December 4, 2020

I, Science

The science magazine of Imperial College

What is epigenetics, and why the fuss? Charlotte Mykura explains.
DNA_methylation wikipedia_1024w
DNA that is methylated in the central cytosine molecules

The field of epigenetics has exploded in the last 15 years. Epigenetics is the study of the way in which DNA develops and responds to the environment; not the DNA code itself, but the way in which the DNA is folded, its chemical nature and protein content. These have huge influences over gene expression and thus cell phenotype (its observable characteristics).

A large portion of Imperial College funding now goes towards epigenetic research. Why are we seeing such rapid growth in this field? Biological perspective has fundamentally changed. The Human Genome Project (Wikipedia; UK; USA) predicted that perhaps hundreds of thousands of protein-coding genes would be found nestled within our DNA. However, only around 20,000 genes were found. This is far fewer genes than are found in the humble nematode worm. How can the complex Homo sapiens have so few genes?

The answer lies in how our genomes are epigenetically regulated. Chemical groups and proteins bound to the DNA alter how, when and where genes are expressed or silenced. An unfathomable number of pathways alter how our DNA behaves. Epigenetic pathways are flexible and can be changed during development, making them a prime focus of research.

epigenetics by AJCann
DNA wraps round nucleosomes to form chromatin

The MRC Clinical Sciences Centre has a range of laboratories studying epigenetic process. For example, the Chromatin Biology Group now aims to discern mechanisms that govern epigenetic processes. Proteins known as ‘Readers’, ‘Writers’ and ‘Erasers’ that modify the specific marks present on DNA regions are now being investigated.

Not only is epigenetic research essential for our understanding of how life exists, it is also furthering our understanding of diseases. Professor Richard Brown (Head of the Division of Cancer and Head of the Division of Epigenetics at the Faculty of Medicine, Imperial College) has recently published a paper in Nature Reviews Cancer, exploring how cancer cells can acquire resistance to drugs via alterations to their epigenetic programme.

With twelve state-of-the-art laboratories at the Clinical Sciences Centre and six epigenetic laboratories at the Institute of Developmental and Reproductive Biology, the importance of epigenetic research for medical progress cannot be underestimated, and Imperial College London is right at the forefront of this field.

Charlotte Mykura is a second year PhD student studying Chromatin Biology

Images: DNA methylation (Wikipedia)Epigenetics by AJ Cann