Even though identical twins have identical genomes, they can get different diseases at different times. This is because of non-genetic (epigenetic) changes to their DNA, and these could be used as breast cancer biomarkers, according to research in the journal Carcinogenesis. Early diagnosis and treatment, or even preventive treatment, can make a major difference in the outcomes for breast cancer patients.
When identical twins do not get the same disease at the same time, this is known as "twin discordance." To find out whether this could lead to an epigenetic biomarker for breast cancer, researchers from Bellvitge Biomedical Research Institute (IDIBELL) in Spain looked for epigenetic changes in the blood of 36 pairs of twins, each containing one who had developed breast cancer, and one who had not. Epigenetic changes, including extra methyl groups stuck onto the DNA, act as switches, turning protein production on or off.
They found high levels of extra methyl groups around the gene for a protein called DOK7 in the twins with breast cancer, and this could be seen a few years before clinical diagnosis, suggesting that it could be used as a blood-based biomarker for the risk or early diagnosis of the disease.
The next step is to look more closely at the DOK7 gene, to find out more about its role, explains Dr. Manel Esteller, the research coordinator: "We believe it is a regulator of tyrosine kinases, an anti-tumor drug target already used for the treatment of breast cancer. If DOK7 performs this function, new studies to test drugs with tumor chemopreventive effects in breast cancer could be planned in the future."
- read the press release
- see the abstract