Methylation Patterns Are New Target for ctDNA Analysis

Tests that measure circulating DNA are not entirely new. Yet, until now such tests have been unable to determine the tissue of origin (other than in cases of noninvasive prenatal testing, in which DNA can be determined to be from fetal or maternal origin). But, two recent studies highlight the potential for assessment of methylation patterns. One study found a common methylation signature across cancers and another study found that methylation patterns can trace circulating DNA back to the tissue of origin. In both cases, these discoveries may make noninvasive diagnostics possible for detection of a wide number of conditions. Methylation Patterns May Lead to Pan-Cancer Test Hypermethylation of the ZNF154 CpG island is common across tumors and may have utility as a generalizable marker for circulating tumor DNA (ctDNA), according to a study published in the March issue of the Journal of Molecular Diagnostics. DNA methylation has been known to control gene expression. Previously, researchers at the National Human Genome Research Institute (NHGRI) identified pan-cancer hypermethylation at the ZNF154 CpG island in 15 solid epithelial tumor types from 13 different organs. In the present study they measured the magnitude and pattern of differential methylation of this region across colon, […]