ABSTRACT
We have studied the effect of hypoxia on the expression level of mRNA of the basic enzymes of pentose-phosphate cycle (G6PD, TKT, TALDO1, PGLS and RPIA) and glucose-6-phosphate isomerase (GPI) in U87 glioma cells in relation to inhibition of IRE1 (inositol requiring enzyme 1). It was shown that hypoxia leads to up-regulation of the expression of GPI and PGLS genes and to down-regulation of TALDO1 and RPIA genes in control glioma cells. Changes for GPI gene were more significant than for other genes. At the same time, inhibition of IRE1 modified the effect of hypoxia on the expression of all studied genes. In particular, it increased sensitivity to hypoxia of G6PD and TKT genes expression and suppressed the effect of hypoxia on the expression of GPI and RPIA genes. Additionally, inhibition of IRE1 eliminated hypoxic regulation of PGLS gene and did not change significantly effect of hypoxia on the expression of TALDO1 gene in glioma cells. Present study demonstrated that hypoxia, which often contributes to tumor growth, affects the expression of most studied genes and inhibition of IRE1 modified the hypoxic regulation of pentose-phosphate cycle gene expressions in a gene specific manner and thus possibly contributes to slower glioma growth, but several aspects of this regulation warrant further investigation.
Subject(s)
Endoplasmic Reticulum Stress/genetics , Endoribonucleases/genetics , Gene Expression Regulation, Neoplastic , Neuroglia/metabolism , Pentose Phosphate Pathway/genetics , Protein Serine-Threonine Kinases/genetics , Aldose-Ketose Isomerases/genetics , Aldose-Ketose Isomerases/metabolism , Carboxylic Ester Hydrolases/genetics , Carboxylic Ester Hydrolases/metabolism , Cell Hypoxia , Cell Line, Tumor , Cell Movement , Cell Proliferation , Endoribonucleases/deficiency , Gene Knockdown Techniques , Glucose-6-Phosphate Isomerase/genetics , Glucose-6-Phosphate Isomerase/metabolism , Glucosephosphate Dehydrogenase/genetics , Glucosephosphate Dehydrogenase/metabolism , Humans , Neuroglia/pathology , Protein Serine-Threonine Kinases/deficiency , Signal Transduction , Transaldolase/genetics , Transaldolase/metabolism , Transketolase/genetics , Transketolase/metabolismABSTRACT
OBJECTIVE: The aim of the present study was to examine the effect of chromium disilicide and titanium nitride nanoparticles on the expression level of genes encoding important regulatory factors (IGFBP1, IGFBP2, IGFBP3, IGFBP4, IGFBP5, SNARK/NUAK2, CD36, and PECAM1/CD31) in mouse liver for evaluation of possible toxic effects of these nanoparticles. METHODS: Male mice received 20 mg chromium disilicide nanoparticles (45 nm) and titanium nitride nanoparticles (20 nm) with food every working day for 2 months. The expression of IGFBP1, IGFBP2, IGFBP3, IGFBP4, IGFBP5, SNARK, CD36, and PECAM1 genes in mouse liver was studied by quantitative polymerase chain reaction. RESULTS: Treatment of mice with chromium disilicide nanoparticles led to down-regulation of the expression of IGFBP2, IGFBP5, PECAM1, and SNARK genes in the liver in comparison with control mice, with more prominent changes for SNARK gene. At the same time, the expression of IGFBP3 and CD36 genes was increased in mouse liver upon treatment with chromium disilicide nanoparticles. We have also shown that treatment with titanium nitride nanoparticles resulted in down-regulation of the expression of IGFBP2 and SNARK genes in the liver with more prominent changes for SNARK gene. At the same time, the expression of IGFBP3, IGFBP4, and CD36 genes was increased in the liver of mice treated with titanium nitride nanoparticles. Furthermore, the effect of chromium disilicide nanoparticles on IGFBP2 and CD36 genes expression was significantly stronger as compared to titanium nitride nanoparticles. CONCLUSIONS: The results of this study demonstrate that chromium disilicide and titanium nitride nanoparticles have variable effects on the expression of IGFBP2, IGFBP3, IGFBP4, IGFBP5, SNARK, CD36, and PECAM1 genes in mouse liver, which may reflect the genotoxic activities of the studied nanoparticles.
