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STEM CELL RESEARCH
Methods of obtaining embryonic stem cells
with, perhaps, fewer ethical objections
Sponsored link.
The ethical dilemma:
There is a general consensus that all living matter containing human DNA
is, by definition, human life. This may include human life in the form of a
spermatozoon, ovum, pre-embryo, embryo, fetus, newborn, child, youth or adult.
For that matter, human cancer cells, skin scrapings, saliva, etc. are either
forms of human life or contain human life.
However, there is no consensus about when human life becomes a human person
with fundamental human rights, including the right to life itself. This is the
key factor dividing the U.S. and Canada in the debate over
abortion access.
North
Americans are seriously divided over the human life/human person question:
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Many religious and social conservatives support the pro-life movement.
They
believe that human personhood is attained at conception, or perhaps very
shortly thereafter when cellular division occurs. |
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Many religious liberals, social liberals, and secularists support the pro-choice movement.
They believe that personhood happens much later, during the embryonic or
fetal stage of pregnancy -- or even at birth when the fetus becomes
independent of her or his mother. |
The extraction of human stem cells currently requires the death of an pre-embryo. "In
the standard method of harvesting stem cells, researchers wait five days or so
after fertilization until the embryo has become a ball of up to 150
[undifferentiated] cells. They
obtain stem cells from the interior of the ball, which destroys the embryo."
1
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To most pro-lifers, this procedure involves the murder of a living
person. It is as evil an act as strangling a newborn. An abortion clinic is
considered the
ethical equivalent of the Auschwitz death camp. |
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To most pro-choicers, a pre-embryo is a potential person but not an
actual person. Killing it months before it attains personhood in order to
harvest its
stem cells is a ethically defensible act, when weighed against the
potential treatments and cures that embryonic stem cells should be capable
of providing in the future. |
Some researchers have been trying to find alternatice methods of obtaining
embryonic stem
cells that do not involve the actual death of an embryo. They hope to find a
method of obtaining stem cells that is acceptable to the pro-life movement.
The stakes are very high. Embryonic stem cells have the potential to develop
into almost any of the 220 types of cells found in the human body (e.g. blood cells,
heart cells, brain cells, nerve cells, etc). Rick Weiss of the Washington Post
writes that researchers expect that stem cells from human pre-embryos will be
able to:
"morph into virtually every kind of tissue, including nerves to
replace those destroyed by spinal injuries and cardiac muscle to fill in for
cells lost in a heart attack. Scientists see stem cells as the key to a new
era of regenerative medicine." 10
Some researchers regard them as
offering the greatest potential for the alleviation of human suffering since the
development of antibiotics. Over 100 million Americans and two billion other
humans worldwide suffer from diseases that may eventually be treated more
effectively with embryonic stem cells or even cured.
Adult stem cells can be obtained with few ethical concerns. However their
potential applications are much more restricted than for embryonic stem cells.
Bernard Lo, a bioethics specialist at the University of California - San
Francisco, has asked individuals and groups who are opposed to embryo stem
cell research to make their views on alternative harvesting methods clear at the
outset. He said:
"This work is really driven by a desire on the part of scientists to
address the moral concerns some people have. So those people should say now
if it doesn't settle the problem, to avoid a lot of wasted effort."
Those opposed to embryo stem cell research have apparently done just that.
Within hours of articles being published in the journal Nature's online
web site, many had already expressed their opposition. 2
Advanced Cell Technology (ACT) study using PGD:
ACT is a company located in Worcester, MA which is conducting world-class
research with stem cells. They have used an existing process called "Pre-implantation
Genetic Diagnosis" (PGD). This is a procedure that is usually requested by prospective
human parents who are aware that they are carriers of an incurable
genetically-based disease or disorder, like cystic fibrosis, hemophilia, Huntington disease,
muscular dystrophy, sickle cell disease, Tay Sachs disease, etc. The parents
have been genetically screened. One or both are found to be carriers of a
disease or disorder. They are
concerned about passing the problem to their child.
Fertility clinics use PGD to test embryos produced by the couple for the genetic problem.
Embryos which are found to be free of the disease or disorder are implanted in
the woman's womb; defective embryos are discarded. In this way, PGD can weed out
genetically defective human embryos before they have a chance to develop beyond
the pre-embryo stage.
