[Paleopsych] NYT: Koreans Report Ease in Cloning for Stem Cells
checker at panix.com
Fri May 20 19:03:25 UTC 2005
Koreans Report Ease in Cloning for Stem Cells
By GINA KOLATA
South Korean researchers are reporting today that they have developed
a highly efficient recipe for producing human embryos through cloning,
and then extracting their stem cells.
Writing in the journal Science, the researchers, led by Dr. Woo Suk
Hwang and Dr. Shin Yong Moon of Seoul National University, said they
used their method to produce 11 human stem cell lines that were
genetic matches of patients who ranged in age from 2 to 56.
The method, called therapeutic cloning, is one of the great hopes of
the stem cell field. It produces stem cells, universal cells that are
extracted from embryos, killing the embryos in the process, and that,
in theory, can be directed to grow into any of the body's cell types.
Because the stem cells come from embryos that are clones of
individuals, they would be exact genetic matches and less likely to be
rejected by a patient's immune system. Scientists want to obtain such
stem cells from patients with certain disorders and illnesses to study
the origin of diseases and to develop replacement cells that would be
identical to those a patient has lost in a disease like Parkinson's.
Dr. Hwang said he had no intention of using the method to produce
babies that were clones. "Our proposal is limited to finding a way to
cure disease," he said. "That is our proposal and our research goal."
Previously, the same group produced a single stem cell line from a
cloned embryo, but the process was so onerous that many scientists
said it was not worth trying to repeat it, and some doubted that the
South Koreans' report was even correct.
Things have changed.
The new finding buoyed researchers who had wanted to use such stem
cells to study diseases but had thought it would be years, if ever,
before it would be practical to obtain them. "It is a tremendous
advance," said Dr. Leonard Zon, a stem cell researcher at Harvard
Medical School and the president of the International Society for Stem
Cell Research, who was not involved in the research.
But the report raised concerns among others, who said it was a step
down the slippery slope leading to cloned babies. Richard Doerflinger,
whose title is director of pro-life activities at the United States
Conference of Catholic Bishops, said: "Up until now, people were
beginning to wonder whether human cloning for any purpose was feasible
at all. This development makes it feasible enough to be a clear and
The Korean report will influence the political debate over embryonic
stem cell research, which is unfolding on Capitol Hill. The House is
expected to vote as early as next week on a measure that would expand
federal financing for embryonic stem cell studies. The measure, which
has created deep divisions among Republicans, does not address
therapeutic cloning. But a second bill, introduced by Senator Orrin G.
Hatch, Republican of Utah, would permit taxpayer financing of
therapeutic cloning studies, while prohibiting cloning for
In their new work, the South Korean researchers produced stem cells
that were exact matches for 9 of 11 patients, including 8 adults with
spinal cord injuries and 3 children - a 10-year-old boy with a spinal
cord injury, a 6-year-old girl with diabetes and a 2-year-old boy with
congenital hypogammaglobulinemia, a genetic disorder of the immune
system. Dr. Zon cautioned that "it will take a lot of work" before
stem cells fulfill their promises in medicine, but he said the new
finding would bring scientists significantly closer to the goals.
Dr. Hwang said he had been flooded by requests from researchers who
wanted to visit and study his methods, including Dr. Ian Wilmut, the
researcher in Scotland who created the first cloned mammal, a sheep
named Dolly, in 1996, astonishing scientists who had thought cloning
was biologically impossible. Dr. Wilmut visited the laboratory in
Seoul, and this week Dr. Hwang went to Dr. Wilmut's laboratory at the
Roslin Institute in Edinburgh to help him in his quest to produce
human embryos by cloning and to extract their stem cells.
Others are trying too. In England, the International Center for Life,
in Newcastle upon Tyne, announced it had produced a human embryo by
cloning, although it did not say it had extracted stem cells or gone
through the many detailed steps to prove that they were stem cells and
that they were from a clone, as the South Koreans had done.
Until now, scientists had been studying human embryonic stem cells
extracted from embryos created for that purpose and did not involve
cloning cells from specific patients. They had also obtained stem
cells from embryos created at fertility clinics and donated by couples
who no longer needed them. In addition, scientists are studying mouse
stem cells, working on the difficult task of directing the cells to
develop into specific tissue types.
But researchers wanted embryos that were genetic matches of patients.
The only way to do that was to use embryos that were clones of
patients, and human cloning had seemed all but impossible.
