RESUMO
Interleukin-1beta is up-regulated in the presence of Helicobacter pylori infection. H. pylori infection was associated with E-cadherin methylation. In this study, we examined if IL-1beta could induce promoter methylation of E-cadherin in human gastric cancer cell lines TMK-1, MKN-74 and MKN-7. Cells were treated with IL-1beta (0.025, 0.1, 0.25, 1.0, 2.5 ng/mL) for 6, 12 and 24h. Methylation status was determined by MSP and sequencing. The effects of IL-1beta or H.pylori on the cells, and after blockade with interleukin-1 receptor antagonist (IL-1ra) were tested. Promoter methylation of E-cadherin was induced in all three cells treated with IL-1beta or co-cultured with H. pylori. Treatment of IL-1ra could reverse the phenomena. Our study indicated that IL-1beta is an important step in mediating E-cadherin methylation.
Assuntos
Caderinas/genética , Metilação de DNA , Infecções por Helicobacter/genética , Helicobacter pylori/isolamento & purificação , Interleucina-1beta/farmacologia , Regiões Promotoras Genéticas , Neoplasias Gástricas/genética , Sequência de Bases , Linhagem Celular Tumoral , DNA/genética , DNA/metabolismo , Infecções por Helicobacter/microbiologia , Humanos , Proteína Antagonista do Receptor de Interleucina 1/antagonistas & inibidores , Proteína Antagonista do Receptor de Interleucina 1/fisiologia , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Neoplasias Gástricas/patologiaRESUMO
BACKGROUND: Both serum IL-6 levels and CpG island methylation have been shown to have prognostic significance in gastric cancer, it was suggested that an important link existed between IL-6 and methylation of cancers. AIM: To investigate the prognostic value of IL-6 serum level and the association between serum IL-6 levels and CpG island methylation at p16, DAPK, MGMT and E-cadherin in patients with gastric cancer. PATIENTS AND METHODS: Methylation status was assessed by MSP in 75 surgical specimens of gastric adenocarcinoma. IL-6 serum levels were measured by chemiluminescent enzyme immunoassay (CLEIA). RESULTS: Methylation of p16, DAPK, MGMT, and E-cadherin were present in 53, 48, 32, and 59% of patients. Patients with tumors methylated at p16 and DAPK had lower serum levels of IL-6 compared to unmethylated tumors (1.8 vs. 4.8 pg/ml, p = 0.01 for p16; 1.5 vs. 6.2 pg/ml, p = 0.0001 for DAPK). But there was no difference with MGMT and E-cadherin methylation status. Serum IL-6 levels were also associated with TNM stage (p = 0.001), depth of tumor invasion (p = 0.002), lymphatic invasion (p = 0.01), vascular invasion (p = 0.008), metastasis (p = 0.002) and signet cell histology (p = 0.001). CONCLUSION: IL-6 is of prognostic value for patients of gastric cancer. Low serum IL-6 levels were associated with p16 or DAPK gene methylation in patients with gastric cancer.
