Stem Cell Ethics

Stem Cell Ethics

The study of stem cells have brought about many recent ethical questions and been a topic in many recent ethical debates. What is all the talk about? What exactly is stem cell research and why does it raise so many ethical questions?

Stem cell research is on the forefront of regenerative medicine and biological science. It is the study of certain cells in the inner mass of the embryo that are produced a few days after the embryo forms during the blastocyst stage. They are the most primitive of all human cells. They are undifferentiated cells, which mean the cells are not designated to be any special type of cell, such as a nerve, muscle, or skin cell. The cell's specialization is later influenced by the molecules, which are usually proteins that surround the cell (Marshak 220-223). The proteins are typically produced by the mother, but under certain laboratory conditions, distinctive proteins can be introduced and a definite, mature cell type is produced. The cells that are produced could be implanted into a subject to replace worn out cells, or cells that have been destroyed due to disease or injury.

There are a few problems with the process. The most common being is the same as any other transplant, the body doesn't accept the new cell stem cells if the cells aren't exactly the same as the patients; instead the body's immune system recognizes them as unwanted cells and rejects or destroys them often causing more damage to the body. The most common use of stem cells is bone marrow transplant. Some adult stem cells are usually found in bone marrow, when the marrow is transplanted the cells regenerate and help replace the failing surrounding marrow. However, this type of procedure doesn't involve just stem cells. It relies more on the marrow that is transplanted. The actual amounts of stem cells that are found in the transplanted marrow are so few, about one in every ten thousand cells, that they have little affect on actually replacing marrow. More research into this procedure would make it more fully understood and reduce the chance that the body's immune system would reject the transplanted cells.

Research is being done on animals and has been successful. Studies conducted with rats have indicated that stem cells found in the stem cells found in one tissue were able to produce cells for another type of tissue (Nature). Another experiment was performed on mice, according to the journal "Nature" stem cells from bone marrow were implanted into the heart. The cells that were implanted integrated with the surrounding cells and started to rebuild tissue (Alhous 624). However, due to great genetic differences between animals and humans, actual human stem cell research is needed.

Current research on human adult stem cells only suggests that these cells have potential for use in both research and in the development of cell therapies. For example, there would be many advantages to using adult stem cells for transplantation. If adult stem cells could be isolated from a patient, then allowed to divide and direct their specialization for a specific tissue type, and then transplanted them back into the patient, it is unlikely that such cells would be rejected by the body. The implanted cells would be exactly the same as the donors. With more extensive research that can eliminate all the problems associated with stem cell transplantations, this procedure can help many different people and possibly cure an extensive array of diverse diseases, such as Parkinson's Disease, and other defects like cancer. Methods could be found to replace poorly functioning tissues such as the brain and nervous system. Millions of people could potentially benefit from stem cell based therapies.

However, current stem cell research is not widely accepted, as there are various ethical issues that are involved. It is considered by some people to be reproductive cloning. It is also, by far, not a tried and true clinical procedure. Many experiments need to be conducted to understand the full range of stem cells. Most research that is currently being conducted is on mice and other nonhuman animals. Obviously there are many biological differences between animals and humans making human stem cell research essential if treatments using stem cells could ever be viable.

Why isn't more research being done? There are problems with where the stem cells are generated from. Most stem cells are created using surplus embryos left over from in vitro fertilization. They can be extracted form an adult body, but according to the National Research Council, the process is extremely difficult. They have are found in almost every tissue in the body, but are also very rare and widespread throughout the body, literally one in a million, not to mention difficult to culture (National Research Council 46- 47). They are more commonly grown in a laboratory, directly from an embryo. The cells are allowed to divide and mature to the blastocyst stage. The stem cells are later removed from the rest of the blastocyst which basically kills the embryo. The isolated stem cells can then be implanted into a subject. The cells that are implanted will hopefully integrate with the surrounding cells, reproduce, and continue to function normally.

However, the longer the cells are allowed to grow and reproduce, the greater the risk for the cells to develop genetic mutations. The mutations can be particularly dangerous if the cells are used for regenerative therapy in patients. The cells would be producing mutated tissue to replace the worn tissue in the patient and could prove to be deadly. If new stem cell lines are frequently introduced that risk is eliminated. According to the National research Council, as of today research in the United States is limited to 60 stem cell lines, but research by privately funded laboratories using embryos left over from in vitro fertilization is allowed (46). Some individual states have placed a ban on all research using human