The Stem of the Conflict

Arthur Caplan

Why has there been so much hype in the ongoing debate about public funding for stem cell research in the United States? The answer is simple and can be summarized in one word: abortion. Some forms of stem cell research involving the use of embryos require embryo destruction to extract a stem cell. Others, involving cloning, require transferring a full set of genes from an adult cell into an egg. Both procedures have received heavy criticism from those opposed to embryo destruction or embryo creation by a technique other than sex. While there is a good deal of focus on the problems generated by the power of money in generating bias in science and medicine, the battle over stem cell research makes very clear that religious views can also be a huge source of distortion and bias.

Critics, usually motivated by religious beliefs about the moral status of human embryos and fearful that manipulating or destroying embryos might weaken opposition to the destruction of fetuses, have made embryonic stem cell research their stalking horse in the abortion wars. One of their most irresponsible strategies for convincing public officials (and by extension, all Americans) to ban or at least withhold funding for such research was to argue that work with embryonic stem cells was not needed because anything that could be done with embryonic stem cells for therapeutic purposes could also be done using adult stem cells. Another even more reprehensible stratagem was to argue that modified adult stem cells—so-called IPSCs (induced pluripotent stem cells)—could absolutely do the job expected of embryonic stem cells. The case for the adequacy of adult stem cells never made any sense except as willful ignorance fueled by religious dogma. The case for IPSCs as the alternative answer to using embryos has now, predictably, been debunked, showing that wishes built on religious desires are not a substitute for rigorous science.

As I have tried to point out for more than a decade in commenting on the embryonic stem cell controversy, when people primarily steeped in religious dogma about embryos argue that science shows one type of research that does not involve embryo destruction to be just as good as another, watch out! Arguing from a committed religious point of view about which line of stem cell research is the most promising is akin to asking biblical fundamentalists whether they think random genetic mutations, geographic isolation, environmental selection, or divine purpose has played the greatest role in driving evolution.

The claim that adult stem cells could be a valid alternative to embryonic stem cell research never made a lick of scientific sense. But that never stopped anti-embryonic stem cell critics from repeating this bit of scientific treacle. Those who winced at the use of human embryos contended that since the body has many naturally occurring cells that can repair damaged human cells—known as adult stem cells—and since these have been used to cure many people while embryonic stem cells have not, then there is no need to pursue embryonic stem cell research. Father Thad Pacholczyk, leading Roman Catholic religious authority on the matter of the science of stem cell research, noted that “dozens of diseases are currently treatable using these [adult] stem cells, including sickle-cell anemia, leukemia, spinal cord injury, and heart disease.” Embryonic stem cells, however, he went on, have not cured anyone of anything. Ergo, who needs to bother with embryonic stem cell research funding?

I am not sure what Father Thad was talking about regarding treating spinal cord injuries, which as far as I know remain completely incurable. But it is true that bone marrow transplants have been used as part of curing various blood disorders in a lot of children and adults. And indeed, bone marrow is one type of adult stem cell. That is where the truth of this argument ends and unbounded hype, driven by moral opposition to embryonic stem cell research, begins.

The research behind bone marrow transplantation began in the 1950s. It received generous government grant support for the next fifty years. It is still awash in government grants. Embryonic stem cells were first discovered in 1998. Research involving those cells has received only minimal funding from any source since then. Nearly every scientist who works in the stem cell area, even those who work only with adult stem cells, will tell you that success in that area says nothing about the scientific case for funding and doing embryonic stem cell research.

If science does not support the adequacy of adult stem cells, then what about IPSCs? Is fooling adult cells into acting like embryos the magical solution to the embryonic stem cell quandary? It is if you let your values about the inviolate nature of embryos override your science.

Conservative columnist Charles Krauthammer led the hype machine on this subject. Back in 2007, an announcement was made that researchers in Japan had discovered how to reprogram adult skin cells to resemble embryonic stem cells. Krauthammer immediately declared that George Bush had been right to ban public funds for embryonic stem cell research (hey, I thought President Bush claimed—and still claims in his recent book—that this was a “compromise”) since there was now a way to create “a magical stem cell that can become bone or brain or heart or liver” without using human embryos.*

“Magical”—really? Could there be any claim more fraught with bias than declaring that any biomedical discovery is ready to go right from the lab to your doctor’s office?

Making adult cells into embryo-like cells remains the current darling of critics of research involving embryos. But the technique is barely understood. Its safety has long been a source of huge concern to those working in the area.

A new study published earlier this year confirmed those fears. Writing in the journal Nature, a team led by Yang Xu, professor of molecular biology at the University of California, San Diego, showed that IPSCs triggered immune reactions when implanted into mice. In some cases, the cells were completely destroyed by the animals’ immune systems.

Although the studies were done in rodents, the findings raise doubts over the future use of IPSCs in humans. Xu told the media that “the assumption that cells derived from IPSCs are totally immune-tolerant has to be reevaluated before considering human trials.” In English, he is saying that somehow in the course of turning adult stem cells into embryonic-like cells, the immune system sees them as foreign tissue and kills them. This is not a good thing if you are using these modified cells to try to cure diseases.

So what is the take-home message from all of this? In the early days of research in a new area, no one can say with any certainty what will work or even that anything will work. Research is difficult and often fails. When it works, it takes what can seem like forever to figure out why, how, and for whom it works.

Relying on pronouncements about what is the best direction for scientific research by those with huge ethical stakes in the game—in this case, those opposed to the destruction or manipulation of embryos, no matter what their source or fate—makes for very poor science policy. If your child suffers from diabetes, if you are a veteran with a severed spinal cord or a grandparent beset with Parkinsonism or a failing heart, then you deserve honest, unconflicted, unbiased information about what is the best strategy to follow to find treatments and cures. Due to the noise generated by the ongoing war over abortion, accurate information has been very difficult to hear.


* 222986/celling-vindication/charles-krauthammer.

Arthur Caplan

Arthur Caplan is director of the University of Pennsylvania’s Center for Bioethics and a nationally prominent voice in the debates over cloning and other bioethical concerns.

Why has there been so much hype in the ongoing debate about public funding for stem cell research in the United States? The answer is simple and can be summarized in one word: abortion. Some forms of stem cell research involving the use of embryos require embryo destruction to extract a stem cell. Others, involving …

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