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Embryonic Stem Cell Development Raises Ethical Concerns

August 24, 2006 at 6:25 PM EDT
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SPENCER MICHELS, NewsHour Correspondent: Word that scientists have a new method for harvesting stem cells from human embryos without destroying them has some scientists hoping the discovery could break the political logjam over the highly controversial research.

The new technique was first outlined yesterday on the journal Nature’s Web site. After a fertilized egg is created through in vitro fertilization, it divides into eight cells, called blastomeres, becoming an early-stage embryo. Scientists then remove one of the cells and biochemically coax it into producing a line of embryonic stem cells. The remaining seven-cell embryo is unharmed and still capable of continuing to grow.

The CEO of the California company that conducted the research had this to say.

WILLIAM CALDWELL, CEO, Advanced Cell Technology: In this case, we do not destroy the embryo. That’s the whole purpose of what we perceive to be a major scientific breakthrough.

SPENCER MICHELS: The method is similar to that used by fertility clinics called pre-implantation genetic diagnosis, in which one cell is removed to screen for genetic disorders like Down syndrome.

Until now, human embryonic stem cell lines have been created by taking the inner-cell mass from a later-stage embryo, in which there are more than 100 cells. In the process, the embryo is destroyed.

And for that reason, in August 2001, President Bush banned U.S. scientists from using federal funds to create new stem cell lines from embryos. But the president’s order did allow funding for research on existing stem cell lines.

A White House spokesperson yesterday said the stem cell advance was a step in the right direction, but added, “Any use of human embryos for research purposes raises serious ethical concerns. This technique does not resolve those concerns.”

Officials at the National Institutes of Health said yesterday, “It’s unclear whether the new technique can meet the tough federal standard designed to protect embryos.”

Explaining the procedure

RAY SUAREZ: For more, we're joined by the leader of the project's research team, Dr. Robert Lanza. He's the vice president of the company that did the work, Advanced Cell Technology. And Richard Doerflinger, deputy director for pro-life activities at the U.S. Conference of Catholic Bishops.

RAY SUAREZ: Dr. Lanza, what's the result of this technique? After this procedure is performed, what do you have?

DR. ROBERT LANZA, Advanced Cell Technology: Well, we have developed a single-cell biopsy technique that allows us to create embryonic stem cells without harming the developmental potential of the resulting embryo.

RAY SUAREZ: So after the extraction is done, you have one removed cell from which stem cell lines can be derived?

DR. ROBERT LANZA: Exactly. It's a biopsy procedure exactly identical to that used in PGD, so what we propose is that, before that cell is sent off for testing, if we allow the cell to divide, we can then bring it back into the laboratory and, without any additional harm to that embryo, we have the potential then to create an embryonic stem cell line that would be genetically identical for the child.

So there would be very much a benefit if that child were to develop a disease in the future, such as heart disease or diabetes. They would have an identical set of cells that they could use for transplantation without the need for drugs that, of course, have side effects such as cancer and infection.

And the added benefit is the cells are immortal. They grow forever, and they could be shared with the entire scientific community. And these could very much hopefully increase the number of lines available for federal funding and thus give this field a very badly needed jump-start.

RAY SUAREZ: It's been wildly reported that the embryo, after this extraction, is not made any less viable by the procedure, that there's no effect on, for instance, if a child is born from that embryo downstream. How do you know that?

DR. ROBERT LANZA: Well, that's absolutely correct. There's a very considerable body of scientific literature that has looked at this, and the survival rate of the embryo after biopsy is exactly the same as a non-biopsied embryo. And also the rate of implantation and also pregnancies is identical.

We did a study in Nature last year in mice where we biopsied the embryos, implanted them into the animals. And we found that the number of healthy, live pups was exactly identical to those that were implanted that were not biopsied. So I think so far this does not appear to injure the embryo. In fact, you or I probably lost a cell or two during embryonic development.

RAY SUAREZ: So as far as your belief goes, you think this will pass the muster put out by the federal government and on Capitol Hill for embryonic stem cell research?

DR. ROBERT LANZA: Well, I think there are several things to consider here. One is, is whether or not President Bush will agree. And the second, of course, is what the Congress will do.

We know we have very strong support in both the House and the Senate, so we believe that this certainly might sway some of the people teetering, and that whatever the president decides, it would probably in the end, if he does not go along with this, hopefully be overridden by the Congress.

The other point I would like to make, though, is that we do not advocate the use of this procedure outside the context of PGD. In PGD, the cell is already being removed, so we can do this without any added risk and very much a benefit.

