Stem cell research: the basics types of research, medical status, and ethical drawbacks

What is Stem Cell Research? [1]

Stem cells are an unspecialized cell from which all of the specialized cells of the organs of the body develop. This process of specializing cells for a specific function is called differentiation. Stem cells are originally found in embryos as they develop; adult organisms retain stem cells in their fully developed organs to serve as a repair system for worn-out or diseased organs. As such, they are very helpful, as they can regenerate after long periods of inactivity.

There are two main kinds of stem cells: embryonic stem cells, adult stem cells, otherwise known as somatic cells, and induced pluripotent stem cells (iPSCs). Other types include amniotic stem cells and those cells coming from umbilical cord blood.

Stem cells proliferate –that is, they can renew themselves repeatedly. These replicas gradually specialize through a series of steps, determined by the genes of the cell. Scientists are still trying to find what stimuli cause the basic stem cells to differentiate, that is, to develop into different types of tissue. Because of their ability to rejuvenate damaged tissue, stem cells can be used in transplants to help in redeveloping organs.

Types of Stem Cells Research

Embryonic, adult, and induced pluripotent stem cells are the three major branches of stem cell research. As can be guessed from the names, embryonic stem cells are from embryos and adult cells are from adults. Induced pluripotent are adult stem cells that have been genetically altered so that they have many of the properties of embryonic stem cells. Likewise, investigation is underway in the area of cells of amniotic fluid and umbilical cord blood.[2]

Embryonic Stem Cells [3]

Embryonic stem cells are obtained in cell culture, which is the growing of cells in a laboratory under certain conditions.[4] They originate in the process of in vitro fertilization, when an egg is fertilized outside of the mother’s womb. Most embryos used in experimentation and stem cell research are donated “extras” from in vitro fertilization processes. These are in the pre-implantation stage, meaning that the embryos are at the phase when, if they were in their mothers’ wombs, would not yet be implanted in the uterus. Embryonic stem cells were once grown over mouse feeder cells, providing the stem cells with nutrients as well as giving them a place to latch onto. However, there was the risk of viruses from the mouse feeder cells, and scientists have found another solution. Thus, embryonic stem cells are cultured in labs and are under strenuous research.

These cells are pluripotent. This means that, if under the right circumstances, embryonic stem cells in culture will regenerate without specializing into tissues. The process of differentiation, occurring naturally in the mother’s womb, takes place when stem cells cluster together to form embryoid bodies, which will spontaneously differentiate into tissues and organs. This will also happen in culture, if controlling factors are not maintained. Scientists have learned how to control the actual procedure of differentiation in embryonic stem cells. However, as of yet no medical use has been found for embryonic stem cells[5]. In addition to this, use of embryonic stem cells causes ethical disturbances amongst some people, both scientists and laity.

Adult Stem Cells

Adult stem cells were originally taken from the bone marrow of adults.[6] Now, scientists have discovered stem cells in many different organs[7]; perhaps every organ in the body has its own stem cells. These live in “niches” in their organs and will not divide or differentiate until necessary to repair worn-out, dead, or diseased tissue.[8] Nevertheless, unlike embryonic stem cells in culture, they will differentiate if they divide; they usually will differentiate into the type of tissue in which they “abide.” Yet science has found that it is possible for genetically altered adult stem cells to transdifferentiate, namely, that they can develop into tissues other than the tissue wherein they originated. It is not known if this occurs in human beings.[9]

At times, it is difficult to research somatic stem cells, as the adult stem cells are sometimes called, because once removed from the body the ability of these cells to divide is restricted. An attempt is underway to figure out a way to grow large amounts in culture. This is a slight disadvantage in conducting research.[10]

Adult stem cells hold the most promise in future medicine.[11] According to the National Institutes of Health, adult stem cells “are currently the only type of stem cell commonly used to treat human diseases.”[12] Scientists are currently trying to come across a method of manipulating the stem cells to treat certain diseases in a more efficient manner.[13]

Induced Pluripotent Stem Cells (iPSCs)

Adult skin cells can be reprogrammed to have properties very similar to that of embryonic stem cells.[14] These genetic revisions are known as induced pluripotent stem cells, abbreviated as iPSCs. The iPSCs, having embryonic characteristics, feature the pros and cons of embryonic stem cells.[15] There are no ethical issues in the employment of iPSCs, as there is in the use of embryonic cells. Regrettably, iPSCs are presently produced using risky viruses, but scientists have eliminated much of the dangerous factors, making iPSCs reasonably safe.[16]

