DNA methylation analysis of multiple genes in thymic epithelial tumors

Aim: To investigate DNA methylation levels of a panel of genes in thymic epithelial tumors (TETs). Materials & methods: We selected 15 genes among the most promising epigenetic biomarkers of TETs and evaluated their methylation levels in 71 TET samples. Results: thymic carcinomas (TCs) showed hypermethylation of GHSR and ELF3 genes and reduced IL1RN methylation levels compared with thymomas (TMs) and healthy thymic tissues. RAG1 was hypomethylated in TMs compared with healthy thymic tissues. No difference in the methylation levels of the investigated genes was seen among TM stages and subtypes. No changes in blood methylation levels of the investigated genes were seen among TET subtypes. Conclusion: The present study confirms GHSR, ELF3, IL1RN and RAG1 as TET epigenetic biomarkers.