title: Expression of the class II tumor suppressor gene RIG1 is directly regulated by p53 tumor suppressor in cancer cell lines.
abstract: Recent studies indicated that the RIG1 (RARRES3/TIG3) plays an important role in cell proliferation, differentiation, and apoptosis. However, the regulatory mechanism of RIG1 gene expression has not been clearly elucidated. In this study, we identified a functional p53 response element (p53RE) in the RIG1 gene promoter. Transfection studies revealed that the RIG1 promoter activity was greatly enhanced by wild type but not mutated p53 protein. Sequence specific mutation of the p53RE abolished p53-mediated transactivation. Specific binding of p53 protein to the rig-p53RE was demonstrated using electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) assay. Further studies confirmed that the expression of RIG1 mRNA and protein is enhanced through increased p53 protein in HepG2 or in H24-H1299 cells. In conclusion, our results indicated that RIG1 gene is a downstream target of p53 in cancer cell lines.
authors.affiliation: Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan, ROC.
authors.forename: Tzu-Hui
authors.initials: TH
authors.lastname: Hsu
authors.forename: Chin-Chen
authors.initials: CC
authors.lastname: Chu
authors.forename: Shun-Yuan
authors.initials: SY
authors.lastname: Jiang
authors.forename: May-Whey
authors.initials: MW
authors.lastname: Hung
authors.forename: Wen-Chieh
authors.initials: WC
authors.lastname: Ni
authors.forename: Huai-En
authors.initials: HE
authors.lastname: Lin
authors.forename: Tsu-Chung
authors.initials: TC
authors.lastname: Chang
mesh_terms: D001483:Base Sequence; D045744:Cell Line, Tumor; D015972:Gene Expression Regulation, Neoplastic; D016147:Genes, Tumor Suppressor; D006801:Humans; D018168:Receptors, Retinoic Acid / Q000235:genetics*; D020218:Response Elements / Q000235:genetics; D014158:Transcription, Genetic / Q000235:genetics; D015533:Transcriptional Activation / Q000235:genetics; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
chemical_list: C437968:PLAAT4 protein, human; D018168:Receptors, Retinoic Acid; D016159:Tumor Suppressor Protein p53