What is the Moral Question in Stem Cell Research? PDF Print E-mail

Posted March 21, 2003

by Carol Shanholtzer, microbiologist, Patty June, M.D., and Terry Schlossberg

Stem cells can be recovered from a variety of sources. Research to discover their healing and restorative potential is not immoral except as that research requires the destruction of human beings, as in the case of human embryonic stem cell research. The moral concern arises because those who are aborted and those slated for destruction as "surplus" embryos in fertility clinics are regarded as potential sources of stem cells for experimentation.

Stem cells are available from a variety of sources
Scientists also have discovered other sources for stem cells in umbilical cords, bone marrow, placenta, and adult fatty tissue. The April 2001 issue of the scientific journal Tissue Engineering reported cells found in human fat can be made to grow into healthy cartilage, muscle and bone cells. The Washington Post, reporting on these new discoveries, wrote that they "have begun to shatter a long-held belief that embryos and fetuses are the only significant source of stem cells...."1

Researchers from the National Human Genome Research Institute in Bethesda, MD and New York Medical College in Valhalla, NY, isolated stem cells from the bone marrow of male mice which turned successfully into healthy heart-muscle cells when they were injected into the damaged hearts of female mice.

The Coalition of Americans for Research Ethics in Alexandria, VA reports that adult stem cells have been used successfully in clinical trials to treat cartilage defects in children; restore vision to legally blind patients; and relieve systemic lupus, multiple sclerosis, rheumatoid arthritis and severe combined immunodeficiency disease.2

The necessary moral distinction
Stem cell research is still at an early stage and the comparative results of using cells from different sources is not yet known. If a human being must be killed in order to obtain the desired stem cells (as is the case in embryonic stem cell research), the act is immoral. The moral principle that we ought to seek to uphold in stem cell research is that it is unethical to destroy (kill) the donor in order to get material to accomplish an intended good: the ends do not justify the means.

What is a stem cell?
The human body consists of many different types of cells. There are three main cell lines within the embryo. Ectoderm will become epidermis (the outer layer of skin), nervous system, lens, and hair. Mesoderm will develop into blood, muscle, bone, urogenital systems, connective tissue, and inner layer of the skin (dermis). Endoderm will develop into lining of the entire gastrointestinal tract, liver, pancreas, thyroid. Those cells are all very different from each other.

When a new human being is conceived, he goes through a process of early cell multiplication prior to implantation in the uterus of the mother. First from a one, then two, four, and eight-celled zygote, he continues to develop to the blastocyst stage at which implantation normally occurs. By this time there has been some differentiation of the cells: the outer cells form the placenta and membranes, and the inner cluster forms the embryo.

The earliest cells are called "pluripotent" stem cells, meaning they have potential to become any cell. At some point, a cell begins to differentiate and develop in one direction, limiting the possibilities for what it can turn out to be from that time on. It takes further steps in differentiation and ends up being a cell with one specific function, such as a neutrophil white blood cell to fight bacterial infections. But early on, had it gone another direction, it could have turned out to be a red blood cell or a lymphocyte to fight viruses. It had the potential to become anything back when it was a pluripotent stem cell.

In the early stages of a human being, all the cells are these "pluripotent" stem cells. However, the blood that is in a baby’s umbilical cord after birth ("cord blood"), which is the baby’s blood (not the mother’s), still contains some stem cells (mixed in with mature cells). Adults produce blood cells in their bone marrow, and even adult bone marrow contains stem cells (along with other cells in varying stages of development). Stem cells can be harvested from sources such as umbilical cords, placentas, bone marrow, and fat tissue without harm to the donor.

Adult stem cells may not act exactly like cord blood stem cells. And cord blood stem cells may not act exactly like embryonic stem cells. Sources of stem cells that do not require the destruction of a human being are a legitimate course of pursuit for stem cell research.

Endnotes
1."Human Fat May Provide Stem Cells," Apr. 10, 2001.
2. Gene Tarne letter to the editor, Washington Times, Apr. 20, 2001.

Carol Shanholtzer is a microbiologist with the Veterans Administration in Minneapolis, MN. Patty June is a pediatrician in Moultrie, GA. Both are members of the PPL board of directors. Terry Schlossberg is executive director of Presbyterians Pro-Life.

 

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