WHAT IS DNA METHYLATION?
DNA methylation is a chemical mark on DNA
DNA methylation is a chemical mark that is added to DNA at different positions during gestation.
DNA methylation is part of the “epigenetic” program of our genes. When DNA methylation happens at several important positions in genes it can silence the function of the gene.
This is how the same gene can be expressed or silenced in different cells in our body.
DNA methylation a binary code for programming DNA
DNA methylation: the genome software
These genomic Apps make sure that our body functions properly
Each tissue is properly programmed to ensure our health and well being. Each cell type has its unique combination of methylation marks and as a consequence a unique combination of genes that are active and silent.
Changes in DNA methylation can cause disease
Mapping DNA methylation changes could detect disease
Changes in DNA methylation alter the way cells and tissues operate and can convert a healthy tissue to a diseased tissue.
More than three decades ago Szyf has suggested that changes in DNA methylation would cause diseases such as cancer.
Therefore, DNA methylation is a great platform for detecting and treating disease.
Studies from the laboratory of Szyf at McGill University showed that one can reverse cancer in an animal model by blocking the protein that adds methylation groups to DNA. This has been replicated by many studies since.
More recently Szyf has shown that by examining DNA methylation in white blood cells, it is possible to detect liver cancer early.
The environment can cause changes in DNA methylation
Studies in by Jirtle and his colleagues in 2004 showed in a mouse model that maternal diet during pregnancy affects DNA methylation of her offspring and change their coat color and risk of obesity and other conditions.
Studies by Szyf, Weaver, Meaney and colleagues discovered that maternal care and behavior affects DNA methylation of her offspring and how they react to stress later in life.
These studies launched the fields of behavioral epigenetics and epigenetic psychiatry.
These discoveries provided the first evidence that both psychological and physical environments can affect DNA methylation.
DNA methylation is potentially reversible by both physical and behavioral interventions
DNA Methylation and the Epigenetic Clock
A paradigm shift in the search for biological age markers has happened with the discovery of the “epigenetic clock” by Horvath.
It was discovered that the level of methylation of certain genes in our DNA changes as we age.