Stem cell research is the field of study aimed at benefiting the human race using stem cells. It is from stem cells that all the other cells of the body develop and differentiate to form specialised cells with specific functions, such as brain cells or blood cells. Under the right conditions, these stem cells divide to form many daughter cells identical to the original cells. Stem cells are the only cells in the human body which have the natural ability to generate new cell types. Stem cell research has developed methods to make these stem cells develop into most of the 220 types of cells in the human body. The main goals of stem cell research are said to be to determine the mechanisms that govern cell differentiation, as well as uncover methods of treating and curing fatal injuries and diseases. (Buzhor, et.al., 2017). The abilities of stem cells and stem cell research has many helpful possibilities which are being explored, but this field of research isn’t without problems; serious concerns over the ethics of using stem cells for research – especially concerning the methods used for producing and harvesting these stem cells – have arisen.
Possibilities of stem cells
The different sources of stem cells
Embryonic stem cells make up the bulk of stem cells used for research. The cells are extracted from embryos at an age of about 5 days, when they have between 150 and 250 undifferentiated cells. These stem cells can then divide into more stem cells and be used to differentiate into the widest possibilities of specialised cells, at which stage they are called pluripotent stem cells which are useful for research and medical purposes. To date, however, these stem cells haven’t been used to cure many diseases and have only been successfully used in patients with eye disorders. After in-vitro fertilisation, only the most viable embryos are selected to be implanted into the female. Thereafter, the excess embryos are either donated, such as for research, or they are preserved or discarded. (Buzhor, et.al., 2017)
Stem cells in the umbilical cord and amniotic fluid are similar to embryonic stem cells, in that they can also develop into most specialised cell types. The umbilical cord is said to be the richest source of stem cells. (Mayo Staff Clinic, 2013)
Adult stem cells are extracted from adult tissues and are found mainly in bone marrow and the peripheral system, but are also found in small numbers in other tissues such as fat. They are more difficult to extract than embryonic stem cells and cannot differentiate into as many different types of cells as embryonic stem cells can, although newer research has suggested that the stem cells can differentiate into a wider array of cells than previously thought, such as stem cells in the bone marrow being able to develop into heart muscle cells. (Siegel, 2013)
Adult cells can also be altered to have the characteristics of embryonic stem cells, which are known as induced pluripotent stem cells. They can thus also differentiate into most cell types like ordinary embryonic stem cells can. These regular adult cells, such as skin cells, are transformed by genetic reprogramming to allow them to act like embryonic stem cells. The benefits of being able to do this reprogramming, is that the transformed cells can be used instead of embryonic stem cells, reducing the chance of the immune system of a patient rejecting the cells, since they come from the patient. (Siegel, 2013). Connective tissue cells have been successfully transformed into functioning heart cells, resulting in improved survival time and heart function of animals with heart failure that were treated with these cells. (Kington, 2017)
After obtaining stem cells from any viable source, each stem cell can be divided and used to create groups of cells, all originating from single stem cells. These groups of identical stem cells, which are grown in a lab, are called stem cell lines. They continue to grow and replicate, creating larger groups of new stem cells, but they do not differentiate into specialised cells. These cells can then be frozen for storage for use at a later stage or used for research. (Mayo Staff Clinic, 2013)
Therapeutic cloning, or somatic cell nuclear transfer, is a process whereby researchers use an egg cell without its nucleus, and inject the nucleus from a donor’s somatic cell into this egg, and thereby create a clone of the donor. This egg then forms a bastocyst from which stem cells can be obtained and used to generate stem cell lines which are all identical in genetic makeup as the donor. The benefit of using these cells is that they are less likely to be rejected by the donor since they are genetically identical to the donor. (Siegel, 2013)
How can stem cell research benefit the understanding of diseases?
There is much interest in the capabilities of stem cell research to help us understand the functioning of cells and diseases as well the effect of diseases on cells, tissues and ultimately the human body as a whole. Scientists and researchers see an exciting possibility for using stem cells to help us as the victims of many diseases understand the causes and effects of bacteria, fungi, viruses and parasites on the human body, which promises many possible improvements to a variety of medical avenues. (Mayo Staff Clinic, 2013)
One way in which stem cells can help in the area of diseases is that researchers can learn to understand how diseases and mutations develop in the body and spread from there, by attentively observing how stem cells mature and specialise to become bone cells or nerves, tissues and organs. (Kington, 2017). This will allow for a better understanding of how genetics work in the early stages of cell development and thus why and how cells develop abnormally and lead to birth defects, cancer and other medical problems. This will help scientists be able to develop medicine for certain diseases and guide them in how to use stem cells to cure diseases. (Mayo Staff Clinic, 2013)
How can stem cell research benefit medicine?
