RENEE MONTAGNE, host:
Embryonic stem cells - scientists are enthusiastic about their potential for treating a variety of diseases. Of course these cells are also controversial, since obtaining them means destroying an embryo. Now scientists in New York say they may have found cells that are just as promising, but don't start with an embryo.
NPR's Joe Palca has more.
JOE PALCA: A few years ago scientists in Japan said they found stem cells with remarkable properties in the testes of adult mice. Not only could the stem cells turn into sperm, they could, under the right conditions, be turned into any cell you like - skin, muscle, brain, you name it.
But Marco Seandel says there was a problem.
Dr. MARCO SEANDEL (Memorial Sloan-Kettering Cancer Center, New York): These are relatively rare cells mixed in with a huge number of other different types of cells, some closely related, some, you know, much different.
PALCA: Seandel is at Memorial Sloan-Kettering Cancer Center in New York.
Dr. SEANDEL: What one needs is a very efficient way to pull out the ones that one's interested in.
PALCA: So Seandel and colleagues at Weill Cornell Medical College set out to find a way to distinguish these cells from all the others in the testes. As they report in today's issue of the journal Nature, they found one. All these cells have a protein called GPR125 poking out of them.
Dr. GEORGE DALEY (Children's Hospital, Boston): Having the GPR125 as a marker is a very important tool for fishing the cells out of an otherwise very complex mixture.
PALCA: George Daley is a stem cell biologist at Children's Hospital in Boston. But finding GPR125 in mice is just the start.
Dr. SEANDEL: There's a lot of unanswered questions, the most key of which is whether or not they can replicate this with human cells.
PALCA: If they can, it would open up some interesting possibilities for therapies.
Dr. SEANDEL: One of the more grandiose goals would be to take a testes biopsy, put these cells in culture and then be able to coax them to become whatever tissue you think a person might need.
PALCA: To treat a disease. That's for the future. For now, Marco Seandel says he and his colleagues are getting ready to begin their search for these special cells in humans. Although he admits finding volunteers to donate testicular tissue may be challenging.
Dr. SEANDEL: From what I'm told, there's very little discomfort involved.
PALCA: So does that mean Seandel and his colleagues are planning to donate their own tissue?
Dr. SEANDEL: We've talked about that here in the lab. No one's volunteered so far.
PALCA: Seandel says the goal for the moment is to perfect their techniques for obtaining these cells from mice.
Joe Palca, NPR News, Washington.