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15-Hydroxyprostaglandin Dehydrogenase Is Down-regulated in Gastric Cancer

2009; American Association for Cancer Research; Volume: 15; Issue: 14 Linguagem: Inglês

10.1158/1078-0432.ccr-08-2518

1557-3265

Alexandra Thiel, Aparna Ganesan, Johanna Mrena, Siina Junnila, Antti I. Nykänen, Annabrita Hemmes, Hsin‐Hsiung Tai, Outi Monni, Arto Kokkola, Caj Haglund, Tatiana V. Petrova, Ari Ristimäki,

Helicobacter pylori-related gastroenterology studies

We have investigated the expression and regulation of 15-hydroxyprostaglandin dehydrogenase (15-PGDH) in gastric cancer.Clinical gastric adenocarcinoma samples were analyzed by immunohistochemistry and quantitative real-time PCR for protein and mRNA expression of 15-PGDH and for methylation status of 15-PGDH promoter. The effects of interleukin-1beta (IL-1beta) and epigenetic mechanisms on 15-PGDH regulation were assessed in gastric cancer cell lines.In a gastric cancer cell line with a very low 15-PGDH expression (TMK-1), the 15-PGDH promoter was methylated and treatment with a demethylating agent 5-aza-2'-deoxycytidine restored 15-PGDH expression. In a cell line with a relatively high basal level of 15-PGDH (MKN-28), IL-1beta repressed expression of 15-PGDH mRNA and protein. This effect of IL-1beta was at least in part attributed to inhibition of 15-PGDH promoter activity. SiRNA-mediated knockdown of 15-PGDH resulted in strong increase of prostaglandin E(2) production in MKN-28 cells and increased cell growth of these cells by 31% in anchorage-independent conditions. In clinical gastric adenocarcinoma specimens, 15-PGDH mRNA levels were 5-fold lower in gastric cancer samples when compared with paired nonneoplastic tissues (n = 26) and 15-PGDH protein was lost in 65% of gastric adenocarcinomas (n = 210).15-PGDH is down-regulated in gastric cancer, which could potentially lead to accelerated tumor progression. Importantly, our data indicate that a proinflammatory cytokine linked to gastric carcinogenesis, IL-1beta, suppresses 15-PGDH expression at least partially by inhibiting promoter activity of the 15-PGDH gene.