[Paleopsych] NYT: Koreans Report Ease in Cloning for Stem Cells

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Fri May 20 19:03:25 UTC 2005


Koreans Report Ease in Cloning for Stem Cells
http://www.nytimes.com/2005/05/20/science/20clone.html

    By [2]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
    present danger."

    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
    reproduction.

    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
    process worked.

    "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
    their paper.

    "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
    article.



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