If our genome is defined as the complete set of DNA in our bodies, the epigenome is defined as the chemical modifications in our DNA as a result of lifestyle factors like what we eat, how much we sleep, and how high our daily stress levels are. These epigenetic alterations in our DNA regulate which genes are expressed to enable proper cell function, making them key markers of cell health together with genetic mutations. Indeed, both mutations and epigenetic dysregulation are observed in many types of cancer. However, whether cancers can develop from epigenetic changes alone in the absence of mutations has been a mystery until now.
Researchers at the University of Montpellier wanted to shed light into this mystery by disrupting the Polycomb group protein, a protein that controls the epigenome during embryotic development. When they turned off this protein in fruit flies, the flies started to develop tumors, much like those that develop when a tumor gene is mutated. However, in this case, the tumor development was not caused by a direct mutation but was associated with changes in the epigenome, causing cells to lose their identity and proliferate.
These results suggest that epigenetic alterations play a crucial role in mediating changes that can drive tumor initiation and progression. It will be exciting to test whether these findings hold true in more complex organisms such as mice and if solutions that aim at restoring the cell’s epigenome can be used for cancer treatment. Furthermore, the paper highlights the importance of lifestyle choices, which can alter the epigenome and thus affect cancer incidence. This is especially important given today’s frenetic lifestyle where stress is high and the time to eat healthy or exercise is limited.
This study was performed by Viviana Parreño at the University of Montpellier with corresponding authors Anne-Marie Martinez and Giacomo Cavalli.
Correspondent: Allegra Carlotta Scarpa
Original Article: Transient loss of Polycomb components induces an epigenetic cancer fate (Nature)
Press Article: No mutation, tumour initiation (Nature)
Image Credits: iStock