Researchers Clone Human Embryo for Stem Cells
NewsMax.com Wires
Thursday, Feb. 12, 2004
WASHINGTON Researchers in South Korea have become the
first to successfully clone a human embryo, and then cull from it
master stem cells that many doctors consider key to one day
creating customized cures for diabetes, Parkinson's and other
diseases.
This is not cloning to make babies, but to create medicine.
It's sure to revive international controversy over whether to
ban all human cloning, as the Bush administration wants, or to
allow this "therapeutic cloning" that might eventually let
patients grow their own replacement tissue.
Embryonic stem cells are the body's building blocks, cells from
which all other tissue types spring. They're present in an embryo
only days after conception and are ethically sensitive because
culling stem cells destroys the embryo.
Scientists have used therapeutic cloning to partially cure
laboratory mice with an immune system disease. And they know how to
cull stem cells from human embryos left over in fertility clinics.
But attempts to clone human embryos, so the resulting stem
cells would be genetically identical to the patient who needs them, have failed until now.
Scientists from Seoul National University say they succeeded
largely because of using extremely fresh eggs donated by South
Korean volunteers and gentler handling of the genetic material
inside them.
The lead scientist, veterinary cloning specialist Woo Suk Hwang,
will unveil the research Thursday at a meeting of American
Association for the Advancement of Science. Details will be
published in the journal Science.
'Elegant'
It's elegant work that provides long-anticipated proof that
human therapeutic cloning is possible, said stem-cell researcher
Dr. Rudolf Jaenisch of Whitehead Institute for Biomedical
Research in Cambridge, Mass.
Still, "it's not of practical use at this point," Jaenisch
cautioned.
Years of additional research are required before embryonic stem
cell transplants could be considered in people, he stressed.
But it's sure to renew debate over whether all forms of human
cloning should be banned. The U.S. House of Representatives last year voted to do that, but the Senate stalled over whether there should be an exception for some research.
U.S. scientists almost universally want a ban on cloning for
reproduction, because the high rate of birth defects in cloned
animals shows the technique is too dangerous.
'Wise'
But the South Korean research is "one tiny step closer to some
medical use. It would be a wise thing to support," said Laurie
Zoloth, a Northwestern University bioethicist. "It is clearly time, now that it is more tangible, to set in place a process where we
can have some kinds of experiments supported and some things
banned."
Internationally, the United Nations recently postponed a
decision on what kinds of human cloning to ban. The United States
is pushing for a total ban. Britain is leading the call for cloning
for medical experiments to be left unhindered.
The Seoul researchers collected 242 eggs from 16 unpaid
volunteers. Each woman also donated some cells from her ovary.
Using the same process as is used to clone animals, they removed
the gene-containing nucleus of each egg and replaced it with the
nucleus from the donor's ovarian cell.
Chemicals jump-started cellular division, resulting in 30
blastocysts, early-stage embryos that contain a mere 100 cells.
From those, they harvested just one colony of stem cells, a small
success rate.
But those stem cells were a genetic copy of the donor, and began
forming muscle, bone and other tissues in test tubes and when
implanted into mice, the Seoul team reported.
Now, the team is studying how to direct which tissues those
cells form, said Woo, who pledged in an e-mail interview to make
the new cell line available to other interested scientists.
But Jaenisch lamented that many U.S. scientists couldn't work
with the new cell line. Bush administration policy forbids any
federally funded research on stem cells from embryos destroyed
after Aug. 9, 2001.
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