Direct Conversion of Cells From
One to Another
May Make Embryonic Stem Cell Research Obsolete
By Dave Andrusko
"The new direct-conversion
approach avoids embryonic stem cells and the whole notion of
returning to an early state. Why not just go directly from one
specialized cell to another? It's like flying direct rather than
scheduling a stopover.'
-- From "Scientists trick cells into switching
identities," by Malcolm Ritter of the Associated Press.
If
you read Wesley Smith's blog entry in Part One, you know that
there is potentially an incredible twist in the ferocious debate
over whether there really is an acceptable alternative to
harvesting stem cells from human embryos. (Forget for a moment
that there's been no progress in humans whatsoever from ESCR--embryonic
stem cell research. The onus always is on anyone who stands in
the way of "progress" which just so happens to require the
further debasement of the sanctity of human life to show they
have another way.)
Malcolm Ritter's analysis, which
ran yesterday in newspapers all over the country, not only says
yes, but heck, yes. His first three sentences neatly summarizes
what follows:
"Suppose you could repair tissue
damaged by a heart attack by magically turning other cells into
heart muscle, so the organ could pump effectively again.
Scientists aren't quite ready to
do that. But they are reporting early success at transforming
one kind of specialized cell directly into another kind, a feat
of biological alchemy that doctors may one day perform inside a
patient's body."
In explaining the new research
Ritter casually comments that it is "two steps beyond the
familiar story of embryonic stem cells..." That "story"--really
a fairy tale--fanaticizes about embryonic stem cells being
coaxed into becoming all type of cells, such as blood and brain
cells. But Ritter notes that "Using embryonic stem cells is
proving to be inefficient and more difficult than expected," a
huge understatement.
The new technique, if successful,
is also a step beyond so-called induced pluripotent stem cells--IPSCs--which
is ethically acceptable because it does not cause the
destruction of a human embryo. As Ritter points out in 2007,
"They got skin cells to revert to a state resembling embryonic
stem cells [IPSCs]. That opened the door to a two-part strategy:
turn skin cells from a patient back into stem cells, and then
run the clock forward again to get whatever specialized cell you
want. "
But what does this
"direct-conversion" approach-- for example, turning human skin
cells into blood cells---accomplish? It avoids the use of
embryonic stem cells altogether, on the one hand, "and the whole
notion of returning to an early state," on the other. Ritter
asks, "Why not just go directly from one specialized cell to
another? It's like flying direct rather than scheduling a
stopover." (See Part Three for an example of direct conversion.)
(The more-than-you-or-I
need-to-know-but-is-interesting to explain how all this is done
can be summarized in three sentences. We know from our high
school biology that every cell in our body carries the same DNA
code. However a cell's identity depends on "its lineup of active
genes"--in other words not all genes are active at the same
time. "So, to convert a cell, scientists alter that combination
by inserting chemical signals to activate particular genes,"
Ritter writes.
This is all in the experimental
stage, but the promise is extraordinary. "I think everyone
believes this is really the future of so-called stem-cell
biology," John Gearhart of the University of Pennsylvania, one
of many researchers pursuing this approach, told Ritter.
Please send your comments on
Today's News & Views and National Right to Life News Today
todaveandrusko@gmail.com. If you like, join those who are
following me on Twitter at
http://twitter.com/daveha. |