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New work reveals no need for work on Embryonic Stem Cells
Embryonic Stem Cells no longer needed?
- Multipotent Adult Progentior Cells.
- Research recently revealed seems to show that there are "stem
cells" in adult bone marrow that are multipotent. Catherine Verfaillie at the
University of Minnesota has isolated cells from the bone marrow of 70 out of one hundred
volunteers. They call the cells multipotent adult progenitor cells MAPC's for short. These
cells are seen to be as versatile as Embryonic Stem Cells.
- The cells have been extracted/isolated from the bone marrow of mice rats
and humans in a series of stages. Cells that don't grow under certain conditions or that
don't carry certain surface markers are gradually eliminated. These remaining cells seem
to grow indefinitely in culture (like ESCs). Some cell lines have been growing for two
years without apparent ageing.
- Proof of versatility.
- Using retroviral marking Verfaillie has shown that has shown that
descendants of these cells can turn into muscle, cartilage, bone, liver and different
types of neuron and brain cells. Further proof of plasticity is seen in the insertion of a
single human MAPC into a very early mouse embryo. When born analysis of the mice showed
that the MAPC had contributed to all of the body's tissues.
- Non Cancerous.
- Work with treatments using embryonic stem cells has shown that
undifferentiated ESCs implanted into a body lead to cancerous tumours. However the work
with MAPCs seems to indicate that they do not develop in to cancerous masses when injected
into adult bodies.
- Concerns still to be answered.
- The work so far doesn't prove that MAPCs can become e.g. A working neuron
even though they show the markers of neural tissue. (Freda Miller, McGill University) Her
team think that rare MAPCs are present in bone marrow tissue, others say her process may
actually create the cells (Neil Theise of New York University Medical School) "The
data looks good" says Ihor Lemischka of Princeton University, but has yet to be
- Source of above:
- New Scientist 26/01/02
- If MAPCs truly differentiate into the full range of cell types within the
body then the need for the work with embryonic stem cells would be over.
- Embryonic Stem Cells
- Since ESCs are controversially derived from human foetuses and embryos.
The ethical dilemma would be removed. The cells would be derived from a persons own bone
marrow (or other tissue MorphoGen Pharmaceuticals of San Diego says it has found
them in skin and muscle as well as bone marrow). These would be genetically identical and
body parts generated from them would not be rejected.
- There would then be no need for the nuclear replacements and the
development of the technology that would lead to therapeutic cloning. It may be still too
early to say whether this route will deliver the desired results, but if so the banning of
work on ESCs would also cut the route that would enable the production of cloned babies.
- Would this be good or bad ? For many the answer is already simple.
Cloning is against human decency and integrity because it makes a baby and therefore a
human being a neither desired for there own sake, not an individual but a replacement, and
will inevitably lead to many psychological problems for those so generated.
- Black Market Medicine
- We know though that even if we ban cloning in most civilised countries,
there will be countries without the laws and regulations and the proper ethical controls
and committees. Our history with illegal substances has shown that if you make something
illegal or too hard to do legally, than you create a black market in the product or
service. In which there is no regulation other than what is wanted and can be paid for.
Abortion driven underground lead to terrible abuse and exploitation of women with unwanted
- Similarly this hope of "reproductive cloning" which for some
may be the only way in which they will see a child of their own body, if driven
underground, will lead to similar exploitation of those with this heartfelt need or desire
to reproduce. Far better is the path which enables proper ethical supervision,
counselling, regulation and sanitary medical processes and good pre and post natal care,
than one which by secrecy makes all these more dangerous or non-existent.
- A Possible path around the problems of DNA transfer
- There are still problems with the transfer of nuclear DNA, and the
disruption caused by transfer processes and this gross handling of eggs still may cause
genetically derived health problems in later life. Active eggs generated from MAPCs may
offer a better and more stable path for reproductive cloning.