Zhou JJ, Wang Y, Xie Y, Zhao Y, Gu Y.
Helicobacter pylori induces demethylation of the Calmodulin gene promoter in gastric cancer cells.
Shijie Huaren Xiaohua Zazhi 2012;
20:1838-1842. [DOI:
10.11569/wcjd.v20.i20.1838]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To explore the expression of Calmodulin (CaM) gene in gastric cancer tissue and the relationship between the methylation level of the CaM gene promoter and Helicobacter pylori (H. pylori) infection.
METHODS: The expression of the CaM gene in 30 cases of gastric cancer and matched tumor-adjacent gastric tissue and metastatic lymph nodes was assessed by real-time fluorescence quantitative PCR. The relationship between CaM gene expression and H. pylori infection was analyzed. Methylation of CpG islands in the CaM gene promoter was measured by bisulfite modified sequencing method in gastric cancer cells infected with H. pylori and stably transfected with the H. pylori cytotoxin-associated protein A (cagA) gene.
RESULTS: The relative expression level of the CaM gene in cancer tissue was 2.08 times higher than that in tumor-adjacent gastric tissue (P < 0.05). The relative expression level of the CaM gene in H. pylori-positive gastric cancer was 6.11 times higher than that in the H. pylori-negative group (P < 0.05). The demethylation at -276 bp in the CaM gene promoter was detected in H. pylori-infected and cagA-overexpressed gastric cancer cells.
CONCLUSION: H. pylori, though secreting the virulence factor CagA, up-regulates the expression of the CaM gene in gastric cancer possibly by inducing the demethylation of the CaM promoter.
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