Are you more than your genes?

How your environment can alter the way your genes behave

July 27, 2015

Your genes are unique and they form the basis of who you are; but they aren’t the whole story. Have you ever wondered how your childhood experiences might affect your long-term health? Or why your heart cells are different from your liver cells, even though they contain the exact same genetic code? Epigenetics research is seeking to answer these questions and more. Listen to Dr. Eric Marcotte, Associate Director of CIHR’s Institute of Genetics and CIHR’s Institute of Neurosciences, Mental Health and Addiction, explain how this exciting field of research could change the way we view health.


Dr. Eric Marcotte

Audio interview

Transcript

This is David Coulombe for CIHR News.

When we looked at the definition of epigenetics on the web, we found out that it is the study of cellular and physiological trait variations that are not caused by changes in the DNA sequence.

To have a better understanding of epigenetics, my guest today is Dr. Eric Marcotte. He is the Associate Director for the Institute of Genetics and the Institute of Neurosciences, Mental Health and Addiction at the Canadian Institutes of Health Research.

David Coulombe: Dr. Marcotte, welcome to this interview.

Dr. Eric Marcotte: Thank you, David.

DC: Maybe for the first question, we all know what genetics is, but we know less about epigenetics. What is it exactly?

EM: When we talk about genetics, we tend to describe it as the fundamental blueprint, or the building blocks of life. What we mean by that is that the genes contain all the basic information for what it means to create a living being. But the problem is, how do you go from a blueprint to actually building a living being? What provides the detailed instruction manual for how to actually assemble those building blocks? That’s where epigenetics comes in.

Technically, epigenetics means everything above or around the genes. But practically it means all the factors that control the expression of genes. So, to give you a good example, consider that every cell in your body has the same DNA and has the same genes. But a heart cell looks very different from a brain cell or a kidney cell or a fat cell. The reason for that is that during development, different epigenetic programs came into place that directed the cells down a certain path. Now, epigenetics is more than just building a body though. It’s also about how we respond to the things that happen to us. And some of those can be very long-lasting and have long-term changes and impacts on our health.

DC: Very interesting. So what is the impact of the environment on peoples’ health? Maybe you can give us some examples.

EM: Sure. Well, since DNA doesn’t actually change in our life, it’s the epigenetic programming that can be influenced by our environment. And some of these can be very long-lasting. So for example, there’s evidence now that in some cases a single exposure to a toxic chemical can have long-lasting epigenetic changes throughout a person’s life. And of course when we talk about environment, it’s not just the physical environment. How we’re brought up, the foods we eat, how much exercise we get... These are all environmental influences that can have long-term impacts on our health, and many of them are believed to be through epigenetic mechanisms.

DC: Dr. Marcotte, why is epigenetics so important in terms of research and impact on the patients?

EM: I think it’s because when you think about – when we talk about – something, for example, being programmed (you were programmed for a certain disease or a certain health problem), what we’re talking about really is the combination of the genes we’ve inherited and the environmental exposures which have prepared us to either have a higher or lower risk for certain types of disease. And we really see this in the complex or chronic diseases, as we call them. These are things like heart disease, diabetes, Alzheimer’s, even some cancers. These are diseases that are not typically controlled by a single gene-type event; it’s a combination of factors. What we’re trying to do in epigenetics is really understand the how and why some people develop these diseases while others don’t. Ultimately, we hope that will lead to better treatments for these diseases; but in the short-term, what we’re really looking for is trying to understand and find those sorts of tell-tale signs that will tell us when someone is at risk long before they start showing symptoms.

DC: And what are the breakthroughs in that field and what can we expect in the near future?

EM: Well, cancer is a field where epigenetics has already led to some new treatments. There are several epigenetic drugs on the market for cancer treatments for certain types of cancer, and there are a lot more in development. I would say here though that a key point is that epigenetics is not only about trying to develop markers for disease. It’s also about understanding different treatment responses. This is very important with cancer where some patients respond to some drugs and not others, and that can be through epigenetic mechanisms as well. This is something we also see through all kinds of complex diseases like inflammation, chronic pain, and various types of neuropsychiatric conditions. I think on that last point, the mental health field is where we’ve seen a number of pivotal findings by Canadian researchers in recent years, suicide in particular is one that occurs to me. There has also been a lot of work in the area of neurodevelopmental conditions like autism and related spectrum disorders. Recently too, I can think of some promising findings I’ve seen in neurodegenerative conditions, usually in combination with other big international research groups.

I think, to sum that all up, I would say that it’s a very exciting time for research in this field, with potential for major discoveries ahead of us, and with Canada being right at the forefront.

DC: Dr. Marcotte, thank you very much.

EM: Thank you.

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