Correlation of DNA methylation and lymph node metastasis in papillary thyroid carcinoma

Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer with a primarily good prognosis, and its 10-year survival rate is over 90%. However, PTC is prone to early lymph node metastasis.Thyroid cancer tissues from PTC patients with lymphatic metastasis and normal tissues were collected for DNA methylation analysis. Different methylation sites, different methylation regions, gene-enriched pathways, and protein-protein interactions (PPIs) were analyzed.There were 1004 differentially methylated sites in the PTC group versus the control group; these involved 479 hypermethylated sites in 415 related genes, 525 hypomethylated sites in 482 related genes, 64 differentially methylated regions located in the CpG island region, 34 differentially methylated genes closely related to thyroid cancer, and 17 genes with differentially methylated genes in the DNA promoter region.NDRG4 hypermethylation and FOXO3, ZEB2, and CDK6 hypomethylation were associated with PTC lymph node metastasis.