Another medical avenue which can be improved by stem cell research is medicine, specifically for the improvement of drugs for cardiac toxicity, but for other disease-specific medicines as well. Certain types of stem cells can be used to test new medication before testing it on people or animals. While this possibility is still in its early stages of research, it seems plausible to researchers to be able to use differentiated stem cells to be able to test the quality, effectiveness and safety of investigational drugs, and then develop the medicine before further testing. The effects would be monitored and a medication can be issued to the next stage of research if the medication causes the desired result on the stem cells, without harmful implications or side effects. (Mayo Clinic Staff, 2013)
How can stems cells be used to treat diseases?
In general, stem cell research itself is still in its early stages, and there is not much that stem cells can thus far be used for compared to what researchers and doctors are hoping they could be used for. Through the use of stem cells, researchers hope to discover ways to cure some of the most common and some of the worst diseases known to man, including Alzheimer’s, Parkinson’s and other neurodegenerative diseases, diabetes, heart disease, cancer, stroke, arthritis or even injuries such as spinal cord injury or burns. (Buzhor et.al., 2017)
Methods of directing stem cells, mainly embryonic stem cells, to become certain types of specialised cells have been tested and achieved successfully. After stem cells have been grown in a lab, the stem cells can be manipulated to specialise into cells such as nerve cells, blood cells or any other specific types of cells. These specialised cells, heart cells for example, after being implanted into a person by being injected into the specific target area or tissue, such as the heart muscle, can help regenerate tissue and thus help repair defective tissue. (Buzhor, et.al., 2017)
Stem cell transplants have been successfully completed in many patients, with promising results. These transplants make use of umbilical cord blood or adult stem cells and transplant these stem cells into the patient, which is called bone marrow transplanting. The stem cells, after being injected into the patient, help the patient’s immune system fight against diseases like leukemia or certain types of cancer. Human cells or tissues are often destroyed by disease or injury, in which case the tissue needs to be replaced or the patient needs an organ transplant. In such cases where tissue needs to be replaced, stem cells can help regenerate the cells of the patient that were damaged by disease, or even by radiation or chemotherapy. The stem cells can then create new tissue in the affected areas after adapting to the tissue needed. The possibility of these stem cells curing degenerative diseases such as heart failure is also being explored, as well as using stem cells to cure diseases or treat injuries for which no good therapy is available. (Coghlan, 2017)
Ethical problems concerning stem cells
When does life begin?
The majority of ethical issues concerning stem cell research concern the use of embryonic stem cells, since these cells are extracted from live embryos of humans, and thus result in the death of a human embryo. The contradicting views of whether this is ethically correct stem mainly from the differing views on where life begins.
Opponents’ views (against embryonic stem cell research)
Early-stage embryos are used to generate embryonic stem cells. These embryos are obtained through the process of in-vitro fertilisation which involved the fertilisation of a sperm cell and an egg cell. Many opponents believe that life begins at conception and that using these embryos for scientific research is the same as using any other humans. Opponents see it as unethical to use humans for scientific research and believe that one should also not be allowed to destroy human life for purposes of research or even for the purpose of improving another human’s life. The embryo is seen by the opponents as fundamentally a human being with interests and rights which need to be protected. Any form of life after conception should thus not be tampered with or used for research, but solely for reproductive purposes. Destroying this embryo is therefore seen as unjust killing or murder of an innocent human being.
The question many opponents ask is why researchers need to use embryonic stem cells, if stem cells from other sources are available. Researchers have discovered that adult stem cells are much more versatile and adaptable than originally thought, and can thus be used with near equal success to embryonic stem cells.
Supporters’ views (for embryonic stem cell research)
Many people are of the understanding that embryonic stem cells are obtained by fertilisation of sperm cells and egg cells and the creation of embryos all for the sole purpose of using the stem cells for research thereafter. This can be done, but this is a misunderstanding, since the guidelines of the National Institutes of Health in many countries make clear how donations and research may be conducted, including that it is stated that human embryos may only be used for research if the embryo is no longer needed after being created by in-vitro fertilisation. (Kington, 2017) The donation of embryos to research is made with informed consent from the donors after embryos have been made by in-vitro fertilisation with the goal of usage for reproductive purposes. They would first have been determined as not fit for clinical use and were therefore no longer needed for implantation into the woman’s uterus. Most of these excess embryos are discarded after not being selected for use, so donation to research seems a much more beneficial option than being discarded. These embryos therefore have no potential to become human beings anyway, but have huge potential benefits for research and are extremely valuable for scientific study. (Siegel, 2013)
While the opponents claim that embryos are live humans, the supporters argue that embryos, at the age of 5 days, cannot yet be classified as human beings since they are only clusters of undifferentiated cells, have no human features, and do not function in a coordinated way. Supporters feel that the embryo can only be seen as a human being from day 16 when cell differentiation starts and the cells actually form part of a functioning being.
