Good Morning My Friends,
Another message found this morning and one of future hope to those with
blood disorders and malignancies. Hope this sheds some sunshine on your
day.
VA Researchers Mass-Produce Stem Cells in Lab
SEATTLE, July 6 /PRNewswire/ -- U.S. Department of Veterans Affairs
researchers and their colleagues have developed a technique to
dramatically increase numbers of mouse stem cells, the bone marrow
"mother" cells that evolve into all the body's different types of blood
cells. "If we can do this with human stem cells, we could revolutionize
gene therapy for blood cell disorders and have a major impact on bone
marrow transplantation," said Gerald J. Roth, M.D., chief of hematology
at the VA Puget Sound Health Care System in Seattle and professor of
medicine at the University of Washington.
Roth, study principal investigator, and Stephen Bartelmez, Ph.D., co-
principal investigator at the Seattle Biomedical Research Institute and
UW assistant professor of pathobiology, first author Mayumi Yagi, Ph.D.,
and associates report their results in the July 6 issue of the
Proceedings of the National Academy of Sciences. "Being able to expand
stem cells outside of the body has been our holy grail for decades,"
Bartelmez said.
Bone marrow stem cells can develop into all the specialized blood cells
that perform functions such as destroying bacterial invaders or
transporting oxygen to body tissues. Normal stem cells are key to the
success of bone marrow transplants used to treat diseases such as
leukemias, in which the patient's marrow churns out wildly dividing and
nonfunctional white blood cells. "Stem cells are the cells that save the
patient's life," Roth pointed out.
Stem cells also play a critical role in gene therapy for disorders
caused by a defective gene. If a healthy gene can be inserted into stem
cells with an abnormal counterpart, Roth noted, all the offspring cells
of that stem cell will carry the normal gene. Unfortunately, attempts at
gene therapy often have been hampered by needs of the harmless
"retrovirus" commonly used to ferry normal genes into cells. This type
of virus cannot insert the new gene into a cell's genetic material
unless the cell is dividing, and dividing stem cells usually yield more
specialized offspring that contain the new gene. "So the new gene
doesn't end up in real stem cells and you haven't solved the problem,"
Roth said. "Getting stem cells to divide into many more stem cells could
have enormous impact on the future of gene therapy."
Researchers previously tried to increase numbers of mouse stem cells in
laboratory cultures by separating them from all other bone marrow cells
and then stimulating them intensely with a mix of protein growth factors
that normally spur cell growth and division. The cells either produced
few offspring stem cells, however, or divided into more specialized
offspring.
In their study, Roth and his colleagues started with whole bone marrow
containing stem cells along with blood vessels, fat cells and other
cells found in marrow. They then supplied just one growth factor called
thrombopoietin over a period of several months. "We used a different
mix, different stimulation and different timing," Roth said, "and it
worked." The stem cells reproduced themselves. Further, instead of the
10-fold increase in stem cells obtained in some earlier studies, the VA
team's technique produced a million-fold increase. The next step, Roth
said, is to attempt the same technique with human cells.
Other authors of the PNAS paper include Kindred A. Ritchie, M.D., Ph.D.,
Ewa Sitnicka, Ph.D., and Carl Storey, B.S. The U.S. Department of
Veterans Affairs and the National Institutes of Health supported the
research.
SOURCE U.S. Department of Veterans Affairs
God Bless You All,
marty auslander
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