DNA methylation: an epigenetic mark of cellular memory

Profiling changes to DNA modification in cells over time may help scientists create personalised cancer treatments. Gene expression can be controlled by the addition of methyl groups to DNA without any change in DNA sequence. This process is vital to healthy cell development, but scientists now know that abnormal DNA methylation plays a role in the progression of diseases like cancer. Joseph Costello at the University of California and Mirang Kim at the Korea Research Institute of Bioscience and Biotechnology reviewed understanding of DNA methylation and showed how cells retain some DNA methylation patterns as a form of memory. This means that the origins of faulty methylation states can be traced in individual tumor cells. Tracking these methylation patterns may help researchers unravel the history of individual tumors, and could inform personalised therapies.