Research Profiles – Epigenetics: Filling in the missing details

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When researchers cracked the genetic code, society gained a powerful new perspective on human health. With this discovery came a new set of tools for studying, and possibly treating, disease. Illnesses such as Huntington's disease and cystic fibrosis were traced back to alterations in single genes. And as genetic research became more technologically advanced, scientists began identifying genetic variations linked to more complex illnesses, such as cancer and heart disease.

But to date, the search for genetic markers of disease suggests that gene mutations alone cannot explain the causes of most complex diseases. There just doesn't seem to be enough genetic variation between the healthy and the sick. It is becoming increasingly apparent that the genetic code as written isn't the whole story.

A new field of research, known as epigenetics, is filling in some of the missing details. As we develop in the womb and throughout our lives, environmental factors alter our DNA – not the genetic code itself, but the molecules that control the activity of our genes. These changes, which may be caused by toxins, dietary habits or even life experiences, affect which genes are turned on, when, and for how long. Two of the most important epigenetic changes are DNA methylation (adding methyl molecules to DNA) and modifications to histones (the large proteins that DNA strands wrap around).

Epigenetics is providing new clues to the interaction between our direct physical environment and our genetic background. Researchers are now using the same technologies that revealed the sequence of the human genome to uncover the epigenome -- the epigenetic modifications that control gene activity.

CIHR has formed a new initiative, the Canadian Epigenetics, Environment and Health Research Consortium (CEEHRC), to explore the role epigenetics plays in health. Researchers funded under this Roadmap Signature Initiative will work to identify the epigenetic changes associated with disease, how environmental stimuli create these changes, and whether or not these changes can be passed from parent to child. The initiative will also promote the translation of the research findings into diagnostic tests, novel medical treatments, and health policy.

Research in this field is already enhancing our understanding of diseases as diverse as autism, asthma, schizophrenia and inflammatory bowel disease. It is helping researchers identify the underlying mechanisms that can disrupt an otherwise healthy genetic code. Through epigenetic research, we can build a more complete picture of the causes (and potential cures) of many human illnesses.

We are excited to present a series of profiles highlighting a small sample of the epigenetics projects that CIHR currently supports.

  • Using a Bigger Net– Drs. Luigi Bouchard and Diane Brisson at the ECOGENE-21 laboratory of the Chicoutimi Hospital are studying epigenetic changes in genes associated with gestational diabetes.
  • Shifting the Paradigm – Dr. Arturas Petronis at the University of Toronto is developing a cohesive epigenetic theory to define the underlying causes of diseases as dissimilar as inflammatory bowel disease and schizophrenia.
  • The Scars of Abuse – A research team at McGill University is studying the epigenetic changes in child abuse victims, and whether these changes increase suicide risk.
  • Tracking the Onset of Autism Spectrum Disorder – Rosanna Weksberg discusses her research on the epigenetic changes associated with various environmental exposures during development.

We hope you enjoy these profiles, and stay tuned for more developments from CEEHRC.

Dr. Anthony Phillips
Scientific Director
CIHR Institute of Neurosciences, Mental Health and Addiction

Dr. Paul Lasko
Scientific Director
CIHR Institute of Genetics

Dr. Morag Park
Scientific Director
CIHR Institute of Cancer Research