A new study by scientists from the International Agency for Research on Cancer (IARC) examines the DNA of mitochondria, the powerhouses of cells, and provides the first reported evidence of DNA methylation patterns of the mitochondrial genome at high resolution. Notable differences were seen between the methylation patterns in normal cells and in cancer cells. The study found methylation predominantly at non-cytosine–phosphate–guanine (CpG) sites.
The study presents and addresses the technical considerations that have thus far impeded the study of mitochondrial epigenetics and discusses the potential functional consequences of methylation of mitochondrial DNA in normal cells and cancer cells.
Cancer cells have a greater need for energy compared with normal cells, and mitochondrial dysfunction plays an important role in cancer biology. Therefore, the insights provided by this study into the regulation of energy metabolism may be important to gain a more complete understanding of the processes responsible for tumour growth. These findings could open up new avenues to identify novel cancer biomarkers or methods to target the energy metabolism of cancer cells.
Patil V, Cuenin C, Chung F, Rodriguez Aguilera JR, Fernandez-Jimenez N, Romero-Garmendia I, et al.
Human mitochondrial DNA is extensively methylated in a non-CpG context
Nucleic Acids Res, Published online 6 September 2019;