Of the genes showing significant changes in DNA methylation, two features were observed. First, alcohol treatment resulted in more genes with a higher methylation level than normal in the HCP (increased methylation of 485 genes vs. decreased methylation of 262 genes), while the reverse was seen in the LCP (decreased methylation of 1,093 genes vs. increased methylation of 710 genes) (chi-square p-value <2 × 10−16, Fig. 5A). Second, more methylation alterations (both increased- and decreased-methylation) were found in ALC-NTO (1781 methylation changes) than in ALC-NTC (1394 methylation changes). Similar to the first profile, in the HCP region, a greater number of genes displayed increased methylation in ALC-NTO (491 genes) than in ALC-NTC (316 genes). In LCP, the number of genes showing decreased methylation was greater in the ALC-NTO (1290 genes) than in ALC-NTC (903 genes) (Fig. 5B and C).