On the other hand, if this were to be applied to healthy embryos, well, there's a procedure that has to be imposed on that embryo that may have some risks that we're not aware of, however minimal. So until we have further data on that, we really shouldn't proceed in that direction.

RAY SUAREZ: And, quickly, that acronym, PGD, what does that stand for?

DR. ROBERT LANZA: Pre-implantation genetic diagnosis. And this is basically a tool that is used for couples who have not been able to have a baby any other way. And by looking at the cell, they can decide which group of embryos they feel would optimize the odds of that woman having a pregnancy and a child.

Costs of research

RAY SUAREZ: Well, Richard Doerflinger, Dr. Lanza's group has maintained that this new procedure answers some of the ethical challenges posed by critics. Does it?

RICHARD DOERFLINGER, U.S. Conference of Catholic Bishops: Well, let me answer that in two steps. One is, would it answer it if it was actually what he described it as? And that's an interesting question. But, first, let's figure out what he really did.

They didn't do what he just described. They did not obtain one cell from each embryo and leave the embryo alive. In fact, they took 16 embryos, completely dismantled them, took four to seven cells from each and destroyed all of the 16 embryos. They ended up with 91 individual separated cells from those 16 embryos, and they could only get two cell lines out of that.

It was a very disruptive, very wasteful, very inefficient procedure, and it left all the old embryos dead, just like the old method did.

RAY SUAREZ: Is that the case, Dr. Lanza?

DR. ROBERT LANZA: Actually, that's a misrepresentation to some extent. We did this research in two stages. First, we developed a biopsy technique similar to that used in PGD. So, for instance, we started out with eight embryos. We removed one of these blasphemers exactly the same way as it would be done in the clinic, and we allowed all of those embryos to develop on.

And of those eight, six of those went on to become beautiful, hatching blastocysts, which we froze down and are still very viable. That's exactly the same success rate as we saw with non-biopsied embryos in our lab.

The second phase of the experiment was designed to say, "Now, if we remove that cell, can we turn that into an embryonic stem cell line?" Now, that was a scientific question that we didn't have the answer to. The question is, can that cell that's removed using this technique in the Petri dish then be turned into an embryonic stem cell line? And that is the purpose of this paper.

And in fact, in that paper, we did, in fact, create 19 embryonic stem cell outgrowths and two stable lines that have grown now for over eight months, and are genetically identical, and capable of turning into virtually all of the cell types in the body.

RICHARD DOERFLINGER: Out of 91 cells obtained from 16 embryos, which you destroyed. I'm just talking about the paper you published. Don't tell me about unpublished research you did somewhere else.

DR. ROBERT LANZA: Mr. Doerflinger...

RICHARD DOERFLINGER: That's not a misrepresentation of your paper.

DR. ROBERT LANZA: We have a...

RICHARD DOERFLINGER: I just described exactly what you did.

DR. ROBERT LANZA: We have a difference of philosophy. You think that these hundreds of thousands of...

RICHARD DOERFLINGER: We have a different relationship to the truth.

RAY SUAREZ: Let him finish.

DR. ROBERT LANZA: ... be discarded, you think that they should be thrown away or not used where as we think, as scientists, if those, instead of being thrown away, could be useful to help people with treatments and cures, there's a very real human tragedy out there. And as a scientist, I'm not taking sides in this religious debate. My goal is to help alleviate pain and suffering.

RAY SUAREZ: Go ahead, Mr. Doerflinger.

RICHARD DOERFLINGER: The tragedy is that scientists who should be devoted to the truth are lying. This experiment that you published in Nature killed all the 16 embryos.

Now, we can talk about, what if you had succeeded and could publish getting one cell line from one cell from an embryo? Then we'd talk about the dangers of the pre-implantation genetic diagnosis technique, which you're downplaying, but which the NIH and many other scientists have said is a very uncertain risk to the embryo.

The idea that the embryos that actually survived that technique can go on, may implant and be born, first of all, leaves out the fact that the only reason that biopsy is done is to detect and throw away the embryos that are found to have a genetic defect, the very embryos that would have needed a stem cell treatment. Only the ones found to have no genetic problem, some of them, a minority of them end up being born alive.

RAY SUAREZ: Well, let me ask you this...

RICHARD DOERFLINGER: It's a destructive procedure, as well.

Ethical questions

RAY SUAREZ: ... if the objection in this debate has been that, in order to obtain cells from which stem cell lines can be produced, you have to destroy the embryo, if what Dr. Lanza is describing is a technique that may make it possible to develop stem cell lines without destroying embryos, does that hold promise for finding some common ground in this ongoing debate over stem cell research?

