Gene regulation is controlled by proteins called transcription factors,
which determine the differentiated state of cells. Pluripotent stem cells
such as embryonic stem cells have the potential to differentiate into any
cell type, depending on the cellular environment and regulation of signaling
pathways. Gene regulation studies in stem cells led to the discovery
that only four transcription factors are necessary and sufficient to revert
differentiated cells into pluripotent stem cells. Using gene transfer techniques
to insert these four genes into differentiated skin cells, researchers
were able to generate induced pluripotent stem (iPS) cells. Transferring
the iPS cells to culture media containing a specific mixture of growth factors
causes them to differentiate into a variety of cell types. Differentiated
iPS cells are being used for biochemical studies and for the treatment of
human diseases such as diabetes and Parkinson disease.
Everyday BioChem 