New Stem-Cell Growth Technique Emerges
STEVE INSKEEP, host:
This is MORNING EDITION from NPR News. I'm Steve Inskeep.
New research could drastically alter the national debate over human embryonic stem cells. Scientists from a private company have developed a way to make the precious stem cells without destroying an embryo in the process. NPR's Joe Palca has been covering this story and is in the studio this morning. Good morning.
JOE PALCA reporting:
INSKEEP: So what do these scientists do exactly?
PALCA: Well, first of all, we have to say this is worked on in mice. So we're talking mice at this point. But this is a company called Advanced Cell Technology in Worcester, Massachusetts. Basically, what they did was they created an embryo, a mouse embryo in the lab using egg and sperm and then they let the embryo grow till it reached about eight cells, and then they took one of these cells out and used that single cell to generate the embryonic stem cells, cultured it with other cells, and got the stem cells to grow. And they took the other seven cells and showed that that was still possible, if you put that back into a female mouse, to get a mouse pup.
INSKEEP: So if this would also work in humans, why would that drastically alter the debate over this?
PALCA: Well, the idea is that, first of all, there is a similar technique in humans. It's called pre-implantation genetic diagnosis, at least the similar technique of taking a single cell from an embryo. And if that works in hu--I mean, if this could be shown to work in humans--and it has not; they can do the cell sampling but they haven't run the stem cells--but if it should be shown to work in humans, the idea is, well, you've got an intact embryo that's still capable of going on to produce a baby. And so if you're only taking one cell from the embryo, you're not harming the embryo. And so suddenly the whole notion that you can only get embryonic stem cells by destroying an embryo goes away, you can get them and still let the embryo go on and survive.
INSKEEP: Well, is that approach likely to satisfy people who have criticized and resisted this kind of research?
PALCA: Well, to some I think it would actually. But there's still some issues to consider. First of all, pre-implantation genetic diagnosis is a procedure that's used for couples who have a known history of genetic disease. And there's still some risk. It's been used, but there's still possibly some risk of taking a single cell from a developing embryo. And it's not clear what kind of a risk that is. Plus, that single cell, while it has been removed and can generate stem cells, in some sense still has the potential to become an embryo itself and therefore a potential life. And so people who are opposed to taking potential lives of embryos might still be opposed to this.
But, see, the whole thing here is people have been trying to come up with an interesting way around this problem of destroying an embryo, and there's another paper also in the current issue of Nature that talks about using a genetic manipulation, a combination of genetic manipulation and cloning to create embryos--this is again in mice--to create embryos that do not have the potential to grow into a mouse but still can be used to harvest embryonic stem cells.
INSKEEP: So people would not be creating fresh life, which people would also object to...
PALCA: That's right. But the problem here is that we have the famous buzzword `cloning,' which immediately raises alarm bells. And if you think about it, it's a procedure that's OK for mice, and people haven't objected to cloned mice, but what about the notion that you're cloning a human embryo, but you're specially cloning it in a way that you know it will be defective? So cloning a defective embryo, defective in the sense that it can't turn into a baby, that has some people on edge. And yeah, at the same time--and this is why the debate is so tricky--some people have suggested this cloning defective embryos or cloning non-reproductively competent embryos as a way around the debate because they say, `Look, if we're making an embryo that can't turn into a baby, we're not destroying it if we take stem cells from it.'
INSKEEP: So two possible ways around this impasse...
INSKEEP: ...over embryonic stem cell research--can you just remind us very briefly of what the stakes are in finding some way around that?
PALCA: Well, I think the reason, first of all, it's become such a debate is that the scientific community has embraced embryonic stem cells, in a way, as a potential for treating diseases. Few things have generated this kind of interest. And so they're very keen, scientists are very keen to study these cells, see if they can develop the therapies that people think they can, and so they're trying to find ethical ways around the objections that some have raised to the research.
INSKEEP: Joe, thanks very much.
PALCA: You're welcome.
INSKEEP: That's NPR's Joe Palca.