The medical, moral and political debate over the need for embryonic stem-cell research remains fierce, with multiple medical reports in the past 18 months describing ways to produce disease-treating stem cells without destroying human embryos.
Stem cells are the body’s master cells, the basic building blocks from which a person’s tissue and organs develop. Scientists say the cells hold promise for treating — and perhaps curing — diseases such as Parkinson’s, diabetes and cancer.
Proponents of embryonic stem-cell research think these types of cells hold the greatest potential for medical breakthroughs because they have the ability to grow into any type of cell in the body if scientists learn how to direct their development.
But critics of embryonic stem-cell research, including President Bush, say destroying or tampering with a human embryo is immoral.
“We recoil at the idea of growing human beings for spare body parts or creating life for our own convenience,” Mr. Bush has said.
The president and others favor research that involves stem cells from adults and children, which can be obtained without harming the donor. Examples include stem cells taken from bone marrow and other organs and tissue, and from placentas left over from live births.
Some stem-cell researchers and others who closely observe the field think scientists will find viable alternatives to embryonic stem cells that are not morally objectionable.
“I believe we could get the equivalent of embryonic stem cells through technological solutions that do not require the creation and destruction of embryos,” said Dr. William B. Hurlbut, a consulting professor at Stanford University’s Neuroscience Institute.
“Had we acknowledged this possibility early and put our energies to the task, we would probably have found an answer by now,” said Dr. Hurlbut, also a member of the President’s Council on Bioethics.
“An alternative is going to happen,” said Dr. Markus Grompe, head of the Stem Cell Research Center at Oregon Health and Science University in Portland. He says he uses “mouse embryo stem cells all the time” in his lab work but never human embryonic stem cells because of moral concerns.
B.D. Colen, spokesman for the Harvard Stem Cell Research Institute, is disturbed by the attention being given to those with moral concerns about embryonic stem cells.
“When did we start basing science policy in this country on what are fundamentally religious beliefs?” he asked.
Finding alternatives
A White House report on stem-cell research, released Jan. 9 by the Domestic Policy Council, stated that there should be a way “to create human pluripotent cells,” meaning flexible cells such as embryonic stem cells, that “can transform into many or perhaps all of the different cell types in the body in cells derived without embryos.”
The report, “Advancing Stem Cell Science Without Destroying Human Life,” highlighted “tremendous scientific progress of late in exploring methods of deriving pluripotent stem cells without destroying embryos.”
Research developments cited by the White House and other critics of embryonic stem-cell research include:
On Jan. 7, scientists at Wake Forest University School of Medicine reported that a type of cell found in amniotic fluid has significant versatility in terms of the type of body tissue it can become and could be used to treat a variety of diseases.
The cells, discarded by the developing fetus and retrieved easily during prenatal testing, are easier to control in the laboratory than embryonic stem cells, according to authors of the report, published online in the journal Nature Biotechnology.
In August 2006, researchers at Advanced Cell Technology (ACT), a California-based firm, reported that they had devised a method to create human embryonic stem cells without harming embryos, They said their technique involved taking a single cell, or blastomere, from a 2-day-old embryo after the fertilized egg divided into eight cells. The researchers said the rest of the embryo could be allowed to grow into a healthy human.
But the White House report charged that the technology ACT deployed “did in fact destroy every one of the human embryos used.”
Dr. Robert Lanza, director of research and development at ACT, disagreed.
“The embryo was not harmed or destroyed and remains frozen just like the embryos at in-vitro clinics,” he said.
In March 2006, German researchers disclosed that they had isolated stem cells from the testicles of adult mice that appeared similar to embryonic stem cells. They were optimistic the same type of cells could be extracted from human testicles.
In October 2005, Dr. Rudolf Jaenisch of the Massachusetts Institute of Technology reported he had produced stem cells with the same capabilities as traditional embryonic stem cells through a process that has come to be known as altered nuclear transfer without cloning.
The technique used in mice relies on deactivating a gene essential for formation of an embryo.
Dr. Jaenisch modified mouse DNA and inserted it into an egg whose own genetic material had been removed. After the altered DNA was inserted, cells began to divide and formed an unorganized clump of cells from which stem cells were then retrieved.
Dr. Hurlbut said the method has been recommended for further exploration in animal studies by the presidential advisory panel on bioethics on which he serves and has been endorsed by 35 religious leaders or groups
In August 2005, British scientists announced they had found a way to derive embryoniclike stem cells in umbilical-cord blood.
