Adult cells are behind much of stem cell success so far

The great potential moral controversies and political party
alignments associated with stem cell issue makes the subject
a hot topic.


Human stem cells can be obtained from human embryos,
produced either by in vitro fertilization of human eggs or
cloning via somatic cell nuclear transplant, or adults.

The often stated advantages of embryonic stem cells are 1)
their great promise, 2) their potential to form every cell
type, 3) their rapid proliferation, 4) their lack of
rejection and finally, 5) their usefulness in drug testing
and disease models.

However, from a scientific and medical point of view these
advantages are less clear.

The "great promise" of embryonic cells is often stated by
scientists that either hold key patents or are strongly
supported by biotech companies pursuing embryonic cells
commercially.

Every type of stem cell may be useful for injuries but are
unlikely to cure most diseases, as underlying causes of
uncured diseases are often not known. Stem cells may
alleviate the symptoms for several years but not affect the
disease process. Other areas of research are actively being
studied on disease processes so stem cells are not the
magic silver bullet in diseases.

The "potential of embryonic stem cells to possibly form
every cell type" in the body is amazing but is of little
clinical relevance. As long as a stem/progenitor cell is
capable of forming the cell types needed for a particular
injury or disease, the capability to form every cell type
is a moot point.

Furthermore, there are numerous supporting studies that
stem cells derived from adults have the same potential.
Sources of adult stem cells include the skin, fat, bone
marrow stromal cells, umbilical cord and many other sites
in the body.

The "rapid proliferation of embryonic stem cells" is rather
ironic claim in that the quality cited for the superiority
of embryonic stem cells is actually responsible for causing
serious problems. Rapid growth is not always a desirable
quality, as clearly seen with weeds in a garden or cancer
in the body.

In an animal model of Parkinson's disease, rats injected
with embryonic stem cells showed a slight benefit in about
50% of the rats, but one-fifth of the rats died of brain
tumors caused by the embryonic stem cells.

The "lack of rejection of embryonic stem cells" is a clever
twist of words. It is true that embryonic cells are not
rejected. However, to be useful as a therapy, the cell must
mature into a particular cell type.

When the cell matures, it is recognized by the immune
system as foreign and is rejected. However, it has also
been argued that this is the reason for the great need for
human cloning (somatic cell nuclear transplant) so the
problem of rejection of embryonic stem cell can be avoided.

This field is in its infancy, and only a very few studies
have been done to even demonstrate the feasibility of this
in experimental animals. Pursuing this extreme measure when
the human body is full of stem/progenitor cells that would
not be rejected is one of the most absurd directions ever
observed in the history of science that is supposedly being
promoted to help people.

"Usefulness in drug testing and disease models" is not a
reasonable claim because tissue models and drugs need to be
tested on mature tissue, not embryonic cells. There are
numerous tissue cultures model systems of muscle, skin,
etc., that are routinely used in drug and disease models.

The advantages of stem cells derived from adult stem cells
are virtually unknown to the American public. The most
profitable, not the best, treatment for people is not
surprisingly getting the most publicity.

The greatest advantage of adult stem cells is that it's
usually possible to use a person's own stem cells, which is
the safest stem cell option for people. This avoids the
problems of rejection, disease transmission, chromosomal
abnormalities and uncontrolled growth.

One problem with embryonic stem cells that is rarely
mentioned is that methods have yet to be developed to grow
these cells in a manner that does not induce significant
chromosomal abnormalities.

If one looks at the human clinical trials or research using
experimental animals, the record for adult stem cells
compared to embryonic stem cells is extremely impressive.
In examining only the scientific evidence, one wonders why
the controversy even exists.

Parkinson's disease: When a transplant consists of
embryonic/fetal tissue, the stem/progenitor cells are the
only cells that survive. In two clinical trials using
embryonic/fetal tissue, devastating deterioration at one
year after treatment occurred in about 15% of these
patients that was believed to result from cellular
overgrowth or from rejection of the foreign cells/tissue
derived from embryo or fetus.

These results are in striking contrast to the report on a
patient who received his own adult stem cells, who had
almost full recovery for several years after the
transplant.

In a recent animal study, human embryonic stem cells not
only did not cause improvement in an animal model of
Parkinson's disease but also caused tumor formation.
Another direction of hope for Parkinson's disease is the
use of growth factors.

Diabetes: Diabetes, like Parkinson's disease, is a disease,
so it may not be possible to cure diabetes with any type of
stem cells but only dissipate the symptoms for several
years. Recently, insulin independence was reported in a
person after receiving cells from her mother.

Also encouraging were results found in animal studies that
blocking the autoimmune reaction can reverse diabetes in
mice. There are also several reports that adult stem cells
can develop into insulin-secreting cells.

Spinal cord injury: The comparison of results with adult
and embryonic stem cells is even more dramatic. Although
mice receiving embryonic stem cells made the front page of
many newspapers and extensive web coverage, a paper
published by Zurita and Vaquero found almost total recovery
from complete paralysis in rats using adult stem cells from
bone marrow. Transplants of tissue containing one's own
stem cells is safe and causes some improvement in people
with severe, chronic spinal cord injury.

Heart disease: Several recent studies patients with heart
attacks report benefit from adult stem cells derived from
bone marrow. Clinical trials have also shown improvements
in some patients with heart failure after using one's own
adult stem cells in treatment.

Similar comparisons can be made for a variety of diseases
and injuries. But the successes with adult stem cells will
never make headlines or be heard by the majority of the
American public.

Although it may take years for these adult stem cell
treatments to be commonly available, the results with adult
stem cells will eventually end a controversy that should
never have existed in the first place. The controversy may
end even sooner than that with last month's report of
embryonic stem cells can be derived from sperm, as reported
in the most recent edition of "Nature."

Get More info on how you can benefit from your own Stem Cells
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Jean Peduzzi-Nelson is an associate professor in the
department of anatomy and cell biology Wayne State
University School of Medicine in Detroit.