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Stem Cell Research and Human Cloning
Questions and Answers
From the United States Conference of
Catholic Bishops
www.usccb.org
What is a stem cell?
A stem cell is a relatively unspecialized cell
that, when it divides, can do two things: make another cell like itself,
or make any of a number of cells with more specialized functions. For
example, just one kind of stem cell in our blood can make new red blood
cells, or white blood cells, or other kinds - depending on what the body
needs. These cells are like the stem of a plant that spreads out in
different directions as it grows.
Is the Catholic Church opposed to all stem cell
research?
Not at all. Most stem cell research uses cells
obtained from adult tissue, umbilical cord blood, and other sources that
pose no moral problem. Useful stem cells have been found in bone
marrow, blood, muscle, fat, nerves, and even in the pulp of baby teeth.
Some of these cells are already being used to treat people with a wide
variety of diseases.
Why is the Church opposed to stem cell research
using the embryo?
Because harvesting these stem cells kills the
living human embryo. The Church opposes the direct destruction of
innocent human life for any purpose, including research.
If some human embryos will remain in frozen storage and ultimately be
discarded anyway, why is it wrong to try to get some good out of them?
In the end we will all die anyway, but that gives
no one a right to kill us. In any case, these embryos will not die
because they are inherently unable to survive, but because others are
choosing to hand them over for destructive research instead of letting
them implant in their mother’s womb. One wrong choice does not justify
an additional wrong choice to kill them for research, much less a choice
to make taxpayers support such destruction. The idea of experimenting
on human beings because they may die anyway also poses a grave threat to
convicted prisoners, terminally ill patients, and others.
Haven’t doctors, scientists, and
commentators said that embryonic cell research will lead to the cure of
many diseases?
Some have made this claim, but fact this is
largely speculation. Embryonic stem cells have never treated a human
patient, and animal trials suggest that they are too genetically
unstable and too likely to form lethal tumors to be used for treatment
any time soon. Years ago it was said that stem cells from embryos would
be the most useful because they are so fast-growing and versatile, able
to make virtually any kind of cell. But those advantages become
disadvantages when these cells make tumors, creating a condition worse
than the disease. Yet many supporters remain wedded to this approach,
having invested a great deal of money and effort and hoping they can
still make it work. This kind of exaggerated “promise” has misled
researchers and patient groups before – most obviously in the case of
fetal tissue from abortions, which a decade ago was said to promise
miracle cures and has produced nothing of the kind.
Is the Church telling us to choose the
lives of embryos over the lives of suffering patients?
No. It is calling us to respect both, without
discrimination. We must help those who are suffering, but we may not
use a good end to justify an evil means. Moreover, treatments that do
not require destroying any human life are at least as promising – they
are already healing some conditions, and are far closer to healing other
conditions than nay approach using embryonic stem cells. The choice is
not between science and ethics, but between science that is ethically
responsible and science that is not.
Is embryonic stem cell research
advancing so slowly because this research is banned in the United
States?
No. Embryonic stem cell research is fully
allowed in the United States – there is no federal law (and almost no
state law) against it. The government has only set some limits on the
number of embryonic stem cell lines eligible for federal funding.
Supporters disappointed at failures using these cells sometimes blame
this stem cell research “ban” (which is not really a ban at all). But
as noted above, the much more serous obstacle lies in the nature of the
cells, which are not working out as some predicted.
Did the federal government in 2001
forbid funding any embryonic stem cell research?
No. In
fact, the federal government gave $25 million to human embryonic stem
cell research last year. But on August 9, 2001, President Bush said
that federally funded research would use only embryonic stem cells
already in existence (obtained by destroying embryos prior to that
date). In this way, he reasoned, federally funds could be used to
explore this research, without encouraging researchers to destroy new
embryos in order to obtain federal grants. Some of these existing stem
cell samples have been used to create more than 20 cell lines for
research, and others remain in storage for possible use in creating new
cell lines in the future. There is no legal limit on the amount of
funding that can be used for this avenue; if the total funding for it is
relatively small, that is chiefly because researchers are not requesting
the funds as they are finding other avenues more promising.
Can stem cells be stored in a bank?
Yes, like donated
blood or bone marrow, they can be frozen and banked. In 2003, for
example, Congress approved funds to help create a nationwide umbilical
cord blood stem cell bank, in light of the many clinical benefits being
discovered from these cells now usually discarded after live births.
Many of the embryonic stem cell samples eligible for federally funded
research under the current policy also remain frozen in banks, to be
thawed and turned into stem cell lines when needed.
What is a stem cell line?
It is an ongoing,
living colony of stem cells in a laboratory, from which cells can be
obtained for research or other uses. Sometimes these are called
“immortal” cell lines, but that is misleading because they do eventually
deteriorate. Embryonic stem cells are said to be easier to grow in a
stem cell line, but they also tend to develop serious genetic
abnormalities associated with cancer.
What are the advantages of harvesting donor cells from the intended
recipient of the stem cell therapy?
Because these cells
come from the patient, they are exact match and will not be rejected by
the body as foreign tissue. Also, because no foreign substance is
placed in the body, there are fewer regulatory barriers to their medical
use/
Who
is funding stem cell research? What role is federal funding playing in
the determining research priorities?
Many private
foundations and for-profit biotechnology companies fund stem cell
research, but the federal government (especially through the National
Institutes of Health) remains the largest source of funds. The
government’s funding priorities have a large influence on the direction
that medical research takes. Since available research funds began being
diverted toward exploring embryonic stem cell research, some very
promising adult stem cell avenues for treating juvenile diabetes, spinal
cord injury, Parkinson’s disease, etc have been underappreciated and
underfunded. Many advances in these fields have emerged from other
countries.
What is human cloning and how is it related to stem cell research?
In human cloning, the
DNA from the nucleus of a person’s body cell is inserted into an egg
whose own genetic material has been removed, and the egg is then
stimulated to begin embryonic development. The resulting cloned embryo
would genetically be an almost identical twin to the person supplying
the body cell. This research overlaps with the stem cell issue. That
is, human cloning might be done to create an embryo who will be
destroyed to provide stem cells genetically matched to patient, so the
cells will not be rejected as foreign tissue. But some cloning research
is done for other purposes – for example, to create embryos with
devastating illnesses from the body cells of sick patients, to study the
early progress of that disease. Most embryonic stem cell research
involves embryos created by vitro fertilization, not cloning.
Why does the Church oppose human cloning?
Cloning is a
depersonalized way to reproduce, in which human beings are manufactured
in the laboratory to preset specifications. It is not a worthy way to
bring a new human being into the world. When done for stem cell
research, it involves the moral wrong of all embryonic stem cell
research (destroying an innocent human life for possible benefit to
others) plus an additional wrong: It creates human beings solely in
order to kill them for their cells. This is the ultimate reduction of a
fellow human being to a mere means, to an instrument of other people’s
wishes.
Does opposition to cloning and embryonic stem cell research come only
from one theological or political view?
No. Serious moral
concerns about these practices have been raised by an array of both
religious and secular groups, including some who disagree with the
Catholic Church about abortion – Friends of the Earth, the United
Methodist Church, etc. The human cloning ban supported by the Church
has been approved by the House of Representatives by an overwhelming
bipartisan majority. Many other countries (including Canada, France,
Australia, Germany and Norway) have passed similar bans. Opposition to
the idea of treating early human life as a mere object or commodity in
the laboratory transcends religious and political divisions.
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