Melanoma is a malignant
tumor of melanocytes and is considered to be the most aggressive
cancer among all
skin diseases. The pathogenesis of
melanoma has not been well documented, which may restrict the research and development of
biomarkers and
therapies. To date, several genetic and epigenetic factors have been identified as contributing to the development and progression of
melanoma. Besides the findings on
genetic susceptibilities, the recent progress in epigenetic studies has revealed that loss of the
DNA hydroxymethylation mark,
5-hydroxymethylcytosine (5-hmC), along with high levels of DNA methylation at promoter regions of several tumor suppressor genes in
melanoma, may serve as
biomarkers for
melanoma. Moreover,
5-Aza-2'-deoxycytidine, an epigenetic modifier causing DNA demethylation, and ten-eleven translocation family
dioxygenase (TET), which catalyzes the generation of 5-hmC, demonstrate therapeutic potential in
melanoma treatment. In this review, we will summarize the latest progress in research on DNA methylation/hydroxymethylation in
melanoma, and we will discuss and provide insight for epigenetic
biomarkers and
therapies for
melanoma. Particularly, we will discuss the role of
DNA hydroxymethylation in
melanoma infiltrating immune cells, which may also serve as a potential target for
melanoma treatment.