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[IP] Adult stem cells show new promise
>From this morning's Seattle Times--
Friday, June 21, 2002 - 12:00 a.m. Pacific
Adult stem cells show new promise
By Justin Gillis
The Washington Post
Researchers have isolated a type of cell from bone marrow that seems capable
of transforming itself into most or all of the specialized cells in the
body, a finding likely to fuel the debate over the ethics of stem-cell
The finding was reported by researchers at the University of Minnesota and
published online yesterday by the journal Nature. It heightens the prospect
that therapies scientists are trying to create - cures for diabetes,
Parkinson's disease, hemophilia and many others - can be made entirely with
adult cells, alleviating moral concerns over using discarded embryos and
fetuses as tissue sources.
There's been conflicting evidence about whether cells found in adults might
be as useful as those derived from embryos. But the work by Catherine
Verfaillie, known as a fastidious and cautious researcher, was widely
acknowledged as the most definitive evidence to date that adult cells may be
almost as versatile as embryonic cells.
Austin Smith, a prominent researcher in Scotland who has criticized some
prior studies using such cells, called the Verfaillie paper "extraordinary."
The work is still at an early stage, however, and Verfaillie asked that it
not be used as a political weapon to fight simultaneous work on embryonic
and fetal cells.
"I think it is going to be important to be in a position to really compare
and contrast the cells," she said, with the ultimate goal of determining
"which cells are going to work for which therapy."
As if to underscore that point, Nature simultaneously published work at the
National Institutes of Health showing that embryo-derived cells can vastly
alleviate symptoms similar to those associated with Parkinson's disease in
mice. That work, led by Ron McKay, is one of the most convincing
demonstrations to date that such embryonic cells may be useful in medical
The cells in McKay's experiments, derived from mouse embryos, took up
residence at the right spot in the brains of adult mice and produced
dopamine - a critical substance that is in short supply in Parkinson's
disease - in exactly the way that would be needed to relieve the symptoms of
the ailment. It's far from proof of a cure, but "it's absolutely definitive
evidence that these cells can work in the brain," McKay said.
The more unexpected finding was that of Verfaillie, director of the
University of Minnesota's Stem Cell Institute. With the paper, she joined
the company of biologists who are overturning the dogma that animal
development proceeds in one irreversible direction, from the unspecialized
cell formed when sperm and egg fuse to the highly specialized cells of an
Hints of her work had been emerging for two years in papers and scientific
conferences, and scientists had been eagerly awaiting it. Many other reports
have emerged in recent years of various adult cell types being able to
perform unexpected feats of transformation. But Verfaillie has discovered
what appears to be the most flexible adult-derived cell yet.
She calls the cells in question "multipotent adult progenitor cells." She
and her colleagues have isolated them from mice, rats and people, though
they are only able to do so in 70 to 80 percent of the people they test, for
In animal experiments, the cells proved to lack certain characteristics of
embryonic stem cells, which are capable of making every tissue in an
animal's body. But they shared many other characteristics and proved able to
transform into cells of the liver, lung, gut, blood, brain and other organs.
They have proven particularly amenable to transformation into liver cells,
but not very willing, at least so far, to become heart cells.
Many of the types of experiments Verfaillie reported, which involved
injecting the adult cells into developing mouse embryos, cannot ethically be
done in humans. But further animal experimentation may clear the way to use
the cells in treating human disease. Several scientists cautioned that this
will take years, at best.
Verfaillie's results suggest the tantalizing possibility that every adult
may carry around the raw material of his or her own repair kit - one that
nature is somehow failing to use in many diseases, but that scientists might
be able to exploit to make new tissues and revivify failing organs.
Cells derived from a person's bone marrow would be unlikely to be rejected
by the immune system, a potential problem with treatments based on
embryonic- or fetal-derived cells.
Verfaillie said the cells might even be useful for correcting genetic
diseases. They could be taken out of the body, a repaired gene could be
inserted, doctors could grow many copies and then the cells would be
inserted into a deficient organ such as the liver, along with manipulations
to get them to turn into functional liver cells.
The Verfaillie work "is a nice research paper," said John Gearhart, a
biologist at Johns Hopkins University in Baltimore and one of the two
American scientists known for isolating human embryonic and fetal stem
cells. "I think it's good, solid work. We'll see where it goes."
Verfaillie's work was particularly welcomed yesterday by opponents of
embryonic stem cell research. They have long contended that adult-derived
cells offer just as much promise and don't pose the same moral concerns as
Copyright ) 2002 The Seattle Times Company
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