To produce a clone, scientists slip the genetic material from a
patient's cell into an unfertilized egg from another person whose
genetic material has been removed. The genes from the patient's cell
take over, directing the egg to divide and develop into an embryo that
is genetically identical to the patient. About five days later, when
the cloned embryo contains about 100 cells and is about 0.08 inch in
diameter, it changes its form, looking like a ball of cells encased in
a sphere. That ball of cells, when removed and grown in the
laboratory, becomes the embryonic stem cells.
The process, however, fails more often than it succeeds, and, in
humans, it seemed to fail almost all the time. In a previous report,
published last February, Dr. Hwang and Dr. Moon used 248 human eggs to
produce a single embryonic stem cell line, a group of cells that came
from one embryonic cell and could grow on a petri dish.
But this time, with a handful of technical improvements that mostly
involved methods for growing cells and breaking open embryos, they
used an average of 17 eggs per stem cell line and could almost
guarantee success with the eggs of just one woman obtained in a single
month. It did not matter whether the patient whose cells were being
cloned was young or middle-aged, male or female, sick or well - the
"You almost have no reason not to do it," said Dr. Davor Solter, the
director of the Max Planck Institute for Immunobiology in Freiburg,
Germany. He added that it seemed more efficient to clone and obtain
human stem cells than to do the same experiment in animals, although
no one knows why.
Seven states ban any type of human cloning and 11 have laws that
prevent embryonic stem cell research, said Lori B. Andrews, a law
professor at Chicago-Kent College of Law, and federal money is
restricted to research using stem cell lines approved by the Bush
administration in 2001. Where such work is legal, however, increasing
numbers of scientists, including Dr. Zon, say they have private
financing and plan to go forward using cloning to produce stem cells.
Dr. John Gearhart, a stem cell researcher at Johns Hopkins University,
said the new paper would provide an impetus. "I think you will see
more people in the game," he said.
Not everyone is excited.
Dr. Leon Kass, chairman of the President's Council on Bioethics,
commented in an e-mail message that "whatever its technical merit,
this research is morally troubling: it creates human embryos solely
for research, makes it much easier to produce cloned babies, and
exploits women as egg donors not for their benefit."
The South Korean government, which paid for the new study, has made it
a crime to implant a cloned embryo into a woman's uterus, Dr. Hwang
said. "It should be banned throughout the world," he added.
The study included 18 women who provided eggs.
The South Korean scientists worked hard, said Dr. Gerald Schatten of
the University of Pittsburgh School of Medicine, who visited their
laboratory and helped the scientists, whose English is limited, write
"They work 365 days a year except for leap year, when they work 366
days," Dr. Schatten said. "They have lab meetings at 6:30 every
morning except Sunday, when they have them at 8."
Few would venture into the cloning arena if the science was not so
promising, researchers say. Of course, they say, there is a long way
to go from stem cells to therapy.
"It's going to take a lot of work," said Dr. Ronald McKay, a stem cell
researcher at the National Institutes of Health. "But we want this to
work - it's not a theory. My technical and professional judgment tells
me this is really important."
Dr. Kass, however, says that cloning and extracting stem cells from
the embryos is not the only way to do such work. A majority of the
President's Council on Bioethics called for a moratorium on cloning
for research, he said, and the council recently suggested other ways
of getting stem cells that could develop into the desired tissue types
and that would match a patient's own cells "without these violations
and moral hazards."
Opinion polls have had varied results, often depending on the words
that are used to describe the work. In a recent Gallup poll, just 38
percent of respondents approved of cloning embryos for research.
Another poll, which used the term "somatic cell nuclear transfer"
instead of "cloning," found that 72 percent approved.
Dr. Hwang's paper goes a step further, using "S.C.N.T." instead of
"somatic cell nuclear transfer."
Dr. Ruth Faden, the executive director of the bioethics center at
Johns Hopkins, said the moral debate would change if the research led
to new treatments with dramatic benefits for some patients. "That
could really shake it up," she said.
But Dr. Richard Land, the president of the Southern Baptist
Convention's ethics and religious liberty commission, said his group
would not be assuaged.
"We believe a cloned embryo is a human being," Dr. Land said. "We
should not be the kind of society that kills our tiniest human beings
in order to seek a treatment for older and bigger human beings."
Sheryl Gay Stolberg contributed reporting from Washington for this
More information about the paleopsych