title: Hypoxic regulation of the expression of genes encoded estrogen related proteins in U87 glioma cells: eff ect of IRE1 inhibition.
abstract: The aim of the present study was to examine the effect of inhibition of endoplasmic reticulum stress signaling, mediated by IRE1 (inositol requiring enzyme 1), which is a central mediator of the unfolded protein response on the expression of genes encoded estrogen related proteins (NRIP1/RIP140, TRIM16/EBBP, ESRRA/NR3B1, FAM162A/E2IG5, PGRMC2/PMBP, and SLC39A6/LIV-1) and their hypoxic regulation in U87 glioma cells for evaluation of their possible significance in the control of glioma cells proliferation.
  
  
  
  The expression of NRIP1, EBBP, ESRRA, E2IG5, PGRMC2, and SLC39A6 genes in U87 glioma cells, transfected by empty vector pcDNA3.1 (control) and cells without IRE1 signaling enzyme function (transfected by dnIRE1) upon hypoxia, was studied by a quantitative polymerase chain reaction.
  
  
  
  Inhibition of both enzymatic activities (kinase and endoribonuclease) of IRE1 signaling enzyme function up-regulates the expression of EBBP, E2IG5, PGRMC2, and SLC39A6 genes is in U87 glioma cells in comparison with the control glioma cells, with more significant changes for E2IG5 and PGRMC2 genes. At the same time, the expression of NRIP1 and ESRRA genes is strongly down-regulated in glioma cells upon inhibition of IRE1. We also showed that hypoxia increases the expression of E2IG5, PGRMC2, and EBBP genes and decreases NRIP1 and ESRRA genes expression in control glioma cells. Furthermore, the inhibition of IRE1 in U87 glioma cells decreases the eff ect of hypoxia on the expression of E2IG5 and PGRMC2 genes, eliminates hypoxic regulation of NRIP1 gene, and enhances the sensitivity of ESRRA gene to hypoxic condition. Furthermore, the expression of SLC39A6 gene is resistant to hypoxia in both the glioma cells with and without IRE1 signaling enzyme function.
  
  
  
  Results of this investigation demonstrate that inhibition of IRE1 signaling enzyme function affects the expression of NRIP1, EBBP, ESRRA, E2IG5, PGRMC2, and SLC39A6 genes in U87 glioma cells in gene specific manner and these changes possibly contribute to the suppression of the cell proliferation. Most of these genes are regulated by hypoxia and preferentially through IRE1 signaling pathway of endoplasmic reticulum stress.
authors.affiliation: Department of Molecular Biology, Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv, Ukraine|Department of Pediatrics, National Bohomolets Medical University, Kyiv, Ukraine
authors.forename: D O
authors.initials: DO
authors.lastname: Minchenko
authors.affiliation: Department of Molecular Biology, Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv, Ukraine
authors.forename: O O
authors.initials: OO
authors.lastname: Riabovol
authors.affiliation: Department of Molecular Biology, Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv, Ukraine
authors.forename: O O
authors.initials: OO
authors.lastname: Ratushna
authors.affiliation: Department of Molecular Biology, Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv, Ukraine
authors.forename: O H
authors.initials: OH
authors.lastname: Minchenko
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics; D027682:Cation Transport Proteins / Q000235:genetics; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D059865:Endoplasmic Reticulum Stress; D004722:Endoribonucleases / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D005909:Glioblastoma / Q000235:genetics*; D005910:Glioma / Q000235:genetics; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics; D024101:Mitochondrial Proteins / Q000235:genetics; D009363:Neoplasm Proteins / Q000235:genetics; D009687:Nuclear Proteins / Q000235:genetics; D000078723:Nuclear Receptor Interacting Protein 1; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D011960:Receptors, Estrogen / Q000235:genetics; D011980:Receptors, Progesterone / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics; D000070584:Tripartite Motif Proteins; D000072258:Tumor Hypoxia / Q000235:genetics*; D044767:Ubiquitin-Protein Ligases; D000097983:ERRalpha Estrogen-Related Receptor
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D027682:Cation Transport Proteins; D004268:DNA-Binding Proteins; D004722:Endoribonucleases; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D000078723:Nuclear Receptor Interacting Protein 1; D017346:Protein Serine-Threonine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D014157:Transcription Factors; D000070584:Tripartite Motif Proteins; D044767:Ubiquitin-Protein Ligases; D000097983:ERRalpha Estrogen-Related Receptor; C486647:FAM162A protein, human; C000627127:NRIP1 protein, human; C115297:PGRMC2 protein, human; C418627:SLC39A6 protein, human; C117731:TRIM16 protein, human; C528229:ERN1 protein, human