Man who helped start stem cell war may end it
By Gina Kolata Published: November 22, 2007
If the stem cell wars are indeed nearly over in the United States, no
one will savor the peace more than James Thomson.
Thomson's laboratory at the University of Wisconsin was one of two
that in 1998 plucked stem cells from human embryos for the first
time, destroying the embryos in the process and touching off a
divisive national debate.
And on Tuesday, his laboratory was one of two that reported a new way
to turn ordinary human skin cells into what appear to be embryonic
stem cells without ever using a human embryo.
The fact is, Thomson said in an interview, he had ethical concerns
about embryonic research from the outset, even though he knew that
such research offered insights into human development and the
potential for powerful new treatments for disease.
"If human embryonic stem cell research does not make you at least a
little bit uncomfortable, you have not thought about it enough," he
said. "I thought long and hard about whether I would do it."
decided in the end to go ahead, reasoning that the work was important
and that he was using embryos from fertility clinics that would have
been destroyed otherwise. The couples whose sperm and eggs were used
to create the embryos had said they no longer wanted them.
Nonetheless, Thomson said, announcing that he had obtained human
embryonic stem cells was "scary," adding, "It was not known how it
would be received."
But he never anticipated the extent and rancor of the ensuing debate.
For nearly a decade now, the issue has bitterly divided patients and
politicians, religious groups and researchers.
Now with the new technique, which involves adding just four genes to
ordinary adult skin cells, it will not be long, he says, before the
stem cell wars are a distant memory.
"A decade from now, this will be just a funny historical footnote,"
he said in the interview.
As for the science behind it, the thrill of discovery, he
said, "Surprisingly, there is no 'Wow' moment," either from 1998 or
now."
Both times, the discovery came after he had spent months rigorously
testing the cells to be sure they really were stem cells, worrying
all the while that they could die or be lost to contamination. When
he knew he had succeeded, the suspense was gone.
But he knows what he wrought. Stem cells, universal cells that can
turn into any of the body's 220 cell types, normally emerge only
fleetingly after a few days of embryo development. Scientists want to
use them to study complex human diseases like Alzheimer's or
Parkinson's in a petri dish, finding causes and treatments. And, they
say, it may be possible to use the cells to grow replacement tissues
for patients.
The problem until now had been the source of the cells - human
embryos.
The topic, says R. Alta Charo, a University of Wisconsin
ethicist, "took on an almost iconic quality, the same way Roe v. Wade
has."
But Thomson, 48, did not set out to throw bioethical bombs. All he
wanted, he said, was to answer the most basic scientific questions
about cellular development.
First there was a degree in biophysics from the University of
Illinois. As a graduate student, Thomson began working with mouse
embryonic stem cells and then, with federal support, he extracted
stem cells from monkey embryos. After earning two doctorates from the
University of Pennsylvania, one in veterinary medicine and one in
molecular biology, he continued research at his own laboratory at the
University of Wisconsin.
Eventually he realized, though, that studying mice and monkeys could
take him only so far. If he wanted to understand how human embryos
develop and why their development sometimes goes awry, he needed
human stem cells. But, he says, he hesitated.
In 1995, he began consulting with two ethicists at his university,
Norman Fost, a physician, and Charo, a law professor. His plan was to
use unwanted embryos from a fertility clinic.
Fost was impressed.
"It is unusual in the history of science for a scientist to really
want to think carefully about the ethical implications of his work
before he sets out to do it," Fost said.
But Fost and Thomson guessed wrong about what would bother people
most. They thought it would be what Fost termed "the technological
power" of stem cells. What if someone put human stem cells into the
brain of a rat, for example?
"I thought at the time that this was possibly the biggest issue,"
Fost said. "It was unprecedented in the history of biology. It's
the 'Help, get me out of here' scenario. Let's say the rat brain
turns out to be entirely human cells. What's going on in there? Is it
a human brain? And how would you study it - you can't ask the rat."
Meanwhile, as Thomson was planning his effort to obtain human
embryonic stem cells, another discovery changed his entire view of
development. In 1997, Ian Wilmut, a scientist in Scotland, announced
the creation of the first cloned mammal, Dolly, cloned from frozen
udder cells from a long-dead sheep.
Wilmut had slipped an udder cell - a cell that normally would never
be anything but an udder cell - into an egg whose genetic material
had been removed. The egg somehow brought the udder cell's
chromosomes back to the state they had been in when embryo
development first began.
Four years ago he and, independently, Shinya Yamanaka of Kyoto
University, set out to figure out a way to mimic what an egg can do.
Both groups succeeded and both discovered that all they had to do was
add four genes to the cells and the cells would turn into what look,
so far, just like stem cells.
More work remains, but Thomson is confident that the path ahead is
clear.
"Isn't it great to start a field and then to end it?" he said.
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StemCells subscribers may also be interested in these sites:
Children's Neurobiological Solutions
http://www.CNSfoundation.org/
Cord Blood Registry
http://www.CordBlood.com/at.cgi?a=150123
The CNS Healing Group
http://groups.yahoo.com/group/CNS_Healing
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