Decitabine effect as related to promoter methylation level and CpG content. Panel A. Genes are stratified by promoter CpG content (increasing from left to right) and methylation level (low methylation in top row, high methylation in bottom row). Plotting post-treatment expression level as a function of basal levels demonstrates the distribution of promoters in each bin (orange dots) in the context of all promoters (blue dots). Panel B. Summary of -log p-value from Wilcoxon signed-rank test assessing the likelihood that basal expression < post-treatment expression. The dotted line corresponds to -log10 of 0.05. The promoter category with the most significant trend toward up-regulated genes has highly methylated promoters with intermediate CpG content. As methylation level decreases, up-regulation is apparent in progressively more CpG dense promoters.
Rubinstein et al. BMC Medical Genomics 2010 3:4 doi:10.1186/1755-8794-3-4