title: Che-1 sustains hypoxic response of colorectal cancer cells by affecting Hif-1α stabilization.
abstract: Solid tumours are less oxygenated than normal tissues. Consequently, cancer cells acquire to be adapted to a hypoxic environment. The poor oxygenation of solid tumours is also a major indicator of an adverse cancer prognosis and leads to resistance to conventional anticancer treatments. We previously showed the involvement of Che-1/AATF (Che-1) in cancer cell survival under stress conditions. Herein we hypothesized that Che-1 plays a role in the response of cancer cells to hypoxia.
  
  
  
  The human colon adenocarcinoma HCT116 and HT29 cell lines undepleted or depleted for Che-1 expression by siRNA, were treated under normoxic and hypoxic conditions to perform studies regarding the role of this protein in metabolic adaptation and cell proliferation. Che-1 expression was detected using western blot assays; cell metabolism was assessed by NMR spectroscopy and functional assays. Additional molecular studies were performed by RNA seq, qRT-PCR and ChIP analyses.
  
  
  
  Here we report that Che-1 expression is required for the adaptation of cells to hypoxia, playing an important role in metabolic modulation. Indeed, Che-1 depletion impacted on HIF-1α stabilization, thus downregulating the expression of several genes involved in the response to hypoxia and affecting glucose metabolism.
  
  
  
  We show that Che-1 a novel player in the regulation of HIF-1α in response to hypoxia. Notably, we found that Che-1 is required for SIAH-2 expression, a member of E3 ubiquitin ligase family that is involved in the degradation of the hydroxylase PHD3, the master regulator of HIF-1α stability.
authors.affiliation: UOSD SAFU, Department of Research, Diagnosis and Innovative Technologies, Translational Research Area, Regina Elena National Cancer Institute, Via E. Chianesi 53, 00144, Rome, Italy. tiziana.bruno@ifo.gov.it.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Bruno
authors.affiliation: Department of Chemistry, "Sapienza" University, Rome, Italy.
authors.forename: Mariacristina
authors.initials: M
authors.lastname: Valerio
authors.affiliation: Department of Chemistry, "Sapienza" University, Rome, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Casadei
authors.affiliation: UOSD SAFU, Department of Research, Diagnosis and Innovative Technologies, Translational Research Area, Regina Elena National Cancer Institute, Via E. Chianesi 53, 00144, Rome, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: De Nicola
authors.affiliation: UOSD Oncogenomic and Epigenetic Unit, Regina Elena National Cancer Institute, Rome, Italy.
authors.forename: Frauke
authors.initials: F
authors.lastname: Goeman
authors.affiliation: UOSD SAFU, Department of Research, Diagnosis and Innovative Technologies, Translational Research Area, Regina Elena National Cancer Institute, Via E. Chianesi 53, 00144, Rome, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Pallocca
authors.affiliation: UOSD SAFU, Department of Research, Diagnosis and Innovative Technologies, Translational Research Area, Regina Elena National Cancer Institute, Via E. Chianesi 53, 00144, Rome, Italy.
authors.forename: Valeria
authors.initials: V
authors.lastname: Catena
authors.affiliation: UOSD SAFU, Department of Research, Diagnosis and Innovative Technologies, Translational Research Area, Regina Elena National Cancer Institute, Via E. Chianesi 53, 00144, Rome, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Iezzi
authors.affiliation: UOSD SAFU, Department of Research, Diagnosis and Innovative Technologies, Translational Research Area, Regina Elena National Cancer Institute, Via E. Chianesi 53, 00144, Rome, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Sorino
authors.affiliation: UOSD SAFU, Department of Research, Diagnosis and Innovative Technologies, Translational Research Area, Regina Elena National Cancer Institute, Via E. Chianesi 53, 00144, Rome, Italy.
authors.forename: Agata
authors.initials: A
authors.lastname: Desantis
authors.affiliation: Department of Chemistry, "Sapienza" University, Rome, Italy.
authors.forename: Cesare
authors.initials: C
authors.lastname: Manetti
authors.affiliation: UOSD Oncogenomic and Epigenetic Unit, Regina Elena National Cancer Institute, Rome, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Blandino
authors.affiliation: UOSD SAFU, Department of Research, Diagnosis and Innovative Technologies, Translational Research Area, Regina Elena National Cancer Institute, Via E. Chianesi 53, 00144, Rome, Italy.
authors.forename: Aristide
authors.initials: A
authors.lastname: Floridi
authors.affiliation: UOSD SAFU, Department of Research, Diagnosis and Innovative Technologies, Translational Research Area, Regina Elena National Cancer Institute, Via E. Chianesi 53, 00144, Rome, Italy. maurizio.fanciulli@ifo.gov.it.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Fanciulli
mesh_terms: D051017:Apoptosis Regulatory Proteins / Q000235:genetics*; D015687:Cell Hypoxia; D049109:Cell Proliferation; D015179:Colorectal Neoplasms / Q000737:chemistry / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic; D005947:Glucose / Q000378:metabolism; D045325:HCT116 Cells; D019073:HT29 Cells; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000737:chemistry* / Q000235:genetics*; D055550:Protein Stability; D012097:Repressor Proteins / Q000235:genetics*; D017423:Sequence Analysis, RNA
chemical_list: C402637:AATF protein, human; D051017:Apoptosis Regulatory Proteins; C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D012097:Repressor Proteins; D005947:Glucose
keywords: Che-1/AATF; HIF-1α; Hypoxia; Metabolism; PHD3/EGLN3; SIAH-2