When you hear the words “stem cell research” it is inevitable that certain people come to mind. “Superman” Christopher Reeves, who had Spinal Cord Injury, and Michael J. Fox who has been suffering from Parkinson’s disease —they are only some of the many who are clamoring for support and funding of this new biotechnology. This medical breakthrough has been making the headlines and has sparked numerous debates involving not only scientists, patients and their families, but also politicians and religious groups. Stem cell therapy promises to treat and even cure numerous medical conditions wherein there is destruction or degeneration of tissues and organs. Today, what is being utilized for treatment in such conditions would be organ transplant. Yet we are all aware of the sad fact that there are more patients than donors. It is therefore understandable why millions today are putting their hopes on stem cells. The objective of this paper is to take a closer look at stem cell research, the ethical issues surrounding it, and prove why its discovery is considered science at its best.
Definition of Stem Cell
A stem cell is basically, an undifferentiated cell, which has the potential to develop into any of the other cell types in the body. It has “the ability to divide for indefinite periods in culture and to give rise to specialized cells.” (NIH, 2004)
There are 3 different sources of stem cells. One is from the blastocyst, an embryo which is around 5-6 days old; from fetal tissues such as umbilical cord blood; and lastly from adult tissues such as the bone marrow. Those harvested from the fetal tissues or adult bone marrow, are considered as “adult” stem cells. These are considered as multipotent cells, or having limited capacity to differentiate into other cell types. Only one type of stem cell, however, has been considered as “pluripotent” or being able to give rise to virtually all cell types in the body – this is the embryonic stem cell.
Because of this unique ability to proliferate and evolve into different cells depending on the environment which they are put in, the stem cells would theoretically be able to repair many types of damaged tissue. Take for example, diseases such as diabetes and Parkinson’s, conditions which occur because of defects in one of just a few cells types. Replacing the diseased cells with healthy ones offers patients hope of treatment or even cure.
Benefits of Stem Cell Research
Let us briefly look into statistics given by the Centers for Disease Control and Prevention as to the top three medical conditions affecting Americans today. About 61 million people have some form of cardiovascular disease. This includes heart attacks and strokes which are the first and the third leading cause of deaths respectively. It has been estimated that around 950,000 die of heart disease every year, roughly one death for every 33 seconds.(CDC, 2004) Cancer is the second leading cause of death, and it will kill more than 57,000 of Americans this year. (American Cancer Society, 2005) Stem cell research can be used to create novel therapies for these ailments, and one can just imagine how many lives it could potentially change. Studying how stem cells proliferate can also help scientists have a better understanding of our genetic make-up and possibly use these cells for treatment of many genetic disorders.
If stem cell therapy research holds so much promise, why then are some groups in society against it?
Ethical Issues in Stem Cell Research
Much of the controversy surrounding the issue of stem cell research is focused on how scientists will be able to isolate the stem cells from their source, especially since the cell which is believed to have the greatest potential or “pluripotent” is the embryonic stem cell. It was in 1998 when a group of scientists from the University of Wisconsin-Madison led by James Thomson were able to successfully isolate and culture embryonic stem cells. Thomson used blastocysts from surplus embryos from in-vitro fertilization to create several stem cell lines.
This is where the ethical problem of stem cell research lies: in order to harvest the much-needed stem cells, the embryo must be destroyed. The idea of stem cell research is being marketed as a potential cure or therapy that could alleviate the sufferings of millions of people who have debilitating medical conditions. Yet it is ironic that this “miracle cure” would at the same time make one question and look into the value of a human life at its very beginnings. It all boils down to one’s view of the value of the human embryo.
Those who argue in favor of the research claim that there is no actual harm done because the embryos that are used for research are actually “surplus” from couples who choose in-vitro fertilization as a treatment for infertility. Alternatively, researchers have harvested stem cells from aborted fetuses. They argue that they are actually just making use of these resources which were going to be disposed of anyway. The blastocyst is considered as “pre-human” or something that is only “potentially” a human being. The focus is on the exciting prospects of what stem cells can bring to the future, that there is the potential for curing crippling conditions. Stem cell research can save a person from losing his memory, or from being forced to live in a wheelchair.
Those who oppose stem cell research on the other hand, claim that, “the end does not justify the means”. In the statement of the Coalition of Americans on Research Ethics, “embryos are not mere biological tissues or clusters of cells; they are the tiniest of human beings.” (Do No Harm, 1999) Life begins at conception. Even at 5 or 6 days from fertilization, or at the blastocyst stage, the embryo is already human, complete with all its genetic material. The blastocyst should not therefore, be considered as merely a clump of cells under the microscope, or something that is only “potentially” a human being. Another fact to consider is that in any form of research or clinical trials involving humans, it is imperative that the participants give their “informed consent”. In the case of research using human embryos, they are helpless and have no say regarding their right to choose to undergo it or not.
Amidst the controversy and heated debates involving embryonic stem cell research, science continues with its discoveries. The adult stem cell has been considered as having limited capacity to differentiate, not “pluripotent” like the embryonic stem cell. The NIH reported that “…there is no clear evidence that stem cells from adults, human or animal, are pluripotent. In fact, there is no evidence that adult stem cells have the broad potential characteristic of pluripotent stem cells.” (NIH, 2000) Unlike embryonic stem cells which have the capacity to reproduce indefinitely in the laboratory, adult stem cells are thought to be present only in minute quantities and are difficult to isolate. Looking into the latest reports on clinical trials using adult stem cells however, prove this notion to be wrong. Stem cells can now be isolated from numerous tissues, umbilical cord blood, non-embryonic sources, and have been demonstrated to be able to transform into different cell types. Other advantages are that compared to the embryonic stem cell, there is no issue of “transplant rejection” and there has been no report of cancer or teratoma formation with adult stem cells.
Literature just over the past few years are full of news on how adult stem cells have been successfully used. Most of these studies of course were performed on mice, but there are a few successful ones reported in humans, specifically with regards to cancer and heart failure. It is not surprising that embryonic stem cell research together with all its controversies will soon be forgotten, and it may be abandoned in favor of the adult stem cell.