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Physician-Lawmakers Debate Stem Cell Research

The House of Representatives is set to vote Tuesday on a bill sponsored by Rep. Michael Castle (R-Del.) lifting restrictions on federally funded embryonic stem cell research. The measure makes embryos left over from in vitro fertilization procedures eligible for research as long as donors consent to the research in writing. The bill has sparked sharp debate among lawmakers who promote the potential of embryonic stem cell studies and those who object to the destruction of embryos in the name of finding disease cures. Todd Zwillich sat down with two physician-lawmakers on opposite sides of the issue as they debated the benefits and pitfalls of the research.

Rep. Joe Schwartz (R-Mich.), a supporter of embryonic stem cell research, is an otolaryngologist and head and neck surgeon. He practiced medicine for 31 years before being elected to his first term in Congress in 2004.

What, in your view, is the scientific potential of embryonic stem cell research?

The potential is the treatment of disease as we have not known it before. It's the ability to reproduce from embryonic stem cells any of the more than 200 different types of cells in the body when needed to treat disease. This includes spinal cord injuries, pancreatic islet cells for juvenile diabetics, dopamine-secreting cells for Parkinson's. That potential only rests in embryonic stem cells themselves, not in adult stem cells or in cord blood cells, which have only the potential to form new blood cells themselves.

This is about as pro-life as it gets, and I look at it very much like organ donation. We're using tissue from another individual to help people, to cure disease, to move the ball forward and treat things that we heretofore have not been able to treat.

In August of 2001, President Bush set a policy restricting federal research funding to stem cell lines already derived at the time. Some 77 cell lines were included in the limits. Has the policy been adequate?

It wasn't adequate the day the president announced the policy and it certainly isn't adequate now. As it turned out there maybe were only 22 stem cell lines or so that had any adequacy whatsoever. They are all contaminated with mouse feeder cells, which means they can't be used on humans, so as a result there is no federally supported embryonic stem cell research going on in the United States right now. Only private research, and studies backed by various state governments like the initiative in California, have proceeded. What we need is embryonic stem cell research under NIH guidelines, and if we do this, I believe we could carry on embryonic stem cell research ethically and productively.

The Ethics of Stem Cell Research

The research envisioned in Tuesdays' bill requires that embryos be destroyed to allow the collection of this type of stem cells. Can this research be done ethically? How do you view the tradeoff between destroying embryos and finding potential disease cures?

The Castle bill takes cognizance of the fact that what we are asking is that embryos which would be destroyed anyhow, as excess from in vitro fertilization, could be used if donated by the owner, for no compensation whatsoever. The bill takes into consideration the fact that these would be destroyed.

What we are doing is actually something that I believe is very strongly pro-life, and that is using these stem cells to treat disease. We should use them for research, and in a decade, or 15 years, or 20 years, we should be able to induce stem cells to differentiate into these various cells that we need for these treatments, whether its spinal cord injuries, Parkinson's, ALS, diabetes. You name it, the potential is there, and I don't believe that what we are doing is destroying embryos. We are in fact preserving stem cells from these embryos and hopefully growing them in lines that can be induced to differentiate into cells that can save lives.

Laboratories in other countries are doing this research. If the United States limits it, won't we be left behind?

We're behind already. We're behind, Japan, China, [South] Korea, the United Kingdom, and probably some countries in continental Europe as well. The problem, especially with the recent announcement of an improved somatic cell nuclear transplant technique in South Korea [or "therapeutic cloning," the transfer of the genetic material of adult cells into embryo cells] is that it only shows how fast the train is moving on embryonic stem cell research. It is moving and we need to be a part of it in the United States. The way to do that safely, ethically, and morally is to have the NIH and the secretary of HHS come up with guidelines that allow large university laboratories and medical center labs in the U.S. to proceed with stem cell research much as the rest of the world has done.

Embryonic Stem Cells vs. Adult Stem Cells

There are other types of stem cell research, such as those using adult stem cells or cells from umbilical cord blood. Do we still need embryonic stem cell research?

I support all stem cell research, and there have been some successes there. But with cord blood stem cells, it is mostly stem cells that will differentiate [develop] only into blood cells and not other types of cells. I certainly encourage that type of research. I encourage research with adult stem cells because there is some promise there as well. But the promise of cells that can differentiate to any cell in the body rests only with embryonic stem cells.

Most members of Congress are not physicians. What kind of questions do your colleagues ask you when considering how they will vote, both those that agree with you and those that don't?

The questions I'm asked are good ones. People want to understand the science and what we're really talking about when we talk about embryonic stem cells. They want to understand how these cells are derived and how the process works. They want to be assured that we are not proposing to do anything that in the final analysis is unethical or immoral. I believe we give people quite good assurances.

