title: Involvement of interferon regulatory factor 1 and S100C/A11 in growth inhibition by transforming growth factor beta 1 in human hepatocellular carcinoma cells.
abstract: Growth inhibition by transforming growth factor (TGF)-beta 1 has been attributed to the induction of cyclin-dependent kinase inhibitors, among which p21/Waf1 plays a major role in many biological contexts. In the present study, two new intracellular mediators for the induction of p21/Waf1 by TGF-beta 1 were identified in a human hepatocellular carcinoma cell line (JHH-5) expressing mutant-type p53. After addition of TGF-beta 1 to JHH-5 cells, a marked increase of the p21/Waf1 expression preceded the inhibition of DNA synthesis. Expression of IFN regulatory factor (IRF)-1, a known transacting factor for p21/Waf1 promoter, was elevated just before or in parallel with the increase of p21/Waf1. Transduction of antisense IRF-1 inhibited the increase in p21/Waf1 in JHH-5 cells treated with TGF-beta 1 and partially released the cells from the growth arrest by TGF-beta 1. Expression of S100C/A11, a member of the Ca(2+)-binding S100 protein family, also markedly increased after addition of TGF-beta 1. S100C/A11 protein was translocated to and accumulated in nuclei of TGF-beta 1-treated JHH-5 cells, where p21/Waf1 was concomitantly accumulated. When a recombinant S100C/A11 protein was introduced into nuclei of JHH-5 cells, DNA synthesis was markedly inhibited in a dose-dependent manner in the absence of TGF-beta 1. Prior transfection of p21/Waf1-targeted small interfering RNA efficiently blocked decrease of DNA synthesis in JHH-5 cells caused by TAT-S100C/A11 or TGF-beta 1 and markedly inhibited expression of p21/Waf1 protein in the cells. These results indicate that IRF-1 and S100C/A11 mediate growth inhibition by TGF-beta 1 via induction of p21/Waf1.
authors.affiliation: Department of Cell Biology, Okayama University Graduate School of Medicine and Dentistry, Okayama, Japan. hiromiya@md.okayama-u.ac.jp
authors.forename: Masahiro
authors.initials: M
authors.lastname: Miyazaki
authors.forename: Masakiyo
authors.initials: M
authors.lastname: Sakaguchi
authors.forename: Ichiro
authors.initials: I
authors.lastname: Akiyama
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Sakaguchi
authors.forename: Seishi
authors.initials: S
authors.lastname: Nagamori
authors.forename: Nam-Ho
authors.initials: NH
authors.lastname: Huh
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D045744:Cell Line, Tumor; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000502:physiology*; D006801:Humans; D050856:Interferon Regulatory Factor-1; D008113:Liver Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D010750:Phosphoproteins / Q000096:biosynthesis / Q000502:physiology*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D009418:S100 Proteins / Q000096:biosynthesis / Q000502:physiology*; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D053773:Transforming Growth Factor beta1; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis / Q000235:genetics
chemical_list: C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D004268:DNA-Binding Proteins; C494257:IRF1 protein, human; D050856:Interferon Regulatory Factor-1; D010750:Phosphoproteins; D012333:RNA, Messenger; D009418:S100 Proteins; C508960:TGFB1 protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D016159:Tumor Suppressor Protein p53; C072337:S100A11 protein, human