Epigenetics is the study of changes in gene expression or cellular phenotype (observable characteristics) caused by mechanisms other than changes in the underlying DNA sequence – hence the name epi (over, above, outer) genetics, some of which are able to be inherited. Essentially it refers to functionally relevant modifications to the genome that do not involve a change in the nucleotide sequence.
It is also a reflection of the genome’s response to the environment, resulting in chemical modifications of the actual DNA (addition of methyl groups) and of enzymes or proteins that control the structure and/or activity of the genome.
Whereas the DNA (genome) sequence (code) does not change, the epigenome will, affecting which genes are expressed, and possibly leading to abnormal cellular behaviour and cancer.
For example, a certain protein may be involved in not allowing a certain gene to be expressed (direct the production of a product) but changes to this protein may allow expression, upsetting a biochemical balance. Dangerously, this change may survive cell division and continue to be enforced.
Conversely, some genes express proteins involved in tumour suppression, and any epigenetic changes can prevent this expression, and allow tumour growth.
Any technology which can artificially interfere with epigenetic behaviour can have an effect on cell growth and function, and potentially reverse a cancerous trend or direction.
One such place that studies epigenetics/epigenomics in Canada is the Michael Smith Genome Sciences Centre in Vancouver, BC, one of 2 Canadian centres studying epigenetics under the umbrella of the Canadian Epigenetics, Environment, and Health Research Consortium,. Here with massive DNA sequencing power, scientists are seeking to determine how short lived or stable alterations in protein or DNA (DNA can be modified by methylation without a change in sequence) can allow our genomes to develop disease or stay healthy.
Already, clinical trials are being carried out using epigenetic therapeutic approaches, to treat leukemia, and this is just the beginning.
Studies continue as well in Europe, Germany, USA, Italy, Japan, South Korea, and as part of the International Human Epigenome Consortium Assay Standards working group.
Excerpted in part from http://biotechnologyfocus.ca/?p=2203