Stem cell research, an important breakthrough in the field of science related to the treatment of diseases has been a subject of controversies ever since the debated research began. The research has faced obstacles in the form of bans on federal funding, criticism from different sections of society etc. However there is a clear moral imperative, shared across many religions, to relieve suffering and promote healing. This is a strong ground on which religious arguments for the research are based.
Stem cell research – What is it exactly?
Let us understand what stem cells are. Stem cells are cells found in most organisms, and theoretically have the ability to renew themselves mitotically, differentiate into a plethora of cell types and under conducive conditions, develop into mature cells with specialized functions say the pancreas, skin or cells in the heart muscle etc. Where do these stem cells come from? There exist three prime sources of obtaining stem cells –adult cells, cord cells and embryonic cells.
Adult stem cells can be obtained from the bone marrow and the peripheral system. The bone marrow is an extremely rich source of adult stem cells. But this method can be extremely painful because it involves excruciating destruction of the bone marrow. Extraction from the peripheral system involves no damage to the bone marrow, but this procedure consumes time. Adult stem cells are a cut above cord cells and embryonic cells because they are abundant and it is easier to find an exact DNA match. The body’s immune system, on most occasions fails to reject them.
Umbilical cord cells are another abounding source. Cord cells are extracted during pregnancy and stored in cryogenic cell banks as a type of insurance policy for future use on behalf of the newborn. The donation and storage of cord cells is similar to blood banking. These cells can be stored in advance and therefore are available whenever required.
Embryonic stem cells are grown in labs from human embryos. These can last up to a year in a lab without much difficulty as compared to adult stem cells. When the cells of an embryo have not begun to differentiate, the embryo is known as a ‘blastocyst’. Embryonic stem cells are isolated from the inner cell mass of blastocysts and can be replicated in the form of stem lines.
How stem cell research benefits us
Stem cells can be used to study genetic disorders relating to blood, muscle, brain and even diseases like diabetes. Attempts to treat heart diseases, Parkinson’s and Alzheimer’s have also been made. Neural cells in the brain and spinal cord that have been damaged can be replaced by stem cells. In the treatment of cancer, cells destroyed by radiation or chemotherapy can be replaced with new healthy stem cells that adapt to the affected area, which could be any given part of the human body. Dead cells of almost any kind, no matter the type of injury or disease, can be replaced with new healthy cells thanks to mind-boggling flexibility of stem cells
Although stem cell research is a breakthrough in the treatment of many diseases, there are some serious drawbacks. Embryonic stem cells stored over time have been shown to create the type of chromosomal anomalies that create cancer cells. It is difficult to harness the ability of stem cells to divide after transplantation; in other words they may continue to grow unabated and form tumors. There can be a chance that transplanted stem cells might differentiate into the wrong type of tissue, or that they may be rejected by the recipient’s immune system. Although limited success in restoring lost function has been achieved in animal experiments, one must agree that it is difficult to predict what might happen where humans are concerned. Mice treated for Parkinson’s with embryonic stem cells have died from brain tumors in as much as 20% of cases.
The ethical debate
Most of the objections to the research in this field are related to embryonic stem cells. The extraction of stem cells from this type of an embryo requires its destruction. In other words, it requires that a human life be killed and is intrinsically immoral for some. Proponents point out that in the natural reproductive process, human eggs are often fertilized but fail to implant in the uterus. A fertilized egg, they argue, might have the potential for human life, but it cannot be considered equivalent to a human being until it has at least been successfully implanted in a woman’s uterus. In vitro fertilization clinics routinely create more human embryos than are needed over the course of a fertility treatment, and are therefore left with excess embryos that are often simply discarded. Proponents of research hold that it is morally permissible to use such embryos for potentially life-saving biomedical research. Opponents object to this argument, however, saying that such research would still condone the destruction of embryos. It is thought that at least half of fertilized eggs in normal human reproduction do not survive when they fail to implant in the uterus. One can make an analogy from this natural process of destruction of embryos to stem cell research. Embryonic stem cell research begins with the blastocyst, which exists before implantation. When this group of cells has divided to make a small group of cells, the stem cells are extracted and the blastocyst is destroyed.
Some ask; why not avoid this controversy and just use adult stem cells? While adult stem cells have been used in scientific inquiry, embryonic stem cells provide a promising area for medical research because these cells are more plastic, i.e. it is easier to encourage them to become other cell types. Plus there are added concerns that adult stem cells may not reproduce as accurately as embryonic stem cells, with adult stem cells losing genetic information after multiple cell divisions.
India and stem cell research: What next? : The Centre for Stem Cell Research at Christian Medical College, Vellore has recently succeeded in reprogramming cells drawn from adult mice and making them function like embryonic stem cells. India is the fifth country, after Japan, US, China and Britain, to achieve these results.
The debate over stem cell research may continue for ages, challenging ethics after every new breakthrough. But we, as concerned citizens must realize that science cannot be categorized as ethical or unethical. Most people however would agree on the fact that a vast majority of scientists are ethical people. It is up to us to realize that a developing society needs a lot more to relish the fruits of scientific progress.