title: Silencing of YY1 downregulates RIZ1 promoter in human osteosarcoma.
abstract: RIZ1 isoform, but not RIZ2, is commonly silenced in many types of tumors. In osteosarcoma cells, RIZ1 protein is very abundant. The silencing of YY1 protein, a recent target gene in osteosarcoma cells, reduced the expression of RIZ1 protein. Here we show that RIZ1 overexpression is a transcriptional event documented by Western blot, RT-PCR, and promoter assays. YY1 protein binds and cooperates to positive regulation of the RIZ1 promoter and its presence reduced the dimethyl lysine 9 histone 3 by chromatin immunoprecipitation assays. These results indicate that overexpression of YY1 in osteosarcoma cells plays a key role in positive regulation of RIZ1. The coexpression of RIZ1/YY1 proteins suggests a tandem regulatory mechanism in human osteosarcoma cells and tissues.
authors.affiliation: Department of General Pathology, 1st School of Medicine, II University of Naples, Naples 80138, Italy.
authors.forename: Ciro
authors.initials: C
authors.lastname: Abbondanza
authors.forename: Filomena
authors.initials: F
authors.lastname: de Nigris
authors.forename: Caterina
authors.initials: C
authors.lastname: De Rosa
authors.forename: Raffaele
authors.initials: R
authors.lastname: Rossiello
authors.forename: Giovanni Alfredo
authors.initials: GA
authors.lastname: Puca
authors.forename: Claudio
authors.initials: C
authors.lastname: Napoli
mesh_terms: D001483:Base Sequence; D001859:Bone Neoplasms / Q000235:genetics*; D045744:Cell Line, Tumor; D047369:Chromatin Immunoprecipitation; D004268:DNA-Binding Proteins / Q000235:genetics*; D015536:Down-Regulation; D020868:Gene Silencing; D011495:Histone-Lysine N-Methyltransferase; D006801:Humans; D007150:Immunohistochemistry; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics*; D012516:Osteosarcoma / Q000235:genetics*; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000235:genetics*; D050986:YY1 Transcription Factor / Q000235:genetics / Q000502:physiology*
chemical_list: D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D014157:Transcription Factors; D050986:YY1 Transcription Factor; C494698:YY1 protein, human; D011495:Histone-Lysine N-Methyltransferase; C093563:PRDM2 protein, human