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Scientists have announced another first in cloning. They have cloned a primate embryo. Researchers in Oregon said they used cloned monkey embryos to make embryonic stem cells. A few years ago, South Korean scientists said they had done this with human cells, but that turned out to be a fraud. The journal that published this new work took the unusual step of having an independent laboratory verify the results.
NPR's Joe Palca has more.
JOE PALCA: Here's why scientists have wanted to clone embryos from adult cells and then use those embryos to make embryonic stem cells. What if I could take a couple of skin cells from the inside of your cheek and magically turn them into new blood cells or insulin-producing cells or brain cells? Then, if you needed a blood transfusion or developed diabetes or started suffering from Parkinson's disease, I could transplant those cells back into you, and hopefully they would treat what ails you. And since the starting cells originally came from you, they'd be tailor-made to you, and your immune system wouldn't reject them.
It turns out, there is a way to do that magical transformation. It's the same technique that Scottish scientists used to create Dolly, the clone sheep. Basically, you put the starter cell into an egg from which you've removed the nucleus, wait a few days, and if you've done everything right, you get a cloned embryo. Then, you can get stem cells from that embryo.
Scientists have been able to do this with mouse cells, but the real payoff will come when they can do it in humans. No one's pulled that off yet. But now, Shoukhrat Mitalipov and his colleagues at the Oregon National Primate Research Center in Beaverton say they've done it in monkeys.
Mitalipov said during a teleconference earlier today that the process isn't very efficient for deriving stem cell lines.
Dr. SHOUKHRAT MITALIPOV (Oregon National Primate Research Center): We used 150 eggs to derive one cell line. So, of course, it's quite inefficient.
PALCA: But, he says, his work proves it can be done. Careful scrutiny by both the editors of Nature, the journal where the research will be published, and an independent lab, could find no flaws in Mitalipov's science. Of course, Mitalipov's work is in monkeys, not humans. But Mitalipov thinks it will work with humans.
Dr. MITALIPOV: We only worked with monkeys. However, we hope that the technology we developed will be useful for other labs who's working on human subjects, with human eggs and human cells.
PALCA: Labs around the world are trying to make this work for humans. But even if it does, stem cell biologist Irv Weissman from Stanford University says it will be a while before stem cells derived this way will get into a patient.
Dr. IRV WEISSMAN (Stem Cell Biologist, Stanford University): If you're hoping that tomorrow or five years from tomorrow this particular discovery, even if it had been done with human cells rather than primate, will lead to a therapy, you're just jumping the gun.
PALCA: Weissman thinks the more immediate application will be making cell lines from patients with specific diseases, not so much for treating the patients, but for studying their diseases.
Arnold Kriegstein agrees. Kriegstein runs the stem cell program at the University of California, San Francisco.
Dr. ARNOLD KRIEGSTEIN (Director, Neural Stem Cell Center, University of California, San Francisco): You can take a skin cell from a patient who's suffering from a genetic disease for which we don't really understand what the genes might be. And you can take that cell - create a stem cell line where the entire stem cell line is composed of cells that inherit the disease gene or genes. You can then use that to model the disease in a dish. And that can help you develop drug therapies that would help treat that disease.
PALCA: Kriegstein says the new work makes that hope closer to reality.
Joe Palca, NPR News, Washington.