Have you ever heard of a relatively new area of study called stem cells? Perhaps you have, whether it’s good or bad or unbelievable, it’s a start. Stem cells are a topic of controversy and have been for decades now. They were not successfully identified and cultured until 1981 by Martin Evans and Matt Kauffman, but since then they have been a constant symbol for the future of biology and of medicine.
Stem cells are cells able to develop into a variety of adult cells ranging from muscle cells, to liver cells, or even nerve cells. There are three main levels of potency to these cells as well. The first level is totipotent which would be something like a zygote that can differentiate into any and every other classification of cell. Then the cells become slightly more specific making them pluripotent. Cells in this level of potency are able to form all cells of the body, except a placenta. An example of a cell in this category would be a cell from any of the three germ layers in an embryo. Finally, the last major classification of a stem cell is multipotent. This means that the stem cell has already programmed a fate for its future and will only become cells related to that fate. For instance, the stem cells of bone marrow, hematopoietic stem cells, which will become white blood cells, red blood cells, and platelets.
However, stem cells are often placed in two categories based on origin rather than usefulness. There are embryonic stem cells and adult stem cells. Embryonic stem cells are primarily pluripotent cells, so they are able to become a wide range of other adult cells. The adult stem cells however, being multipotent, can only become cells specific to their previously defined destinations and are not as useful. This is where controversy arises. Embryonic stem cells, although very helpful, must come from a human embryo (a fertilized egg). This has been the source of controversy for years as to whether it is morally acceptable to use these cells.
So, let’s examine both sides of this controversy and you can decide for yourself. First, from the point of view of an objector to stem cell research. Many people consider embryos to be babies or at the least a potential human. Therefore, to use the cells as a treatment, you would be murdering an innocent life. Some claim that even if the embryo was unlikely to develop to maturity, it was never given the chance to try and therefore is the murder of a child. This argument ultimately comes back to the abortion debate and to when we consider to be the beginning of life. Does life begin upon conception, at gastrulation, at the first heartbeat or brainwaves? There is still a large debate there, but this article is not about that. This article is on stem cells. Therefore, our next argument supporting embryonic stem cell research states that the cells are taken from umbilical cords or from left over in vitro embryos. This fact implies that the only embryonic stem cells used would have been removed as waste if not implemented in research or medicine. They claim also that by implementing embryonic stem cells, many lives could be saved.
Now that we know the background and the controversy surrounding stem cells, lets see what all the hype and the hope is about. Scientists across the globe have been working with stem cells as much as their governments allow. They are making vast predictions in the wake of high hopes from successful clinical studies. Scientists estimate that if research is allowed, that embryonic stem cells will be used to grow new tissues and repair old ones. They claim this treatment could be used to cure degenerative disorders such as Alzheimer’s, arthritis, dementia, and others. They also claim it could allow them to rebuild heart tissue in those struggling with heart disease and not only repair damage done to their hearts, but prevent further damage. These cells have already proven, in rats, the ability to regrow entire networks of blood vessels, nerves, and muscle. From these studies, researchers believe the cells could be used to help severe burn victims, stroke survivors, people with spinal cord injuries and even with macular degeneration. The research goes as far as to claim that stem cells could be the cure for metabolic disorders such as diabetes. It is easy to understand how there is so much hopefulness and excitement surrounding stem cell research. With the few possible benefits listed above, millions of lives could be saved and improved for years to come. The possibilities appear to be endless and it seems by implementing these studies, the quality of life would soar for people across the globe, but is this the reality? Is this a future to look forward to or a fantasy?
The reality of stem cell research is still exciting, but not nearly as promising as scientists have made it appear. The truth is that the FDA in the U.S. has only approved one form of stem cell therapy since their discovery in 1981. The treatment approved is using hematopoietic stem cells to repair and replenish the stem cells lost due to cancer or other degenerative disorders. However, these cells have only been approved for use on the blood and bone marrow. Embryonic stem cells have not been approved for use in clinical trials yet, but research continues, and the hope is that someday it may be. Due to the politics involved and the moral controversy surrounding embryonic stem cells, it may be many years before any clinical trial is approved involving them. Although, many countries are experimenting with adult stem cells found throughout the body in hopes of replicating and utilizing them to fulfill the same purposes. One specific area of stem cell research actually dates to the 1960’s, before stem cells were isolated and identified. Ernest McCulloch and James Till discovered that cells could be reverted to their more primitive states. As was found many years later, it is possible to revert some cells back into pluripotent stem cells. This process is difficult, time consuming, and hard to maintain once the cells are reverted, but research is being done to try and remedy this. The costs would be high, and it is unknown now whether it will ever be practical to use these reverted cells, but the data is out there. “Induced pluripotent stem cells” officially have their own classification under adult stem cells now.
As you can see above, even the adult, multipotent stem cells can have many possibilities for cell fate. Hematopoietic stem cells are also special because for every cell they produce, they also replicate themselves to ensure the continuation of blood cell production. Perhaps this is why the FDA was so willing to approve this form of treatment in those with bone marrow disorders or cancer. It is essentially a blood transfusion, but better. Scientists hope to someday be able to use other stem cells as transfusions throughout different areas of the body like in the mice. The photo above is from past research demonstrating the success of using embryonic mice stem cells to repair damaged heart tissue and regrow blood vessels in mice.
So, in conclusion, the reality of stem cell research may be small, but there is plenty of hope still present for the future. Due to the moral issues and the overall controversy, it may be years or even decades before the world reaches the caliber of clinical trials from above or the kind of treatments that were promised. However, that doesn’t mean we will never obtain them. The world is changing every day and as years pass so do opinions. Back in old movies there was always an old man on the street trying to sell “miracle elixirs” to cure anything you could think of. The elixirs obviously never worked, but maybe with funding and a little bit of luck it will, and that elixir could be stem cells someday. So, decide for yourself. Do you think stem cell research is the next frontier or do the moral objections outweigh the promises for the future?
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