The ACT scientists did not perform their research on human embryos. They
studied two-day old mouse embryos which had gone through three cell divisions after
fertilization. Each embryo then consisted of
eight-cells. One of the eight cells, called a "blastomere," was carefully removed from each embryo. The
embryos' seven remaining cells continued to develop. Previous research has shown
that one or even two cells can be removed from an eight-cell embryo without any
adverse effect. The embryos were implanted in the
wombs of mice, and continued to mature into normal baby mice.
The single cell that was removed from each mouse embryo was found to behave like
embryonic stem cells. The researchers ended up with only a single stem cell from
each embryo -- rather than about 150 stem cells as are harvested from an entire embryo.
Still, methods exist to produce endless numbers of stem cells from a single
cell. Lanza was able to find the optimum culture and environment to grow a
colony of embryonic stem cells from the single cell. 10
The lead ACT researcher, Robert Lanza, said:
"The most basic objection to embryonic stem cell research is the fact
that embryos are deprived of any further potential to develop into a
complete human being. We have shown in a mouse model that you can generate
embryonic stem cells using a method that does not interfere with the
developmental potential of the embryo." 3
He said that the entity has "no inherent
principle of unity, no coherent drive in the direction of the mature human form."
4 During a separate interview, he said:
"Many people, including the president, are concerned about destroying
life while trying to save it. We're showing a method by which you can create
stem cells without destroying the embryo." 5
Lanza suggested that when fertility clinics
perform human PGD to detect genetic diseases, they could:
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Remove the single cell as usual. |
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Allow it to divide into two cells. |
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Use one of the cells to test for genetic problems. |
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Use the other cell to establish a stem cell line. 1 |
The stem cells would then be a perfect genetic match for the person into
which the embryo develops.
Lines of stem cells would then be a byproduct of existing PGD testing. No
embryo would be killed in the process. The scientists hope, perhaps naively,
that this technique might be acceptable to the pro-life community.
Negative reactions to the PGD procedure:
To many pro-lifers, the idea of creating a number
of persons in the form of embryos, testing them, rejecting any that do not meet
certain criteria, and eventually allowing the latter to die is mass murder. It
bears similarities to the process that the Nazis used as Auschwitz to separate
desirable workers from the rest of the prisoners, and routing the latter to the
gas ovens for extermination.
Some negative reactions:
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The Roman Catholic Church has not responded formally as
of 2005-OCT-18 (three days after the paper was published in the Journal Nature.)
5 They are expected to condemn both
techniques. On the article's publication date, the Associated Press reported initial
comments by Richard Doerflinger. He is the deputy director of pro-life
activities for the U.S. Conference of Catholic Bishops. He said that PGD
is itself unethical for two reasons:
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It places the embryo at risk of damage which could kill it. |
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He said that PGD is mainly a procedure "to select out genetically
imperfect embryos." 1 |
Since the PGD procedure itself is prohibited by the Church, any byproduct --
such as stem cells -- would probably be equally condemned. | |
The Rev. Tad Pacholczyk, director of education for the National
Catholic Bioethics Center in Philadelphia, said that Catholic teaching
disapproves of PGD because it is a violation of the embryo and is not aimed
at helping the embryo. In addition, research on animals has shown that a
single cell extracted from an embryo has the potential to initiate a
pregnancy if it is implanted in a uterus. Thus, destroying the cell would be
murdering a human person. 6 | |
Professor Richard Gardner, chairperson of the UK's Royal Society's
working group on stem cells research and cloning, said:
"The idea that ethical fears will be allayed is a red herring. It is
difficult to see any parent willing to risk having cells extracted from
their own child while it is an embryo, unless it is to create stem cells in
case that particular child needed them in the future." 3 | |
Josephine Quintavalle, of the UK-based Comment on Reproductive Ethics,
said that: |
"...there is no evidence yet that taking stem cells will
not cause harm later on."
She commented that the technique interferes:
"...with the natural process, and you have to ask why someone
would want these stem cells. I think scientists would be far better to
concentrate on other areas of stem cell research such as amniotic and
adult stem cells which show far more promise." 3
It may be worth noting that adult stem cell research has been ongoing for
over a decade and is now producing useful treatments. Embryonic stem cell
research is quite new and has yet to progress to human trial stage. However,
researchers generally agree that embryonic stem cells offer much greater
long-term potential.
