Our results demonstrated an aberrant methylation pattern at a CTCF binding site downstream the WT1 gene, which is associated with an elevated WT1 transcriptional activity.
Our data indicate that the methylation status of a not-yet-described regulatory element within the NNAT locus that contains four potential CTCF binding sites determines the expression level of NNAT and the nearby located BLCAP_v2a transcript, thereby suggesting a functional role in the aberrant upregulation of NNAT in WT.
We describe a 2.2-kbp microdeletion in the H19/insulin-like growth factor 2 (IGF2)-imprinting center eliminating three target sites of the chromatin insulator protein CTCF that we believe here is necessary, but not sufficient, to cause BWS and Wilms' tumor.
However, some WTs with normal imprinting of IGF2 also show aberrant methylation of CTCF binding sites, indicating that methylation of these sites is necessary but not sufficient for LOI in WT.