RENEE MONTAGNE, host:
This is MORNING EDITION from NPR News. I'm Renee Montagne.
The dream of scientists in regenerative medicine is to use stem cells to repair diseased or damaged organs. Scientists in Canada have taken an important step toward realizing that dream. They established an efficient way to turn human embryonic stem cells into heart cells.
NPR's Joe Palca has more.
JOE PALCA: In theory, human embryonic stem cells can turn into any cell type in the body. And since embryonic stem cells can grow indefinitely in the laboratory, they've become a potentially inexhaustible supply of skin or nerve or heart cells that could be used to replace cells damaged or destroyed by disease. In practice, getting embryonic stem cells to turn into the cell you want is tricky.
Now, Gordon Keller and his colleagues at the McEwen Center for Regenerative Medicine in Toronto appear to have cracked the problem - at least when it comes to making heart cells. As Keller reports in the journal Nature, the trick is adding the right growth factors at just the right time.
Dr. GORDON KELLER (McEwen Center for Regenerative Medicine): Timing is absolutely essential in getting it right. If you miss that window, you basically fail.
PALCA: The cells Keller makes with his technique are actually quite versatile. Christine Mummery is a stem cell researcher at the Hubrecht Laboratory in the Netherlands. She says Keller's technique allows you to obtain the different kinds of cells that make up the heart.
Dr. CHRISTINE MUMMERY (Researcher, Hubrecht Laboratory): You can select out the cells that are going to become specifically heart cells or vascular cells.
PALCA: Vascular cells are the ones that make up the blood vessels that run through the beating heart muscle cells. Now, just having these cells doesn't mean you're instantly at a place where you can give them to patients.
Dr. MUMMERY: Repairing a human heart is, of course, very difficult. It's even proven difficult to repair a mouse heart.
PALCA: And you'd certainly want to start with mice or some other lab animal before you started giving these cells to humans.
Dr. MUMMERY: There were some major challenges of how you get the cells to integrate, how you get them to survive long term, and things like that.
PALCA: So it will be some time before heart stem cells will become a routine part of treatment for patients with heart problems. Both Mummery and Gordon Keller do see a nearer term benefit for these cells. They could be used to screen potential heart medications. If a new compound does damage to these cells in a laboratory dish, it's probably not something you'd want to put into a patient.
Joe Palca, NPR News, Washington. Transcript provided by NPR, Copyright NPR.
