title: Epstein-Barr virus immortalization of human B-cells leads to stabilization of hypoxia-induced factor 1 alpha, congruent with the Warburg effect.
abstract: BACKGROUND
  Epstein-Barr virus (EBV) encodes six nuclear transformation-associated proteins that induce extensive changes in cellular gene expression and signaling and induce B-cell transformation. The role of HIF1A in EBV-induced B-cell immortalization has not been previously studied.
  
  
  RESULTS
  Using Western blotting and Q-PCR, we found that HIF1A protein is stabilized in EBV-transformed lymphoblastoid cells. Western blotting, GST pulldown assays, and immunoprecipitation showed that EBV-encoded nuclear antigens EBNA-5 and EBNA-3 bind to prolylhydroxylases 1 and 2, respectively, thus inhibiting HIF1A hydroxylation and degradation. Immunostaining and Q-PCR showed that the stabilized HIF1A translocates to the nucleus, forms a heterodimer with ARNT, and transactivates several genes involved in aerobic glycolysis. Using biochemical assays and Q-PCR, we also found that lymphoblastoid cells produce high levels of lactate, lactate dehydrogenase and pyruvate.
  
  
  CONCLUSIONS
  Our data suggest that activation of the aerobic glycolytic pathway, corresponding to the Warburg effect, occurs in EBV-transformed lymphoblastoid cells, in contrast to mitogen-activated B-cells.
authors: Department of Microbiology, Tumor and Cell Biology (MTC), Karolinska Institutet, Stockholm, Sweden.
authors: Suhas
authors: S
authors: Darekar
authors: Konstantinos
authors: K
authors: Georgiou
authors: Mariya
authors: M
authors: Yurchenko
authors: Surya Pavan
authors: SP
authors: Yenamandra
authors: Georgia
authors: G
authors: Chachami
authors: George
authors: G
authors: Simos
authors: George
authors: G
authors: Klein
authors: Elena
authors: E
authors: Kashuba
mesh_terms: D021581:Active Transport, Cell Nucleus; D000332:Aerobiosis; D001402:B-Lymphocytes / Q000378:metabolism* / Q000473:pathology / Q000821:virology*; D002467:Cell Nucleus / Q000378:metabolism; D002472:Cell Transformation, Viral; D019309:Epstein-Barr Virus Nuclear Antigens / Q000378:metabolism; D006019:Glycolysis; D004854:Herpesvirus 4, Human / Q000502:physiology*; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D061986:MCF-7 Cells; D011393:Procollagen-Proline Dioxygenase / Q000378:metabolism; D055550:Protein Stability; D014158:Transcription, Genetic
chemical_list: C421621:EBNA-5 protein, Epstein-Barr virus; D019309:Epstein-Barr Virus Nuclear Antigens; C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D011393:Procollagen-Proline Dioxygenase