Stem Cells from Amniotic Fluid and Umbilical Cord Blood

Amniotic stem cells are taken from the amniotic fluid which surrounds a baby in the womb; the resulting cells are very similar to embryonic stem cells and do not result in ethical issues.^[17] Another source of stem cells is in the umbilical cord blood. “Most hospitals discard cord blood after a baby’s birth, despite the fact that the blood contains stem cells that can be used in transplants for as many as eighty serious medical problems. Those include the most prevalent types of leukemia, metabolic disorders like Tay-Sachs disease, blood related conditions such as sickle cell anemia and severe anemia problems. ‘People literally are dying on the transplant list who could be cured with this,’ said Dr. Brian Mason.”[18]

Medical Advantages and Disadvantages

Because of its greatest potential for pluripotency, most scientists tend to favor the embryonic stem cell.[19] In the same way, iPSCs[20] and amniotic stem cells[21] have this capacity for pluripotency. In addition to this, these types of cells can easily be grown in culture and, unlike somatic cells, can differentiate into any type of tissue.[22] Seen in this light, embryonic stem cells seem to be the best possibility for advancement in medicine.

On the other hand, transplants with embryonic stem cells have unceasingly had the same results – the formation of tumors. While most tumors are originally benign, the insecure genes of embryonic stem cells may very well make the tumors cancerous.[23] Since adult stem cells are mature, they are genetically stable and therefore do not form tumors.[24] Glenn McGee said, “The emerging truth in the lab is that pluripotent stem cells are hard to rein in. The potential that they would explode into a cancerous mass after a stem cell transplant might turn out to be the Pandora’s box of stem cell research.” (qtd. in Jonietz)

There is also the danger that, in transplantation, the patient’s organs may reject the embryonic stem cells, and rejected cells are permanently trapped in the body. As adult stem cells can in fact be taken from the patient’s own body, there is no risk of rejection from somatic stem cells that derive from the patient. Additionally, iPSCs differ from embryonic stem cells in this regard; if the patient’s skin cells are used to make iPSCs, then the risk of rejection is no more.[25]

In fact, embryonic stem cells are not even close to safe use in transplants. “The field of embryonic stem cells faces enormous hurdles to overcome before these cells can be used in humans. The two key challenges to overcome are making the stem cells differentiate into specific viable cells consistently, and controlling against unchecked cell division once transplanted. Solid data of stable, functioning islet cells from embryonic stem cells in animals has not been seen.”[26] As the National Institutes of Health informs, currently adult stem cells are the only type of stem cell used in transplantation in humans. They treat a huge number of diseases, including diabetes and cancer of the kidneys.[27]

One false hope placed in embryonic stem cells is the cure of Alzheimer’s. “[T]he infrequently voiced reality, stem cell experts confess, is that, of all the diseases that may someday be cured by embryonic stem cell treatments, Alzheimer’s is among the least likely to benefit… [G]iven the lack of any serious suggestion that stem cells themselves have practical potential to treat Alzheimer’s, the Reagan-inspired tidal wave of enthusiasm stands as an example of how easily a modest line of scientific inquiry can grow in the public mind to mythological proportions. It is a distortion that some admit is not being aggressively corrected by scientists. ‘To start with, people need a fairy tale,’ said Ronald D.G. McKay, a stem cell researcher at the National Institute of Neurological Disorders and Stroke. ‘Maybe that’s unfair, but they need a story line that’s relatively simple to understand.’”[28] Another illusion is the treatment of diabetes with embryonic stem cells; as said in the Wall Street Journal, attempts to create beta cells producing insulin from embryonic stem cells have failed, despite years of research and ample funding. Already, adult stem cells can alleviate diabetes.[29]

In addition to the bountiful promises of somatic stem cells, hope also resides in umbilical cord blood stem cells. “Umbilical cord blood stem cells can now help suffering patients with six dozen illnesses, and show promise in treating many more. Due to a lack of national coordination and funds for cord blood banking, 4 million samples of cord blood are discarded in hospital nurseries every year – a tragedy that Washington-area Channel 4 News calls ‘throwing away the future.’”[30] The article “Medical Hope in Umblicical Cord Blood: Researchers Find Its Healing Powers May Provide Cures for Many Deadly Maladies,” featured in the Chicago Tribune, says, “Early research in animals suggests that cord blood may provide a new bounty of cures and treatments for many other medical conditions, including heart attack, Parkinson’s disease, stroke, Alzheimer’s disease, muscular dystrophy, diabetes, spinal cord injury and amyotrophic lateral sclerosis. ‘This is all new biology, which could have an unlimited potential,’ said Dr. Paul Sanberg, director of the University of Southern Florida’s center for aging and brain repair.”[31] At Duke University Medical Center, cord blood stem cells are the savior of infants with fatal nervous disorders. One such illness conquered was Krabbe’s Disease, an enzyme disorder which results in loss of eyesight and hearing, cognitive deterioration, and eventually death before the age of two. Dr. Maria Escolar says, “Our oldest survivor is 6 ½. She’s now running, jumping and doing well in school.”[32]

