STEM CELL RESEARCH:
Ethical and Unethical Kinds
by Dr. Daniel Criswell (Ph.D. molecular biologist)
FROM SWORD & TROWEL 2005 No
1
In November 2004, California voters passed a ballot measure providing
$3 billion for stem cell research to find cures for a plethora of degenerative diseases.
Many prominent individuals made pleas for the passage of this measure including
California Governor Arnold Schwarzenegger, former First Lady Nancy Reagan, and
actors Michael J Fox, who suffers from Parkinson’s Disease (PD), and Christopher
Reeve, who died recently.
But what is stem cell research and why is there a controversy concerning the
use of stem cells in medicine? If these cells can provide a cure for many who suffer from
degenerative diseases such as Parkinson’s, Alzheimer’s, and diabetes, why would anyone
object to stem cell research?
The objection is not regarding the use of stem cells, but from
the source of those stem cells. By definition, stem cells are capable of self-
renewal and differentiating into many cell types to form tissues in humans and other
organisms. A pre-embryo (an embryo less than 14 days old) possesses stem cells that
are totipotent, which means they are capable of differentiating into any one of the 200 cell
types in the human body. This potential to differentiate into any cell type of the body has
encouraged scientists to pursue embryonic stem cell research for medical applications.
Stem cells persist throughout development and into the adult where they are
referred to as multipotent adult stem cells. Adult stem cells are capable of differentiating
into one of several (multipotent) cell types, but presumably not into any cell type
(although this dogma is now being challenged). Adult stem cells can be collected from a
donor or even from the individual needing treatment, whereas the collection of embryonic
stem cells requires destruction of the embryo (which we presume to be a human
individual).
From a scientific perspective adult stem cells have several clinical advantages
over embryonic stem cells. Adult stem cells are maintained throughout the body, they are
currently used in many clinical applications, and if a patient uses his own adult stem cells,
an immune response causing tissue rejection is avoided. Recent progress in research
involving adult stem cells may make the use of the ethically challenged embryonic stem
cells irrelevant.
Multipotent adult stem cells can be found in many regions of the body called
stem cell niches, and collecting cells from these niches neither creates a viable embryo
nor harms the donor. These niches have been identified in many locations including the
kidneys, hair follicles, nervous tissue, and bone marrow. From these niches several
different cell types are generated to replace worn-out, diseased, or damaged cells that no
longer function. The haemopoietic stem cells found in bone marrow provide a good
example of adult stem cell function. These cells can differentiate into various blood cell
types including erythrocytes (red blood cells), thrombocytes (platelets), and several types
of leucocytes (white blood cells).
Additional adult stem cells found in bone marrow differentiate into bone,
cartilage, and fat cells. Multipotent stem cells are also found in umbilical cord blood and
can be collected and stored at birth with no discomfort or threat to the life of the infant or
mother.
Adult stem cells from these niches are currently being used to treat a number of
diseases and more applications are in clinical trials. Adult stem cells from bone marrow
are used to treat more than 70 diseases including leukaemia and breast cancer. In addition
to these treatments, bone marrow transplants have been shown to supply stem cells that
regenerate cells in the liver. The exact mechanism has been possibly but not conclusively
identified.
Using stem cells from another niche in the body will make it possible to treat
an individual who is suffering from organ failure with their own stem cells, eliminating
an immune response that frequently leads to tissue rejection of a transplanted organ.
Austrian researchers have successfully treated stress induced incontinence in women
using muscle-derived stem cells taken from the arm of the patient. Clinical trials with
neural stem cells to treat a neurodegenerative disease (ALS), and bone marrow stem cells
to replace damaged heart tissue from the effects of myocardial ischaemia have also
demonstrated the potential of adult stem cell treatments. Animal models indicate that
adult stem cells may be effective in treating diabetes, blindness, and heart failure as well.
These are just a few of many examples of the success of adult stem cells in regenerating
damaged tissues.
Even with the success of adult stem cell research, the potential of (unethical)
embryonic stem cells to develop into any human cell type is the driving force of stem cell
research. To acquire these cells, the trophoblast (the protective covering of the embryo) is
stripped away and the inner cells are harvested after the initial zygote has undergone
several divisions. These cells grow on media containing nutrients and biochemical factors
that stimulate development into various cell types. Using this technology, scientists hope
to regenerate tissues and organs for those who suffer from many degenerative diseases.
An even more disturbing procedure to acquire embryonic stem cells approved
by the California ballot measure is somatic cell nuclear transfer (SCNT). In this procedure
a nucleus is removed from a donated ovum (human egg) and a nucleus with a full set of
chromosomes from a donor somatic cell (any cell of the body except sex cells) is
implanted into the enucleated ovum. The developing cells from the genetically engineered
individual are grown on media and extracted as described above for embryonic stem cells.
If SCNT looks like cloning, that’s because it is! Creating embryonic stem cells
through SCNT for the purpose of treating diseases has been termed ‘therapeutic cloning’
because, theoretically, the resulting cells will only be used to treat diseases. However,
SCNT was the same method used to clone Dolly the sheep and other animals, and
although science has labeled this ‘reproductive cloning’ the two procedures are virtually
the same in the early stages.6 Presently, no one has succeeded using SCNT for human
therapeutic or reproductive cloning, but success in getting human stem cells through
SCNT will certainly lead to the knowledge and use of human cloning.
Stem cell use will benefit man in treating a multitude of human disorders, but
science and society must be careful to respect the life of the unborn by using only those
cells that can voluntarily be donated from adult individuals. Scripture has much to say
about man’s responsibility to treat all stages of human life as sacred. Furthermore, we are
specifically told not to murder, which includes abortion. However, science and society are
on the verge of allowing another form of abortion and using it to obtain what belongs to
someone else.
These differing worldviews, biblical versus secular, are eloquently spelled out
in this statement by Anne McLaren in a commentary in Nature magazine.
‘For those who believe the human embryo from the one-cell stage onwards has
absolute moral value, equal to that of a newborn baby or an adult, any embryo
research . . . is tantamount to murder. But life is continuous . . . and although a new
genetic constitution comes into being at fertilisation, many people, feel that moral
value develops gradually.’ [Emphasis added.]
This statement attempts to explain the justification of harvesting embryonic
stem cells even though adult stem cells are readily available and effectively being used to
treat diseases without the moral baggage that plagues embryonic stem research. It seems
as long as an evolutionary worldview of man dominates scientific inquiry we will
continue to see a disregard for the sanctity of human life and continue down the ‘slippery
slope’ towards total godlessness.
Dr Griswell is a member of the faculty of the Institute for Christian
Research. The full article may be consulted on the Institute’s web site, together
with references (www.icr.org).
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