Aberrant gene promoter methylation of p16, FHIT, CRBP1, WWOX, and DLC-1 in Epstein-Barr virus-associated gastric carcinomas.

Abstract

Alterations in global DNA methylation and specific regulatory gene methylation are frequently found in cancer, but the significance of these epigenetic changes in EBV-associated gastric carcinoma (EBVaGC) remains unclear. We evaluated global DNA methylation status in 49 EBVaGC and 45 EBV-negative gastric carcinoma (EBVnGC) tissue samples and cell lines by 5-methylcytosine immunohistochemical staining and methylation quantification. We determined promoter methylation status and protein expression for the p16, FHIT, CRBP1, WWOX, and DLC-1 genes in tissues and studied the correlation between CpG island methylator phenotype (CIMP) class and clinicopathological characteristics. Changes in gene methylation and mRNA expression in EBVaGC cell line SNU-719 and in EBVnGC cell lines SGC-7901, BGC-823, and AGS were assessed after treatment with 5-aza-2'-deoxycytidine (5-aza-dC), trichostatin A (TSA), or a combination of both, by methylation-specific PCR and quantitative real-time RT-PCR. Global genomic DNA hypomethylation was more pronounced in EBVnGC than in EBVaGC. Promoter methylation of all five genes was more frequent in EBVaGC than in EBVnGC (p < 0.05). p16 and FHIT methylation was reversely correlated with protein expression in EBVaGC. Most (41/49) EBVaGC exhibited CIMP-high (CIMP-H), and the prognosis of CIMP-H patients was significantly worse than that of CIMP-low (p = 0.027) and CIMP-none (p = 0.003) patients. Treatment with 5-aza-dC and/or TSA induced upregulation of RNA expression of all five genes in SNU-719; meanwhile, individual gene expression increased in EBVnGC cell lines. In summary, EBV-induced hypermethylation of p16, FHIT, CRBP1, WWOX, and DLC-1 may contribute to EBVaGC development. Demethylation therapy may represent a novel therapeutic strategy for EBVaGC.

• Authors: Dan He, Yi-wang Zhang, Na-na Zhang, Lu Zhou, Jian-ning Chen, Ye Jiang, Chun-kui Shao
• Journal: Medical oncology (Northwood, London, England) (Med Oncol) Vol. 32 Issue 4 Pg. 92 (Apr 2015) ISSN: 1559-131X [Electronic] United States
• PMID: 25720522 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Biomarkers, Tumor
• CDKN2A protein, human
• Cyclin-Dependent Kinase Inhibitor p16
• DLC1 protein, human
• DNA, Neoplasm
• GTPase-Activating Proteins
• Neoplasm Proteins
• RNA, Messenger
• Receptors, Retinoic Acid
• Tumor Suppressor Proteins
• fragile histidine triad protein
• retinoic acid binding protein I, cellular
• Oxidoreductases
• WW Domain-Containing Oxidoreductase
• WWOX protein, human
• Acid Anhydride Hydrolases

Topics

• Acid Anhydride Hydrolases (genetics)
• Apoptosis
• Biomarkers, Tumor (genetics)
• Cell Proliferation
• CpG Islands (genetics)
• Cyclin-Dependent Kinase Inhibitor p16
• DNA Methylation
• DNA, Neoplasm (genetics)
• Epigenesis, Genetic (genetics)
• Epstein-Barr Virus Infections (genetics, mortality, pathology, virology)
• Female
• Follow-Up Studies
• GTPase-Activating Proteins (genetics)
• Gene Expression Regulation, Neoplastic
• Herpesvirus 4, Human (pathogenicity)
• Humans
• Immunoenzyme Techniques
• Male
• Middle Aged
• Neoplasm Proteins (genetics)
• Neoplasm Staging
• Oxidoreductases (genetics)
• Prognosis
• Promoter Regions, Genetic (genetics)
• RNA, Messenger (genetics)
• Real-Time Polymerase Chain Reaction
• Receptors, Retinoic Acid (genetics)
• Reverse Transcriptase Polymerase Chain Reaction
• Stomach Neoplasms (genetics, mortality, pathology, virology)
• Survival Rate
• Tumor Cells, Cultured
• Tumor Suppressor Proteins (genetics)
• WW Domain-Containing Oxidoreductase