title: Transcriptional machinery of TNF-α-inducible YTH domain containing 2 (YTHDC2) gene.
abstract: We previously demonstrated that a cellular factor, cyclosporin A (CsA) associated helicase-like protein (CAHL) that is identical to YTH domain containing 2 (YTHDC2), forms trimer complex with cyclophilin B and NS5B of hepatitis C virus (HCV) and facilitates HCV genome replication. Gene expression of YTHDC2 was shown in tumor cell lines and tumor necrosis factor (TNF)-α-treated hepatocytes, but not in untreated. However, the function of YTHDC2 in the tumor cells and the mechanism by which the YTHDC2 gene is transcribed in these cells is largely unknown. We first evaluated that the role of YTHDC2 in the proliferation of hepatocellular carcinoma (HCC) cell line Huh7 using RNA interference and found that YTHDC2-downregulated Huh7 were significantly decreased cell growth as compared to control. We next demonstrated that the cAMP response element (CRE) site in the promoter region of the YTHDC2 gene is critical for YTHDC2 transcription. To further investigate the transcription factors bound to the CRE site, we performed chromatin immunoprecipitation assays. Our findings demonstrate that c-Jun and ATF-2 bind to the CRE site in Huh7, and that TNF-α induces the biological activity of these transcription factors in hepatocytes as well as Huh7. Moreover, treatment with the HDAC inhibitor, trichostatin A (TSA), reduces YTHDC2 expression in Huh7 and in TNF-α-stimulated hepatocytes. Collectively, these data show that YTHDC2 plays an important role in tumor cells growth and activation/recruitment of c-Jun and ATF-2 to the YTHDC2 promoter is necessary for the transcription of YTHDC2, and that HDAC activity is required for the efficient expression of YTHDC2 in both of hepatocyte and HCC cells.
authors.affiliation: Laboratory of Biology, Azabu University School of Veterinary Medicine, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Tanabe
authors.affiliation: Laboratory of Biology, Azabu University School of Veterinary Medicine, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan.
authors.forename: Junpei
authors.initials: J
authors.lastname: Konno
authors.affiliation: Laboratory of Biology, Azabu University School of Veterinary Medicine, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan.
authors.forename: Kenya
authors.initials: K
authors.lastname: Tanikawa
authors.affiliation: Laboratory of Biology, Azabu University School of Veterinary Medicine, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan. Electronic address: sahara@azabu-u.ac.jp.
authors.forename: Hiroeki
authors.initials: H
authors.lastname: Sahara
mesh_terms: D001483:Base Sequence; D006528:Carcinoma, Hepatocellular / Q000235:genetics / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D018899:CpG Islands; D019175:DNA Methylation; D017931:DNA Primers; D055785:Gene Knockdown Techniques; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics / Q000473:pathology; D011401:Promoter Regions, Genetic; D034622:RNA Interference; D016601:RNA-Binding Proteins / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D016601:RNA-Binding Proteins; D014409:Tumor Necrosis Factor-alpha; C585900:YTHDF2 protein, human
keywords: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; ATF-2; BAC; CAHL; CRE; Cell growth; ChIP; CsA; CyPB; DMSO; FBS; FLuc; G6PDH; HCC; HCV; HDAC; IKK; IL-1β; IL-6; IκB kinase; JNK; MTT; NF-κB; NS5B; PBS; PMA; RIP1; RNA helicase; RT-PCR; TNF receptor-associated death domain protein; TNF receptor-associated factor; TNF-α; TRADD; TRAF; TSA; YTH domain containing 2; YTHDC2; activating transcription factor 2; bZIP; bacterial artificial chromosome; basic leucine zipper; c-Jun; c-Jun N-terminal kinase; cAMP response element, HDAC, histone deacetylase; chromatin immunoprecipitation; cyclophilin B; cyclosporin A; cyclosporin A (CsA) associated helicase-like protein; dimethyl sulphoxide; fetal bovine serum; firefly luciferase; glucose-6-phosphate dehydrogenase; hepatitis C virus; hepatitis C virus NS5b protein; hepatocellular carcinoma; interleukin 1 β; interleukin 6; nuclear factor κB; phorbol myristate acetate; phosphate-buffered saline; receptor-interacting protein 1; reverse transcriptase-polymerase chain reaction; shRNA; short hairpin RNA; siRNA; small interfering RNA; trichostatin A; tumor necrosis