I hope you are staying well during these difficult times. Our lab has stayed open during the first five months of the pandemic (March through July), but our work slowed greatly. It will be a while before we are functioning at our pre-COVID level. We are responding to the pandemic by assessing the immune response in breastmilk, there is a new COVID-study recruitment page on the website. The serial milk samples that we collect today will be a valuable resource for researchers now, and in the future, as we learn more about the health effects of SARS-CoV2.
Our breast cancer-related work continues. Your archived milk samples along with annual follow-up are helping us discover biomarkers that could be used to indicate whether a woman is at increased risk of developing breast cancer, a first step towards preventing the disease. In a paper published this year in Human Molecular Genetics, my colleagues and I compared markers on DNA (called DNA methylation) in the milk of women who developed breast cancer after donating milk with to DNA from the milk of a control group of women who did not develop breast cancer.
DNA methylation is important because it can turn genes on and off, providing controls in normal tissues that are upset in cancer cells. When a gene is turned “on” in a particular cell, the protein for which it codes is made, whereas when the gene is turned “off” the cell will no longer make the protein. Turning genes off and on in specific cells and tissues alters the behavior of the specific cell at that location, despite all the cells in our body having the same DNA. Milk contains lots of cells, some of the cells have sloughed from the inside of the gland, these are called epithelial cells. Other cells in the milk are part of the immune system. By studying the DNA methylation pattern of the cells in milk we are identifying the early changes leading to breast cancer. Using array technology, which allowed us to examine over 450,000 DNA methylation cites, we identified 58 locations on the milk sample DNA that differed in methylation between the women who developed cancer and the control group. Many of these differences occurred in genes with known roles in the development of breast cancer, supporting the idea that the DNA in milk can be used to assess breast cancer risk of individual donating women.
This work would not have been possible without the participation of all of you. Thank you.