Figure 3.

Southern blot analysis of the methylation status at the KvDMR1 locus. DNAs from six randomly selected HCCs and matched normal livers were double-digested with BamHI and HpaII, a CpG methylation-sensitive restriction enzyme. EST AA155639 was used as a probe to detect the KvDMR1 locus, as described by Mitsuya et al. (10). The maternal locus, which is hypermethylated, is detectable as a 6.0-kb fragment, whereas the demethylated paternal locus is detectable as a 2.6-kb fragment. Lanes with DNAs digested with BamHI or MspI (methylation-insensitive) were internal controls. In three samples, the maternal-specific methylation was lost specifically in the HCC DNA. Li, normal liver; HCC, hepatocarcinoma; Mat, maternal methylation; Pat, paternal methylation.