CpG site hypermethylation of E-cadherin and Connexin26 genes in hepatocellular carcinomas induced by a choline-deficient L-Amino Acid-defined diet in rats

✍ Scribed by Toshifumi Tsujiuchi; Kyoko Shimizu; Yumi Itsuzaki; Mariko Onishi; Eriko Sugata; Hiromasa Fujii; Kanya Honoki

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 188 KB
• Volume: 46
• Category: Article
• ISSN: 0899-1987
• DOI: 10.1002/mc.20268

✦ Synopsis

Abstract

We investigated DNA methylation patterns of E‐cadherin and Connexin26 (Cx26) genes in rat hepatocellular carcinomas (HCCs) induced by a choline‐deficient L‐Amino Acid‐defined (CDAA) diet. Six‐wks‐old F344 male rats were continuously fed with a CDAA diet for 75 wks, and were then killed. A total of five HCCs were obtained, and genomic DNA was extracted from each HCC for assessment of methylation status in the 5′ upstream regions of E‐cadherin and Cx26 genes by bisulfite sequencing, comparing to two normal liver tissues. The five HCCs showed highly methylated E‐cadherin and Cx26 genes, while these genes in two normal liver tissues were all unmethylated. For analysis of gene expression, real‐time quantitative reverse transcription (RT)‐polymerase chain reaction (PCR) was performed. Expressions of E‐cadherin and Cx26 genes were significantly reduced in the five HCCs (P < 0.0001 and P < 0.001, respectively) compared to normal liver tissues, correlating with their methylation statuses. These results suggested that hypermethylation of E‐cadherin and Cx26 genes may be involved in the development of HCCs induced by a CDAA diet in rats. © 2007 Wiley‐Liss, Inc.