Study: Adult Mice Cells Mimic Embryonic Stem Cells

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This is ALL THINGS CONSIDERED from NPR News. I'm Robert Siegel.

MELISSA BLOCK, Host:

And I'm Melissa Block.

German researchers have made a discovery that could change the ethical landscape for scientists working on embryonic stem cells. They found cells in mice testes that seem to have all the key attributes of embryonic stem cells. If humans have similar cells, it would no longer be necessary to destroy embryos to obtain embryonic stem cells.

Joining me now to discuss the finding and its implications is NPR's Joe Palca.

Joe, we're hearing, usually, that what happens in mice doesn't necessarily translate to humans. Why is this considered more promising?

JOE PALCA: Well, it could be the same here too, that's one possibility.

But I think in the world of stem cell research, a lot of the things that have originated in mice have turned out to be something that happened in humans. I mean, embryonic stem cells were first discovered in mice, and later that set off a search to find them in humans. And I think the other thing is we're talking about very fundamental biological processes. And, we're not talking about something, you know, like a cancer tumor that has many, many kinds of qualities. These are very basic to how an animal is generated.

BLOCK: The cells that these German researchers found in mice testes, how are they like embryonic stem cells and how are they different?

PALCA: Well, the way they're like them is that, you know, the key elements of embryonic stem cells is that they renew, they keep growing indefinitely, in the laboratory, apparently indefinitely. Although if that's forever, we don't know for sure.

The other thing they do is they can turn, in the laboratory, into any cell type. So you can actually see beating heart cells, if you let them grow in the laboratory.

And the third thing is that if you inject these embryonic stem cells into a mouse embryo and then watch what happens, the mouse has bits of the daughter cells that go into all the parts of the mouse. So you can tell that the cells that you put in are actually turning into every cell type in a live mouse.

So, that's what these cells appear to have done. That's what these scientists have shown in the Journal of Nature, that these cells do just like embryonic stem cells.

How are they different? I think that's something they haven't figured out yet. They don't seem to be different.

BLOCK: And as we mentioned, this could change the ethical landscape for people doing this kind of research.

PALCA: Well exactly. I mean, the whole issue, people are convinced that embryonic stem cells have special qualities, but I don't think anybody's thrilled to death at the notion that you have to destroy an embryo in order to get them. So there've been lots of people trying to approach ways of finding cells that have all the qualities of embryonic stem cells that people think are important without getting them from embryos.

And this is clearly one, a new and very promising way. And I'm sure the German scientists have already said they've begun to look for these same cells in humans.

BLOCK: Part of the problem, I guess, for research has been, can you make stem cells that are tailored to a particular individual. Would this finding help in that?

PALCA: Well, I, you know, I presume so. I mean, you know, for an individual there could be a biopsy and then if the cells were found they could be grown out. But I, you know, I think that issue is a little bit of a side issue at this point.

There's so much to learn about embryonic stem cells just in general that there's no need for specific ones. And then the other thing is that the value of embryonic stem cells is probably going to come for something much broader than an individual therapy. I mean, it's very difficult to do something just for one individual. We do it, I mean, stem cells from bone marrow transplants are done, but its very hard and I think they want to find something that's more generic.

BLOCK: NPR's Joe Palca, thanks very much.

PALCA: You're welcome. Transcript provided by NPR, Copyright NPR.