Breaking news: Johns Hopkins scientists have developed a
new and reliable method to turn blood cells back to stem cells, making it
possible for the primitive state to develop into any cell type in the body. The
Public Library of Science (PLos) says that this is "chapter two" in
an ongoing effort to revert various types of cells back to stem cells, which
are highly qualified for clinical and research use. “Taking a cell from
an adult and converting it all the way back to the way it was when that person
was a 6-day-old embryo creates a completely new biology toward our
understanding of how cells age and what happens when things go wrong, as in
cancer development,” say Zambidis, assistant professor of oncology and
pediatrics at the Johns Hopkins Institute for Cell Engineering and the Kimmel
Cancer Center.
Chapter one, which apparently took place last spring, was
the successful process of transforming adult blood cells into heart cells. Now
Zambidis and his colleagues are coaxing adult blood cells back into
induced-pluripotent stem cells (iPS). These are reprogrammed to an
embryonic stage, opening a whole new world of possibilities and efficiencies. As
explained in the article below, the Zambidis' method of producing these iPS
cells is extremely efficient and virus free, boosting odds of success from 1-2%
to 50-60%.
Traditionally, scientists used viruses, which delivered a
package of genes initiating a series of processes that converted the cells from
one type, back to their stem cell state. This was pretty risky
considering that introducing viruses drastically increases the chance of genes
mutating and producing cancers in the newly transformed cells. In place
of using viruses, Zambidis' team now uses plasmids, rings of DNA, which briefly
replicate inside cells and then degenerate. It was also found that
growing in their natural bone-marrow environment stimulated growth.
"For the new study, the Johns Hopkins team took cord blood
cells, treated them with growth factors, and used plasmids to transfer four
genes into them. They then delivered an electrical pulse to the cells, making
tiny holes in the surface through which the plasmids could slip inside. Once
inside, the plasmids triggered the cells to revert to a more primitive cell
state. The scientific team next grew some of the treated cells in a dish alone,
and some together with irradiated bone marrow cells, " as explained in an
article from www.hopkinsmedicine.org.
When scientists compared the growth between the blood cell method with
iPS cells from hair and skin, they found the iPS cells from blood stem cells
treated with four genes and cultured along with bone marrow cells was far
superior. These converted into their primitive state within 14 days.
Additional and effective methods to produce virus-free iPS
cells may open the doors to other developmental stem cell therapies, along with
providing a more accurate picture of cell development and biology.
The study's co-authors were Park, Huo, Peters, Talbot,
Verma, Zimmerlin, and Kaplan. They were supported by grants from the
National Heart, Lung, and Blood Institute, the National Cancer Institute, the
National Institutes of Health, and the Maryland Stem Cell Research Fund.
No comments:
Post a Comment