title: NECAB3 Promotes Activation of Hypoxia-inducible factor-1 during Normoxia and Enhances Tumourigenicity of Cancer Cells.
abstract: Unlike most cells, cancer cells activate hypoxia inducible factor-1 (HIF-1) to use glycolysis even at normal oxygen levels, or normoxia. Therefore, HIF-1 is an attractive target in cancer therapy. However, the regulation of HIF-1 during normoxia is not well characterised, although Mint3 was recently found to activate HIF-1 in cancer cells and macrophages by suppressing the HIF-1 inhibitor, factor inhibiting HIF-1 (FIH-1). In this study, we analysed Mint3-binding proteins to investigate the mechanism by which Mint3 regulates HIF-1. Yeast two-hybrid screening using Mint3 as bait identified N-terminal EF-hand calcium binding protein 3 (NECAB3) as a novel factor regulating HIF-1 activity via Mint3. NECAB3 bound to the phosphotyrosine-binding domain of Mint3, formed a ternary complex with Mint3 and FIH-1, and co-localised with Mint3 at the Golgi apparatus. Depletion of NECAB3 decreased the expression of HIF-1 target genes and reduced glycolysis in normoxic cancer cells. NECAB3 mutants that binds Mint3 but lacks an intact monooxygenase domain also inhibited HIF-1 activation. Inhibition of NECAB3 in cancer cells by either expressing shRNAs or generating a dominant negative mutant reduced tumourigenicity. Taken together, the data indicate that NECAB3 is a promising new target for cancer therapy.
authors.affiliation: Division of Cancer Cell Research, Institute of Medical Science, The University of Tokyo, Shirokanedai, Minato-ku, Tokyo, Japan.|Division of Molecular Pathology, Institute of Medical Science, The University of Tokyo, Shirokanedai, Minato-ku, Tokyo, Japan.
authors.forename: Hiroki J
authors.initials: HJ
authors.lastname: Nakaoka
authors.affiliation: Division of Cancer Cell Research, Institute of Medical Science, The University of Tokyo, Shirokanedai, Minato-ku, Tokyo, Japan.
authors.forename: Toshiro
authors.initials: T
authors.lastname: Hara
authors.affiliation: Division of Cancer Cell Research, Institute of Medical Science, The University of Tokyo, Shirokanedai, Minato-ku, Tokyo, Japan.|Division of Molecular Pathology, Institute of Medical Science, The University of Tokyo, Shirokanedai, Minato-ku, Tokyo, Japan.
authors.forename: Seiko
authors.initials: S
authors.lastname: Yoshino
authors.affiliation: Division of Molecular Pathology, Institute of Medical Science, The University of Tokyo, Shirokanedai, Minato-ku, Tokyo, Japan.
authors.forename: Akane
authors.initials: A
authors.lastname: Kanamori
authors.affiliation: Graduate School of Medicine, Nagoya University, Tsurumai-chou, Nagoya, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Matsui
authors.affiliation: Graduate School of Medicine, Nagoya University, Tsurumai-chou, Nagoya, Japan.
authors.forename: Teppei
authors.initials: T
authors.lastname: Shimamura
authors.affiliation: Division of Molecular Virology and Oncology, Cancer Research Institute, Kanazawa University, Kakuma-machi, Kanazawa, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sato
authors.affiliation: Division of Molecular Pathology, Institute of Medical Science, The University of Tokyo, Shirokanedai, Minato-ku, Tokyo, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Murakami
authors.affiliation: Division of Cancer Cell Research, Institute of Medical Science, The University of Tokyo, Shirokanedai, Minato-ku, Tokyo, Japan.|Faculty of Medicine, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Takara-machi, Kanazawa, Japan.
authors.forename: Motoharu
authors.initials: M
authors.lastname: Seiki
authors.affiliation: Division of Cancer Cell Research, Institute of Medical Science, The University of Tokyo, Shirokanedai, Minato-ku, Tokyo, Japan.|Division of Molecular Pathology, Institute of Medical Science, The University of Tokyo, Shirokanedai, Minato-ku, Tokyo, Japan.
authors.forename: Takeharu
authors.initials: T
authors.lastname: Sakamoto
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D001665:Binding Sites; D002135:Calcium-Binding Proteins; D063646:Carcinogenesis / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D006019:Glycolysis; D006056:Golgi Apparatus / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D051793:Hypoxia-Inducible Factor 1 / Q000378:metabolism*; D006899:Mixed Function Oxygenases / Q000378:metabolism*; D012097:Repressor Proteins / Q000378:metabolism*; D050801:Ternary Complex Factors
chemical_list: C117536:APBA3 protein, human; D048868:Adaptor Proteins, Signal Transducing; D002135:Calcium-Binding Proteins; D002352:Carrier Proteins; D051793:Hypoxia-Inducible Factor 1; C412571:NECAB3 protein, human; D012097:Repressor Proteins; D050801:Ternary Complex Factors; D006899:Mixed Function Oxygenases; C439790:HIF1AN protein, human