Stem Cell Research has been the topic of passionate debate within the public and political arena. Due to its potential for treatment of various diseases and injuries, stem cell research has received much support however it has also created controversy and presented examinations of ethical issues. Stem cell research is one of the most exciting fields of biology today, yet as it generates new discoveries, it also raises many questions (Stem).
Stem cells are unique because they have the ability to give rise to many types of cells within the human body, and while their full potential remains unclear, researchers believe that stem cells will have an important impact on the treatment of various diseases and disorders (Young). Because stem cells could be used to generate various cells and tissues for transplantation, researchers hope "to develop heart muscle cells from human pluripotent stem cells and transplant them into the failing heart" muscles of heart attack victims (Young).
Three different types of stem cells have been identified: unipotent, multipotent, and pluripotent cells (Young). Pluripotent cells have the potential to give rise to many different types of cells. Multipotent cells give rise to certain types of cells, such as blood and skin stem cells, that perform specific functions. Unipotent cells can give rise only to a single type of cell (Young). While unipotent and multipotent cells exist throughout life, evidence suggests that pluripotent cells predominantly exist in embryos and fetuses, and offer the greater potential for medical research since they can divide indefinitely, self renew and be stimulated into precursors for many different cell types (Young).
Stem cell research has the potential for a number of applications. For example, they could provide information about general human development, such as the factors that lead to cellular specialization (Young). Moreover, researchers could test the safety and efficacy of drugs using a human cell line prior to using animal or human subjects: a new drug could be tested on a human cell line to incorporate the particular disease that the medication is designed to treat (Young). Furthermore, stem cells could be used to generate cells and tissues to treat diseases and disorders that act to destroy or impair certain cell types and tissues. Referred to as 'cell therapies,' they offer hope to individuals who suffer from disorders such as Parkinson's and Alzheimer's diseases, spinal cord injury, stroke, burns, heart disease, diabetes, osteoarthritis and rheumatoid arthritis (Young).
Although there are a number of sources for stem cells, each varies in terms of their versatility and usefulness. They can be derived from embryos, fetal tissue, umbilical cord blood, and adult tissue (Young). Fetal stem cells are derived from aborted or stillborn fetal tissue. Embryonic stem cells can come from excess embryos created in fertility clinics for in vitro fertilization, from embryos created specifically for the purpose of research, or from embryos created via somatic cell nuclear transfer (SCNT) (Young). Using SCNT, the nucleus is removed from a donated egg, replaced with the nucleus from a somatic cell, and then induced to divide into an embryo; this process could reduce rejection problems associated with transplantation of stem cells because the replacement nucleus comes from the individual to who the stem cells are given (Young). Generally, embryonic and fetal stem cells are pluripotent and offer the greatest potential, whereas stem cells that come from umbilical cord blood or adult tissues are mainly multipotent or unipotent (Young).
The controversy surrounding stem cell research concerns the source of the stem cells. Different issues are involved when the stem cells come from surplus embryos obtained from fertility clinics, as opposed to embryos created via somatic cell nuclear transfer or fetuses from abortion procedures (Young). The main opposition to such research involves moral and/or religious concerns rather than legal or constitutional, especially in the United States where religious and ethical principles tend to influence lawmaking (Young).
Using stem cells derived from excess IVF embryos from fertility clinics for medical research has raised serious public concern and has created an ethical dilemma in which the benefits of research must be weighed against respect for the potential of life of an embryo (Young). Opponents to this research believe that embryos that could possibly develop into a human life deserve to be protected and preserved and that the destruction of such embryos is the same as mutilating and killing a child (Young). Although admirable, this argument tends to ignore the fact that fertility clinics store excess embryos for only a limited time before destroying them, moreover, there is no support for the idea that preventing research on these embryos would somehow put an end to the destruction of embryos in fertility clinics (Young).
With the intent of preserving human life, policies that limit research on embryos are usually based on the premise that an embryo is a person or a potential person (Young). For example, the United States Constitution states that no "person" shall be denied life without due process of law, yet for an embryo to be granted this protection, it must be considered a person (Young). This is the source of heated debate: some people believe that personhood begins at birth, while others believe that human life begins at conception (Young). The majority opinion in Roe v. Wade determined that the unborn are not 'person' with respect to the law, yet many jurisdictions safeguard the embryo as if it were a potential person (Young). Opponents to embryonic sources of stem cells have a much stronger case in 'potential personhood' jurisdictions, but even in the U.S., viable fetuses are often offered some degree of protection (Young).
Opponents are also concerned that doctors in fertility clinics will create extra embryos to use in their own stem cell research or sell them to other researchers, however regulations that govern stem cell research usually include provisions that prohibit doctors in fertility clinics from using excess embryos in their own research and from receiving money or incentives for the embryos (Young). Yet such regulations do not prevent doctors from using more surreptitious means to perform research on excess embryos or from selling them to other unethical researchers, thus even if stem cell research is prohibited, concerns will still exist (Young).
Opponents are also concerned that women and their doctors will create embryos for the sole purpose of creating a source of stem cells to be used for transplantation into a needy patient, especially a relative or child with a life-threatening disease (Young).
Supporters of stem cell research believe that saving an existing life outweighs the destruction of an embryo, particularly since embryos are routinely created and destroyed for in vitro fertilization (Young).
Anti-abortionists fear that allowing researchers to use fetal tissue will encourage abortion among women who might otherwise not have an abortion, believing that these women might justify the abortion due to the potential positive use of the fetus (Young). Critics claim that this argument assumes that women are incapable of making rational decisions, and that it is doubtful that a woman would choose to have an abortion based simply on the potential that the fetal tissue might be used in research (Young). Opponents are also concerned that women might also be swayed to abort due to financial incentives or to support research that might benefit a relative or loved one. This has led federal lawmakers to prohibit a woman from specifying the recipient of the fetal tissue, and should the woman be unaware of her options, "legislators could require that prior to the abortion procedure a woman be given the option to donate the fetal tissue for research purposes or discard it completely (Young).
However, the issue that sparks the most debate involves obtaining stem cells from embryos created via somatic cell nuclear transfer. Although researchers claim they have no intention of re-implanting cloned embryos and allowing them to fully develop in the uterus, there is still great concern that cloning embryos for stem cell research is just "one step closer to cloning humans" (Young). Great Britain prohibits human cloning but does allow the use of SCNT, while other countries, including the U.S., believe that cloning embryos should be prohibited until stem cell research has proven beneficial (Young). Researchers at the University of Wisconsin have successfully transformed human embryonic stem cells into blood-making cells, and hope that these cells will help a patient establish a tolerance "so that organs or tissues derived from the same stem cells could then be transplanted without immune rejection problems," thereby reducing the need for cloned embryos to overcome transplantation rejection (Young).
For more than twenty years, scientists struggled to grow embryonic stem cells, and then in 1998 Dr. James Thomson succeeded in growing and nurturing populations of human embryonic stem cells (Seely). Thomson, who is a John D. MacArthur Professor at the University of Wisconsin School of Medicine and Public Health, and is a faculty member of the Genome Center of Wisconsin, pioneered the work that led to the first isolation of embryonic stem cell lines from a non-human primate in…