title: Hypoxia up-regulates SERPINB3 through HIF-2α in human liver cancer cells.
abstract: SERPINB3 is a cysteine-proteases inhibitor up-regulated in a significant number of cirrhotic patients carrying hepatocellular carcinoma (HCC) and recently proposed as a prognostic marker for HCC early recurrence. SERPINB3 has been reported to stimulate proliferation, inhibit apoptosis and, similar to what reported for hypoxia, to trigger epithelial-to-mesenchymal transition (EMT) and increased invasiveness in liver cancer cells. This study has investigated whether SERPINB3 expression is regulated by hypoxia-related mechanisms in liver cancer cells. Exposure of HepG2 and Huh7 cells to hypoxia up-regulated SERPINB3 transcription, protein synthesis and release in the extracellular medium. Hypoxia-dependent SERPINB3 up-regulation was selective (no change detected for SERPINB4) and operated through hypoxia inducible factor (HIF)-2α (not HIF-1α) binding to SERPINB3 promoter, as confirmed by chromatin immuno-precipitation assay and silencing experiments employing specific siRNAs. HIF-2α-mediated SERPINB3 up-regulation under hypoxic conditions required intracellular generation of ROS. Immuno-histochemistry (IHC) and transcript analysis, performed in human HCC specimens, revealed co-localization of the two proteins in liver cancer cells and the existence of a positive correlation between HIF-2α and SERPINB3 transcript levels, respectively. Hypoxia, through HIF-2α-dependent and redox-sensitive mechanisms, up-regulates the transcription, synthesis and release of SERPINB3, a molecule with a high oncogenic potential.
authors.affiliation: Department of Clinical and Biological Sciences, Unit of Experimental Medicine and Interuniversity Center for Liver Pathophysiology, University of Torino, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Cannito
authors.affiliation: Department of Medicine, University of Padova, Italy.
authors.forename: Cristian
authors.initials: C
authors.lastname: Turato
authors.affiliation: Department of Clinical and Biological Sciences, Unit of Experimental Medicine and Interuniversity Center for Liver Pathophysiology, University of Torino, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Paternostro
authors.affiliation: Department of Medicine, University of Padova, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Biasiolo
authors.affiliation: Department of Oncology, University of Torino, Italy.
authors.forename: Sebastiano
authors.initials: S
authors.lastname: Colombatto
authors.affiliation: Department of Plastic Surgery and Burn Unit Skin Bank, CTO Hospital, Torino, Italy.
authors.forename: Irene
authors.initials: I
authors.lastname: Cambieri
authors.affiliation: Department of Medicine, University of Padova, Italy.
authors.forename: Santina
authors.initials: S
authors.lastname: Quarta
authors.affiliation: Department of Clinical and Biological Sciences, Unit of Experimental Medicine and Interuniversity Center for Liver Pathophysiology, University of Torino, Italy.
authors.forename: Erica
authors.initials: E
authors.lastname: Novo
authors.affiliation: Department of Clinical and Biological Sciences, Unit of Experimental Medicine and Interuniversity Center for Liver Pathophysiology, University of Torino, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Morello
authors.affiliation: Department of Medicine, University of Padova, Italy.
authors.forename: Gianmarco
authors.initials: G
authors.lastname: Villano
authors.affiliation: Department of Medicine, University of Padova, Italy.
authors.forename: Silvano
authors.initials: S
authors.lastname: Fasolato
authors.affiliation: Department of Public Health and Pediatric Sciences, University of Torino, Italy.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Musso
authors.affiliation: Pathology Unit, San Giovanni Battista Hospital, Torino, Italy.
authors.forename: Ezio
authors.initials: E
authors.lastname: David
authors.affiliation: Department of Biomedical, Experimental and Clinical Sciences "Mario Serio", University of Firenze, Italy.
authors.forename: Ignazia
authors.initials: I
authors.lastname: Tusa
authors.affiliation: Department of Biomedical, Experimental and Clinical Sciences "Mario Serio", University of Firenze, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Rovida
authors.affiliation: Department of Clinical and Biological Sciences, Unit of Experimental Medicine and Interuniversity Center for Liver Pathophysiology, University of Torino, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Autelli
authors.affiliation: Gastroenterology and Hepatology Division, San Giovanni Battista Hospital, Torino, Italy.
authors.forename: Antonina
authors.initials: A
authors.lastname: Smedile
authors.affiliation: Unit of Hepatobiliary Surgery and Liver Transplantation, University of Padova, Italy.
authors.forename: Umberto
authors.initials: U
authors.lastname: Cillo
authors.affiliation: Department of Medicine, University of Padova, Italy.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Pontisso
authors.affiliation: Department of Clinical and Biological Sciences, Unit of Experimental Medicine and Interuniversity Center for Liver Pathophysiology, University of Torino, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Parola
mesh_terms: D000951:Antigens, Neoplasm / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics* / Q000378:metabolism; D015153:Blotting, Western; D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D015687:Cell Hypoxia; D045744:Cell Line, Tumor; D015972:Gene Expression Regulation, Neoplastic; D019073:HT29 Cells; D056945:Hep G2 Cells; D006801:Humans; D007150:Immunohistochemistry; D008113:Liver Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D034622:RNA Interference; D017382:Reactive Oxygen Species / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015843:Serpins / Q000235:genetics* / Q000378:metabolism; D015854:Up-Regulation; D000099162:Endothelial PAS Domain-Containing Protein 1
chemical_list: D000951:Antigens, Neoplasm; D051792:Basic Helix-Loop-Helix Proteins; D017382:Reactive Oxygen Species; D015843:Serpins; D000099162:Endothelial PAS Domain-Containing Protein 1; C051072:squamous cell carcinoma-related antigen