Stem cells produce all human tissue – researchers only partially understand these processes. Doctors still hope to harness the potential of stem cells for medicine.
A single stem cell, the fertilized egg, brings forth a whole human being. Along the way, it produces a variety of other stem cells that make up the organs and tissues. A fascinating process that doctors want to use to treat previously incurable diseases. But before that, researchers still have to clarify some open questions.
What is common to all stem cells? Your development potential. Normal (or differentiated) body cells have reached an endpoint; they will barely change until they die. Stem cells, on the other hand, retain the ability – and the task – to evolve (differentiate) and produce the cells of the tissues and organs.
And what differentiates the different stem cell types? An essential point in their development potential. Embryonic stem cells are pluripotent, from which all human tissue can arise. Adult stem cells, on the other hand, are multipotent; they are fixed on a single tissue – heart or skin or muscle. And so adult stem cells are also named after the tissue from which they came.
Scientists are very interested in how these processes work. What exactly distinguishes a stem cell from a tissue cell? What happens during development and how can you control it? A better understanding of these processes will require much more time and effort.
Applications in medicine
This effort is well spent: stem cells are supposed to give medicine new options. However, it is necessary for researchers to direct their viability in the right direction. This is the only way to produce the desired tissue cells and the risk of cancer.
Adult stem cells have been an integral part of medicine for more than 40 years. Cells from the bone marrow started, but the umbilical cord blood also helps in the treatment of blood cancer and hereditary diseases. And burns help stem cells from the skin.
But the development of new therapies using adult stem cells has stalled. An example is the treatment of heart attacks: It was started with great hopes, but the success has so far remained modest, and a decisive breakthrough is not foreseeable. It seems that not the stem cells themselves are important, but the substances that secrete them.
Others are focusing on embryonic stem cell therapy, whose development has picked up significantly recently. Initial experiments indicate that embryonic cells pose no threat to patients. However, many people reject these cells for ethical reasons – embryonic stem cell therapies may therefore never prevail in the clinic.
The ethics of stem cell research
Greater opportunities are given as a new type of stem cells, which is artificially generated in the laboratory. Although these induced pluripotent stem cells (iPS cells) are similarly viable as their embryonic cousins, they are ethically quite uncontroversial. It is still unclear how iPS cells behave in humans, but here too the first study has already been started.
Ethics and stem cells, everyone immediately thinks about the destruction of embryos. Certainly a difficult issue with far-reaching implications. Unfortunately, this will not be the only tricky point.
The combination of stem cell and gene technology opens up the frightening option for people to deliberately change their genetic material. Fully viable stem cells can now be easily generated in the lab and genetically engineered. No one has yet tried to breed a human from it, but with mice, this is already possible. So this technique is not immune to abuse. But so far these horror visions remain a pure theory. However, real efforts are being made to use the healing potential of stem cells for medicine. It will certainly take many more years, but perhaps some incurable disease will lose its horror in the future.