Figure 4. DNA methylation status of seven selected genes in HBHC and adjacent liver tissue.

COBRA analysis were performed as amplified PCR of sodium bisulfite-converted genomic DNAs, PCR products incubated with BstUI to measure the methylation rate and samples without incubation with BstUI were listed as control. Selected PCR products were cloned into T-A clones and sequencing. Five samples of each alleles listed were shown by black and white circles represent methylated and unmethylated CpG dinucleotides respectively. "MI" was the abbreviation of methylation index, calculated as the percentage of the methylated dinucleotides versus total. Detail methylated sites were marked in red, the position of COBRA primers is also shown in blue, covering the region was respect to the transcription start site. AJ was the abbreviation of adjacent liver tissue.