban on therapeutic as well as reproductive cloning last year. Green is opposed to using embryonic stem cells. However, in his campaign appearances, he trumpets his support for stem cell research, as it applies to adult stem cells.
Adult stem cells, which are extracted from humans without destroying any embryos, are far less controversial - but they're also far less versatile than embryonic stem cells. Bone marrow transplants serve as a big example of adult stem cells at work.
The confusion over issues such as adult vs. embryonic stem cells, or therapeutic vs. reproductive cloning, adds to the fog surrounding the stem cell debate. Another obfuscating factor has to do with just how close scientists might be to stem cell cures: Most experts say it will be years if not decades before we reach the goal of transplanting custom-made cells to cure what ails us.
In the nearer term, human embryonic stem cells are more likely to provide tissues in a Petri dish, suitable for drug testing or even for the development of new therapies - but not for direct transplantation.
"Nationally, the press, the public, the scientific community and the investment community have all gotten in the habit of overselling each new study," Charo said.
And why is that? "It's because it got so politicized," she said.
So here we are, at another politicized turning point on a par with President Bush's veto of stem cell legislation. Keep watching our political coverage for updates from Missouri, Wisconsin and elsewhere, and tune in our special section on stem cell research for the scientific side of the debate.
