Biologist Robert Lanza of Advanced Cell Technology in Worcester, Mass., reports his team's findings in this week's issue of the journal Nature. He discusses his work in more detail on the weekly Nature. Listen to that interview below:
Scientists Wednesday unveiled a new technique that they say could break the political deadlock over human embryonic stem cells.
Embryonic stem (ES) cells are special cells that have the potential to form any tissue in the body. Someday, researchers hope they could be used for dramatic new medical treatments.
Obtaining embryonic stem cells, however, has always meant destroying embryos, and that's proved unacceptable to many people, including President George W. Bush.
Now, researchers say they can get stem cells without harming an embryo. But not everyone is convinced.
The new advance comes from the laboratory of biologist Robert Lanza of Advanced Cell Technology in Worcester, Mass. A couple of years ago, Lanza was at conference when someone asked him a question: Why do scientists have to destroy embryos to get stem cells? Couldn't they learn a lesson from fertility clinics?
Stem Cells from a Single Cell?
Those clinics routinely remove a single cell from an embryo for genetic testing, to make sure the baby will be healthy. Hundreds of children have been born after these tests. So why couldn't scientists also remove a single cell and use it to create more stem cells?
"I responded basically saying, 'That would be a great idea, but we don't know how to do that," Lanza says.
He says one of the problems is that single cells are lonely, and aren't easy to grow. "If you pluck a cell out of an embryo and place it into a plastic dish, it's obviously not going to be happy," he says.
But the question got Lanza thinking. "And when I came back from the meeting," he says, "I was going down the steps to the building, and I hit myself on the side of the head and said, 'Ah ha! I know how to do that."
Getting a Boost from Neighboring Cells
He realized that a single cell might have a shot if it shared its lab dish with some special roommates — some other cells that already know how to be embryonic stem cells.
"If we could give it some company, and some company that would give it the right signals — the right environmental cues that say, 'You are supposed to be an embryonic stem cell'— that might be sufficient," Lanza says of his team's strategy.
So Lanza's lab took donated embryos and started trying. The result? Two dishes of new stem cells, each grown from a single cell.
Lanza says this way of producing stem cells shouldn't be controversial.
"Many people, including President Bush, are concerned about destroying life in order to save life," Lanza says. "However, this study shows now that it's possible to create embryonic stem cells without destroying the embryo, and thus without destroying its potential for life."
The results appear in the journal Nature.
Lanza says his company's next step is to work with a fertility clinic. The clinic would talk to clients that are having their embryos screened for genetic diseases and ask them to donate a cell. Technicians would take one cell from the embryo, as usual.
But then, instead of sending it out for testing immediately, they would wait a few hours to let the cell replicate. If the cell divided into two, one would go for testing, the other would be used for Lanza's stem-cell research.
Some scientists say the idea is intriguing, but they urge caution. Arnold Kriegstein is a stem-cell researcher at the University of California, San Francisco.
Kriegstein says that, first of all, "any advance of this sort, exciting as it may be, would really need to be replicated before we can really embrace it wholeheartedly."
Other experts question whether families undergoing genetic testing will want to participate. And even if they do, scientists couldn't get federal funds under the current White House policy. (Last month, President Bush vetoed legislation that would have changed the policy in a way that would allow funding of this kind of stem-cell research.)
If White House policy changed, there's still another hurdle. James Battey, head of the stem-cell task force at the National Institutes of Health, says Congress has barred federal funding for any research that poses a serious risk to an embryo.
"Can we say with absolute assurance that removal of a single cell from an eight-cell embryo doesn't damage the embryo in any way?" Battey says. "The answer is no, we don't know that."
Lack of Long-Term Studies
There have been no long-term studies of the children born after single-cell removals. That's one reason some experts are skeptical that this new study will end the ethical debate.
Leon Kass, a professor at the University of Chicago, recently chaired the President's council on bioethics. He predicts that as long as embryos are involved in the creation of stem cells, the controversy is likely to continue.
"The holy grail in this field," Kass says, "is to get cells which are every bit as capable as embryonic stem cells without using embryos at all."
Kass says one option would be to reprogram a cell from an adult so that it can act like a stem cell. And Lanza says his company has been doing that kind of research. But so far, it hasn't worked as well as taking a single cell from an embryo.