Figure 1. Bar graph showing the distribution of the location of CpG probes that were identified in the hypomethylated DNA fraction after treatment with 5-Aza 2’–deoxycitidine (DAC).

In the 22Rv1 cells, we identified 11,212 probes with reduced methylation, representing 4922 genes (p<0.05) post-DAC treatment. In the DU-145 cells, we identified 32,511 CpG probes (representing 8008 genes, p<0.05) that showed reduced methylation after treatment. Interestingly, both cell lines showed similar distribution patterns of CpG locations. In the 22Rv1 cells, 25% CpG probes were found in promoter regions while 69% probes were located intragenically and 6% were located in intergenic regions. In the DU-145 cells, 22% CpG probes were found in promoter regions while 72% probes were located intragenically and 6% were located in intergenic regions.