Thus, overall, embryonic stem cells have many hurdles to leap before consideration in healthy transplants. In contrast, cord blood stem cells provide expectations for the future, and adult stem cells are the solution for scores of diseases. The list is very impressive and is very convincing. None can batter down the use of somatic stem cells when faced with the fact that they combat seventy-three diseases, with many more applications underway, whereas embryonic stem cells treat not a single infirmity.[33]

Adult Stem Cells	Embryonic Stem Cells
Cancers	NONE
Brain Cancer
Retinoblastoma
Ovarian Cancer
Skin Cancer: Merkel Cell Carcinoma
Testicular Cancer
Tumors: Abdominal Organs Lymphoma
Non-Hodgkin’s Lymphoma
Hodgkin’s Lymphoma
Acute Lymphoblastic Leukemia
Acute Myelogenous Leukemia
Chronic Myelogenous Leukemia
Juvenile Myelomonocytic Leukemia
Chronic Myelomonocytic Leukemia
Cancer of the Lymph Nodes: Angioimmunoblastic Lymphadenopathy
Multiple Myeloma
Myelodysplasia
Breast Cancer
Neuroblastoma
Renal Cell Carcinoma
Various Solid Tumors
Soft Tissue Sarcoma
Ewing’s Sarcoma
Waldenstrom’s Macroglobulinemia
Hemophagocytic Lymphohistiocytosis
POEMS syndrome
Myelofibrosis
Auto-Immune Diseases
Diabetes Type I (Juvenile)
Systemic Lupus
Sjogren’s Syndrome
Myasthenia
Autoimmune Cytopenia
Scleromyxedema
Scleroderma
Crohn’s Disease
Behcet’s Disease
Rheumatoid Arthritis
Juvenile Arthritis
Multiple Sclerosis
Polychondritis
Systemic Vasculitis
Alopecia Universalis
Buerger’s Disease
Cardiovascular
Acute Heart Damage
Chronic Coronary Heart Disease
Ocular
Corneal Regeneration
Immunodeficiencies
Severe Combined Immunodeficiency Syndrome
X-linked Lymphoproliferative Syndrome
X-linked Hyper Immunoglobulin M Syndrome
Neural Degenerative Diseases and Injuries
Parkinson’s Disease
Spinal Cord Injury
Stroke Damage
Anemias and Other Blood Conditions
Sickle Cell Anemia
Sideroblastic Anemia
Aplastic Anemia
Red Cell Aplasia
Amegakaryocytic Thrombocytopenia
Thalassemia
Primary Amyloidosis
Diamond Blackfan Anemia
Fanconi’s Anemia
Chronic Epstein-Barr Infection
Wounds and Injuries
Limb Gangrene
Surface Wound Healing
Jawbone Replacement
Skull Bone Repair
Metabolic Disorders
Hurler’s Syndrome
Osteogenesis Imperfecta
Krabbe Leukodystrophy
Osteopetrosis
Cerebral X-Linked Adrenoleukodystrophy
Liver Disease
Chronic Liver Failure
Liver Cirrhosis
Bladder Disease
End-Stage Bladder Disease

Figure 5: Comparing medical uses for adult verses embryonic stem cells. Data for table taken from Do No Harm.

Ethical Concerns

Many ethical issues arise over the use of embryonic stem cells, because of the widely held belief in both science and religion that an embryo is a human being. Obtaining embryonic stem cells affects the destruction of the embryo, and thus means the destruction of a human life. The problem is situated around whether an embryo is a human being or not. If an embryo is not human, there are no qualms about the matter. If an embryo is a human, then embryonic stem cell collection is murder.

