In new studies published by three independent teams of scientists, skin cells of mice were successfully converted into stem cells. Specialists explain what the findings mean for human stem cell research and the potential for bypassing the controversial use of embryonic stem cells.
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In Washington today, the House of Representatives debated and voted on funding for stem cell research. At the same time, there was important news published in two science journals about a potential breakthrough in the field.
The basic finding:
Scientists took skin cells from mice and added viruses containing four specific genes. That caused the skin cells to be reprogrammed to behave like embryonic stem cells, which could then be used to treat diseased tissue and organs.
To walk us through both the science and the politics, we're joined by Kenneth Miller, a cell biologist and professor at Brown University — for the record, he's also one of the advisers to the NewsHour's Science Unit — and Rick Weiss, a science reporter for the Washington Post.
Well, starting with you, Professor Miller, explain this a bit more, this new method to us. How does it work?
KENNETH MILLER, Cell Biologist:
Well, it works in a very simple way. About a year ago, a Japanese laboratory at Kyoto University analyzed the genes that were active in embryonic stem cells. And by a very careful process of elimination, they determined that there were four essential genes whose activation was required to keep stem cells in a state where they could develop into other cell types.
What they then did, and two other laboratories did, as well, is to take these four genes, take ordinary skin fibroblast cells from a mouse, ordinary adult cells, and, by some very clever genetic engineering, get these genes into the cells. Once those genes were put in the cells, and the cells containing them were identified, and those genes were activated, they then grew those cells for a while, and they discovered a couple of things.
First of all, they discovered that the cells formed colonies that looked like embryonic stem cells. Then they analyzed their genetics and discovered that the right genes were turned on and the right genes were turned off to act like stem cells. And, finally, they put them to what you might call the acid test, which is to see whether or not these cells could develop into all the issues in the body and, in one case, in one laboratory experiment, actually become fully functional adult organisms, and these cells passed every single test.
So what are the potential benefits here? What would it be used for?
Well, there's nothing to be used for right now. This is still a highly experimental technique. You might refer to it as proof of concept. And what I mean by proof of concept is the concept is that unlocking the developmental potential of a cell doesn't require an embryo. It doesn't require an embryonic cell.
All it requires is understanding the signals that turn cells on to the proper developmental pathway to produce the tissues in the body, and these experiments are proof of concept. So, in effect, a door is now opened to researchers everywhere to run in and exploit this idea and try to find a way to develop genuine therapies from this scientific breakthrough.
So, Rick Weiss, the news here that flashed around the world was that here is a potential way to avoid the ethical issue that has been so rife in this debate.
RICK WEISS, Science Reporter, Washington Post:
Right. I mean, the whole problem with embryonic stem cell research, since embryonic stem cells were first discovered back in '98, has been that the only way to get them is to destroy human embryos, which is really crossing a moral and ethical line for a lot of people in this country. This presents the possibility of just turning ordinary cells into human embryonic stem cells, essentially getting around that whole ethical dilemma and letting the field go forward.