What are stem cells?
Embryonic stem cells are cells from which all possible cell types can develop, whether nerve cells, muscle cells, blood cells, or many others. They are present in the early embryonic stage of organisms, for example in the blastula of humans.
Adult stem cells are cells that have already specialized in a certain cell type, for example neural stem cells or hematopoietic stem cells. These can still develop into various subtypes of this cell type. As the name suggests, adult stem cells are found in mature organisms.
Induced stem cells are stem cells that have been obtained from previously specialized cell types by essentially "reprogramming" them. Using four specific growth factors, any cell type can be reprogrammed back into a stem cell. This groundbreaking discovery by Shinya Yamanaka and Kazutoshi Takahashi was first published in 2006. The discovery of induced pluripotent stem cells has opened up enormous possibilities for research and medicine. For the first time, it was now possible to obtain human stem cells without using human embryos. Yamanaka received the Nobel Prize for Physiology or Medicine in 2012 for his discoveries.
What stem cell research is currently being conducted?
Stem cell research is a rapidly developing field. One fascinating area is organoids: organoids are three-dimensional cell models that, in their composition and cell types, resemble organs. These models make it possible to study biological processes directly in human tissues. For example, a skin cell from a person can be reprogrammed into an induced pluripotent stem cell. From this, for example, a brain organoid can be created, which is similar to a human brain in cell type and composition. This can then be used to study processes in the brain. Adult intestinal stem cells can also be used to grow organoids directly, which can then be used in drug research, for instance. For example, organoids were used to test potential new drugs for pancreatic cancer (1).
Adult hematopoietic stem cells from bone marrow have been used for several decades to treat leukemia. There are great hopes in the field of regenerative medicine: for example, there are first promising clinical studies in the field of ophthalmology. In addition, there is progress in research into the treatment of Parkinson's disease with stem cells.
Further information
Overview of international regulation and studies with stem cells: https://link.springer.com/article/10.1186/s13287-024-04065-9?fromPaywallRec=false
The legal situation in Switzerland has been regulated since 2005 by Art. 5 ff. of the Stem Cell Research Act. In Switzerland, embryonic stem cells may be obtained from surplus human embryos from reproductive medicine.
Switzerland occupies an important position in international research in the field of stem cells. The BAG continuously publishes the trials with human embryonic stem cells approved in Switzerland:
Source
1. Hirt CK, Booij TH, Grob L, Simmler P, Toussaint NC, Keller D, et al. Drug screening and genome editing in human pancreatic cancer organoids identifies drug-gene interactions and candidates for off-label treatment. Cell Genomics. February 2022;2(2):100095.
