More MS news articles for September
on Stem Cells
Volume 16, Issue 17, 10, Sep. 2, 2002
By Richard Gallagher
Self-renewal and the capacity to differentiate into a multitude of mature
cell types have made stem cells the hottest ticket in biomedicine. But
there are questions aplenty, scientific and otherwise.
Do we need more stem cell lines? President Bush may believe that the available
lines are sufficient, but these are derived fro1m blastocysts produced
in fertility clinics. Maximizing the impact of stem cells in medicine calls
for new lines derived from specific diseases, like cancers.
Must therapeutic cloning be used to generate new lines? Yes, transplanting
nuclei from cells of adults with genetic disorders into enucleated eggs--therapeutic
cloning--provides the obvious route to study disease development. In the
longer term this approach could also provide genetically matched tissues
Is transdifferentiation real? After five frantic years, current thinking
hovers between "maybe" and "probably." While promising, most scientists
do not (yet) consider transdifferentiation to be a replacement for therapeutic
Have stem cells been used successfully in animal models of disease? Yes,
most notably embryonic stem cells have been induced in vitro to become
midbrain neural stem cells; transplanted into a rat model of Parkinson
disease, these cells became functionally integrated and reversed behavioral
Have human clinical trials similarly achieved symptom relief? Too soon
to tell; controlled studies are very rare. Re-searchers using cells derived
from human fetuses have had some promising results, but cell-based therapies
are likely to be many years away. And while biotech is beginning to engage,
thus far none of the major pharma companies has shown much enthusiasm.
Can a lid be kept on expectations? Hard to see how. The clamor from patients
is growing, understandably so. Media coverage is incessant and has to strike
a difficult balance between tomorrow's promise and today's reality.
Have science journals led by example? Not completely. To quote a recent,
creditably self-censuring article in Science magazine, "Plasticity was
such a hot phenomenon in the late 1990s that journals, including Science,
were snapping up and publishing partial--or what are now seen as questionable--results."
Have the social, political, economic, legal, religious, and ethical issues
been engaged? Most vigorously, and at the highest levels. The importance
of the debate is without question but there is currently a lack of consensus,
to a dangerous extent. Unfortunately, participants often seem insufficiently
informed on scientific aspects and the full medical potential of stem cells.
How has the research community responded? In many countries, scientific
academies and associations have provided reports; scientists have participated
unstintingly in expert panels and committees; and the science journals
have provided outstanding coverage.
Research will flourish, but where? It depends in part on legislation that
emerges from the debate. Right now certain countries, such as the United
Kingdom, Sweden, France and Australia, are more accommodating than others,
such as the United States and Germany. Will a "reverse brain drain" result?
If your important question was missed, please let me know.
©2002, The Scientist Inc.