Epigenetic Marks on DNA May Indicate Breast Cancer Risks

It’s hard not to know someone who has been affected by breast cancer. Nearly one in eight women will battle this disease in her lifetime and for those women affected it becomes the battle for their life. Early detection and medical advances stem the tide of this disease, but each study brings us a little closer to unlocking ways to combat it.

While women (and men) with a family history are at higher risk for developing breast cancer, a recent study has  uncovered that the answer might not rely completely on genetics, but that heritable epigenetics may contribute to discovering who is at risk. The study conducted by researchers at The University of Melbourne and published in Nature Communications looked at 210 people from 25 multiple-case breast cancer families. It revealed 24 previously unknown epigenetic changes that alter a woman’s risk of developing breast cancer without involving variants in the DNA sequence.

While everyone is born with a set genetic code, epigenetic marks written on top of the DNA dictate whether or not specific genes are expressed. Some of these marks occur when a methyl group attaches to part of the DNA and it becomes methylated.

DNA methylation is a known breast cancer risk factor and previous research has shown that global methylation levels in blood-derived DNA associate with the disease. In the study scientists systematically scanned the genome to find the places where these DNA methylation points are heritable.

Professor Southey, from the Department of Clinical Pathology at the University of Melbourne and Chair of Precision Medicine at Monash University, said “This ground-breaking work is not only helpful for women from families with many cases of breast cancer, it will improve breast cancer risk prediction for all women, and pave the way for the development of epigenetic therapeutics for breast cancer.”

Only about 20% of women carry the genetic markers known for breast cancer risk, including mutations in genes like BRCA1 and BRCA2. Most women with family history of breast cancer do have no known genetic susceptibility.  This study may show why that is the case.

A person can inherit lots of things from their family’s epigenetics from mental illness to cancer. The environment, diet and stress are just some of the factors that can alter a person’s epigenetics, and they are able to pass some of those changes down through future generations. Knowing what epigenetic factors affect breast cancer can assist with early detection, treatment and prevention. This study can also open the door into researching epigenetic causes of other heritable diseases as well.

Source

Jihoon E. Joo, James G. Dowty, Roger L. Milne, Ee Ming Wong, Pierre-Antoine Dugué, Dallas English, John L. Hopper, David E. Goldgar, Graham G. Giles, Melissa C. Southey. Heritable DNA methylation marks associated with susceptibility to breast cancer. Nature Communications, 2018

Resource

University of Melbourne. “Familial breast cancer not only inherited genetically, finds new study.” ScienceDaily. ScienceDaily, 28 February 2018.