WASHINGTON (AP) — 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
This is not cloning to make babies, but to create medicine.
It immediately revived 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.
“We have to do this research because of its promise for
treating disease,” said Dr. Moon Shin-yong of Seoul National
University, who co-led the new research.
Without cloning, stem cells won’t be genetically identical
to the patient who needs them, causing “a rejection problem,
and we would like to overcome it,” Moon told The Associated
Press. “This kind of science should be conducted in South
Korea and in the United States. It is very important to
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 can cull
stem cells from human embryos left over in fertility clinics.
Attempts to clone human embryos, to supply stem cells, have
failed until now.
The Seoul scientists say they succeeded largely because of using
extremely fresh eggs donated by South Korean volunteers and gentler
handling of the genetic material inside them.
Moon and colleague Woo Suk Hwang discussed the research
yesterday at a meeting of the American Association for the
Advancement of Science. Details will be published in the journal
It’s elegant work that provides long-anticipated proof
that human therapeutic cloning is possible, said stem-cell
researcher Dr. Rudolf Jaenisch of the Whitehead Institute for
Biomedical Research in Cambridge, Mass.
“It’s not of practical use at this point,”
Years of additional research are required before embryonic stem
cell transplants could be considered in people, he stressed.
Critics immediately urged Congress to ban all forms of human
cloning. The House last year voted to do that, but the Senate
stalled over whether there should be an exception for some
“The instrumentalization of human life for the benefit of
others demeans the value of all human life,” said Sen. Sam
Brownback (R-Kan.) who has sponsored legislation for a complete
There’s nothing to stop the next cloned embryo from being
used for pregnancy, contended Richard Doerflinger of the U.S.
Conference of Catholic Bishops.
“The how-to instructions have been posted,” he said.
“If you can bring an embryo to the one-week-old stage, you
can implant that embryo in the womb. Once you do, no government can
stop you unless they want to coerce abortions.”
Stem-cell proponents hailed the research as a crucial first step
to one day alleviating diabetes, Parkinson’s and other
“It does show what is possible and provides hope to
millions,” said Daniel Perry of the Coalition for the
Advancement of Medical Research.
U.S. scientists almost universally want a ban on reproductive
cloning because the high rate of birth defects in cloned animals
shows the technique is too dangerous.
The South Korean research is “one tiny step closer to some
medical use,” 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.”
“With 100 million patients waiting for breakthroughs in
transplant medicine, it would be unethical to stop the research,
especially now,” added Carl Feldbaum of the Biotechnology
Industry Organization. With “an uncertain political climate
… its no coincidence that much of the groundbreaking work in this
field is being done overseas.”
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.
Those stem cells began forming muscle, bone and other tissues in
test tubes and when implanted into mice, the Seoul team
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.
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.