Scientists and society as a whole
must consider the ethical implications of stem cell
research. Different
ethical issues are raised by the wide range of stem
cell research activities. In 2005, the National
Academies published guidelines for scientists who do
research with human embryonic stem cells to encourage
responsible and ethically sensitive conduct in their
work. Although the guidelines are not expressly legally
binding, many researchers have voluntarily adopted
them as a guide to what constitutes appropriate conduct
in human embryonic stem cell research. Yet for
some people, such guidelines are inadequate because
they aim to govern a practice that they see as intrinsically
unethical.
As the science advances, it is essential that scientists;
religious, moral, and political leaders; and society as a
whole continue to evaluate and communicate about
the ethical implications of stem cell research.
The National Academies' Guidelines for Human Embryonic Stem Cell Research [top]
In order to provide all scientists—those working in universities and private
companies and with both public and private funding—with a
common set of scientific and ethical guidelines, the National
Academies published the
Guidelines for Human Embryonic Stem Cell
Research in 2005. The report outlines the need for institutional oversight
mechanisms for monitoring all human embryonic stem cell
research and provides specific guidance regarding the derivation of
new stem cell lines.
Under the guidelines, certain activities, such as
experimenting on human embryos by inserting stem cells into them,
are not permitted. The guidelines also require that all egg, sperm, and blastocyst donations follow appropriate
informed consent and confidentiality procedures. Because the ethical and technical questions associated with
human embryonic stem cell research are likely to change as science advances, in 2006, the National Academies
established a panel of experts to monitor and review scientific developments and changing ethical, legal, and policy
issues and to prepare periodic reports to update the guidelines as needed.
Learn more about this ongoing activity.
Is an Embryo a Person? [top]
The controversy over embryonic stem cell research
touches on some of the same fundamental questions
that society has grappled with in the debates over contraception,
abortion, and in vitro fertilization. The
questions at the center of the controversy concern the
nature of early human life and the legal and moral status
of the human embryo.
Embryonic stem cell
research often involves removing the inner cell mass
from "excess" blastocysts that are unneeded by couples
who have completed their fertility treatment
(Learn more). This
prevents those blastocysts from continuing to develop.
Although such blastocysts would likely be discarded
(and thus destroyed) by the clinics in any case, some
believe that this does not make it morally acceptable
to use them for research or therapeutic purposes. They
believe that the life of a human being begins at the
moment of conception and that society undermines a
commitment to human equality and to the protection
of vulnerable individuals if blastocysts are used for
such purposes.
Some cultures and religious traditions
oppose the use of human life as a means to some other
end, no matter how noble that end might be. Other
traditions support embryonic stem cell research
because they believe that the embryo gains the moral
status of a human being only after a few weeks or
months of development. Many traditions emphasize
obligations to heal the sick and ease suffering—goals
for which embryonic stem cell research holds great
potential—and favor embryonic stem cell research for
this reason. Several religious groups are currently
involved in internal discussions about the status of the
human embryo and have not yet established official
opinions on the matter.
Public opinion polls suggest
that the majority of both religious and non-religious
Americans support embryonic stem cell research,
although public opinion seems divided about the creation
or use of human blastocysts solely for research.
The Relationship of Stem Cell Research to Reproductive Cloning [top]
Although cloning and stem cell research are often
lumped together in the context of ethical debates, the
goals and results of the two are very different. The
common factor between current attempts at reproductive
cloning and stem cell research is a laboratory
technique called nuclear transfer.
Using
nuclear transfer,
scientists can create blastocysts containing stem
cells that are "clones" of a single adult cell by inserting
the genetic material from an adult cell (for example,
a skin cell) into an egg whose nucleus has been
removed. Scientists hope that they could derive stem
cells from the cells inside such blastocysts and grow
replacement tissues that are genetically matched to
specific patients, thus offering patients a safer alternative
to traditional tissue transplants.
Reproductive cloning, such as the process that was
used to create Dolly the sheep, also uses the nuclear
transfer technique. However, instead of removing
the inner cell mass to derive a stem cell line, the blastocyst
is implanted into the uterus and allowed to
develop fully. In 2002, the National Academies
issued the report
Scientific and Medical Aspects of
Human Reproductive Cloning, which concluded
"Human reproductive cloning should not now be
practiced. It is dangerous and likely to fail."
The Ethics of Human-Animal Chimeras [top]
Chimeras are organisms composed of cells or tissues
from more than one individual. Chimeras have been
produced for research for many years, but when
human and animal cells are mixed in the laboratory,
there is a clear need for heightened ethical consideration.
Cells from different organisms can be combined
either in the early developmental stages (for example,
introducing human cells into a mouse blastocyst to
observe certain developmental processes) or after an
individual is fully developed (for example, implanting
human stem cell-derived pancreatic cells into a mouse
to test their ability to function in a living body).
Chimeras are considered essential for advancing stem
cell research to viable therapies, since no therapy can
be tested in humans without research in animals first.
Some people believe that the creation of chimeras
involving human cells for medical research is morally
acceptable as long as the chimera has no level of
human consciousness. Therefore, research in which
it is possible for human stem cells to produce part of
an animal's brain should be conducted with great
care. The National Academies' guidelines prohibit
the introduction of human cells into the blastocyst
of a non-human primate, or the introduction of any
animal or human cells into a human blastocyst. The
guidelines also prohibit the breeding of human-animal
chimeras in the unlikely event that any human
genetic material would be contained in their reproductive
cells.
Is it legal? [top]
As of the summer of 2006, all forms of stem cell research in the U.S. are legal at
the federal level. That is, it is not illegal to make or work with new
embryonic stem cell lines. However, the use of federal funds for
human embryonic stem cell research is restricted to the cell
lines that were available as of August 9, 2001. Therefore, the
derivation of new embryonic stem cell lines can only occur
when scientists are working with non-federal funding. Some
states and private foundations have been supporting this work.
Some requirements of federal law, such as human
subjects protections, apply to state- and privately funded stem
cell research. For a complete discussion of the mechanisms
for oversight of stem cell research, see the National Academies'
report
Guidelines for Human Embryonic Stem Cell Research.
It is legal to conduct research using blastocysts and to derive
new cell lines in most states, with some exceptions. Because
stem cell legislation is an area of active debate, please
visit the National Conference of State Legislatures
to learn about the laws in a particular state.
This Web page is based on
Understanding Stem Cells: An Overview of the Science and Issues from the National Academies.
