Eight Questions About the Stem Cell Debate
by Todd Aglialoro - June 3, 2009
Reprinted with permission.
Embryonic stem-cell research (ESCR) has taken a place next to abortion and same-sex marriage as a preeminent polarizing moral issue. Celebrities marshaled by the late Christopher Reeve agitated in favor of federal funding for and unfettered access to embryonic stem cells, which apparently hold the key to curing ailments great and small.
Former Democratic presidential candidate and vice-presidential nominee John Edwards went so far as to promise shortly before the 2004 election that if he and John Kerry were voted into office, "people like Christopher Reeve are going to walk, get up out of that wheelchair and walk again."
That election is long past, but the ethics debate continues. The Church throughout the country and the world has proved as vocal and unified in opposition to ESCR as it has for any other politically tinged issue today. The United States Council of Catholic Bishops (USCCB) ran a full-page ad in national newspapers condemning ESCR as an assault on human life, asserting that "science does not have to kill in order to cure." A prominent Vatican ambassador warned that ESCR "raises ethical issues of the highest order" by making "one human life nothing more than the instrument of another." For the last several years, parish pro-life groups have begun to extend to ESCR the same level of concern with which they'd been treating abortion and euthanasia. Many of the Church's most prominent moral theologians and bioethicists have applied themselves meticulously to the issue, dissecting its moral and medical nuances in papers, conferences, and think-tank reports.
As a pro-life Catholic observer of (but not player in) such efforts, I'd given my assent to the Church's position and come to understand in a very limited way the principles behind it, without trying too hard to become better informed. It was easy going, naturally supporting the consensus pro-life position and reflexively opposing the sinister plans of liberal Hollywood, social-engineering politicians, and corrupted modern medicine. For a while that seemed good enough.
I also perceived, in a lazy, intuitive way, that ESCR was an iconic battleground in the culture wars, combining elements of abortion, cloning, in vitro fertilization (IVF), and eugenics. Riding on the issue's resolution was more than just the development of this or that cure or therapy, it seemed to me, but a major shift in our nation's – and the Western world's – fundamental cultural attitude toward human life: whether we are to be its master or its steward and servant.
But I lacked fluency in the terms of the debate. While I could agree with the Church's position, I couldn't adequately represent it. I knew there was a lacuna in my understanding; it was only the size of a few cells, but it gaped.
So I set out to fill that hole, and in what follows I'd like to share with you the result of that effort.
Be advised first that I am no scientist. (I passed high school chemistry – just – by amusing the teacher with made-up names for the elements I couldn't memorize.) Mine was a decidedly lay approach, and I've tried to make my findings accessible to a lay audience.
I'll say this at the outset: What I discovered about ESCR proved to be more complex (and fascinating) than I'd ever imagined, and the stakes for its potential outcome more crucial – and potentially more terrifying – than I had ever feared.
What are stem cells, anyway, and why are scientists so enthusiastic about them?
Cells are the building blocks of the body, the simplest and most basic units of life – God's organic Lego pieces. As each Lego piece has its own shape and use, each cell has a character and function proper to it. But stem cells are distinguished from the body's other cells by their native potential to develop into and give rise to many different kinds of cells. Most of the body's cells are specialized: a hair cell is a hair cell, a brain cell a brain cell, and so on. But stem cells have in them the power to become and to produce any of these and more.
Stem cells are present in the very first days after a new human life is conceived. They replicate themselves in every specialized direction, spawning development of human organs and tissue in a microcosmic explosion of vigorously reproducing cells. Adult humans also have a supply of stem cells to produce specialized cells that will replace ones lost to time, illness, and attrition.
This ability to become any number of different kinds of cells (known by degrees as multipotency or pluripotency) through a process called differentiation isn't the only trick stem cells possess.
They also have a unique and prodigious capacity for self-renewal, or proliferation. In an adult human body, stem cells tend to proliferate into the types of cells in which they reside – providing more building blocks for blood, muscle, and the like. However, properly cultivated by scientists in a lab setting, a group of "parent stem cells" can yield millions of undifferentiated stem cells, each possessing in turn this marvelous will to replicate itself many times. These theoretically stable groups of self-replicating, unspecialized stem cells, or "lines," can then be manipulated by scientists into becoming various types of specialized cells – with an eye toward therapeutic application. Much of current stem-cell research focuses on figuring out why stem cells have this dual capacity for self-replication and remaining unspecialized, as well as on determining the precise combinations of environmental signals that make stem cells give rise to desired specialized cells.
What are some of these "therapeutic applications"?
