MAY 21, 2018 12:00 PM PDT

Epigenetics & Cancer: DNA Modification Impacts

WRITTEN BY: Mauri Brueggeman

More and more research is going into stopping cancer and other diseases before they start.  That is the basis for public health areas like traditional epidemiology; however, epigenetics is a newer approach beginning to have a foothold in disease prevention and early diagnosis with the goal of catching disease warnings before physiological symptoms manifest themselves.

Epigenetics Fundamentals

Epigenetics is the study of gene expression changes through biological modification rather than through alteration of genetic code.  Similar to genotype vs phenotype, one deals with what your genetic code actually is versus how that genetic code is expressed on the outside.  The study of these changes includes three main systems of heritable modifications including DNA methylation, chromatin remodeling, histone modification, and non-coding RNA associated gene silencing.  Epigenetics, as a field of study, began in the mid-twentieth century with the aim of combining genetics and developmental biology together.  The term “epigenetics” was actually coined back in 1942 by Conrad Waddington based on the Greek word “epigenesis” which describes the impact of genetic expression on development.  Waddington studied Drosophila under environmental stress to try to explain particular phenotypic changes observed compared to those not exposed to stressors.

Environmental & Lifestyle Effects

The most explored and well-understood epigenetic modification is DNA methylation; however, there is renewed interest in these modification processes as part of a host of disorders including cancers, neurological disorders and more.  Researchers are focusing on how the environment and individual lifestyle might affect gene expression and epigenetic change.  Historical research has demonstrated that environment and sociological impacts can have epigenetic effects on offspring and future generations as a result.   Examples include studies of children whose mothers were exposed to the Dutch famine of 1944-1945.  Those children born during that period have increased rates of coronary heart disease and obesity after maternal exposure to famine in early pregnancy than those not exposed to famine. The result is speculated to be the result of the degree of DNA methylation present in the insulin-like growth factor II (IGF2) gene; decreased methylation was found in the population of offspring whose mothers were exposed to famine.  There are more studies that illustrate the impact of DNA methylation on gene expression.

Initially, it was believed that most of our epigenetic change occurs during development from embryo to fetus into childhood.  While it is accepted that epigenetic changes are less observed in adulthood, epigenetic changes do occur over the human lifespan and in fact, researchers are beginning to believe that some may be able to be reversed.  Some of these post-development reverses include environmental changes like pollution exposure and nutritional changes like embracing a ketogenetic diet.  One study found that the high fat and low carb diet could improve mental abilities through structural chromatin change via histone modification. 

Epigenetics & Cancer

As more molecular advances are made in terms of the human genome as well as in creating structural models of molecules and cellular components necessary for physiological function, the focus epigenetics will expand in parallel.  More studies are coming out discussing findings of epigenetic changes (either initial or reversals) leading to regulation or dysregulation of biological processes involved in the pathogenesis and development of cancer.  And not just one type of cancer.  These changes are being targeted for research because there are possibilities that epigenetic regulatory complexes can affect change on DNA methylation, histone or chromatin modifications to impact transcriptional regulation.

Epigenetics in the Future

There are groups already envisioning and researching ways to utilize circulating tumor DNA (ctDNA), which is released from affected cells, or profiles of DNA modifications found in different cancers.  Groups, like the new team at Stanford Medicine’s Precision Health & Integrated Diagnostics Center, are focused on finding ways to prevent or identify disease very early before true damage has been done.  The group, for example, anticipates developing peripheral blood screening testing for known epigenetic profiles tied to early cancerous development or changes indicative of cancer potential.  Some cancer markers are well known and well-studied, like BRCA in Breast Cancer; these are changes to genetic sequences that can be identified prior to breast cancer development and patients can be informed of their risk.  What is being proposed by Standford’s group is to be proactive, like in BRCA gene presence advisement, rather than reactive, as is the case with many cancer disorders.  The group has suggested that by collecting precise measurements of individuals’ health over a period of time to identify changes indicative of cancerous disorders sooner than current methods available.

Sources: Stanford MedicineGenomics, Proteomics, & BioinformaticsScience Direct;  What is Epigenetics: FundamentalsProceedings of the National Academy of Sciences of the USAMolecular Basis of DiseaseJohns Hopkins Medicine

 

About the Author
  • Mauri S. Brueggeman is a Medical Laboratory Scientist and Educator with a background in Cytogenetics and a Masters in Education from the University of Minnesota. She has worked in the clinical laboratory, taught at the University of Minnesota, and been in post secondary healthcare education administration. She is passionate about advances and leadership in science, medicine, and education.
You May Also Like
DEC 18, 2019
Genetics & Genomics
DEC 18, 2019
Learning More About The Genetic Adaptations Cancer Relies On
Cancer cells can adapt to mutations in the genome that might kill the cells by altering the activity of their genes....
JAN 03, 2020
Drug Discovery & Development
JAN 03, 2020
New Drug Combo Reverses Breast Cancer
Researchers from Georgetown University have found that combining a drug used for epilepsy, bipolar disorder, and migraines with a drug used to ease blood p...
FEB 04, 2020
Health & Medicine
FEB 04, 2020
World Health Organization Outlines Strategy to Eradicate Cervical Cancer
Today—World Cancer Day—the World Health Organization (WHO) announced a draft of a global strategy to eliminate cervical cancer as a public heal...
FEB 07, 2020
Genetics & Genomics
FEB 07, 2020
Mutations That Lead to Cancer May Occur Decades Before Diagnosis
As our cells age or divide, errors can accumulate in the genome they carry, which can lead to cancer, and a variety of environmental and genetic factors ca...
FEB 04, 2020
Cancer
FEB 04, 2020
The role of SRR in colorectal cancer
Researchers from Osaka University have recently discovered a new function of the multifunctional enzyme entitled serine racemase (SRR). According to the te...
FEB 14, 2020
Cancer
FEB 14, 2020
Cataloging Cancer: DNA fingerprints at work
New research published as part of a global Pan-Cancer Project highlights the world’s most comprehensive catalog to date of DNA fingerprints of cancer...
Loading Comments...