DNA Methylation Levels of Melanoma Risk Genes Are Associated with Clinical Characteristics of Melanoma Patients

Abstract

In melanoma development, oncogenic process is mediated by genetic and epigenetic mutations, and few studies have so far explored the role of DNA methylation either as predisposition factor or biomarker. We tested patient samples for germlineCDKN2Amethylation status and found no evidence of inactivation by promoter hypermethylation. We have also investigated the association of clinical characteristics of samples with the DNA methylation pattern of twelve genes relevant for melanomagenesis. Five genes (BAP1, MGMT, MITF, PALB2, andPOT1) presented statistical association between blood DNA methylation levels and eitherCDKN2A-mutation status, number of lesions, or Breslow thickness. In tumors, five genes (KIT, MGMT, MITF, TERT, andTNF) exhibited methylation levels significantly different between tumor groups including acral compared to nonacral melanomas and matched primary lesions and metastases. Our data pinpoint that the methylation level of eight melanoma-associated genes could potentially represent markers for this disease both in peripheral blood and in tumor samples.