Body part regeneration: From science fiction to reality
Several lizards and salamanders are able to regrow their limbs. Several worms, and other creatures, can regenerate almost any part that is lost — even a head. The latest genetics research into body part regeneration has been encouraging.
iPSCs are adult stems cells that have reverted to a more pluripotent state. They remind scientists of stem cells which enable lizards and zebrafishs to regrow limbs. Understanding the regrowth of limbs could help scientists to promote nerve regeneration when a limb has been severely damaged but is not lost. The peripheral nervous system of humans has the capacity to regenerate, but the extent of injury will determine whether or not this occurs. Understanding the stem cell physiology of zebrafish, and other animals, could help clinicians bridge the gap. Knowledge gained could also impact the development of treatments that promote nerve regeneration in the central nervous systems, such as the spinal cord following an injury.
Regeneration is a natural human process, but repeated cycles of regeneration can increase the risk of cancer. For example, liver cancer can be caused by disease primarily because the organ produces cells to replace damaged ones. In cirrhosis, and in certain viral infections where regeneration is able to overcome liver degradation for a period of time, this can happen. Prometheus escaped this fate. However, we do not know how the process will work on humans if a regenerative stem cell system based on iPSCs is used on a large-scale. It is exciting and promising to learn about regenerative medicine. We are still at an early stage and should take reports of limb regeneration with caution.