Figure 2.

DNA methylation levels for the three DMRs of the IGF2/H19 locus for each subgroup of adrenocortical tumors. (A) Schematic presentation of the IGF2/H19 locus. IGF2 harbors 9 exons whereas H19 harbors five exons, which are indicated by the black and white squares. Transcription start sites are indicated with arrows. The IGF2/H19 locus has three differential methylated regions (DMRs) named DMR0, DMR2 and H19 DMR. The parental-specific (M=maternal allele, P=paternal allele) DNA methylation status is presented by black bars for each DMR (black=methylated, white=unmethylated). The H19 DMR makes up the imprinting control region (ICR) of the locus containing seven CTCF biding sites. For each DMR a number of CpG sites were analyzed (DMR0=3, DMR2=26, CTCF2=17, CTCF3=11, and for CTCF6=15) and the DNA methylation levels correlated highly between the three sites (ρ>0.75, P=2.2×10⁻¹⁶, Spearman's correlation). Each CpG site is presented as a filled circle. (B) The mean DNA methylation levels of single CpG sites are shown for each of the four adrenocortical tumor subtypes (Conn's adenoma, ACBTs, PCCs, and ACCs).