Short answer: You name it. In theory, any health condition caused by damaged, malfunctioning, failing, or missing cells, tissues, or even entire organs might be ameliorated by the introduction of new cells and tissue grown from unspecialized stem cells. Cells ravaged by cancer could be replaced. Stem cells injected into the brain could help stroke victims recover some of their mental functions by physically filling in the gaps caused by the stroke with new specialized neurons. Autoimmune diseases like multiple sclerosis, Lou Gehrig's disease, and diabetes – in which the body's immune cells attack healthy cellular proteins – could be cured by removing faulty white blood cells and replacing them with newly cultivated ones. Experts liken stem cells to an all-purpose repair squad, traveling through the body and adapting themselves to fix damage as circumstances demand. Stem-cell researchers are trying, above all, to find a way to put that repair squad to work on demand.
The limits of stem-cell therapy potential stretch nearly as far as the imagination, which is one big reason why the ethics debate has become so heated. Earnest proponents of unfettered stem-cell research, with visions of easing the suffering of millions, cannot understand why any moral or political limits should be placed on their efforts.
Realistically, how close are we to seeing these kinds of things happening?
It's a good question. Dr. Gilbert Meilaender, a professor of Christian ethics at Valparaiso University and former member of President Bush's Council on Bioethics, thinks we shouldn't hold our breath. "We're still quite far from realizing any of this promise in human beings – at least from embryonic stem cells," he says. (There has been some limited success in therapies involving adult stem cells – more on that later.) "It might be that in a couple decades from now, someone might get up out of his wheelchair and walk," he says, but "there's something cruel about the kinds of hype that public discourse encourages. It's cruel to promise people suffering serious degenerative diseases that if we just push ahead maybe in three years from now all will be well." He hastens to add that there's nothing wrong with dreaming big, "painting pictures of the marvels that might be possible some day," but dreaming researchers "must keep in sight fundamental honesty."
Some scientists have in fact sheepishly admitted that the research community has been painting a slightly too-rosy picture. "To start with, people need a fairy tale," remarked Ronald D. G. McKay of the National Institute of Neurological Disorders and Stroke to the Washington Post in early 2004 – in a left-handed defense of such tactics.
Apart from fostering (or at least failing to counter) overly optimistic predictions in the media and the general public's understanding, the scientific community has seen its own arguments and assumptions shift with each new development. For example, new insights into Alzheimer's, once thought to be a prime candidate for embryonic stem-cell therapy, now suggest that stem cells will be of little or no use in combating the disease. Despite advocates' use of the passing of former president Ronald Reagan to rally support for Alzheimer-directed ESCR, experts in the disease are skeptical. According to the Columbia University Medical Center's Michael Shelanski, "I think the chance of doing repairs to Alzheimer's brains by putting in stem cells is small."
Serious questions also abound in other areas where embryonic stem-cell therapy was thought to have strong potential. For one, the body tends to reject foreign tissue. Potential recipients of embryonic stem cells would not be related to the embryo from which the cells or differentiated tissues were cultivated, so those cells and tissues are likely to be regarded as alien by the body and attacked by the immune system. (As we'll see below, however, some observers believe that scientists already envision a practical – though somewhat sinister – solution to this problem.)
Embryonic stem-cell therapies also run the risk of "tracking in" – like mud into a living room – undifferentiated embryonic stem cells with the cultivated, differentiated tissues. These simply don't belong in an adult body, and the body reacts to them badly. This has been the case even with those potential embryonic stem-cell therapies generally considered more promising, such as for Parkinson's disease. While some trials with mice have produced growth of the particular brain cells that Parkinson's victims lose, common side effects such as the development of deadly tumors mean that a similar treatment for humans is at best still a long way off.
At this point, despite the promise and the promises, there has yet to be a single case of successful therapeutic use of embryonic stem cells in humans.
What about adult stem cells? Are we having any success with those?
Yes; and a resounding yes when compared with the meager results of ESCR. "All the therapies that can be done today can only be done with adult stem cells," says neuroscientist Rev. Tad Pacholczyk, priest of the Diocese of Falls River, Massachusetts, and director of education for the National Catholic Bioethics Center. There's no question in his mind which source for stem cells holds the greater medical promise: Every documented instance of effective therapeutic stem-cell use has involved adult stem cells. This is why, he notes, virtually every dollar from venture capitalists in this area has gone to adult stem-cell researchers.
Adult stem cells avoid the two major roadblocks that embryonic stem cells face. Since they originate with the patient, there's no problem of genetic incompatibility leading to immune rejection; the body recognizes its own. And if undifferentiated stem cells are tracked in along with differentiated tissue, the body takes that in stride too. Unlike embryonic stem cells, adult stem cells – the "repair crew" – belong in the adult body. Adult stem cells are virtually "rejection-proof," says Father Pacholczyk, and they don't have embryonic stem cells' propensity for causing tumors.
