title: 15-hydroxyprostaglandin dehydrogenase is down-regulated in gastric cancer.
abstract: OBJECTIVE
  We have investigated the expression and regulation of 15-hydroxyprostaglandin dehydrogenase (15-PGDH) in gastric cancer.
  
  
  METHODS
  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.
  
  
  RESULTS
  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).
  
  
  CONCLUSIONS
  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.
authors: Department of Pathology, HUSLAB and Genome-ScaleBiology Research Program, University of Helsinki, Helsinki, Finland.
authors: Alexandra
authors: A
authors: Thiel
authors: Aparna
authors: A
authors: Ganesan
authors: Johanna
authors: J
authors: Mrena
authors: Siina
authors: S
authors: Junnila
authors: Antti
authors: A
authors: Nykänen
authors: Annabrita
authors: A
authors: Hemmes
authors: Hsin-Hsiung
authors: HH
authors: Tai
authors: Outi
authors: O
authors: Monni
authors: Arto
authors: A
authors: Kokkola
authors: Caj
authors: C
authors: Haglund
authors: Tatiana V
authors: TV
authors: Petrova
authors: Ari
authors: A
authors: Ristimäki
mesh_terms: D001374:Azacitidine / Q000031:analogs & derivatives / Q000494:pharmacology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D018899:CpG Islands / Q000235:genetics; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D019175:DNA Methylation / Q000187:drug effects; D000077209:Decitabine; D015232:Dinoprostone / Q000378:metabolism; D015536:Down-Regulation; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D006911:Hydroxyprostaglandin Dehydrogenases / Q000235:genetics* / Q000378:metabolism; D007150:Immunohistochemistry; D053583:Interleukin-1beta / Q000494:pharmacology; D009578:Nitrobenzenes / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D013449:Sulfonamides / Q000494:pharmacology; D014162:Transfection
chemical_list: D016861:Cyclooxygenase Inhibitors; D053583:Interleukin-1beta; D009578:Nitrobenzenes; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D013449:Sulfonamides; C080955:N-(2-cyclohexyloxy-4-nitrophenyl)methanesulfonamide; D000077209:Decitabine; D006911:Hydroxyprostaglandin Dehydrogenases; C035859:15-hydroxyprostaglandin dehydrogenase; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D015232:Dinoprostone; D001374:Azacitidine