W. Evans, Ph.D., Ph.D.
Veritas Ministries International
Veritas Institute for the Study of Bioethics and Public Values, USA
is a Stem Cell?
During the initial days
of development, the human embryo exhibits the remarkable ability to
diversify along specified molecular pathways that will eventually give rise
to nearly every cell and tissue found in the human body. Some of these
tissues will retain their ability to regenerate throughout life, including
your skin and hair. These amazing cells also have the capacity to
renew themselves and to develop into other cell types. In this lies
their power to transfix the biomedical community and the popular
imagination. Indeed, should we learn how to harness and direct the
mechanisms of human ES cell differentiation, the possibilities are
astonishing. Stem cells are found in both humans and animals, and may
be retrieved either from embryos or from mature organisms. When
removed from a human embryo, they are referred to as human embryonic stem
Potential Benefits of Human Stem Cell
Some scientists envision
a day when we will have the means to artificially grow various youthful
human organs that are totally compatible with the recipient, thereby
eliminating risk of transplant rejection. Others long for a day when
ES cells might be introduced into a patient and directed toward tissue
repair, such as the regeneration of a damaged nervous system in spinal
injury. Stills others are thrilled by the idea that we may one day
correct congenital human defects while yet in the womb. Indeed, there
would seem to be no limits to the stem cell’s potential contributions to
humanity’s future health and well being.
To hear the usual
advocate for human ES cell experimentation, the aforementioned
promises—and more—are almost within our reach. Senator Ted
Kennedy, representing the typical proponent educated by newspaper-science,
has said that curtailing embryonic stem cell research would be tantamount to
a "tragic betrayal" of patients who hope for cures. "It would
be unacceptable to offer these patients and families the promise of
effective stem cell research but deny them the reality of it” (Boston
Globe, September 5).
Newsweek put it
similarly: “That may be the most tragic consequence of squelching what is,
more than anything, a quest for knowledge.” Notice that the
prevailing attitude is that if something can be done it ought to be done!
The writers continue: “We simply don’t know how embryonic cells might
help people who are suffering and dying today. By banning the
research, we uphold the most extreme view of the sanctity of life, but at a
price: foreclosing the possibility of doing all we can to improve the lot of
The Current State of Human Stem Cell
The isolation of the stem
cell was first described in 1981 in experiments being carried out on the
mouse. In November of 1998, scientists reported that they had
successfully isolated and cultured human stem cells—a feat which had
eluded the profession for more than two decades and previously thought by
many impossible. In July 2001, the Jones Institute for Reproductive
Medicine in Norfolk, VA announced that it had created embryos (from donated
sperm and eggs) for the express purpose of extracting their stem cells.
A few days later, Advanced Cell Technology in Worcester, MA announced that
it was trying to create embryos through human cloning. Shortly
thereafter, President George W. Bush announced that there would be no federal
funds allowed for purposes of cloning or the destruction of human embryos
for purposes of stem cell research. On November 25, 2001, Advanced
Cell Technology Inc. announced that it had used cloning technology to grow
cells that may eventually serve as a source for stem cells. Advanced
Cell Technology is privately funded.
Currently, no one knows
precisely how ES cells work, much less how to manipulate or direct their
activity. The field of human ES cell research is in its infancy—the
stage of observation. Put simply, more “lines” of human ES cells
will not necessarily speed up biotechnological advancements at this stage;
just as having more people to watch grass grow will not speed up its growth.
Should one day, the field of human ES cell research arrive to a point where
we can control and direct its tremendous capabilities (a conclusion far from
certain and nowhere near imminent), more “lines” in the hands of more
scientists may yield faster and larger fruit. But, again, that day, at
this point, is mere speculation.
The Source for Human Stem Cells
Debate continues to swirl
concerning the appropriate source from which to retrieve human stem cells.
Some maintain that human stem cells ought to be retrieved from embryos.
On this view, it is argued that human ES cells holds the greatest promise
for medical and biotechnological application because of their supposed
plasticity. In other words, the suggestion is that human ES cells are
more primitive in the developmental hierarchy; hence, they offer the
greatest flexibility in research and anticipated therapeutics.
Others maintain that
human stem cells ought to be removed only from more mature adult sources,
such as the liver, brain, or bone marrow. The argument popularly
advanced in an effort to detract from the study of adult stem cells is that
these adult stem cells may not have the plasticity or potency of ES cells
and, hence, may be inferior research material. These claims have yet
to be substantiated. In terms of bioethics, experimentation of adult
stem cells is not as worrisome as human ES cell research, since ES cell
research necessitates the destruction of a human embryo.
The Scientific Perils of Human Embryonic
Stem Cell Research
The bright glare created
by the exciting promises of human ES cell research often obscures the fact
that the field is laced with both significant scientific obstacles and
monumental ethical problems. Indeed, at the time of this writing, only
approximately 15 technical research papers have been produced related to
human ES cell culture and differentiation. During this same time
period, 150 scientific reviews and opinions were published and 1,500
newspaper articles have been produced. One major factor missing from
the sensational press coverage is discussion of the huge, and perhaps
insurmountable, hurdles facing developmental biologists intent on developing
ES cell-based regenerative medicine.
Given that embryonic stem
cell research in mice has had a 17-year lead ahead of those performed in
humans, one would expect that the research in mice should be far more
advanced than the corresponding research in human systems. So far, the
crowning achievement in mouse embryonic stem cell research has been for the
creation of genetically-engineered mice for medical and scientific testing.