Examples of successful adult stem-cell therapy abound – if you look for them. (One consistent gripe of nearly every adult stem-cell proponent I spoke to is what they consider the mainstream media's reluctance to give such therapies the coverage they deserve, preferring instead to play up simplistic ESCR storylines of science versus religion, progress versus fear, etc.) In one well-known example, a few years ago a middle-aged man suffering from Parkinson's disease had stem cells removed from his brain in a relatively simple procedure. The cells proliferated in the laboratory, and some of them were made to become specialized neural cells. These cells were injected into the brain hemisphere that controlled the side of his body with the more severe symptoms, and soon thereafter he experienced significant, lasting improvement. In another case, a paralyzed woman regained partial movement through a therapy that used stem cells painlessly extracted from inside the bridge of her nose – a site rich with stem cells designed for growing new nerves that allow us to retain our sense of smell as we age.
The Web site for the American Coalition for Research Ethics lists 56 separate diseases, from the common to the unpronounceable, for which there have already been at least modestly successful adult stem-cell treatments in humans. One of the latest examples, and perhaps the most dramatic, came in December 2004 when Korean scientists helped a woman paralyzed for 20 years to walk again, using stem cells derived from umbilical-cord blood. Might John Edwards' prediction come to pass after all, though not in the way he intended?
But embryonic stem cells must have some natural advantages. Isn't that why researchers, politicians, and the media have focused on them?
The one noteworthy – and so far wholly theoretical – advantage of embryonic stem cells seems to be their potentially greater plasticity. In theory they can be made to become any one of the 220 cells in the human body, unlike the somewhat less flexible adult stem cells. Although the exact degree of plasticity of adult stem cells is a matter of shifting opinion, and may turn out to be much higher than once thought, in the minds of many researchers the theoretical outer limits of embryonic stem cells' potential are greater. Father Pacholczyk cautions that this is also their greatest drawback: "Embryonic stem cells are so energetic in making any of the cell types of the body, that they are very difficult to control." Embryonic stem cells are the terrible two-year-olds of the microbiological world, bursting with energy and mischief. Their divine programming is to spin off and become every cell in the body – not to be harnessed and quieted and forced to eat their vegetables.
If adult stem cells are providing better results, and if embryonic stem cells are so difficult to work with – and apparently raise serious ethical questions – why are scientists spending so much time and effort on ESCR?
Another past member of President Bush's Council on Bioethics, Princeton jurisprudence professor Robert P. George, says it starts with the scientific mind, to which pluripotent embryonic stem cells, with their high degree of plasticity, are "intrinsically fascinating." So compelling is the potential of these cells that some scientists guard them jealously, worried that "outsiders are trying to impose religious principles on science" – principles that would curb funding and set back understanding.
Meilaender also believes that the "scientific impulse" is to pursue every avenue, especially when motivated by the "language of compassion" that promises to alleviate the suffering of so many. This makes sense, if everything else were equal. Who wants to tell a cancer or Parkinson's patient that there's no cure for him because one possible path to it was deemed too difficult and abandoned?
But there's likely more to it than purely scientific intentions. Father Pacholczyk offers what he thinks are at least four possible additional motives behind the rush to ESCR.
First, not surprisingly, you have to follow the money. Researchers who prepare embryonic stem-cell lines can obtain licenses to those cells and in theory reap great profits down the road if and when therapeutic applications are perfected.
Second – and one reason why there's so much money to be made here – the media and public have "bought into the fairy tale," Father Pacholczyk says, echoing McKay's words. "We've made an act of faith in embryonic stem cells as a panacea for all future health problems." This gives rise to self-perpetuating myths about the potential benefits of ESCR that help drive public and political support for it.
Next, there seems to be a connection between ESCR advocacy and pro-abortion ideology. Were we to pass a law protecting human embryos from research, Father Pacholczyk believes, "there would be immediate ramifications for the entire pro-choice world," and the abortion industry "would feel that threat." With abortion a sacred cow in elite culture and politics, giving legal rights to embryos would make for an uncomfortable dissonance with pro-abortion premises. (Recall abortion groups' knee-jerk opposition to the Unborn Victims of Violence Act for a parallel example.) Even pausing to give moral consideration to embryo rights, simply to permit the question of whether embryonic life ought not to be unreservedly at our disposal, would be an unacceptable deviation from pro-choice orthodoxy.
Lastly, and most compellingly, Father Pacholczyk (himself a scientist of no small qualifications) believes that ESCR presents researchers with a "primordial temptation, like splitting the atom." A researcher, brought face to face with the wonder and power of stem cells, knows he's "coming close to the Tree of Life itself. His desire to master that power can get the better of him, leading him to overstep basic moral boundaries." He draws a comparison to the unscrupulous research by Nazi physicians during World War II, the inhumane experiments on human subjects that were later enumerated in the Nuremberg Trials: Both have used immoral, depersonalizing means to pursue scientific ends.
