The correlation of gene modification between DNA methylation and histone H3 lysine 27 trimethylation in gastric cancer

Abstract

Objective To study the correlation of gene modification between DNA methylation and histone H3 lysine 27 trimethylation in gastric cancer cells. Methods Tumor tissues and normal gastric mucosa in 8 cases of gastric cancer were collected from October 2007 to January 2008. After chromatin immunoprecipitatin linked to microarrays (ChIP-chip) was adopted to profile the variations in H3K27me3 in CpG island regions in tumor tissues and gastric mucosa,four genes were selected. ChIP-qPCR was used to validate the microrray results. Expression analysis by qRT-PCR was performed to confirm the correlation between H3K27me3 and gene expression. MeDIP-qPCR was used to analyze DNA methylation in four selected genes. Results The results of ChlP-qPCR were coincided well with microarray. There were significant differences in DNA methylation of four selected genes between tumor tissue and gastric mucosa (P<0.05). Conclusion There are significant differences in DNA methylation and histone H3 lysine 27 trimethylation of several genes between tumor tissue and gastric mucosa. There is a correlation of gene modification between DNA methylation and histone H3 lysine 27 trimethylation in gastric cancer Key words: Gastric carcinoma; Histone; Trimethylation; Gene modification