Scientists have, however, successfully obtained stem cells from a mouse embryo without destroying the embryo, which should therefore be possible with human embryos but hasn’t yet been attempted. This is a valuable and viable option, since obtaining embryonic stem cells without resulting in the destruction of the embryo would be seen as more ethical, and is also the only way for which federal funding is permitted. (Siegel, 2013)
The question of why researchers need to use embryonic stem cells instead of stem cells from other sources, is answered by the fact that replication of cells, toxins and environmental hazards lead to adult stem cells being more likely to contain abnormalities or harmful mutations, which may affect the treated patient, or be less effective in treatment. (Conger, 2008)
The possibility of humans being cloned with stem cells is another ethical issue, which was the first ethical issue to be brought up against stem cell research. Supporters for cloning humans argue that clones can be used for many purposes, such as for a way to create human tissues and organs for medicinal use. This has the advantage that the tissues created are identical to the donor’s and can thus serve as medicinal backup in case the donor needs tissue or an organ due to disease or injury, and the cells will not be rejected. Opponents against human cloning are of the rightful opinion that man should not be manufacturing humans or manipulating human life.
Stem cells have immense possibilities which will most certainly benefit the human race. Since it is possible to use stem cells which do not come from human embryos, it is thus possible to avoid most of the ethical dilemmas and use stem cells without causing huge controversy. If you or a loved one were the one affected by a life threatening disease or injury, and it was possible to improve one’s quality of life or even cause a complete healing using stem cells, it would make sense to use the cells – without causing death to an embryo and taking a possible life away from a human being – to heal someone. Cloning of human beings, however, is not a necessity concerning development of stem cells, and should not be justifiable since humans should not try to create human life for purposes of research or benefitting another person.
Mayo Clinic Staff. 2013. Stem Cells: what they are and what they do [online], available: http://www.mayoclinic.org/tests-procedures/bone-marrow-transplant/in-depth/stem-cells/art-20048117?pg=1 Accessed on: 29 February 2017.
What is stem cell research? [online], available: http://www.wisegeek.com/what-is-stem-cell-research.htm Accessed on: 5 March 2017.
Buzhor E, Leshansky L, Blumenthal J, Barash H, Warshawsky D, Mazor Y, Shtrichman R. Cell-based therapy approaches: the hope for incurable diseases [online], available: http://www.ncbi.nlm.nih.gov/pubmed/25372080. Accessed on: 7 March 2017.
Kington, R. National Institutes of Health. National Institutes of Health guidelines on human stem cell research [online] 2009. Available: https://stemcells.nih.gov/policy/pages/2009guidelines.aspx. Accessed on: 2 March 2017.
2017. Pros and cons of stem cell research [online], available: http://www.allaboutpopularissues.org/pros-and-cons-of-stem-cell-research.htm Accessed on: 14 March 2017.
Document: Stem cells and neurogenesis [online], available: https://www.dnalc.org/content/0838/0838_DANA_Review_-_Stem_Cells_and_Neurogenesis.pdf?pdf=%2Fcontent%2F0838%2F0838%5FDANA%5FReview%5F%2D%5FStem%5FCells%5Fand%5FNeurogenesis%2Epdf&totalTxt=12&pages=12&cur%5Fpage=1&master=%5Flevel0&myEnterKeyListener=%5Bobject+Object%5D. Accessed on: 23 March 2017.
Siegel, A. 2013. Ethics of stem cell research [online], available: https://plato.stanford.edu/entries/stem-cells/ Accessed on: 25 March 2017.
Coghlan, A. 2017. Clinic claims it has used stem cells to treat Down’s syndrome [online], available: https://www.newscientist.com/article/mg23331113-900-clinic-claims-it-has-used-stem-cells-to-treat-downs-syndrome/. Accessed on: 25 March 2017.
Jones, M. 2017. Stem cell [online], available: https://en.wikipedia.org/wiki/Stem_cell. Accessed on: 30 March 2017
Saad, L. 2006. Stem cell veto contrary to public opinion [online], available: http://www.gallup.com/poll/23827/stem-cell-veto-contrary-public-opinion.aspx. Accessed on: 30 March 2017.
Conger, C. 2008. Could we clone our organs to be used in a transplant? [online], available: http://science.howstuffworks.com/life/genetic/cloned-organ-transplant1.htm. Accessed on: 23 May 2017.
Meregalli M, Farini A, Torrente Y. 2011. Stem cell therapy for neuromuscular diseases [online], available: https://www.intechopen.com/books/stem-cells-in-clinic-and-research/stem-cell-therapy-for-neuromuscular-diseases. Accessed on: 23 May 2017.
Kluwer, W. 2017. Bone marrow transplant [online], available: https://www.drugs.com/health-guide/bone-marrow-transplant.html. Accessed on: 23 May 2017.
Wlikinson, S. 2002. Stem cell research: politics and ethics [online], available: http://debateonhealth.blogspot.co.za/2010/01/stem-cell-research-politics-and-ethics.html. Accessed on: 23 May 2017.