Where do scientists get these stem cells?
Stem cells have been harvested for research from embryos only days and weeks old; from fetuses; from placentas and umbilical cord blood; and from adult human fat, bone marrow, brain tissue, and elsewhere. The embryonic stem cells, in a process perfected in 1998, are extracted from – and thereby kill – embryos conceived through IVF, but not implanted, and later donated to science. Researchers then cultivate them into colonies or "lines" of millions of stem cells.
And it's because the extraction of these cells kills human embryos that the Church condemns ESCR as immoral?
In the first place, yes. These embryos, despite being designated as unwanted spare parts by their parents, are innocent human persons with an inviolate right to life. No end, however noble or compassionate, justifies killing them intentionally. Traditional medical ethics, of course, has long hedged against such behavior by following the simple rule, "First, do no harm." The Church also rejects consequentialist or proportionalist moral theories that would permit scientists to do evil that good may come of it, or even to do a small evil that great good may come of it.
Meilaender points out, too, that we're not talking about an insignificant evil here, although he suspects ignorance of this fact helps buoy popular support for ESCR. "We have to understand what it means to say that this research involves the destruction of embryos," he says. "Some people wonder why we would stand in the way of this research just to keep a couple of unwanted embryos alive."
Even if it were just a matter of killing a handful of embryos, he's quick to point out, that would be wrong in and of itself. But what we're really talking about is "a whole industry of embryo research. Nobody who's paid attention really believes that this is more than a starting point." As research continues, scientists will have to make use of thousands upon thousands of embryos. And not just to harvest their stem cells.
"To really make progress, researchers will want to produce embryos, clone embryos with particular diseases," says Meilaender. Rather than digging into the available pool potluck style, in hope of finding embryos that can be used as "disease models," when the time comes they'll simply make their own custom-cloned, diseased embryonic humans to experiment with. And this is no hysterical slippery-slope prediction, he insists: "This is what the researchers themselves will tell you, in an honest moment."
George agrees. "Scientists are not really interested in IVF spares," he says. "They're just a sideshow."
The specter of human cloning rises again in future theoretical scenarios where ESCR will have in fact yielded practical therapeutic applications. Only a tiny fraction of the some 400,000 frozen embryos cached around the country are earmarked for research; most are being preserved for future implantation. Proven therapies could conceivably create an enormous demand for embryonic stem cells – a demand that normal inventories wouldn't be able to meet. What would fill the gap? An embryo market, perhaps, in which gametes are bought and sold and huge quantities of embryos are brewed up in vitro and stamped, "Laboratory Use Only"? Or better still: therapeutic cloning, by which a patient can get himself a perfect embryonic twin complete with genetically identical, rejection-proof stem cells and tissues.
I finished my layman's investigation into ESCR shaken by the wider-ranging possibilities of this technology. The vocabulary of Catholic moral theology doesn't contain words adequate for what the embryonic stem cell industry may become. Clearly, it's intrinsically immoral to kill embryonic persons directly and intentionally. That is the root of the Church's opposition to ESCR. It's doubly heinous, and more instinctively offensive, to do so for utilitarian purposes – however ostensibly "compassionate" in motive. But what to make of a world in which science has not only scaled the Tree of Life but chopped it down and begun trading its fruit as a commodity?
When did we start down this path? Father Pacholczyk points to widespread acceptance – by Catholics included – of IVF; that's "where we put our foot on the slippery slope," telling ourselves that all we were doing was creating new life. Who could say that was wrong?
But the sad result is a scenario directly comparable to another period in our history in which "we cordoned off a part of humanity," says Father Pacholczyk, "and declared that because that part of humanity was different from us, it was all right to use them in an exploitative fashion. We did it with slavery; now we're doing it with embryonic human life." Meilaender underscores the irony of this comparison: "The course of Western history has been a very long, slow process in the direction of greater inclusiveness in our understanding of who belongs to the human community. Yet in this case we suddenly become less inclusive. Advocates of using embryos need to face up to that."
Is there hope, particularly in the Age of Obama? Leaders in the fight against ESCR agree that if there is any bright spot, it lies in education. Meilaender points to the public's "unease with the eugenic shaping of future generations" and believes that, properly supplemented by the facts, this unease could evolve into a larger dissent against related technologies like ESCR. Father Pacholczyk says that in his experience, as people become better educated about ESCR, they develop a "visceral repugnance to the entire project"; they "begin to think that this is just too much in the direction of Frankenstein, too much toward a Brave New World."
This kind of natural, instinctual disgust may yet succeed in influencing public and political opinion where principled arguments meet a deaf ear. But make no mistake: The Brave New World is here already.
Todd M. Aglialoro is the editor for Sophia Institute Press and a columnist and blogger for InsideCatholic.com.
