Identification of radiation-induced hypomethylated candidate genes. (A) The Venn diagram shows the number of genes displaying differential DNA methylation between 5-aza-dC-treated cells and irradiated cells (2 and 5 Gy). The number of common differentially methylated genes is shown in (i), (ii), and (iii). These common genes were 1.5-fold down-methylated in both 5-aza-dC-treated cells and irradiated cells (2 or 5 Gy). The table shows a summary of candidate genes, which are indicated as (i), (ii), and (iii) (B, C) The DNA methylation changes for the indicated cells treated with 5-aza-dC (x-axis) or IR (2 or 5 Gy; y-axis) are plotted by log-fold change, and individual probes are shown in black. Red dots indicate candidate probes that are down-methylated by both 5-aza-dC and IR (2 or 5 Gy) (left panels). Heatmap analysis shows the final candidate genes indicated by red dots in the scatter plots (right panels) and displays the decreasing methylation levels of the 5-aza-dC- and IR-treated groups compared with controls (mock). The color gradient from green to red displays the β-value and ranges from 0 (unmethylated) to 1 (methylated).