There is quite a lot of intellectual curiosity on the part of members, and they will have to vote as their conscience dictates. I will vote to support embryonic stem cell research and cord blood research, because I believe that along with adult stem cells, we can advance research on all three fronts. We have to get the lead in this sort of research back in the hands of ethical, well- trained American researchers and American universities.

An Opponent of Embryonic Stem Cell Research Speaks Out

Rep. David Weldon, MD, (R-Fla.) specializes in internal medicine and practiced for 15 years before being elected to Congress 10 years ago. He is strongly opposed to embryonic stem cell research.

What, in your view, is the scientific potential of embryonic stem cell research?

I think that doing human embryonic stem cell research may answer fundamental question on human embryo biology, but I seriously question whether they'll ever have any clinical usefulness in managing and treating disease.

In August of 2001, President Bush set a policy restricting federal research funding to stem cell lines already derived at the time. Some 77 cell lines were included in the limits, but has the policy been adequate?

I believe it has. As a matter of fact I was just informed that in Britain, where embryonic stem cell research is fully funded by the government, their investment has been less than the American federal investment under the Bush policy. Also, I continue to be informed that there is an adequate supply of embryonic stem cells at the National Institutes of Health (NIH). The only shortage is in meritorious grant applications. So I think the president's policy has been a good policy. I think the Castle bill we are debating this week is unnecessary.

Embryos must be destroyed in order to collect human embryonic stem cells. Can this research be done ethically? How do you view the trade-off between destroying embryos and finding potential disease cures?

There's really a very serious question about whether embryonic stem cells will ever be useful in treating disease. For example, research scientists have been trying for years to successfully treat diabetic mice. That has been successfully cured using adult mouse stem cells but they have never been able to do it using embryonic stem cells. And of course adult stem cells have been successfully used along with cord blood stem cells in treating over 60 human conditions. There's a lot of human experience that we've accumulated, but there's never been a successful human trial with embryonic cells, and there's really been very limited animal studies to show that embryonic stem cells have any potential at all. It does involve killing an embryo, a human life. And therefore, based on my knowledge of the science and my understanding of the morality and ethics of this, I have consistently said that this is unethical and unnecessary.

Now, I have never moved to make it illegal. I have just wanted to bar the research from receiving federal funds. If private labs and foundations want to fund it, they're perfectly capable and able to do that. The state of California, New Jersey, Harvard University, and a number of other entities are funding human embryonic stem cell studies involving the destruction of human embryos, and of course, the NIH has been funding millions of dollars worth of this research since 2001 on embryos that were destroyed during the Clinton administration. But of course, we've had no clinical treatments emerge from this.

Will U.S. Researchers Be Left Behind?

Laboratories in other countries are doing this research. If the United States limits it, won't we be left behind?

No, actually, I think it's the absolute opposite. I think this research will go nowhere, while if you look at the track record on adult stem cells and cord blood, it has really been huge. Do you know that we now have, as I understand it, 10 children that have been cured from sickle cell anemia using cord blood stem cells. As a physician who used to take care of sickle cell patients in my medical practice, that's breathtaking. You don't even have a successful animal model of treatment of a disease using embryonic stem cells, so my attitude is, let overseas labs invest in this. I don't see it as ever having any clinical utility.

To be clinically useful you have to overcome the problems of tissue rejection and genetic instability with embryonic cells. They tend to form tumors, and they have not performed well in animal trials.

I believe the embryonic stem cell debate will go the way of the fetal tissue research debate. If you go back 10 years and look at those arguments, they were the same as today. Proponents were hyping fetal tissue research as having the potential to cure everything from Parkinson's disease to hangnails, and the research ended up going nowhere. Embryonic research, I predict, will go that same route.

There are other types of stem cell research, such as those using adult stem cells or cells from umbilical cord blood. Do we still need embryonic stem cell research?

I say we don't and I've been saying that for years. You have ethical alternatives. Adult stem cells have now treated over 55 human diseases, including multiple sclerosis and Crohn's disease, quite successfully. There are no issues with tissue rejection there.

These clinical trials are early and we have not yet accumulated long-term data, but I believe you could see some of those interventions moving into mainstream clinical practice. I think there are more than 60,000 people who have been successfully treated with cord blood stem cells in the United States today. The embryonic cells are unlikely to ever make it beyond the research lab into clinical use.

Most members of Congress are not physicians. What kind of questions do your colleagues ask you when considering how they will vote, both those that agree with you and those that don't?

Well, most of my questioning comes from people who agree with me, though I do occasionally get people on the other side who want to talk to me about it just to try to get some facts. But I get questioned about specific things, like 'Is it true that adult stem cells have been used to treat various diseases, and what kind of diseases, and how do they work?' to just general questions about embryonic stem cells. I also get philosophical questions about the beginning of life and questions about nature.

By Todd Zwillich, reviewed by Brunilda Nazario, MD

SOURCES: Rep. Michael Castle (R-Del.). Rep. David Weldon, MD, (R-Fla.).