Epigenetics of skin cancer: Interventions by selected bioactive phytochemicals.

The prevalence and risk of skin cancer have been increasing over past three decades.
Two major types of skin cancer observed in humans are melanoma and nonmelanoma.
Nonmelanoma further subdivided into basal cell carcinoma and squamous cell carcinoma.
Melanoma arises from melanocyte which locates at the bottom layer of skin
epidermis, which primarily protects the skin from being exposed to external factors.
Melanoma is less common among all other types of skin cancers but causes higher
mortality. Epigenetic regulation associated with the transcriptional activation and inactivation
of genes plays a major role in various disease progression including skin
cancer. The major epigenetic changes observed at cellular level include DNA methylation,
histone modifications, and miRNA-mediated
gene regulation. The aberrant pattern
in these epigenetic processes leads to altered expression of several genes involved
in cell cycle, cell proliferation, cell motility, and apoptosis. Several natural bioactive
phytochemicals have been shown to exhibit epigenetic modulatory capability and act
as chemopreventive as well as therapeutic agents. In this review, we mainly discuss
the major epigenetic modifications observed in melanoma and the epigenetic modulatory
role of selected bioactive phytochemicals against the skin cancer.