NYTimes
August 24, 2006


In New Method for Stem Cells, Viable Embryos
By NICHOLAS WADE

Biologists have developed a technique for establishing colonies of human
embryonic stem cells from an early human embryo without destroying it. This
method, if confirmed in other laboratories, would seem to remove the
principal objection to the research.

It could also redirect and intensify the emotional political debate over
current limits on federal financing for research on human embryonic stem
cells, which give rise to the cells and tissues of the body and which
scientists and patient advocate groups see as a potential source for
treatments for diseases like Alzheimer's, Parkinson's and diabetes.

But the new method, reported yesterday by researchers at Advanced Cell
Technology on the Web site of the journal Nature, had little immediate
effect on longstanding objections of the White House and some Congressional
leaders yesterday. It also brought objections from critics who warned of
possible risk to the embryo and the in vitro fertilization procedure itself,
in which embryos are generated from a couple's egg and sperm.

The new technique would be performed on a two-day-old embryo, after the
fertilized egg has divided into eight cells, known as blastomeres. In
fertility clinics, where the embryo is available outside the woman in the
normal course of in vitro fertilization, one of these blastomeres can be
removed for diagnostic tests, like for Down syndrome.

The embryo, now with seven cells, can be implanted in the woman if no defect
is found. Many such embryos have grown into apparently healthy babies over
the 10 years or so the diagnostic tests have been used.

Up to now, human embryonic stem cells have been derived at a later stage of
development, when the embryo consists of about 150 cells. Both this stage,
called the blastocyst, and the earlier eight-cell stage, occur before the
embryo implants in the wall of the womb. Harvesting the blastocyst-stage
cells kills the embryo, a principal objection of those who oppose the
research.

"There is no rational reason left to oppose this research," Dr. Robert
Lanza, vice president of Advanced Cell Technology and leader of the research
team, said in an interview.

With the approach of midterm elections, in which some candidates are already
making the research a central theme, some scientists speculated that
President Bush might embrace the new method as meeting his principal
objection to the research and showing that he had been right all along to
wait for a better technique to turn up.

But Emily Lawrimore, a White House spokeswoman, suggested that the new
procedure would not satisfy the objections of Mr. Bush, who vetoed
legislation in July that would have expanded federally financed embryonic
stem cell research. Though Ms. Lawrimore called it encouraging that
scientists were moving away from destroying embryos, she said: "Any use of
human embryos for research purposes raises serious ethical questions. This
technique does not resolve those concerns."

Last year, Dr. Lanza reported that embryonic stem cell cultures could be
derived from the blastomeres of mice, a finding others have confirmed. He
now says the same can be done with human blastomeres, and that the colonies
of cells behave in the same way as those derived from blastocysts.

Although he used discarded human embryos, he said that anyone who wished to
derive human embryonic stem cells without destroying an embryo could use a
blastomere removed for the test, called preimplantation genetic diagnosis.

"By growing the biopsied cell overnight," he said, "the resulting cells
could be used for both P.G.D. and the generation of stem cells without
affecting the subsequent chances of having a child."

Ronald M. Green, an ethicist at Dartmouth College and an adviser to Advanced
Cell Technology, said he hoped the new method "provides a way of ending the
impasse about federal funding for this research."

Professor Green said he believed the method should be seen as compatible
with the Dickey-Wicker amendment, the Congressional measure that prohibits
using federal money for any research in which a human embryo is destroyed or
exposed to undue risk.

Dr. James Battey, head of the stem cell task force at the National
Institutes of Health, said that it was not immediately clear if the new
method would be compatible with the Congressional restriction, since removal
of a blastomere subjected the embryo to some risk, but that embryos on which
the genetic test was performed seemed to be as healthy as other babies born
by in vitro fertilization.

Mr. Bush has allowed federal financing for research on human embryonic stem
cells, provided they were established before Aug. 9, 2001. Although that
might seem to rule out any new cell lines derived from blastomeres, Dr.
Battey said that was not clear because the embryo would not be destroyed,
and that he would seek guidance on the point.

The federal policy does not affect privately financed stem cell research,
like that done by Advanced Cell.

Critics have a range of objections to deriving human embryonic cell lines
with the new method. The United States Conference of Catholic Bishops, in
particular, oppose both in vitro fertilization and preimplantation genetic
diagnosis, and therefore still object to the research.

Richard Doerflinger, deputy director for pro-life activities at the
conference of bishops, said the church opposed in vitro fertilization
because of the high death rate of embryos in clinics and because divorcing
procreation from the act of love made the embryo seem "more a product of
manufacture than a gift."

Asked if he meant that the parents of a child conceived through in vitro
fertilization would love it less, Mr. Doerflinger said he was referring to
the clinic staff. "The technician does not love this child, has no personal
connection with the child, and with every I.V.F. procedure he or she may get
more and more used to the idea of the child as manufacture," he said.

Dr. Leon Kass, former chairman of the President's Council on Bioethics,
said, "I do not think that this is the sought-for, morally unproblematic and
practically useful approach we need."

Dr. Kass said the long-term risk of preimplantation genetic diagnosis was
unknown and that the present technique was inefficient, requiring
blastomeres from many embryos to generate each new cell line. It would be
better to derive human stem cell lines from the body's mature cells, he
said, a method researchers are still working on.

Dr. Andrew La Barbera, scientific director of the American Society for
Reproductive Medicine, said that more than 2,000 babies had been born in the
United States after a preimplantation genetic diagnosis. There is no sign
yet that they have any greater risk of disease than other in vitro
fertilization babies, but the society needs more data to be sure, Dr. La
Barbera said.

Scientists welcomed the new development but also expressed concerns. Dr.
Irving Weissman, a stem cell expert at Stanford University, said the new
method, if confined to blastomeres derived from preimplantation genetic
testing, would not provide a highly desired type of cell, those derived from
patients with a specific disease.

Many scientists have come to regard this use of the cells, to explore the
basic mechanisms of disease, as more likely to provide new therapies than
direct use of the cells themselves.

Dr. Weissman said the new advance could lead into a "Congressional trap" if
Congress permitted new lines to be established only during the
preimplantation genetic diagnosis procedure. This test looks for only a
handful of diseases, he said, and not for Alzheimer's and the other
degenerative diseases for which better therapies are needed.

Congressional Republicans who led the resistance to the embryonic stem cell
legislation that had bipartisan support in the House and Senate also said
the new technique did not ease their opposition. Brian Hart, a spokesman for
Senator Sam Brownback, Republican of Kansas and a prominent opponent of
federal financing for embryonic stem cell research, said Mr. Brownback's
moral objection remained.

"You are creating a twin and then killing that twin," Mr. Hart said.

Dr. Lanza said, however, that twinning is a phenomenon that occurs at a
later stage of embryonic development and that there was no evidence that a
single blastomere could develop into a person.

Democrats and others who had pushed for added research using embryos that
were ultimately going to be discarded stepped up their criticism of the
president and his allies for holding back science.

"It's tragic that the current Republican Congress continues to rubber stamp
the restrictions that deny federal funding for scientists engaged in medical
research that could save or improve countless lives," said Senator Edward M.
Kennedy, Democrat of Massachusetts.

Political analysts said the new findings could elevate embryonic stem cell
research as a campaign issue by both keeping it in the news and making it
more difficult for opponents to explain their position.

"It paints the pro-life community into a corner," said Stuart Rothenberg, a
nonpartisan analyst of Congressional races. "As a rule, you don't want to
oppose scientific advances."

Gardiner Harris and Carl Hulse contributed reporting for this article.

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