Wednesday April 26 3:49 PM ET
By Maggie Fox, Health and Science Correspondent
WASHINGTON (Reuters) - Senators fighting for legislation to back controversial medical research involving stem cells deployed their biggest weapon on Wednesday in the form of actor Christopher Reeve, who once played Superman and is now paralyzed.
But the senators also invited their own opponents to testify at a committee hearing, including a fellow senator who has spoken out strongly against the research involving stem cells from human embryos.
Both sides agreed that the debate boils down to whether the cells are being taken from potential human beings, or from small collections of cells that would be thrown away if they were not used for research.
Both sides also agree that stem cells offer enormous promise to transform medicine and science, treating or even curing diseases such as Parkinson's, Alzheimer's and diabetes.
"I believe that stem cell research has the potential for a veritable fountain of youth," Pennsylvania Republican Sen. Arlen Specter, who chairs the subcommittee, said.
"The discarded embryos are not going to be used for human life," Specter said. "If there was any possibility, I would be the first to oppose their use for scientific research."
Reeve, who believes stem cell research could help him walk again, agreed.
"Is it more ethical for a woman to donate unused embryos that will never become human beings, or to let them be tossed away as so much garbage when they could help save thousands of lives?" he asked the hearing.
"We have a tool that is a near-miracle," Reeve added. "It would be a criminal waste not to use them."
Specter hopes the Senate will debate his bill, the Stem Cell Research Act of 2000, before the Memorial Day break next month. It would permit the use of federal funds to use stem cells taken from embryos left over from fertility treatment for scientific research.
Current law forbids the use of federal funds for science that would destroy a human embryo, although the National Institutes of Health has interpreted this law to mean its researchers can use the stem cells so long as they are extracted by privately funded researchers.
Stem cells are a kind of master cell for the body. Depending on their source, they have the ability to produce many different kinds of cells.
Embryonic stem cells are pluripotent -- they can become any kind of cell in the body. So far scientists cannot control this process but are learning to do so and they hope to use them to produce tissues for transplant and perhaps even entire organs.
Adult stem cells have been found in the bone marrow, the blood, the brain, liver and other parts of the body and give rise to specific families of cells. Some research suggests that they, too, may be re-programmed to some degree so that blood stem cells could, for instance, produce nerve cells.
Scientists say research needs to proceed on both kinds of cells.
"It's far to early to know if adult stem cells have the same potential as embryonic stem cells," Lawrence Goldstein, a professor of cellular and molecular biology at the University of California at San Diego, told the hearing.
"It is likely to take years to find out if adult stem cells will be useful for treating many diseases that may be treatable sooner with embryonic stem cells," he added.
"We may be on the cusp of a new era of medicine, one in which cell therapy could restore normal function to a variety of affected tissues."
But Kansas Republican Sam Brownback said he did not consider it moral to trade one human life for another, and he considers the embryos to be human lives.
"At the center of this debate is the real question -- is the young human person or property?" Brownback said.
He called stem cell research using embryonic cells "illegal, immoral and unnecessary" and compared it with research done on prisoners by Nazi scientists.
He supports, instead, research using adult stem cells.
"It does not carry the moral baggage," said Dr. Frank Young, a Protestant minister and former commissioner of the Food and Drug Administration.
Dr. Allen Spiegel, director of the National Institute of Diabetes and
Digestive and Kidney Diseases (NIDDK), said this would be cutting off an
entire avenue of research. "I think this would be tying one hand behind
our back," he said.