Last week, PhD and Master students from various European research organizations came to the Institut Curie to follow the 9th Course on Epigenetics. This field of biology, known since the 40’s, has taken advantage of technical improvements to grow rapidly over the last 15 years. Nowadays, it appears that epigenetics mechanisms are involved in so many biological processes that we are only at the beginning of their study. Today’s young researchers have thus a lot of opportunities in front of them and need to be at the top of their game, quickly, to continue their career in this field.
Methylated DNA - By Christoph Bock (Max Planck Institute for Informatics) (Own work) [CC-BY-SA-3.0, source: Wikimedia Commons.
Last week, the 9th Course on Epigenetics, co-organized with the Network of Excellence EpiGeneSys, took place at the Institut Curie in Paris. This event was aimed at Master and PhD students from different European research organizations. These trainees work on various aspects of this still growing field of biology: nuclear organization, DNA repair, epigenetic regulatory elements or chromatin assembly, for example.
In each cell of an individual, around two meters of DNA—the same in every cell—is found in a nucleus approximately five microns across. To fit into the cell, this DNA has to be packed. In comparison, try to put a 20 kilometer-long thread into a tennis ball… This is possible through a series of mechanisms causing progressively denser coiling until, ultimately, the chromosome can be seen as an X shape.
The different states of chromatin - Source: Wikimedia commons.
In the cell, DNA is associated with proteins and this combination is called chromatin. The more condensed the chromatin is, the less accessible the DNA is to enzymes and regulatory complexes. A less condensed state is required for different cellular processes like DNA repair, DNA replication when cells are dividing, or transcription for protein synthesis. All this needs to be highly regulated. This is made possible through epigenetic mechanisms. Histone modifications and DNA methylation are epigenetic marks that control access to DNA, allowing, notably, the control of gene expression without any change to the genetic code. These marks are heritable from one cell generation to the next and explain why cells with the same genome can result in cells as different as a neuron and a lymphocyte that will continue to be a neuron or a lymphocyte after multiple rounds of divisions.
With these basics in mind, it is easier to understand why epigenetics continues to grow and will probably do so for many years to come. Indeed, by understanding its role and mechanism in development, behavior and diseases like cancer, a large field of applications lies ahead.
The course on epigenetics, organized by Dr. Genevieve Almouzni and Dr. Nathalie Dostatni, provides an opportunity for future epigenetics researchers to learn more about epigenetic principles, to meet with young investigators like Petra Hajkova and Claire Rougeulle or more established ones like Leonie Ringrose and Edith Heard, and, more importantly, to develop their own network. This is one way of fostering the continued evolution of the field.
Concerning the future of epigenetics, for Aditya Sankar, a PhD student at the University of Copenhagen, “There is so much complexity, we cannot ignore that everyone, at some point, is working on epigenetics. Any kind of biology is now linked to epigenetics.” For example, the epigenetics approach to cancer leads to new drug development. In addition, epigenetics can be studied from various angles, from molecular biology to computational science.
According to Ricky Lim, a master student at the Centre for Genomic Regulation in Barcelona, “due to technical improvements still in progress, epigenetics is moving from hypothesis-driven science to data-driven science.” Furthermore, he added that “other students from mathematics and physics are interested in helping them to solve these biological questions”, thereby broadening the epigenetics to a very multidisciplinary field.
At this point, a number of Nobel Prizes have been given for the study of epigenetics, including the Nobel Prize for medicine in 2012. It was awarded to Sir John Gurdon who reprogrammed somatic cells into an embryonic state in 1962, and Dr Shinya Yamanaka who generated induced pluripotent stem cells from adult mouse fibroblasts in 2007. All this could be just the beginning, especially with students as willing to learn as the ones attending the course at the Institut Curie.
More information :
Introduction à l’Épigénétique:
The epigenome at a glance: