Special Report
- Human Destiny Stem cells hold promise of cures
By PAMELA SCHAEFFER
Stem cells, hailed as the greatest
medical miracle since antibiotics, yet the new lightning rod for the abortion
debate, are almost daily in the news.
Stem cells are the most versatile of cells: cells capable of
reproducing themselves and also of growing into different kinds of body tissue.
Stem cells are found in embryos and umbilical cords. Reservoirs of specialized
stem cells also exist within our bodies, where they wait for the signal to go
into action, repairing or replacing tissues damaged by age, injury or
disease.
When someone cuts a finger, stem cells kick in to make new skin.
They are also the reason injured lizards can grow new body parts.
If these building blocks of life can be controlled, they hold out
the promise of cures for a variety of debilitating diseases, possibly within
the next 10 years. Researchers hope stem cells will provide cures for diseases
caused by cell failure and for repairing tissues that do not repair themselves.
Heart damage, spinal cord injuries, Parkinsons disease, leukemia, bone
marrow disease and diabetes are among diseases named in connection with stem
cell research. Some researchers also hope that stem cells might eventually be
prompted to make new organs for transplant organs that might not be
rejected by the body.
Scientists say stem cell research may also hold the key to slowing
down the aging process. Among dramatic recent breakthroughs in stem cell
research, scientists have learned to rejuvenate telomeres, regulators that shut
off stem cell division, a major factor in aging.
Researchers are working at stimulating stem cells into growth in
the laboratory and learning how to direct them to diseased or damaged parts of
the body. A major challenge is how to get the beneficial cells to their
intended destinations without triggering immunities or other potentially
serious side effects. Another is how to signal the cells to turn on
and do what researchers want them to do once they get where theyre
supposed to go. Still another is how to prevent the reproducing cells from
turning into malignancies.
From the perspective of the Catholic church and others who oppose
abortion, though, the research presents a serious moral problem. One major
source of stem cells fortunately not the only source is human
embryos, pitting potential cures for terrible afflictions against respect for
human life.
The church doesnt have a position on stem cell
research, but the church does have a position against taking human life for
purposes of research, said Richard Doerflinger, associate director for
policy development in U.S. Catholic bishops Secretariat for Pro-Life
Activities.
Embryonic stem cells, isolated with private funds last year, are
unspecialized pluripotent capable of producing many body tissues.
Using private funds, embryonic stem cells have been obtained from aborted
embryos and from fertility clinics, where parents donate for research
spare embryos produced by in vitro fertilization.
Earlier this year, researchers found that huge stocks of stem
cells can be reproduced from embryonic cells as easily as drug manufacturers
make drugs. But as stem cells are harvested from embryos, the embryos are
destroyed. To abortion opponents, taking cells from unwanted embryos is bad
enough. Producing embryos exclusively for experimentation would be just as bad,
if not worse. One of the big worries about stem cell research from the
perspective of abortion foes is that it would provide a rationale for cloning
human embryos for research.
Since 1995, the federal government has banned using federal funds
for research on human embryos. But scientists and policy makers are pushing
hard against the churchs opposition. In mid-September, the National
Bioethics Advisory Commission urged Congress to remove the ban. But even those
who favor using embryos fear that a public outcry would follow, with negative
effects for research.
Meanwhile, President Clinton has endorsed an equally controversial
loophole proposed by the National Institutes of Health: that federal funds be
released for embryonic stem cell research as long as the cells are harvested
from embryos with private funds.
Clinton said in a statement issued in July, No other legal
actions are necessary at this time, because it appears that human embryos will
be available from the private sector.
Abortion opponents regard that reasoning as tantamount to a sneak
attack. Doerflinger said in a statement that the NIH is proposing a
loophole to the federal law that will not fund the act of
destruction itself but will reward those who destroy embryos, by paying
them to develop the cells and tissues they have obtained by destructive
means.
Fortunately for people hoping for cures, researchers discovered in
a breakthrough early this year that stem cells from adult human bodies might be
just as useful for healing as embryonic cells.
Until recently, specialized stem cells from adults were thought to
be medically useless because of limitations their specializations imposed. But
researchers, using techniques learned from the cloning of Dolly, the sheep, are
learning that adult cells can be reprogrammed to behave like undifferentiated
cells.
In recent months, announcements of new discoveries come almost
weekly. In mid-September, for instance, bone marrow stem cells, thought to make
only bone and blood, were coaxed into making muscle. Before that, bone marrow
cells had produced liver and pancreatic cells. Further, stem cells have been
found in places where they were formerly thought not to exist, such as in the
human brain.
Doerflinger celebrates the potential. It does seem true that
the embryonic stem cell by itself can produce more types of tissue than one
adult stem cell can, but so what? If you can do the same things with three or
four types that you can do with an embryonic stem cells, then the medical
argument for destroying embryos disappears, he said. We would love to
support research that would lead to treatments for disease, but the end
doesnt justify any moral means.
National Catholic Reporter, October 22,
1999
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