Mouse embryonic stem cells in which the DNA has been manipulated can be put
back into a very young embryo, and the embryo will adopt the new cells as
its own. After some breeding, scientists can obtain strains of mice
derived solely from the genetically manipulated ES cell.
Through this procedure,
scientists routinely engineer DNA in mouse embryonic stem cells and generate
mutant mice inflicted with genetic diseases such as cancer, cystic fibrosis
and Alzheimer's disease. Scientists then attempt to find cures for
these sick mice by testing experimental drugs, prior to medical trials in
humans. Thus, the primary achievement of mouse embryonic stem cell
research has not been the successful regeneration of artificial cells,
tissue, or organs but rather the production of new strains of mutant mice.
By popular news accounts,
one would assume that there are thousands of qualified researchers chomping
at the bit to get at the 64 human embryonic stem cell lines referred to by
President Bush. According to popular scenarios, these researchers are
primed and ready to generate entire organs in a dish from the embryonic stem
cells. Soon afterwards these regenerated organs would be ready for
transplantation into diseased patients, offering miracle cures. In
reality, most of the past 17 years of embryonic stem cell research with mice
has been conducted using only 5 or 6 mouse embryonic stem cell lines—not
64. And fewer than 5 lines have been used for genetic engineering.
No organ has ever been artificially grown in a dish. Although neurons
have been derived from embryonic stem cells, this was accomplished only by
the addition of harsh, and sometimes toxic, chemical compounds. In
fact, culturing mouse
embryonic stem cells is truly an art (like gardeners with "green
thumbs") and very few dedicated researchers have been able to perform
embryonic stem cell differentiation experiments with any degree of
scientists naively wishing to incorporate mouse embryonic stem cell
differentiation into their research program attempt to ES cell projects in
their laboratories. Like novice students of the piano, nearly all give
up this line of study within one year of effort. Why is this?
Amongst all cell lines, embryonic stem cells are considered the most exotic
and technically the most challenging to cultivate. Currently,
there are perhaps less than dedicated 10 world-class laboratories in
existence with researchers sufficiently skilled enough to perform embryonic
stem cell differentiation experiments with reproducible results.
Worse, mouse embryonic
stem cells are well known to become cancerous if implanted back into mice.
Without 100% cell separation accuracy, human patients receiving cell therapy
from these sources would risk future development of cancer from the
contaminating embryonic stem cells. Thus, the dream of uniformly
controlled differentiation of embryonic stem cells is, at this point, only a
dream. The host of technical difficulties experienced in mouse
embryonic stem cell research indicates that it is not likely that any
embryonic stem cell therapies will be scaled up for medical treatment in a
cost effective manner any time soon—if ever.
The Ethical Perils of Human Embryonic Stem
most popular discussions in bioethics today, the debate concerning human ES
cell research begins at the wrong end of the issue. We hear much about
the possible suffering that human ES cell research might end—indeed, a
worthy goal—but we hear very little about what it means to be human, or in
what our humanness consists, or when human life begins. We are
repeatedly told that the embryo is not a human being, it is merely
“undeveloped human tissue,” or “cellular life.” As one writer
put it, stem cells are “little knots of magic tissue” (Time July 23,
this is so, then why limit experimentation on the embryo to its first 14
days of “life”? One landmark of fetal development is the formation
of the primitive streak at approximately eight weeks. Why suspend
embryo experimentation between weeks two and eight? The British
Parliament said it was because after 14 days, “we encounter a moral
problem.” And what moral problem is that? It is still,
according to popular belief, but “human tissue” and not human life.
What precisely happens at the stroke of midnight on the 14th day that
affords the human embryo moral standing? Put plainly, if the human
embryo has moral standing and a corresponding right to life it must extend
to its existence during the first 14 days, and it matters not what potential
good may be realized by its destruction. Ethical ends are not achieved
through immoral means.
Some argue that they wish
to experiment only with already aborted fetuses. However, research
using aborted fetuses entangles the researcher in a prior wrong. A
researcher can be guilty of complicity even if he had no role in the
original wrong and his own motives were beyond reproach.
The issues of bioethics,
including embryonic stem cell research, are not the problem. They are
the symptoms of a more fundamental disease—the loss of moral absolutes,
and a widespread failure on the part of our culture to acknowledge God as
both the Creator and sustainer of life. Indeed, human life is
begotten, not made. Human life is a gift from God, not a technological
plaything. Human life is personally fashioned by the hands of God, not
the instruments of science.
One writer put the matter
rightly: “[The nations] seem to be pausing at the brink, waiting to hear
from the church or any other voice on why they should not plunge into the
remaking of humanity. ‘Tell us why we should not proceed to remake
humanity now that we are developing the power to do so’—this is the
challenge presented to Christians.” (Christianity Today, Oct 1,
2001, p. 36). Does humanity stand in need of remaking?
Absolutely. But it needs to be remade from the inside, from the
renewing of the mind, from the circumcision of the heart, from the
regenerating work of the Holy Spirit. In short, our hope lies not in
stem cells, but in the One who created them.
Want to learn more?
Please contact us at:
Institute for the Study of Bioethics and Public Values
Bay, CA 95746
may order the following resources from Veritas
Evans, R.W. “The
Promises and Perils of Human Embryonic Stem Cell Research. Audio
Cassette Tape#: SC0001R
Evans, R.W. “The
Moral Status of Embryos,” in The Reproduction Revolution, John F. Kilner,
Paige C. Cunningham and W. David Hager, ed., ( Grand Rapids, Mich.: Eerdmans
Copyright © 2001 Veritas Ministries International. All rights