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Douglas Powers, chief scientific officer of Boston IVF, a fertility
clinic, said that: ''When you start mixing the obtaining of research
material with a clinical test, you get into a very tricky area." He gave one
example: If
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A cell was removed for PGD evaluation, and |
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The cell was allowed to divide into two cells, and |
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One cell was used to extract its stem cells, and |
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The other cell died before the PGD test was complete, and |
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If there were not a sufficient number of other embryos to test,
then: |
The patient's care would be interrupted. She would have to delay attempts
to become pregnant. | |
Tony Perkins of the Family Research Council expressed concern about
the PGD procedure. He wrote: "it is not clear what effect this would have on
children who are born after having had one of their cells removed while still an
early embryo." 9 | |
Dr. John Shea, who is medical advisor to Campaign Life Coalition,
a Canadian pro-life group, said |
"Sometimes it is possible to remove a cell from an embryo without
killing it, but the point is that to take the risk without benefiting
the embryonic being is unethical according to the standards established
by the Nuremberg Code. They just refuse to admit that the embryo is a
human being and so all the rules regarding medical research on human
beings have to be applied. You have to get consent, and no parent can
consent to allowing medical research on a child that is not intended to
benefit the child." 11
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George Q Daley, a stem cell researcher at Harvard Medical School, notes
that both procedures are in early stages. He said: |
"It's not clear it's going to work in human embryos. And in order to
determine that we'll have to actually do the research on human embryos
and likely destroy some in the process." 4
Whitehead Institute and MIT study:
Rudolf Jaenisch and Alexander Meissner at the Whitehead Institute for Biomedical Research and the
Massachusetts Institute of Technology in Cambridge, MA, also studied
mouse embryos. They used a modified therapeutic cloning
technique. In therapeutic cloning, the aim is to produce stem cells which are a
perfect genetic match to a patient suffering from Parkinson's disease, diabetes,
paralysis, or some other disorder or disease. In this way, they have the
potential to treat or cure the patient without inducing possible rejection.
The researchers removed the nucleus from a skin cell that has been removed
from an
adult mouse. 7 The nucleus is
the component of the cell that contains mouse's DNA. This nucleus was then
inserted into mouse ovum from which the nuclei had previously been removed. The
ovum then started to behave like an embryo.
They refer to this technique as "altered nuclear transfer" It is
slightly different from conventional therapeutic cloning. They added an extra
step before inserting the nucleus into the ovum. They "blocked the action of
a key gene [Cdx2] in the nuclei" so that the resulting "non-embryonic entity"
would not have the capacity of developing into a conventional embryo that could
be implanted in a uterus and induce a pregnancy. They turn off the gene that
controls the development of the outer layer of cells that would eventually
become the placenta. 6 Thus,
it lacks the ability to "establish the fetal-maternal connection" in the
uterus. In essence, they made the
DNA incapable of development so it could not produce a baby mouse. Scientists
argue that "patient-specific" embryonic stem cells can be produced without
destroying any potential human life. Jaenisch said: "They can never, ever,
become a baby." 4
Malcolm Ritter, science writer for the Associated Press, wrote: "This
modified technique, called altered nuclear transfer, has been championed by Dr.
William Hurlbut of Stanford University, a member of the President's Council on
Bioethics. He said the abstract cluster of cells the egg produces is not an
embryo but a 'non-embryonic entity' that lacks an embryo's developmental
potential." Dr. Hurlbut said: "You don't create a living being."
Again, the scientists hope, perhaps naively, that this technique might be
acceptable to the pro-life community.
Negative reactions to the Altered Nuclear Transfer procedure:
The key question with this procedure is whether an embryo-like entity which
has zero potential to develop into a fetus and newborn, is still a human person.
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"... to some bioethicists, an early-stage embryo
that stands no chance of forming anything more advanced lacks a human's
ethical or moral standing." 8 |
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If pro-life movement considers it to be a human person, then they will
feel that it has human rights including the right to live. They will be
unalterably opposed to the technique. |
Some negative reactions:
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Richard Doerflinger disagrees with the belief that the altered nuclear
transfer procedure creates a non-embryonic entity, not an embryo. He said that
the technique seems to first create and then destroy an embryo. That would make
it unacceptable to the Catholic Church. 1 |
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The Associated Press reported that: |
"....the Rev. Tad Pacholczyk called the approach a step in
the right direction. Scientists are already discussing a modified version in
which adding the nucleus to the egg would result in a single stem cell, not
an embryo. He said.