‘An ongoing problem’
But some of the scientists whose work was cited in the White House report complained of misrepresentation by the council, saying they were unhappy that their findings were being used to support arguments that embryonic stem-cell research is unnecessary.
“Our work directly involves the use of human embryonic stem cells,” the researchers said in a letter to members of Congress. The scientists urged passage of expanded federal funding for embryonic stem-cell research, which the Bush administration opposes.
“Science works best when scientists can pursue all avenues of research,” Story Landis, acting chairwoman of the National Institutes of Health’s stem-cell task force, told a Senate committee last month.
“If the cure for Parkinson’s disease or juvenile diabetes lay behind one of four doors, wouldn’t you want the option to open all four doors at once, instead of just one door?” Miss Landis asked.
“The rhetoric for embryonic stem-cell research is more shrill today than ever, but this research is not panning out,” said David Prentice, a senior fellow for life sciences at the Family Research Council, which opposes embryonic stem-cell research.
The development of tumors has been “an ongoing problem” in animal research using embryonic stem cells, according to the White House report and other researchers.
Neurologists at the University of Rochester and Cornell reported in November that brain cells derived from embryonic stem cells dramatically improved the condition of rats with severe Parkinson’s-like symptoms. But they said the treatment also caused a significant problem — the appearance of brain tumors in the rodents.
“In fact, 100 percent of the rats got tumors,” said Mr. Prentice, who is familiar with the research. He added that there have been “at least a dozen” cases of animal studies using embryonic stem cells in which 25 percent to 50 percent of the animals developed tumors.
The White House report does support clinical trials using adult stem cells, which it says “have produced encouraging improvements in patients with a range of disorders and diseases, including leukemia, lymphoma, diabetes, advanced kidney cancer and several genetic blood disorders.”
Mr. Prentice agrees.
“More than 3,000 patients are better today as a result of heart treatments that relied on the patients’ own bone-marrow stem cells,” he said.
What’s more, about 6,000 patients with conditions such as leukemia and sickle cell anemia have been successfully treated with stem cells from umbilical cord blood, Mr. Prentice said.
Funding the research
In 2001, Mr. Bush announced that federal funds could be awarded for embryonic stem-cell research but using only about 70 cell lines that were in existence at the time.
Since that time, $130 million in federal funding has been used for such research, including $40 million last year alone, Dr. Hurlbut said. Nearly $3 billion in federal funds have been used for all forms of stem-cell research, according to the White House report.
Nothing in the federal policy constrains either private or state funding of embryonic stem-cell research. To date, at least six states — California, Connecticut, Illinois, Massachusetts, New Jersey and Wisconsin — have encouraged embryonic stem-cell research or set aside money for it.
In November, voters in Missouri narrowly approved a constitutional amendment that prohibits state officials from banning embryonic stem-cell research. And New Mexico Gov. Bill Richardson, a 2008 Democratic presidential candidate, said he would ask the state legislature to approve a $10 million stem-cell research center at the University of New Mexico. The center would feature research using both embryonic and adult stem cells.
In 2004, California voters approved a ballot measure to allow that state to raise as much as $3 billion through bond sales to fund embryonic stem-cell research.
“But that $3 billion has been locked up in lawsuits” brought by opponents of embryonic stem-cell research, Dr. Hurlbut said.
Even so, he said, “preliminary grants” for the research “are being distributed,” as a result of $150 million Gov. Arnold Schwarzenegger has provided to start the research program and another $40 million in private donations.
The White House Domestic Policy Council report says that “funding [for embryonic stem-cell research] by individual states is expected to add up to several billion dollars in the next few years.”
Meanwhile, some in Congress are seeking to end the restrictions on federal funding for embryonic stem-cell research.
The House voted last month to allow federal funding for new stem-cell lines derived from fertility clinic embryos that otherwise would be discarded. The Senate is likely to pass the measure next month. However, Mr. Bush vetoed an identical bill in July and says he will veto it again.
In another development, New York-based NeoStem, a leader in adult stem-cell technology, has opened the nation’s first walk-in stem-cell center. It provides patients with adult stem-cell collection and banking services for their use in future medical crises.
Researchers Amy Basker-ville and John Sopko contributed to this article.
Please read our comment policy before commenting.