Stem Cell Debate Drives Alternatives
Scientists Search for Way Around Ethical Controversy
Nov. 7, 2006 - Researchers in the U.S. and elsewhere are finding ways to get
around the ethical roadblocks to embryonic stem cell research.
And at a forum in Washington this week, experts are discussing some of the
most promising strategies.
Congress -- with the backing of a majority of Americans -- passed a bill
earlier this year removing the strict limits on federal funding for embryonic
stem cell research. That bill would have cleared the way for
government-sponsored research on the stem cells plucked from embryos left over
at fertility treatments.
But President Bush blocked the measure, citing a belief -- shared by many
religious conservatives -- that the government should not promote research that
destroys human embryos for the sake of harvesting their stem cells.
However, such research remains a hot topic in Washington and is sure to
resurface after Tuesday's elections.
In the meantime, scientists are busy looking for ways to harvest or create
stem cells without harming human embryos or asking women to donate their
"We don't need any eggs or embryos at all," says Shinya Yamanaka,
MD, a professor at the Institute for Frontier Medical Sciences in Kyoto,
Yamanaka describes his lab's early successes in mice creating stem cells
from adult cells. His research involves isolating two dozen chemicals that give
embryonic stem cells their ability to grow into nearly any tissue in the
That property, called "pleuripotency," is what makes scientists
think stem cells can be coaxed to form new tissues that could help cure
Parkinson's and other diseases.
The Japanese researchers found that four of the chemicals, in the right
mixture, transformed connective tissue cells from adult cells into pleuripotent
cells Yamanaka says are "indistinguishable" from embryonic stem
Still, significant problems remain.
"I have to point out, the efficiency … is very low," Yamanaka today
told the scientific conference hosted by the Institute of Medicine. Only one in
1,000 attempts to transform adult cells into stem cells was successful.
Also, the cells formed tumors when implanted in mouse tissue -- a
significant roadblock to using such cells for human treatments.