Germ cell tumors (GCTs) are thought to arise from primordial germ cells (PGCs) that undergo epigenetic reprogramming: erasure of the somatic imprint in the genital ridge, and re-establishment of the sex-specific imprint at gametogenesis in the developing gonad. Previous studies suggested that GCTs show epigenetic patterns reflecting the reprogramming process of PGCs; however, epigenetic alterations of imprinted genes and their relationship with the methylation status of tumor suppressor genes (TSGs) have not been comprehensively studied. We analyzed the methylation status of the H19 and
SNRPN differential methylated regions (DMRs) and the promoter region of 17 TSGs, and the expression status of H19, IGF2 and
SNRPN in 45 GCTs, and found that 25 and 20 were in the normal and abnormal reprogramming pathways, respectively, defined on the basis of the methylation status of the two DMRs and the anatomical
tumor site. The methylation pattern of the H19 and
SNRPN DMRs was total erasure in
seminomas, mostly physiological in
teratomas, and various in
yolk sac tumors. There were no correlations between the methylation status of the H19 DMR and mono- or biallelic expression of H19 or IGF2. Furthermore, we found that
yolk sac tumors had a higher number of methylated TSGs than
seminomas (P < 0.001)
teratomas (P = 0.004) or other childhood
tumors. While TSG methylation was known to have prognostic implications in various
cancers, it did not affect the outcomes of patients with
yolk sac tumor, suggesting that mechanisms of TSG methylation may be different between
yolk sac tumor and other
cancers.