Embryonic Stem Cells Made Without Embryos
JOHN YDSTIE, host:
The debate over research on human embryonic stem cells has taken a dramatic turn. Two research teams have independently shown that it's possible to make cells with all the properties of embryonic stem cells without destroying a human embryo. That would remove the moral objections somehow to this research. It also means it might not be necessary to use cloning techniques to tailor stem cells to individual patients.
NPR science correspondent Joe Palca is covering this story and joins us now.
Joe, let's start with this idea of cloning. How does this new research eliminate the need for, what some call, therapeutic cloning?
JOE PALCA: Well, the idea is, John, that if we wanted to make embryonic stem cells from you - cells that we could use someday to turn into brain cells or turn into pancreatic cells or whatever kind of cell you needed - we could take a skin cell from you and transform the nuclei of the skin cells such that it would go back to a time when it thought it was an embryonic cell. And that's what cloning does.
When Scottish scientists cloned Dolly, the sheep, they showed that they could take a skin cell, or in the case of Dolly, a mammary cell, and put that into an egg. And the egg of the sheep had some magical property that could change the skin cell, reprogram it back or change the mammary cell, reprogram it back into an embryonic cell.
YDSTIE: And that's what we were doing before, but now we have this new (unintelligible).
PALCA: Right. Well, people were trying to do that in human cells using human eggs and human skin cells. But now they found a way by adding these four genes to a skin cell. It seems to do the same thing. It seems to turn to reprogram the nucleus of these skin cells so that they behave just like an embryonic cell. So they could, in theory, turn into any cell you might need for a transplant someday.
YDSTIE: So now at least one prominent researcher says he's planning to abandon his research on cloning as a technique for getting patient-specific embryonic stem cells.
PALCA: Right. Ian Wilmut said that he - he was the Scottish scientist who led the team that created Dolly. He said I've had enough. But there are plenty of scientists who are doing this who say no, it's not time yet. There are still things we don't understand about these new cells, and we really need to pursue the human therapeutic cloning, if you want to call it that, until we're sure that these other cells can do exactly what we want.
YDSTIE: So does this new dramatic development really eliminate the ethical problems of research on stem cells?
PALCA: Well, it probably will. I mean, that's what both sides - proponents and critics - are saying because, in the end, it does appear to have this property. But, as I say, in the short run, I think we're in a period of time when scientists aren't ready to abandon the thing that they've spent some time studying. Just last week there was an indication that getting these cells from primates - they did it in monkeys - that was a possibility. And so I think what they're going to say is, look, the future looks bright. We're just as happy as anybody to be able to get away from using eggs and embryos. They're hard to get. Human eggs are hard to come by. And so it would be a good thing for the future. But for the time being, we still need to pursue it.
YDSTIE: So at the whole point of this is therapies. What are the hurdles that still have to be overcome before these cells that are made using this new technique can be used for actual therapies that help people?
PALCA: Well, there's two kinds of hurdles. Let's start, first of all, by talking about the big hurdle. The big hurdle is that at the moment, even though embryonic stem cells in principle can be turn into any kind of cell and some diseases are - caused was specific cells stops working, the idea that you just squirt this in to a patient and have them do something properly but hasn't - it's not that simple. There's timing issues, there's questions about whether the cells are going to do exactly what you want or something else. So that's a problem.
The other problem is that in the process of making these new cells, this new technique of adding the genetic cocktail, there maybe problems. And so those have to be worked out. There clearly are potential problems, and they have to be solved first.
YDSTIE: NPR science correspondent Joe Palca, thanks very much.
PALCA: you're welcome
YDSTIE: The first embryonic stem cells were isolated in mice in 1981. You can track the history of stem cell research and controversies at npr.org. Transcript provided by NPR, Copyright NPR.
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