DNA hypermethylation at the D17S5 locus and reduced HIC-1 mRNA expression are associated with hepatocarcinogenesis

To examine the significance of aberrant DNA methylation in hepatocarcinogenesis, the DNA methylation status at the D17S5 locus and mRNA expression of a candidate tumor suppressor gene, HIC-1 (hypermethylated-in-cancer), which was identified at the D17S5 locus, in primary hepatocellular carcinomas (HCCs) and their corresponding noncancerous liver tissues were assessed. DNA hypermethylation at the D17S5 locus was detected in 44% of the noncancerous liver tissues showing chronic hepatitis or cirrhosis, which are widely considered to be precancerous conditions, but was not observed in noncancerous liver tissues showing no remarkable histological findings. The incidence of DNA hypermethylation at this locus was significantly higher in HCCs (90%) than noncancerous liver tissues (P