MiR-26a Mediates Ultraviolet B-Induced Apoptosis by Targeting Histone Methyltransferase EZH2 Depending on Myc Expression.

BACKGROUND/AIMS: Ultraviolet B (UVB) damage is the most essential etiological factor in skin carcinogenesis, and apoptosis leads to the efficient elimination of UVB-damaged cells. However, the mechanisms underlying resistance to UVB-induced apoptosis remain unclear.

METHODS: HaCaT and A431 cells were used in the present study. Quantitative real-time PCR, single cell PCR, and western blotting were used to examine cancer-related gene expression at the mRNA and protein levels.

RESULTS: We report that miR-26a, which is upregulated upon UVB irradiation, promotes UVB-induced apoptosis in HaCaT cells by targeting the histone methyltransferase EZH2. Moreover, the UVB/miR-26a/EZH2 regulatory axis largely depends on the MYC expression level. Interestingly, treatment with EZH2 inhibitors significantly enhanced UVB-induced apoptosis.

CONCLUSION: miR-26a/EZH2 might be potential targets for skin cancer prevention and therapy.