Adult stem cell obstacles stress need for SCNT
- by Steven Teitelbaum, MD
November 24, 2006

Editor's Note:  Dr. Teitelbaum, a world renowned medical scientist from the
Washington University School of Medicine in St. Louis, is an avid proponent
of the advancement of new stem cell technologies.  His own experiences as a
researcher using adult stem cells places him in the unique position of
providing an accurate perspective of the relationship between embryonic and
adult stem cell research, noting it is not a contest, but a collaboration.
Teitelbaum was part of a team of three scientists who debunked the false
claim by David Prentice that adult stem cells were being used to treat 65
different diseases. While it is most unusual for the Stem Cell Page to
reprint a year-old Congressional transcript as an editorial, Dr. Teitelbaum
agreed that in this case it is completely appropriate.    -  Jeff Eisen
Testimony of Dr. Steven Teitelbaum
before the Subcommittee on Labor, Health and Human Services
October 19, 2005

Thank you Mr. Chairman,

My name is Steven Teitelbaum.  I'm the Wilma and Roswell Messing Professor
of Pathology and Immunology at Washington University School of Medicine and
I thank the committee for the honor of speaking to you today.

Mr. Chairman, I've been a physician-scientist for more than 30 years.  I've
authored in excess of 300 scientific papers and I'm here to tell you that,
in my estimation, we are facing a unique opportunity in the form of
embryonic stem cell research, to potentially alleviate the misery of our
fellow Americans with a number of presently incurable diseases.  But to get
there, we must do the science.

Opponents of human embryonic stem cell research often articulate their
position as a contest between adult an embryonic stem cells.  Mr. Chairman,
this is not a contest between various types of stem cells.  It is a contest
between us as a society and disease.  We should be moving forward on all
fronts, adult, embryonic and umbilical cord stem cells, to win the battle.
The tool is not important.  What counts is curing our neighbors.

That said, because of their flexibility, embryonic stem cells hold more
promise to ameliorate presently incurable diseases than any other approach.
I stress the word "promise" because we are not there yet and it is my belief
that it will be some time before we are positioned to safely use these cells
for therapy.  But if scientists are prevented from exploring the biology of
human embryonic stem cells, we will never get there.

Mr. Chairman, as you know, human embryonic stem cells can presently be
obtained from two sources, namely the spare products of in vitro
fertilization, which ultimately would be destroyed, and by somatic cell
nuclear transfer, also known as SCNT or therapeutic cloning.  Although both
approaches hold enormous therapeutic potential, I'm particularly taken with
the promise of SCNT because it may alleviate the major complication of
tissue and cell transplantation, namely rejection and its attendant life
threatening consequences.

Mr. Chairman, I'm a bone biologist and physician and as such I see many
patients who have received organ and cell transplants.  These patients
typically develop severe osteoporosis and often have many fractures because
of the harsh medications they must take to prevent rejection of their
transplant. It is my hope that embryonic stem cells, generated by SCNT,
which contain the transplant recipient's own DNA, will reduce the necessity
for these devastating anti-rejection drugs.

But Mr. Chairman, my hopes for SCNT are more personal and hearken back more
than 20 years when I was a young assistant professor.  At that time I became
interested in a genetic disease of the skeleton known as osteopetrosis or
marble bone disease and I want to tell you a story about an afflicted child
who profoundly impacted my life.  Osteopetrosis is a disease in which kids
make too much bone. Consequently, their skulls become very thick and
compress their brains and nerves, such as those leading to the eye.  Bone
also overgrows the bone marrow preventing formation of blood cells.  Until
the story I'm about to tell you, all kids with the malignant form of
osteopetrosis developed fatal neurological complications, including
blindness, and infections due to bone marrow suppression.  These children
invariably died in the first decade, most before the age of five.

In the early 80s, our team thought we had identified the abnormal cell
causing osteopetrosis and concluded it resided in the bone marrow.  We
reasoned, therefore, that if we gave an osteopetrotic infant a bone marrow
transplant, which contains adult stem cells, we might cure the disease.  We
realized the enormous risk of rejection so we waited until we had a perfect
immunological match between the donor and recipient, in this case a 3 month
old little girl you see in the top picture.  So we gave this baby a bone
marrow transplant and achieved the first cure of this disease.  The middle
panel shows her at 3 years of age and the bottom picture, which is recent,
was taken upon her graduation from college.  Senators, being part of a team
which is first to cure a fatal disease, particularly of children, is a
doctor's dream.  It doesn't get any better.

You may be asking yourselves why this guy, who is here as an advocate of
embryonic stem cell research, is telling us about his victory with adult
stem cells.  Senators, I'm recounting the story to underscore the importance
of moving forward on all fronts because regrettably there is a downside to
my tale.  You'll remember that this was a perfect immunological match and
therefore there was little chance of rejection.  Unfortunately, such matches
are extremely rare and therefore we presently cure less than 10% of kids
with osteopetrosis.  The use of SCNT, in which embryonic stem cells contain
the patient's own DNA, if successful, would markedly increase the cure rate
of this disease.  Mr. Chairman, because of my familiarity with osteopetrosis
I'm frequently contacted by parents with afflicted children.  I have to tell
them the chances of curing your child is no more than 10%. I want to tell
them it's greater than 90%.

SCNT, if we pursue it, may get us there.

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