Contrary to some opinions, most scientists affirm that an embryo is, indeed, a unique individual, a living human person. The Developing Human: Clinically Oriented Embryology defines the zygote as follows: “This cell [the zygote] results from the union of an oocyte and a sperm during fertilization. A zygote is the beginning of a new human being (i.e., an embryo).” Patten’s Foundations of Embryology affirms that “[a]lmost all higher animals start their lives from a single cell, the fertilized ovum (zygote)… The time of fertilization represents the starting point in the life history, or ontogeny, of the individual.”(3) According to Keith Moore, “Fertilization is a sequence of events that begins with the contact of a sperm (spermatozoon) with a secondary oocyte (ovum) and ends with the fusion of their pronuclei (the haploid nuclei of the sperm and ovum) and the mingling of their chromosomes to form a new cell. This fertilized ovum, known as a zygote, is a large diploid cell that is the beginning, or primordium, of a human being.” (Essentials of Human Embryology, 2). Do No Harm, an organization whose mission is to protect human life and to promote ethics in science, defends their position against embryonic stem research because, according to science, an embryo at any time is not only living human cells, but also an actual human life in the initial stage of growth. “To deny this, in order to justify destroying human embryos for research, is to deny science to advance an ideology.”[1] Simply put, science says that destroying an embryo is destroying a human in every sense of the word.

On ethical grounds, destroying a human translates as murder. In any society, murder is unacceptable. Various politicians and, unfortunately, scientists themselves try to rationalize the killing of embryos because, as they say, the embryos used in research are “extras” from in vitro fertilization; they will die anyway.[2] As the United States Conference of Catholic Bishops (USCCB) states very competently, all men will die someday, but that does not mean that serial killers, be they medical or not, are doing the world a service.[3]

To add to the killing of embryos, stem cell research sometimes requires their cloning. Providing that embryos are human, clones are indeed entirely a person. Since untwisted science states that an embryo is in fact human, it follows that cloning is an infringement upon the rights of both the clone and the one who is duplicated. Cloning robs a person of his or her right to be a unique individual, as well as diminishing humanity’s procreation to a manufacturing process.[4] Therefore, embryonic stem cell research is ethically offensive for violating inalienable rights of the human race, both to life and individuality.

Yet, in spite of all the ethical controversy, some persist in supporting embryonic stem cell research over somatic stem cells, iPSCs, or others. They believe that the destruction of young life is a forfeit necessary for the advancement of science; embryos are sacrificed to the god of Progress to prop up rickety dreams of using embryonic stem cells in medicine. Both iPSCs and amniotic stem cells are adequate substitutions, yet it is hard to find them much support on the part of a majority of politicians and not a few scientists. They seemingly ignore the advantages of umbilical cord blood and adult stem cells and the disadvantages of stems cells from embryos. One can but wonder what drives them down the unending abyss, while there is every reason to trust in other sources of stem cells. Progress, they repeat, humanity must progress. Yet, as Pope Benedict XVI asserts, “Progress becomes true progress only if it serves the human person and if the human person grows: not only in terms of his or her technical power, but also in his or her moral awareness.”[5] As Cardinal Ratzinger, he stated the conviction that humans are not disposable, since every person is a manifestation of God.[6]

“Research, in such cases, irrespective of efficacious therapeutic results is not truly at the service of humanity. In fact, this research advances through the suppression of human lives that are equal in dignity to the lives of other human individuals and the lives of the researchers themselves.”[7] Research that disrespects the person, no matter how small, “lacks God and humanity.”[8] Benedict’s predecessor, Blessed John Paul II, similarly says, “Any treatment which claims to save human lives, yet is based upon the destruction of human life in its embryonic state, is logically and morally contradictory, as is any production of human embryos for the direct or indirect purpose of experimentation or eventual destruction.”[9]

Michael O’Brien has a final refutation to those, especially Christians, who justify the flouting of human rights to save humanity. He utilizes the quote of Caiaphas from the Gospel of John, “You don’t seem to have grasped the situation at all. You have failed to see that it is better for one man to die for the people than for a whole nation to be destroyed.”[10] Pointing out that Caiaphas used these reasons for justifying the death of Jesus Christ, he subtly hints at the unchristian manner of those abusing the rights of individuals for the “common good.”[11]

Stem Cell Research: Help or Hazard?

In view of the problems of embryonic stem cell research, loss of faith in the entire branch of such research may occur. Such despair is ill founded. While for medical and ethical purposes embryonic stem cells are unpromising, other stem cells hold bright hopes, for both the present and the future. The use of embryonic stem cells destroys life; alternatively, the use of adult, cord blood, or amniotic stem cells or iPSCs can save life, on medical and ethical foundations. Such research should be advanced and supported, and much more will be discovered in the next few years. Science has given a beacon of hope to those suffering otherwise incurable diseases. However, care must be taken to ensure that this beacon does not set humanity ablaze.

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