Feb. 26, 2012 -- Scientists say they have found a way to use ovarian stem cells to perhaps one day help infertile women get pregnant -- or add years to a woman’s reproductive cycle.
In a study published in Nature Medicine, researchers report finding egg-producing stem cells in human ovaries. They also report being able to make some of those ovarian stem cells grow into immature eggs that may someday be useful for reproduction.
At this point, such “seed” eggs can’t be fertilized by sperm. But if scientists are able to entice them to mature and can prove they can be fertilized and grow into embryos -- a feat that has been reported in mice -- it would overturn a long-held scientific belief that women can’t make new eggs as they get older.
“What it does is really open a door into human reproduction that 10 years ago didn’t even exist,” says researcher Jonathan L. Tilly, PhD, director of the Vincent Center for Reproductive Biology at Massachusetts General Hospital, in Boston.
Outside experts agree. They say the findings could have profound importance for reproductive medicine and aging, allowing doctors not only to restore a woman’s fertility but also to potentially delay menopause.
“I think the significance of this work is like reporting that we found microorganisms on Mars,” says Kutluk Oktay, MD, who directs the Division of Reproductive Medicine and the Institute for Fertility Preservation at New York Medical College in Valhalla, N.Y.
“It’s a proof of principle that they could do it,” says David F. Albertini, PhD, director of the Center for Reproductive Sciences at the University of Kansas Medical Center in Kansas City, Kan.
“The world wants to know today if we’re ready to restore fertility in women, whether they’ve aged or been treated for cancer or whatever,” Albertini says, adding that he doesn’t think that’s on the horizon. “This is an extremely rare event, at best.”
The egg-generating stem cells the researchers were able to extract from ovaries were very rare. The researchers only came across one for every 10,000 or so ovarian cells that they counted.
But when they took those cells and implanted them back into human ovarian tissue, they divided and essentially made young eggs.
Tilly says his team stopped short of trying to make one of the eggs functional because “for a lot of reasons, as it should be,” it is illegal in the U.S. to experimentally fertilize human eggs.
“We think the evidence provided clearly indicates that this very unique, newly discovered pool of cells does exist in women,” he says.
A Lot of Potential
“It’s a really exciting result,” says Evelyn Telfer, PhD, a cell biology expert at the University of Edinburgh in Scotland.