Already distinguished by numerous scientific awards, geneticist Edith Heard recently received the CNRS gold medal. Since 2019, she has headed the European Molecular Biology Laboratory (EMBL).
Deciphering genes is not enough to understand how they are expressed and how they function. Epigenetics is the study of all factors (notably chemical) which block or facilitate the expression of genes, without the genetic code being modified (unlike gene mutations).
When the cell duplicates, these factors can be transmitted to daughter cells. But unlike mutations, these “epigenetic marks” are reversible. Edith Heard is a world authority on this booming science.
“No organism lives in isolation”
What does the CNRS gold medal mean to you?
It is a great scientific honor, but also for me recognition from the house that welcomed me for so many years when I was a researcher in France.
Between your 2018 Inserm Grand Prix and today, what has changed in your field?
We now have the tools to manipulate epigenetic machineries, the enzymes that deposit epigenetic marks or remove them. We can degrade them very quickly, which makes it possible to study the impact of epigenetic marks on the cell, a tissue or an embryo…
What is the next frontier?
Capturing more information at the cellular level. Can we measure gene transcription, the proteins present, and epigenetic marks at the same time? We need this to really understand how it works. Until now, we carried out these manipulations and measurements separately, but certain techniques are beginning to allow this integration.
And the next one?
Work on organisms and cells in vivo, in their environment. No organism lives in isolation. If we truly want to understand the molecular basis of life, we must understand life in a natural context. I don’t know who said this sentence but I love it: if the cell is the unit of life of an organism, the ecosystem is the unit of life of the planet. If we want to understand how life on the planet works, we must understand it at the ecosystem level.
“Epigenetic cures have no scientific basis”
The term epigenetics is increasingly used in the field of well-being…
Recognizing that exposure to stress triggers a change in gene expression is not enough to make it an epigenetic phenomenon. A cell reaction to stress can lead to the triggering of transcription factors which will activate genes. Epigenetic factors may be involved, but not necessarily in a major way. “Clinics”, spas, epigenetic cures have no scientific basis. And even measuring the level of methylation (Editor’s note: methylation is one of the most common epigenetic marks) in the blood is not enough to characterize an epigenetic phenomenon.
Is the transmission of epigenetic factors between generations still hotly debated?
This has been well demonstrated in plants and animal organisms such as the “C. elegans” worm (widely used in genetic research). In mammals, the question remains open, but more and more studies indicate that the transmission of epigenetic marks is rare. It is likely that there are no epigenetic marks transmitted by an event, including in the well-studied cases of starvation.
Are there any drugs that affect epigenetics?
Methylation inhibitors, such as decitabine, have long been used against hematological diseases. Now that we are beginning to understand the protein complexes involved in epigenetic marks, there is much research into inhibitors of these complexes. Immunotherapy combined with epidrugs seems a very promising avenue. But we still have difficulty understanding the exact mechanism by which the inhibitor works… Between clinical medicine and research on epigenetics, there is still a long way to go together.
“We need to understand how a woman’s biology is different from a man’s”
You direct a European research institute (EMBL). Do you still have time to do research?
I think it is very important that the people who run large research institutes stay in direct contact with research. So yes, I still run a lab. It’s not me who does the manipulations, but I work with my team.
What would be your Holy Grail?
I have worked a lot on the inactivation of one of the two X chromosomes in female mammals. We realize, more and more, that beyond hormones, there are enormous differences between males and females due to the differential activities of the sex chromosomes. My big challenge is to understand how the biology of a woman or an individual with two X chromosomes is different from that of a man or an individual who only has one basic, but we actually have little knowledge.
Why is it so important to understand it?
For drug treatments, for example, when treating a woman or a man the doses should be different. For now, we treat everyone as if they were men. The trials are carried out on male rodents, the clinical trials are carried out mainly on men… We need to understand how sex influences the effect of drugs.
You will direct the Francis Crick Institute in London in 2025. A return to basics?
I loved running EMBL, but it’s really very large scale and very political. I have six institutes in twenty-nine countries. Francis Crick is an institute in a single country, born from the merger of three institutes including the one where I did my thesis. They do both fundamental research and biomedical research, like at the Institut Curie where I worked for sixteen years. And I will also bring them a little bit of Europe. When we see the fractured state the world is in right now, I realize how important it is for scientists to maintain the spirit of borderless collaborations and synergies.
