Learn about some of the ethical issues surrounding stem cells in medicine.
Regulation of stem cell research
Ethical considerations and discussions have always been part of medicine and research. These discussions can greatly influence rules and regulations that impact the work of researchers and clinicians. A misconception about stem cell research is that scientists can isolate stem cells whenever they like, create stem cell lines, and use these cells in tests as they wish. In reality, the UK has put in place specific regulations for the creation and use of stem cells. These regulations require scientists to submit research proposals to government agencies (the HFEA and the HTA) before creating or using human stem cells. Lawyers, clinicians, ethicists and other scientists evaluate the research proposals to make sure the use of stem cells is appropriate. If researchers want to carry out new experiments with stem cell lines they already made, a new proposal must be submitted for approval.
If approval is given to make new stem cells, UK regulations require that these cells are registered and stored in the UK Stem Cell Bank. The stem cell bank acts as a resource for other researchers to obtain stem cells lines and as a way for the UK to oversee what stem cell lines researchers are making. Scientists can get approval to use cells stored in the stem cell bank rather than making new stem cells. Using existing stem cell lines saves researchers time, labour and guarantees the cells are of consistent quality. It also helps avoid some ethical issues surrounding making new cell lines like embryonic stem cells.
Embryonic stem cells
Embryonic stem (ES) cells can differentiate into any other specialised cell in the body. Studying ES cells allows researchers to learn how the human body develops under normal conditions. Additionally, understanding how these cells are derived and function is essential for developing regenerative medicine treatments.
Ethical discussions surrounding ES cells focus on how ES cells are created. ES are derived in the laboratory from cells collected from a very early embryo, called a blastocyst. A blastocyst develops approximately 5 days after conception and has not yet implanted itself into the mother’s womb. Blastocysts are roughly 150 cells, which is very small, about the size of a pin head. Most blastocysts for scientific and medical research are donated by parents that have undergone an in vitro fertilization (IVF) treatment. The process of collecting ES cells destroys the blastocyst, however, most unused blastocysts from IVF treatments are destroyed anyway. Still, some people ask whether it is justifiable to destroy early embryos at all, even if the research on ES cells might help treat people with diseases and injuries. This ethical discussion has resulted in strict regulations that monitor who can: supply the blastocysts to make ES cells, generate ES cells, and use ES cells once made (see the above section on regulations). The UK government’s regulations on ES cells have attempted to find a balance between different perspectives and values of the UK people in this ES cell debate. Likewise, government rules vary from country to country as the citizens and their governments come to different conclusions on stem cell research.
To a certain extent technologies, such as induced pluripotent stem (iPS) cells, provide a way to end the use of ES cells and avoid ethical issues. However, the reality is that some research will always require the use of ES cells to understand things such as human development and to examine/compare the ability of iPS cells (or any other new cell technology) to differentiate. Also, it is important to realise that iPS cells present some of their own ethical concerns, further discussed below.
Induced pluripotent stem cells
Technologies to create induced pluripotent stem (iPS) cells, or other pluripotent cells, present researchers with exciting scientific possibilities as well as important ethical responsibilities that need to be well regulated. Shinya Yamanaka, the scientist who led the discovery of iPS cells, emphasises the need for regulation. For example, researchers have demonstrated they are able to make eggs and sperm from iPS cells. These reproductive cells were used to create mouse embryos that grew into live-born mice when hosted by a surrogate mother. Should iPS technologies be used to make human embryos from skin cells in a similar manner? Additionally, iPS cell technologies could permit men to make eggs from skin cells, and women to make sperm. This technology is not yet possible in humans, yet there is concern over how these procedures should be regulated.
Another ethical issue with iPS cells (and tissue stem cells) is deciding who owns them. Once iPS cells are created, are the cells the property of the creators, the donor, or both? Should iPS cells be provided to other patients with or without the consent of the original donor? These are just some ethical concerns still unanswered.
Research on animals
Research using animals has played and continues to play a key role in the advancement of medical, biological and veterinary science. It has made a vital contribution to the understanding, prevention, treatment and cure of a wide range of major health problems in both people and animals, including cancer, heart disease and diabetes. Presently, all new medical treatments in the UK, stem cell based or not, are required by law to be tested on animals to make sure they are safe before testing in people.
Medical research institutions have to follow very strict rules and regulations set and checked by the UK Government’s Home Office. These regulations aim to maximise animal welfare and minimise the use of animals as much as possible in research. Researchers must, by law, show that their research could not be carried out using non-animal alternative methods before it can be approved. Additionally, licences to use animals in research are only granted where the potential benefits of the work are likely to outweigh the effects on the animals concerned.
Replacement, Reduction and Refinement In the UK, the legal and ethical use of animals in research is guided by the ‘3 Rs’ – Replacement, Reduction and Refinement. Researchers must replace animal studies with other research methods wherever possible; reduce the number of animals as far as possible while maintaining scientific rigor; and refine experimental and husbandry procedures to improve animal welfare and minimise potential distress. Scientists are developing new technologies to help them to achieve these aims. One such example is the development of technologies that use iPS cells to directly test drugs on a patient’s cells. However, new testing systems will never completely replace animal testing, as there are many biological systems too complex to be recreated in the laboratory. At present, testing the safety of treatments in animals is vital for rapid development of better and safer medicines.
Affording stem cell treatments
Regenerative medicines, in theory, could be developed as personalised medicine, tailored to work specifically for each patient. As wonderful as personalised medicine sounds, this kind of medical treatment would be very costly. Stem cell technologies being created in today’s laboratories are time-consuming and very expensive. This raises questions of: Who will be able to afford these treatments? Will public healthcare include expensive regenerative medicines? Who will decide the balance between cost and a patient’s quality of life?
Ideas are needed to address the affordability and accessibility associated with regenerative medicines. One proposed idea is to create a Global Stem Cell Bank. One of the largest complications of transplanting organs, tissues and cells is immune system rejection of the transplant. The Global Stem Cell Bank could address this complication by carrying different types of stem cells that are matched to the immune system requirements of groups of patients, much like blood banks carry different blood types (A, B, O & Rh blood groups). Costs for making the stem cells could then be shared by everyone using the stem cell bank, making it much more affordable. Also, having stem cells already made, rather than taking weeks or months to make suitable stem cells in a lab, would allow treatments to be performed more quickly from the time of diagnosis.
Responsibility for personal health
Regenerative medicines may one day be able to cure injuries and treat many diseases and injuries. However, will this mean that people no longer need to worry about behaviour that leads to diseases and injuries? Will smokers be able to keep smoking, knowing they can just get fixed up? The same can be asked about other health issues, like heavy drinking, poor eating habits, drug abuse, and even injuries from extreme sports. Should costly regenerative medicine treatments be performed only if the patient is going to change his or her behaviour? Who should pay for treating these individuals if they will likely need to be re-treated in the future? Stem cell treatments may also allow individuals to live longer and longer. Questions about the costs associated with caring for an ageing population need to be asked as the average life span continues to rise.