Fig. 1.

Promoter hypermethylation of STING correlates with its silencing in human melanoma. Correlative analysis between STING promoter methylation (average β-values for 11 probes) and its protein expression in 16 human melanoma cell lines. Cells are colored based on their STING protein expression (red: no expression, purple: low expression, and blue: normal expression) (A). β-value heat map showing DNA methylation levels for 11 STING probes identifies three distinct sample subclasses based on their STING protein expression (STING^absent, STING^low, and STING^normal) among melanoma cell lines (B). Box plots showing the average β-values (six probes) for STING across nevi, primary, and metastatic melanoma samples in GSE86355 (C), GSE12087 (D), and TCGA SKCM datasets (E). Box plot represents the lower, median, and upper quartile, while whiskers represent the highest and lowest range for the upper and lower quartiles. Each data point represents an individual sample. Numbers above boxplots indicate number of samples in each group. The statistical analysis was performed by Bartlett’s test (***P < 0.001; ****P < 0.0001; N.S., not significant) (C–E). Correlative analysis between STING gene expression and promoter methylation (average β-values for six probes) in primary (n = 102) and metastatic (n = 367) melanoma samples (F).