
A New Discovery: Transforming Adult Stem Cells
into Embryonic Ones
Recently scientists discovered that it is possible to take
adult stem cells and make them have capabilities like the embryonic
ones do. Adult stem cells
on their own are much less useful and transformable than embryonic
ones. However, if it is possible to change adult ones to have capabilities
like
embryonic ones, which are much more useful and can transform into almost
any type of
cell, then the adult ones become much more useful. Scientists use
adult skin cells, which have stem cells, and added four genes, and
the cells
with embryonic-like
capabilities are called induced pluripotent stem cells, or iPS. This
could stop the debate over whether or not embryonic stem cells should
be used
in research, as adult ones could be used instead for the same purpose
with the
same capabilities. Adults are already alive and wouldn’t have
to be killed when the cells are taken, so no life is killed and hES-like
stem cells
are
still obtained. This recent discovery could stop arguments about
stem cell research and hES-like cells could still be used.
Current Stem Cell Therapies
There are a few ways in which stem cells are commonly being used today. Adult
stem cells are used in Bone Marrow, Peripheral Blood Stem Cell, and Umbilical
Cord Blood Stem Cell Transplants. All three of these treat illnesses like Leukemia,
other cancers, and some blood disorders.
In
Bone Marrow Transplants, stem cells are taken from adult bone marrow. Bone
Marrow
stem cells produce white blood cells. In this type
of transplant, chemo
and radiation gets rid of the bone marrow and bad white blood cells in a person’s
body. New bone marrow is then put in with good stem cells. New white blood
cells are then produced and hopefully the person is in better health.
In Peripheral Blood Stem Cell Transplants, the blood stem cells in the blood
stream are used. These stem cells are easier to get to and are used in the
same way to cure things as bone marrow ones. The healthy blood stem cells take
the place of the old poorly-functioning ones. However, these blood stem cells
are much less common than bone marrow stem cells and are very sparse.
In
Umbilical Cord Blood Stem Cell Transplants, blood stem cells are taken from
an umbilical
cord. These blood stem cells can replace
the “sick” blood
stem cells, just as in the Peripheral Blood Stem Cell Transplants. There is
less rejection by the body as no features of the cells are noticed by the immune
system. The umbilical cord stem cells are also not very good immune cells so
they probably won’t attack the host.
The Nobel Peace Prize
In 2007, three scientists won the Nobel Peace Prize in the category of Physiology
or Medicine. These scientists carried out experiments on mice having to do
with embryonic stem cells and homologous recombination. They were able to alter
the genes and DNA of the mice, and they had to use ES cells in order for the
alterations to be inherited. Homologous recombination is used to change genes.
One DNA sequence is traded for another inserted one in the chromosome pair.
Where Embryonic Stem Cells come into play is that ES cells must be used otherwise
the alterations can’t be inherited, as ES cells can make germ cells,
used in reproduction. The genetics of the ES cells are altered when the DNA
sequences are swapped and the ES cells are then put into an embryo. The altered
ES cells mix with the normal cells. The embryo is then placed inside a surrogate
mom and is born with partially these new altered genes and partially the normal
genes. When these “half-and-half” mice mate with normal mice, both
normal and completely altered mice are born. The completely altered mice have
only the altered gene in them, none of the normal gene. This allows scientists
to see what that altered gene must have done before by what the change is in
the mouse. This enables scientists to tell which genes do what, which could
potentially help to study, prevent, and possibly cure diseases in the future.