Spermless Technique May Give Scientists Another Stem Cell Source
http://www.abcnews.go.com/sections/living/DailyNews/Newstemcells011022.html
Oct. 22, 2001
BOSTON — A new technique could someday
allow scientists to study stem cells while avoiding government restrictions
on research involving cells derived from embryos.
The technique, exhibited on mouse
cells, allowed scientists to create stem cells without using embryos. Researchers,
led by stem cell biologist Jerry Hall at the Institute for Reproductive
Medicine and Genetics in Los Angeles, announced their discovery today at
the annual meeting of the American Society for Reproductive Medicine.
But for the advancement announced
today, the egg used to generate the stem cells was not fertilized, and
was not capable of generating life.
And while it's too soon to say the
technique will work for people, "Developing an alternate source of [stem
cells] is a really good thing," said Lawrence Goldstein, developmental
scientist and vice chair of public policy for the American Society for
Cell Biology.
President Bush this summer placed
restrictions on the use of cells derived from embryos. The government will
no longer fund any research involving the use of human embryos, only the
use of previously generated stem cells is allowed. Scientists have disagreed
about how many lines of such stem cells there are.
Tricking Eggs
The process Hall and colleagues used
to generate the stem cells is known as parthenogenesis — a form of asexual
reproduction common among insects. Normally, mouse and human eggs require
fertilization for development to occur. In this case a mouse egg was forced
into dividing without the addition of sperm.
"We used chemical stimulation to
trick the egg into thinking it was fertilized," said Hall.
The chemical treatment involved the
addition of ethanol and a molecule involved in cell division, neither of
which causes any lasting effects on the cells that are generated.
The scientists then treated the dividing
cells with "growth factors," which signaled them to develop into nerve
cells. Scientists hope this new type of stem cell can be harnessed for
the treatment of neurological disorders such as Parkinson's and Alzheimer's
disease.
The Next Step
As it stands now, these dividing
cells are not capable of developing into living organisms because the cells
are not derived from a fertilized egg. So when the researchers implanted
the dividing eggs back into the female mice, the cells were not able to
grow into fully developed offspring.
"If we were able to take them to
term it would be an ethical problem," said Hall.
Further research is necessary to
determine if the cells derived from this process are fully functional.
Subsequent work may then be done to duplicate the technique in human eggs.
"The first and most important thing
is: Can we make these cells develop into tissues that are therapeutic?"
said Goldstein.
Unfortunately for men there is no
way to make stem cells from sperm. If this technology takes off, only women
will be able to generate tissue for themselves.
Copyright © 2001 ABCNEWS Internet
Ventures
By Jeff Carpenter
ABC News
Recently, there has been a great
deal of controversy over the use of embryos in science, because some believe
them to be potential human beings.