title: p53-Independent activation of the gadd45 promoter by Delta12-prostaglandin J2.
abstract: A p53-inducible gene, the growth arrest and DNA damage-inducible gene 45 (gadd45), is associated with cell growth inhibition, DNA damage response and DNA repair. Here we report that Delta12-prostaglandin J2 (Delta12-PGJ2), an in vivo metabolite of arachidonic acid, which inhibits cell proliferation, induces gadd45 mRNA in HeLa cells. Because the p53 protein in HeLa cells is inactivated by papilloma virus E6, this type of gadd45 induction appears to be p53-independent. The induction was dose-dependent, and the maximum induction was observed at a concentration of 7.5 microgram/ml. In a time course study, gadd45 mRNA was induced 3 h after the addition of 7.5 microgram/ml Delta12-PGJ2. To investigate the transcriptional mechanism of gadd45 mRNA induction, we cloned a human genomic DNA fragment containing the gadd45 promoter region, and investigated the effect of Delta12-PGJ2 on the gadd45 promoter activity. In HeLa cells, 7.5 microgram/ml Delta12-PGJ2 markedly stimulated the gadd45 gene promoter about 20-fold or more. On the other hand, Delta12-PGJ2 did not stimulate the promoter activity of a reporter plasmid containing only p53 binding sites in HeLa cells, indicating that the gadd45 promoter activation by Delta12-PGJ2 was not mediated by p53. These results suggest that one of the mechanisms of cell growth arrest by Delta12-PGJ2 is mediated through a p53-independent induction of gadd45.
authors.affiliation: Department of Preventive Medicine, Kyoto Prefectural University of Medicine, Kyoto, Kawaramachi-Hirokoji, 602-8566, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Ohtani-Fujita
authors.forename: S
authors.initials: S
authors.lastname: Minami
authors.forename: S
authors.initials: S
authors.lastname: Mimaki
authors.forename: S
authors.initials: S
authors.lastname: Dao
authors.forename: T
authors.initials: T
authors.lastname: Sakai
mesh_terms: D002455:Cell Division / Q000187:drug effects; D003001:Cloning, Molecular; D004249:DNA Damage; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D006367:HeLa Cells; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D007700:Kinetics; D011401:Promoter Regions, Genetic / Q000187:drug effects*; D015230:Prostaglandin D2 / Q000031:analogs & derivatives* / Q000494:pharmacology; D011465:Prostaglandins, Synthetic / Q000494:pharmacology*; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000096:biosynthesis; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D014158:Transcription, Genetic / Q000187:drug effects; D014162:Transfection; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D000097642:GADD45 Proteins
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D015230:Prostaglandin D2; D011465:Prostaglandins, Synthetic; D011506:Proteins; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D016159:Tumor Suppressor Protein p53; D000097642:GADD45 Proteins; C040810:9-deoxy-9,10-didehydro-12,13-didehydro-13,14-dihydroprostaglandin D2