Talking to chromatin : polycomb function in gene environment interactions

A cell uses epigenetic regulation mechanisms to activate or deactivate genetic characteristics, i.e. genes. Epigenetic regulators that belong to the Polycomb group protein complexes are important during normal development and physiological regulation, but they are also involved in the development of cancer. Not much is known yet about the exact way the Polycomb function is steered by the environment of a cell. This dissertation shows that the Polycomb function is dynamically regulated by environmental factors (such as growth factors, cell stress and oxygen), which in turn leads to a changed use of genes. These findings are very relevant for a better understanding of normal development and stem cell biology and also present leads for the development of selective therapies against cancer and applications in regenerative medicine.