Scientists Harvest Stem Cells Without Destroying Embryo
Breakthrough technique might get around moral issues, experts say
WEDNESDAY, Aug. 23, 2006 (HealthDay News) -- In what could prove to be a medical milestone, researchers have succeeded in generating new lines of human embryonic stem cells without destroying the embryo.
The breakthrough may enable scientists to circumvent the ban on federal funding of stem cell research, paving the way for gains in treating or curing diseases such as diabetes, spinal injury and Alzheimer's disease.
"The whole goal of this is to increase the number of stem cell lines available for federal funding and give the field a badly needed jump-start," said Dr. Robert Lanza, senior author of a paper appearing in the Aug. 24 issue of Nature and medical director of Advanced Cell Technology in Worcester, Mass.
Lanza was cautiously optimistic, although he said the final say on whether this strategy could widen U.S. embryonic stem cell research depends on politicians, not scientists.
"The approach described here does not involve the destruction of an embryo, nor does the biopsied cell ever develop into an embryo at any point. Therefore, we hope this method can be used to increase the number of stem cell lines available for federal funding - and thus give the field a badly needed jump-start," Lanza said. "But I guess we'll have to see what the President and Congress have to say about it all."
The promise of embryonic stem cells lies in their ability to be "pluripotent," and develop into any cell type in the body. Experts envision a future where stem cells might help replace diseased or injured tissue, thereby treating a host of ailments.
However, many object to the destruction of embryos inherent in this research. For that reason, embryonic stem cell research in the United States has been severely restricted since Aug. 9, 2001, when President Bush placed limits on federal funding of the field. As of that date, federal funds could only be used to study stem cell lines derived from embryos that had been already been destroyed before the limit was set.
This has turned out to be fewer lines than originally thought, and even fewer high-quality lines.
And while some state and private money has emerged to fill the gap in research funding, experts say it's not been nearly enough. Most scientists agree that federal resources are needed if any credible research gains are to take place.
So far, scientists have obtained embryonic stem cells by taking groups of cells from early embryos before they implant in the uterus. However, this process involves the destruction of the embryo.
Lanza's new paper improves on research his team did last year. In that study, the Massachusetts group succeeded in cultivating mouse embryonic stem cell lines by removing just one cell from the mouse embryo. The procedure is similar to that used for pre-implantation genetic diagnosis, used to check for genetic disorders during in vitro fertilization (IVF). In this case, the mouse embryos survived.
But then, a roadblock. "We tried to apply that to a human system and found that it does not work," Lanza said. "We had to work out a different technique and initially we weren't sure that it was going to work. It was pretty tough. Eventually it worked like a charm."
Here's how. According to Lanza, the new research involved 16 human embryos left over from IVF.
"We used a single-cell biopsy technique to pluck out one cell when the embryo was at the 8-to-10-cell stage," Lanza explained. This is the same stage used for pre-implantation genetic diagnosis. Excising a cell at this point doesn't interfere with the embryo's development, the scientist explained.
However, the cells apparently do not like being co-cultured alone, so they were put into a dish with other cells. This technique worked to keep them alive.
Using this method, Lanza and his team managed to get two stable human embryonic stem cell lines that behaved like conventional embryonic stem cell lines.
"They've now been growing for over eight months, are entirely normal genetically and they were able to generate all of the cell types of the body," Lanza said.
"The real importance of this is the potential that you could have embryonic stem cell lines that are pluripotent from embryos that aren't destroyed," said Paul Sanberg, director of the Center for Aging and Brain Repair at the University of South Florida College of Medicine in Tampa. "If these cell lines were allowed, it could help enhance embryonic stem cell research."
Lanza's company will be working with the scientific community to make the stem cell lines widely available.
"With the right resources, we could recreate as many lines as the scientific community needs without harming the embryos and help other researchers develop the technique," Lanza said. "We could move very quickly."
Next year, he said, Advanced Cell Technology will be filing an investigational new drug application aimed at the eye condition known as macular degeneration.
To learn more about stem cells and stem cell research, head to the International Society for Stem Cell Research.