In some ways, the biology of certain animals is far more robust and effective than that of mammals like apes and humans. More “primitive” organisms, like earthworms, for example, can recover from injuries—such as being cut in half—that would kill a human being. Even some more complex organisms, like some reptiles, can lose an entire extremity, like a tail, but grow it back given enough time to recover, so it’s like the limb was never lost.
This kind of “regenerative healing” is not something that extremely complex organisms like mammals are capable of. If we get injured and lose a limb to amputation, or get into an accident and lose an eye, or lose an organ to disease, such as a kidney, that part of our body is gone and can’t be replaced.
However, this is only the case when it comes to mammals after birth, when they are out in the world and maturing. In actuality, there is a time during the development of human life when it is possible to grow any limb or organ from nothing, and that is the promise of stem cell therapy, a relatively recent development in medical science that is working to unlock the secrets of regenerative healing. But what is it, and how did we get here?
The Power Of Stem Cells
As the name implies, the secret of stem cell therapy lies with a very special group of cells known as stem cells. Stem cells are defined as “pluripotent,” meaning that they are flexible and versatile. A stem cell by itself doesn’t appear to have any use, because it’s not a skin cell, a blood cell, or a brain cell. However, under the right circumstances, a stem cell can become any of these cells.
Stem cells are what is created and used during pregnancy to grow a fully developed baby from a collection of unspecialized cells. Stem cells are sometimes referred to as “master cells” because, unlike most cells in the body after birth, stem cells can “program” themselves to become anything. Once we are born, we largely lose this ability for cells to grow into whatever is required, at least, in the larger numbers that would allow us to replace organs.
The 1960s Discovery
Stem cells are the result of old fashioned scientific investigation. In this case, the discovery came from that most common of scientific resources, lab animals, specifically mice. It was in the 1960s that scientists, working with mice, were able to isolate the properties of certain cells to go beyond the ability to duplicate whatever cell they happened to be. In humans, for example, skin could always grow more skin, and hair could always grow more hair, but hair couldn’t grow nerve cells, or kidney cells, it could only make more of itself.
With mice in the 1960s, however, “low level” stem cells were discovered in blood. Scientists realized that while these low-level stem cells couldn’t grow into hair, skin, or muscle, they could turn into any blood cell required, whether it was red blood cells, white blood cells, or others. This made them “multipotent” and gave scientists their first clues on where to start looking.
It also greatly accelerated medical research, as scientists finally tracked down “pluripotent” cells that are the stem cells they were looking for. By locating and modifying these stem cells, scientists were now able to breed mice with the specific physical characteristics they were looking for. They began to conduct more research on finding the equivalent cells in humans.
Stem Cells & Cancer
It was in the 1980s that medical science felt confident enough about its understanding and application of stem cells that it was deemed safe enough to start using these techniques with humans. As with mice, medical technology “played it safe” and began treatment with “multipotent” stem cells that were less versatile than the pluripotent versions found at birth.
Multipotent stem cells are located in bone marrow, and so these stem cells were used to fight a very specific type of cancer, leukemia. Cancer, in general, is a wide-ranging disease that affects many different parts of the body, but the one common symptom all cancers have is causing a specific part of the body to reproduce flawed/mutant versions of the cells. Eventually these flawed copies outnumber the healthy cells.
Medical science applied stem cells to leukemia treatment, fighting the tendency of cancerous cells to multiply by introducing stem cells that reproduced only healthy blood cells and even encouraged cells around them to do the same. The results were so impressive that stem cell therapy is now one of the official treatments for leukemia.
Research Continues
Because of the effectiveness of stem cells in cancer treatment, there is now a lot of enthusiasm and research being done to apply stem cell therapy to other difficult, or even incurable conditions. From ALS to Alzheimer’s to Autism, there are many applications for stem cell therapy.
