胃癌DNA甲基化差异片段的筛选与分析

目的筛选和分析胃癌和正常胃组织间DNA甲基化差异片段。方法通过甲基化敏感性代表性差异分析法(methylation-sensitive-representationaldifferenceanalysis,MS-RDA),筛选胃癌和正常胃组织间DNA甲基化差异片段,经克隆、测序后进行生物信息学分析。结果获得3个甲基化差异片段CRS1308、CRS1309、CRS1310序列。其中CRS1309和CRS1310已被GenBank收录,登陆号分别为AY887106和AY887107。CRS1309序列与LOC440683基因、LOC440887基因的3'端、DRD5基因均有很高的相似性;CRS1310序列与1999年MinoruToyota在人类结肠癌中分离出的核糖体RNA上的甲基化差异性CpG岛有很高的相似性。结论胃癌和正常胃组织间DNA甲基化存在差异,LOC440683、LOC440887、DRD5基因的异常甲基化可能与胃癌的发生相关,胃癌中CRS1310序列所在核糖体RNA上的CpG岛易发生甲基化。

Isolation and analysis of the differentially methylated DNA sequences of gastric cancer

Objective:To isolate and analyze the differentially methylated DNA sequences 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 genmic DNA were analazed with BLAST program system.Results:Three differentialy methylated DNA sequences, CRS1308,CRS1309,CRS1310,were obtained. CRS1309 and CRS1310 were accepted by GenBank. Studies indicated that CRS1309 was highly similar with three genes LOC440683, LOC440887,DRD5;CRS1310 was concerned with a CpG island ,in ribosomal RNA,isolated from colorectal cancer by Minoru Toyota in 1999. Conclusion:The methylation degree between gastric cancer and normal gastric mucosa is different. The aberrant methylation of LOC440683,LOC440887,DRD5 may be concerned with gastric cancer and CRS1310 is prone to be methylated in gastric cancer.