DNA methylation analysis of melanoma progression to brain metastasis

Melanoma is one of the most aggressive and treatment-resistant cancers. It represents the most life-threatening neoplasm of the skin, and its incidence has been increasing for the last three decades. Melanoma evolves from the local transformation of melanocytes to primary tumors, which can metastasize to multiple organs. Brain metastases represent one of the most significant causes of death in cutaneous melanoma patients. Despite aggressive multi-modality threapy, patients with melanoma brain metastasis have a median survival of less than a year, with a majority of these patients dying as a result of their intracranial disease. We aimed to find brain metastasis-specific molecular markers. To identify alterations in DNA methylation related to brain metastasis, we used Illumina 450K BeadChips to assess differentially methylated regions in melanocytes, primary melanomas, lymph node metastases, and brain metastases. Bisulphite-converted DNA from 40 specimens was hybridised to the Illumina Infinium 450k Human Methylation BeadChip.