RICHARD DOERFLINGER: I think that it's not what he has done, but if he ever did do it, it would still raise the question that you're taking these embryos and making use of them for benefit to others in ways that are of very uncertain risk and will probably end up harming them.

I think there are ways forward. There are ways that involve getting stem cells, including stem cells with the properties of embryonic stem cells, without doing any harm to anyone without deriving them from an embryo.

The Senate unanimously passed a bill like that. The House overwhelmingly voted for it, but not by two-thirds. President Bush has said he's in favor of that, moving forward with ethically sound, medically promising stem cell research, and he intends to promote that by executive action.

This technique, out of all the techniques, the new techniques for getting embryonic stem cells, is the one that was most roundly criticized by members of the president's Council on Bioethics, including people who support cloning and embryonic stem cell research, because you're talking about something that, at its best, is posing uncertain risk, maybe serious risk down the road, even to the children that end up being born alive after the technique.

RAY SUAREZ: Dr. Lanza?

DR. ROBERT LANZA: Yes. Well, first of all, let's make this very clear: Mr. Doerflinger is against all IVF, so there are literally millions of parents who have children that he disagrees with that protocol being used. And I personally believe that...

DR. ROBERT LANZA: ... these parents should have the right to have a child if they choose. And a parent having PGD to have a pregnancy, again, that have had no success using any other technique has the right to have a child. And if this technique increases the probability of them having a pregnancy and the child, that is their decision.

What we are saying is that no added risk, zero added risk, we have the ability to create an embryonic stem cell line that could have very much a benefit for that child, not only for that child, but also for their siblings and also for all of science.

Finding a middle ground?

RAY SUAREZ: Doctor, Mr. Doerflinger said earlier that less mentioned is the fact that, once you do this extraction and find that the embryo is flawed in some way, it can be discarded, which would seem to...

DR. ROBERT LANZA: Well...

RAY SUAREZ: ... which would seem to negate the idea that this could be a sort of ideological middle ground for the warring sides over stem cell research.

DR. ROBERT LANZA: Right. Well, that's a different story what the parents do with their leftover embryos. Let's step back here. Anyone who goes to IVF to have a pregnancy, they will have so many eggs, so they will get anywhere, say, from five to 25. These will be fertilized.

And what will happen then is they will pick the best ones to optimize the chance that they will have a pregnancy, because again, in most cases, they haven't been successful. What PGD does is it takes the subjectivity out of it.

An embryologist looks at a group of embryos and says, "Well, we think these will be the ones most likely to give you a pregnancy." With PGD, you send it off to a lab, and they give you a little more scientific information genetics, and they go, "Aha, this has three times the amount of DNA that it's supposed to have, so that one would never implant, so we're going to put these in and hope that this woman gets pregnant."

What happens with the remaining, as what happens with all of IVF, is they're frozen away. Now, whether or not they're use subsequently or they're sent to make snowflake babies, that's a different story. But what we're saying is there's not a need and there's never a need to destroy any embryos at any point in this process.

RICHARD DOERFLINGER: Well, as he just said, there's a lot of throwing away of embryos in these clinics, and this technique is a way of detecting more to throw away. And it's not because they have three times the DNA. They're doing this for kids that might have had Down syndrome or cystic fibrosis, and some clinics are doing it simply for sex selection.

So, you know, you have problems, ethical problems with IVF. You have ethical problems with pre-implantation genetic diagnosis. This just piggybacks on all of them and adds more of its own.

And maybe some day you would show years from now, which he has not shown today, but you would get a stem cell line from one cell without actually causing any adverse effects on that embryo, but even getting there is going to lead to a lot more destructive research like this in the meantime in which the embryos are destroyed. This is not the way to solve the ethical problem.

RAY SUAREZ: Briefly, before we go, Dr. Lanza implied that there was, in fact, no form of embryonic stem cell research that the Catholic bishops would countenance, that they are against IVF. Is that the case, in vitro fertilization?

RICHARD DOERFLINGER: Well, if you mean stem cells that have the properties of embryonic stem cells, no, we're not against all of it. If you can do this without exploiting or using, or, you know, assaulting embryos, than all the better.

There are 12 major studies now that say there are some cells in umbilical cord in adult blood tissues already that have the properties of embryonic stem cells. Let's explore that. Other scientists are coming forward with cutting-edge research showing you can reprogram adult cells to be more versatile, make them just like embryonic stem cells. No ethical problem whatsoever.

So let's explore all the issues, but let's not ignore the ethical problems and say, "We've solved it," when we haven't.

RAY SUAREZ: Gentlemen, we'll have to leave it there. Thank you.