Seen in that light, he said, the mouse study "is very encouraging. It
reminds us that we have certain tools at our disposal in the scientific
armamentarium that can be used in the direction of seeking an answer to the
ethical impasse." 1 In
a separate interview, he said:"I am very encouraged. We may be able to work around this with some creativity and good
will." 6
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Jaydee Hanson, director of human genetics at
the International Center for Technology Assessment, a group which
opposes stem cell research, said: "This is an attempt to solve an ethical
issue through a scientific redefinition that really doesn't solve the issue."
2 |
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Douglas Melton, a stem cell researcher from at
Harvard University, expects that groups opposed to stem cell research
will still consider the "entity" to be an embryo, even though it has no
potential for development. |
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Tony Perkins of the Family Research Council expressed concern about
this procedure as well. He wrote: "...it is unclear whether such an entity
should be considered not an embryo, or simply an embryo altered for self-
destruction. More animal research is warranted to answer questions raised by
these studies." 9 |
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Markus Grompe, a geneticist at Oregon Health & Science University in
Portland, OR, said: "The concern is that an embryo is being generated that is
doomed to die very soon." 10 |
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Robert P. George, a Princeton professor of jurisprudence and a member of
President Bush's bioethics council said: |
"Nobody should be speaking too quickly here on either side. The way
to find out is to do the careful studies to figure out exactly what
you've got here. It's not a spiritual question. We're not looking for a
soul. The question is, 'Does it have the [biological basis] for
self-construction and self-organization, or is it a fundamentally
disordered growth'? "
Political aspects:
At the time that the papers were published in the
journal Nature, the U.S. Senate was considering a bill that was already passed
by the House of Representatives. It would overturn some of President Bush's
limitations on the funding of stem cell research programs. Some of the bill's
supporters suggest that these alternative approaches might reduce support for
the measure. Daley said:
'If you are supporting these alternatives at the expense of the proposal
to expand access to the stem cells that are available today, you are
essentially voting to delay the research." 6
Site navigation:
References:The following information sources were used to prepare and update the above
essay. The hyperlinks are not necessarily still active today.
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Malcolm Ritter, "Studies show new ways to get stem cells," Associated Press, 2005-OCT-16, at:
http://news.yahoo.com/
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Carl T. Hall & Cornelia Stolze, "Stem cell strides may help resolve ethical dilemmas. New methods preserve viable embryos, but some
opponents skeptical of tactics," San Francisco Chronicle, 2005-OCT-17, at:
http://www.sfgate.com/
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"Hope over stem cell ethical fears," BBC News, 2005-OCT-17, at:
http://news.bbc.co.uk/
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Elizabeth Weise, "Studies show new ways to get stem cells," USA Today, 2005-OCT-16, at:
http://www.usatoday.com/
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Erika Check & Carina Dennis, " 'Ethical' routes to stem cells highlight political divide. Split opens over methods to create nonviable
embryos." Nature, 2005-OCT-16, at: http://www.nature.com/
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Gareth Cook, "New approach reported in stem cell creation," The Boston Globe, 2005-OCT-17, at:
http://www.boston.com/
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"Stem cell end run?" Washington Post editorial, 2005-OCT-24, at:
http://www.washingtonpost.com/
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Peter N. Spotts, "A more ethical way to harvest stem cells? Scientists
are in hot pursuit. Researchers cite progress in efforts to address concerns
about embryo destruction and human cloning," Christian Science Monitor,
2005-OCT-17, at:
http://www.csmonitor.com/
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Tony Perkins, "Embryonic Stem Cell Studies Raise Questions, Not Cures,"
Washington Update, 2005-OCT-17.
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Rick Weiss, "Mice Stem Cells Made Without Harm to Embryos,"
Washington Post, 2005-OCT-17, at:
http://www.washingtonpost.com/
- Cited in the E-Alert for 2005-OCT-19 of the Massachusetts Family Institute.
Copyright © 2005 by Ontario Consultants
on Religious Tolerance
Originally posted: 2005-OCT-17
Latest update: 2005-OCT-20
Author: B.A. Robinson
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