Gastric Cancer
Copyright ©2008 The WJG Press and Baishideng. All rights reserved.
World J Gastroenterol. Mar 7, 2008; 14(9): 1333-1338
Published online Mar 7, 2008. doi: 10.3748/wjg.14.1333
Isolation and bioinformatics analysis of differentially methylated genomic fragments in human gastric cancer
Ai-Jun Liao, Qi Su, Xun Wang, Bin Zeng, Wei Shi
Ai-Jun Liao, Qi Su, Cancer Research Institute, Nanhua University, The First Affiliated Hospital, University of South China, Hengyang 421001, Hunan Province, China
Xun Wang, Bin Zeng, Wei Shi, Department of Gastroenterology, The First Affiliated Hospital, University of South China, Hengyang 421001, Hunan Province, China
Author contributions: Liao AJ and Su Q contributed equally to this work; Liao AJ, Su Q, Wang X, Zeng B and Shi W designed the research; Liao AJ and Wang X performed the research; Liao AJ, Su Q, Wang X and Zeng B analyzed the data; and Liao AJ, Su Q, Wang X and Zeng B wrote the paper.
Correspondence to: Dr. Qi Su, Cancer Research Institute, University of South China, Hengyang 421001, Hunan Province, China. suqi1@hotmail.com
Telephone: +86-734-8279347
Fax: +86-734-8281547
Received: August 3, 2007
Revised: January 2, 2008
Published online: March 7, 2008
Abstract

AIM: To isolate and analyze the DNA sequences which are methylated differentially between gastric cancer and normal gastric mucosa.

METHODS: The differentially methylated DNA sequences between gastric cancer and normal gastric mucosa were isolated by methylation-sensitive representational difference analysis (MS-RDA). Similarities between the separated fragments and the human genomic DNA were analyzed with Basic Local Alignment Search Tool (BLAST).

RESULTS: Three differentially methylated DNA sequences were obtained, two of which have been accepted by GenBank. The accession numbers are AY887106 and AY887107. AY887107 was highly similar to the 11th exon of LOC440683 (98%), 3’ end of LOC440887 (99%), and promoter and exon regions of DRD5 (94%). AY887106 was consistent (98%) with a CpG island in ribosomal RNA isolated from colorectal cancer by Minoru Toyota in 1999.

CONCLUSION: The methylation degree is different between gastric cancer and normal gastric mucosa. The differentially methylated DNA sequences can be isolated effectively by MS-RDA.

Keywords: Gastric cancer; DNA methylation; Differential sequences; Methylation-sensitive representational difference analysis