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Groundbreaking research may develop effective ways of curing diseases, without the ethical dilemmas faced by isolating cells from embryos
Sunday, December 02, 2001
By Alan Russell
We live in exciting times. A cure for diabetes is in our grasp. Treatments for Parkinson's and Alzheimer's seem possible within a decade or two. Accidents that would have left us paralyzed like actor Christopher Reeve may become treatable in the same time-scale. Diseases like muscular dystrophy, which excruciatingly and slowly rip children from their parents, may be reversed. The hope offered by regenerative medicine is truly astounding.
It is hardly surprising that this new world of medicine drives esteemed scientists, theologians, politicians and commentators to deliver opinions on the subjects involved. It is interesting to watch concerned theologians and others interpret science, and to hear scientists talk about when life begins.
At the heart of the debate that was revived last week is the appropriateness of something called "human therapeutic cloning." As the director of one of the world's first institutes for regenerative medicine, and a devout Lutheran, I feel a special responsibility to help explain what this new field is. At the same time, I want to challenge us all to think carefully about what is at stake before we come to a decision on supporting or opposing this line of research.
I write now because of the publicity surrounding the premature announcement of human cloning from a Boston-based company, Advanced Cell Technology. Although the company has not done what it claimed to do -- and although its publication is now under criticism and scrutiny -- it has taken a step toward therapeutic cloning. Now is the time to engage in an informed discussion about what to do next.
It is important to realize that no one in Pittsburgh is cloning humans or currently working with human embryonic stem cells. In Pittsburgh, we have a world-leading group of researchers who focus on cells isolated from adults for treating disease.
Before we address details, it is important to remember that the "scientific truth" we find interpreted by today's newspapers will be disproved by tomorrow's experiment. For those of us in the trenches of research, we wish science was predictable. But in reality, science does not move forward by a continual advancing of knowledge. We take two steps forward, then discover we were wrong and start all over again.
No one, even those with divine connections, can predict what kind of cell-based therapy has what therapeutic potential. What we can say is that, within a decade or so, we will know if some of the hype we hear about in the media will become possible within our children's lifetimes.
Cloning is a simple concept. It means making an identical copy. Think of copying a videotape. In nature, identical twins are clones. Cloning is a natural phenomenon.
For decades, we have known how to encourage cells, like bacteria, to copy themselves and divide. Life was simple when we knew how to clone only bacteria. But in 1997, scientists from Scotland discovered how to clone an animal (Dolly the lamb). And now we find a handful of irresponsible scientists who are trying to produce human clones. This "reproductive" cloning is thought to be evil, immoral and scientifically inappropriate by almost everyone.
The media controversy last year over stem-cell research pitched the "right to embryonic life movement" against the "right to adult quality of life movement." As an outgrowth of that debate, we have been informed by many that "human therapeutic cloning" is an evil form of research, equivalent to cloning babies to harvest their body parts.
If true, this would be a truly scary prospect. However, it is a gross misinterpretation. Human therapeutic cloning may be a very effective way of curing diseases without some of the ethical dilemmas faced by isolating cells from embryos.
Therapeutic cloning is not simple. But we can understand it by simplifying how it might work for us.
Imagine a loved one with liver disease. The only treatment available today is to have a transplant of a new liver or of liver cells. In the therapeutic cloning approach, the patient's mother, for example, would donate an unfertilized egg. Not an embryo, but an egg. Just a single cell with the potential to save a life. Mom's sick daughter would also donate a regular cell -- perhaps just a single cheek cell.
All cells contain DNA, which gives them the ability to reproduce. But cloners have discovered that if one removes the DNA from mom's egg cell (producing an empty cell) and replaces it with her daughter's DNA, the newly produced cell can survive.
This is important. Genetically, that hybrid cell is no longer like the mother's cell but like her sick child's cell. Just imagine: A few microsyringes go from mom's egg to her daughter's cheek cell. We then have in our hand a fresh cell which from now on will look like her daughter's cells.
In a dish, technology will exist to take that cell and simply convince it to multiply -- to clone itself. The resulting cells will not grow into a baby from whom a liver is taken. Instead, they will be convinced to become liver cells and injected into the woman's daughter to save her life.
This takes place in a dish, not in a womb. The process is called cloning because the new cell created in the laboratory has the ability to copy itself again and again before turning itself into the liver cell that your loved one so desperately needs.
A key question lingers: During this process, has a viable new life been created then destroyed?
Science cannot provide this answer. The ability to mix the DNA between human cells in this way is too new to know whether what is made could survive in a womb instead of a dish.
Theologians and politicians cannot answer the question. Until very recently, such cells did not exist. Our understanding of the science is developing more rapidly than our understanding of whether these experiments are morally appropriate.
In the distant future, we may learn how to reprogram dad's cheek cell with his daughter's DNA, and produce cells which turn into the daughter's liver cells. In this instance, we would have done therapeutic cloning without using an egg cell and life will be simple again. It is a brave new world.
The fact that scientists, preachers, politicians and the public are drawn into serious dialogue on the issue of therapeutic cloning is encouraging. But the miracle of life is beyond any of our understanding.
Science, philosophy and theology all share something in common: The truths in each change as we find our path through life. Indeed, just a few decades ago, a heart transplant was considered immoral in some religions, including Catholicism (and in Japan it remains illegal on religious grounds today).
But as the science of transplantation has moved forward, the Catholic Church has revised its thinking on the issue to such an extent that Pope John Paul II was a keynote speaker at a recent transplantation conference in Italy.
Imagine: Within just a few decades, the church became comfortable with a revolutionary medical approach, pioneered in Pittsburgh, that caused such anxiety for years. Determining the morality of therapeutic cloning depends on the subtlety of how the science is performed.
In my view, we must resist the urge for absolutes until we understand in detail what people are doing and why. It may well be that some aspects of therapeutic cloning represent the path by which diseases can be treated without ignoring the sincere beliefs of millions of Americans.
It is also possible that the science will be misused. What seems clear to me is that we are certainly not at a point where an absolute legislative ban on all forms of therapeutic cloning can be justified on any other grounds than political ones.
Alan Russell is executive director of the Pittsburgh Tissue Engineering Initiative. He is also director of the McGowan Institute for Regenerative Medicine at the University of Pittsburgh. 