Aim: To define the DNA methylation landscape of neuroblastoma and its clinicopathological impact.
Materials & methods: Microarray DNA methylation data were analyzed and associated with functional/regulatory genome annotation data, transcriptional profiles and clinicobiological parameters.
Results: DNA methylation changes in neuroblastoma affect not only promoters but also intragenic and intergenic regions at cytosine-phosphate-guanine (CpG) and non-CpG sites, and target functional chromatin domains of development and cancer-related genes such as CCND1. Tumors with diverse clinical risk showed differences affecting CpG and, remarkably, non-CpG sites. Non-CpG methylation observed essentially in clinically favorable cases was associated with the differentiation status of neuroblastoma and expression of key genes such as ALK.
Conclusion: This epigenetic fingerprint of neuroblastoma provides new insights into the pathogenesis and clinical behavior of this pediatric tumor.
Keywords: ALK; CCND1; DNA methylome; development; neuroblastoma; non-CpG sites; nonpromoter methylation.