SUNDAY, Oct. 16, 2005 (HealthDay News) -- New research may have found ways around some of the ethical quandaries plaguing stem cell research in the United States.
Two studies detail innovative ways to derive embryonic stem cell lines without destroying viable embryos; the findings were hailed as promising but preliminary.
"Approaches to get embryonic stem cells from methods in which the embryo is not harmed are clearly very important and a significant advance," said Paul Sanberg, director of the Center for Aging and Brain Repair at the University of South Florida College of Medicine in Tampa.
"These are still early studies that have to be shown in human cells, but they are going in an interesting direction," Sanberg said. "We still need to do research in embryonic stem cells in order to understand basic biology, and having embryonic stem cells in which we don't have ethnical issues associated with it is important, especially in the United States."
The new studies, which involved mice, appear Sunday in the online issue of Nature.
Embryonic stem cells, which are derived from early embryos before they implant in the uterus, have the potential to develop into any type of cell in the body. The hope is that these cells may one day provide treatments or cures for diseases such as diabetes, liver failure, spinal injury, stroke, Alzheimer's disease and heart disease.
But because the embryo is destroyed in the process of acquiring the stem cells, there has been great opposition to this type of research. Currently, there is a ban in the United States on the use of federal funds to create new stem cell lines from embryos leftover from fertility treatments.
Scientists have long been trying to find ways to sidestep the ethical pitfalls. In May, researchers in South Korea announced they had created 11 embryonic stem cell lines without using fertilized eggs. In August, British and U.S. researchers announced they had produced embryonic-like cells from umbilical cord blood. This was followed days later by an announcement from Harvard University researchers that they had found a way to combine embryonic stem cells with human skin cells, which were then reprogrammed to become embryonic stem cells.
In the first study detailed in this week's Nature, researchers, including Rudolf Jaenisch of the Massachusetts Institute of Technology, blocked the action of the Cdx2 gene in preimplantation mouse embryos. This prevented the formation of a cell layer called the trophectoderm that, in turn, prevented the embryos from settling into the uterine wall.
The mouse embryos could still produce embryonic stem cells that could generate all cell lineages. The gene could also be turned back on once the stem cell culture was established.
For the second study, researchers used a tried-and-true fertility technique known as preimplantation genetic diagnosis to derive mouse embryonic stem cell lines. A single cell was taken from the mouse embryo, leaving the rest of the embryo to implant and develop as usual. The single cell was enough to produce several stem cell lines.
"Many people are concerned about destroying life in order to save life," said Dr. Robert Lanza, senior author of the second study and medical director of Advanced Cell Technology in Worcester, Mass. "We show for the first time that we can generate embryonic stem cells that don't interfere with the developmental potential of the embryo. By plucking a single cell, we were able to generate a dozen stem cell lines, all the cell lines of the body. They were totally indistinguishable from normal embryonic stem cells."
Will the technique work in humans? "This was worked on in mice, and mouse stem cells are very similar in biology," Lanza said. "The biology is very similar. We won't know for sure until we do experiments."
Lanza also emphasized that these new investigational methods aren't meant to replace other avenues of stem cell research.
"It's really important that this isn't a substitute for methods that we already know work," Lanza said. "There is a very real human tragedy out there that continues to claim the health and lives of people. A lot of people don't have time to wait for us even if it's only a few months. We need to move ahead with all methods and options available to us."
A statement from Dr. Robert Schenken, president of the American Society for Reproductive Medicine, added a cautionary note.
"The research by Professor Jaenisch and Professor Lanza and their colleagues announced today represent important steps forward in the rapidly evolving field of stem cell science," the statement read. "It is essential to note that both of these studies, while potentially very important, are also very preliminary. There is much work to do before any of this might be applied to human beings. Thus far, our work in many other areas has taught us that in reproductive medicine, what works in animals may not translate well to humans."
If a recent survey by Johns Hopkins University is any indication, there is broad support among Americans for stem cell research.
The survey of 2,212 Americans conducted in September found that two-thirds of respondents approved or strongly approved of human embryonic stem cell research. The support cut across political, religious and socio-economic lines, with fundamentalist and evangelical Christians split evenly on the subject.
More information
To learn more about stem cells and stem cell research, head to the International Society for Stem Cell Research.
