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HEARING
ON HUMAN CLONING
COMMITTEE ON HEALTH, EDUCATION, LABOR AND PENSIONS
U.S.
Senate, Washington DC
March 5, 2002
Testimony
of Stuart A. Newman, Ph.D.
My name is Stuart
Newman. I have been a professor of Cell Biology and Anatomy at New
York Medical College since 1979, where I teach medical and graduate
students and direct a laboratory in developmental biology. This
is the scientific field that studies embryo development, cloning,
regeneration, and stem cells. My work on the development of form
and pattern in animal embryos has been supported over the past 25
years by grants from the National Science Foundation and the National
Institutes of Health. I am currently the recipient of two Federal
grants.
Since my student days I have also been concerned with the uses to
which scientific research is put. Having become convinced that scientists,
who are beneficiaries of public resources, have a deep responsibility
to anticipate what lies down the road in their own fields and to
serve as a resource for the public on the complex issues around
applications of scientific research, I joined with other scientists,
social scientists, womens rights advocates, and environmentalists,
to found the Council for Responsible Genetics in the late 1970s.
The Council is now the Nations oldest organization scrutinizing
and interpreting the new genetic technologies, and has worked to
educate the public on the scientific and social hazards of proposals
to introduce inheritable genetic modifications into humans, including
the allied technology of human cloning. I have placed into the record
several documents from the Council that relate to the issues at
hand, including the Genetic Bill of Rights, which affirms, in part,
that All people have the right to have been conceived, gestated,
and born without genetic manipulation.
I will state from the outset that I, and the Council for Responsible
Genetics as an organization, unequivocally support a womans
right to make her own reproductive decisions. Therefore, while what
I am here to tell you today calls into question technologies that
manipulate, clone, and genetically alter human embryos, these views
do not derive from any notion of the sanctity of the embryo, nor
from attributing to it the status of a human being. Rather, our
concerns derive from two distinct sources:
(i) the irresponsible promotion of another scientifically questionable
biotechnology, in conformity with what is now a recurrent pattern
of playing to investors hopes and patients desperation;
(ii) the destructive social consequences of moving down the technological
path that begins with embryo cloning.
Specifically, cloning embryos for producing embryo stem cells will,
by failing to deliver on its promises, inevitably lead to calls
to extend the lifespan of clonal embryos so as to permit harvesting
developmentally more advanced cells and tissues for research and
potential therapies. The same well-intentioned imperatives that
make some of you unwilling to deny patients who hope for relief
by means of embryo stem cells will make you, or your successors,
susceptible to demands for increased access to improved products
of this work, up to and including full term clones from which to
harvest organs.
I will try to lay out how this will happen. Embryo stem cells are
derived from embryos that are less than two weeks oldthe now
proverbial clump of cells in the bottom of a Petri dish.
If derived from a clonal embryo resulting from transfer into an
egg of a patients somatic cell nucleus, the stem cells will
be a genetic match for the nuclear donor. Transplants derived from
such stem cells will be compatible with the immune system of these
patients. Please note, however, that this will be of little advantage
to patients with type 1 diabetes, whose condition causes them to
immunologically reject their own insulin-producing cells.
While such genetically matched cells may be tolerated by patients
with other conditions, there are still likely problems. Two decades
of research on embryo stem cells in genetically compatible mice
has yielded a handful of studies with modest therapeutic resultsin
all cases less than what has been achieved with grafts of non-embryonic
cells. Despite great efforts, embryo stem cells never become just
one cell type or coherent tissue, but differentiate into disorganized
mixtures of cell types. Most importantly, they are genetically unstable.
If placed in adult mice they cause tumors. There is every reason
to believe that human embryo stem cells, including those from cloned
embryos, would cause cancer in human patients.
To overcome this, if it is indeed possible, will take years of research.
Some say its worth a try, and scientists and companies with
patents on this technology are willing to make the attempt. However,
science and medicine always gravitate toward better technologies.
In fact, Dr. John Gearhart of Johns Hopkins University has isolated
a different kind of human stem cell. These are derived from the
developing gonads of 8-9 week human embryos, and could be obtained
after elective abortion. Like the embryo stem cells, these so-called
embryo germ cells can differentiate into all cell types. Most importantly,
when transplanted into experimental animals they do not cause cancer.
On purely scientific grounds, embryo germ cells show greater promise
than embryo stem cells. Now, if they were derived from clonal embryos
they would be nearly perfect, again in a purely scientific sense.
But interestingly, none of the advocates of permitting embryo cloning
has raised the specter of growing clonal embryos for 8 to 9 weeks
so that genetically matched embryo germ cells could be harvested.
These embryos would, of course, no longer be clumps of cells in
a Petri dish, and some supporters of embryo cloning here might object.
Right now it would be a hot potato, but once we have clonal embryos
for a while and have gotten used to the idea, who would turn a deaf
ear to calls by patients and their loved ones for these superior
therapeutics?
And once stem cell harvesting from two-month clonal embryos was
in place, who could resist the pleas to extend the time-frame so
that liver and bone marrow could be obtained from six-month clonal
fetuses to cure sufferers of life-threatening blood disorders such
as beta-thalassemia, or so that brain lining cells could be harvested
from near-term fetuses to treat Parkinsons sufferers?
I emphasize that all of this makes perfectly good scientific and
medical sense. The only thing that stands in the way is a sense
of propriety concerning the uses to which developing human embryos
and fetuses may be put. Some of you may draw the line at the tiny
clump of cells; others at the two-month embryo; still others somewhat
short of full-term. Wherever each of you decides to leave this particular
train, there will be others who will assert their right to take
it to the next station. After Dolly the sheep was cloned, a British
scientist suggested, tongue-in-cheek, that inactivation of brain-inducing
genes could be used to produce headless full-term human clones for
organ harvesting. To his surprise, Britains most prominent
embryologist publicly replied, Why not? Short of saying
no to embryo cloning, any line that you draw will be a moving boundary.
Few in this room would go along with the more extreme possibilities,
but what about future generations growing up in a world in which
producing clonal embryos for spare parts is medicine as usual?
Not only this, but the scientific publications that will ensue if
embryo cloning proceeds will enable those reckless individuals who
have announced their intention to make full-term clones, and then
genetically-improved clones, to do so. Those who think
that handling clonal embryos as controlled substances in regulated
laboratories will stop the transfer of the technology do not understand
how science works.
This is my prediction: if embryo cloning is permitted, within a
few years frustration over lack of progress in producing safe and
effective therapeutics from embryo stem cells will lead to calls
to permit harvesting of embryo germ cells from 2-3 month clonal
embryos, and we may all find ourselves here again. The rest will
be just a matter of time. But there are other possibilities. Stem
cells derived from adult tissues and umbilical cord blood have already
proved to be effective therapeutics in animal models and in clinical
trials. There is less commercial interest around them since it is
difficult to obtain patents on a patients own cells. Correspondingly,
however, these cells are immunologically compatible with the patient
from whom they are derived. It will take much additional work to
make this technology practical, but scientifically, and societally,
I am convinced that this is the way to go.
(submitted with attachments including: CRG
statement on embryo research; the Genetic Bill of Rights;
and the CRG position paper on human germline manipulation.
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