Subject(s)
Gene Expression/drug effects , Liver/drug effects , Nanoparticles , RNA, Messenger/drug effects , Titanium/pharmacology , Animals , CD36 Antigens/drug effects , CD36 Antigens/genetics , Chromium Compounds/pharmacology , Down-Regulation , Insulin-Like Growth Factor Binding Protein 1/drug effects , Insulin-Like Growth Factor Binding Protein 1/genetics , Insulin-Like Growth Factor Binding Protein 2/drug effects , Insulin-Like Growth Factor Binding Protein 2/genetics , Insulin-Like Growth Factor Binding Protein 3/drug effects , Insulin-Like Growth Factor Binding Protein 3/genetics , Insulin-Like Growth Factor Binding Protein 4/drug effects , Insulin-Like Growth Factor Binding Protein 4/genetics , Liver/metabolism , Male , Mice , Platelet Endothelial Cell Adhesion Molecule-1/drug effects , Platelet Endothelial Cell Adhesion Molecule-1/genetics , Polymerase Chain Reaction , Protein Serine-Threonine Kinases/drug effects , Protein Serine-Threonine Kinases/genetics , RNA, Messenger/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Silicon Compounds/pharmacology , Up-RegulationABSTRACT
OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.
Subject(s)
Endoribonucleases/genetics , Gene Expression Regulation, Neoplastic/genetics , Glioblastoma/genetics , Protein Serine-Threonine Kinases/genetics , Tumor Hypoxia/genetics , Adaptor Proteins, Signal Transducing/genetics , Cation Transport Proteins/genetics , Cell Line, Tumor , Cell Proliferation/genetics , DNA-Binding Proteins/genetics , Endoplasmic Reticulum Stress , Glioma/genetics , Humans , Membrane Proteins/genetics , Mitochondrial Proteins/genetics , Neoplasm Proteins/genetics , Nuclear Proteins/genetics , Nuclear Receptor Interacting Protein 1 , Receptors, Estrogen/genetics , Receptors, Progesterone/genetics , Reverse Transcriptase Polymerase Chain Reaction , Signal Transduction , Transcription Factors/genetics , Tripartite Motif Proteins , Ubiquitin-Protein Ligases , ERRalpha Estrogen-Related ReceptorABSTRACT
OBJECTIVE: The aim of the present study was to investigate the effect of hypoxia on the expression of genes encoding insulin-like growth factors (IGF1 and IGF2), their receptor (IGF1R), binding protein-4 (IGFBP4), and stanniocalcin 2 (STC2) in U87 glioma cells in relation to inhibition of endoplasmic reticulum stress signaling mediated by IRE1 (inositol requiring enzyme 1) for evaluation of their possible significance in the control of tumor growth. METHODS: The expression of IGF1, IGF2, IGF1R, IGFBP4, and STC2 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 qPCR. RESULTS: The expression of IGF1 and IGF2 genes is down-regulated in glioma cells without IRE1 signaling enzyme function in comparison with the control cells. At the same time, the expression of IGF1R, IGFBP4, and STC2 genes was up-regulated in glioma cells upon inhibition of IRE1, with more significant changes for IGFBP4 and STC2 genes. We also showed that hypoxia does not change significantly the expression of IGF1, IGF2, and IGF1R genes but up-regulated IGFBP4 and STC2 genes expression in control glioma cells. Moreover, the inhibition of both enzymatic activities (kinase and endoribonuclease) of IRE1 in glioma cells does not change significantly the effect of hypoxia on the expression of IGF1, IGF1R, and IGFBP4 genes but introduces sensitivity of IGF2 gene to hypoxic condition. Thus, the expression of IGF2 gene is resistant to hypoxia only in control glioma cells and significantly down-regulated in cells without functional activity of IRE1 signaling enzyme, which is central mediator of the unfolded protein response and an important component of the tumor growth as well as metabolic diseases. CONCLUSIONS: Results of this study demonstrate that the expression of IGF1 and IGF1R genes is resistant to hypoxic condition both in control U87 glioma cells and cells without IRE1 signaling enzyme function. However, hypoxia significantly up-regulates the expression of IGFBP4 gene independently on the inhibition of IRE1 enzyme. These data show that proteins encoded by these genes are resistant to hypoxia except IGFBP4 and participate in the regulation of metabolic and proliferative processes through IRE1 signaling.
Subject(s)
Endoribonucleases/physiology , Glioma/metabolism , Glycoproteins/genetics , Insulin-Like Growth Factor Binding Protein 4/genetics , Intercellular Signaling Peptides and Proteins/genetics , Protein Serine-Threonine Kinases/physiology , Somatomedins/genetics , Cell Hypoxia , Cell Line, Tumor , Gene Expression Regulation, Neoplastic , Glioma/pathology , Humans , Receptor, IGF Type 1/genetics , Signal TransductionABSTRACT
OBJECTIVE: The aim of the present investigation 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 encoding glucocorticoid receptor (NR3C1) and some related proteins (SGK1, SGK3, NCOA1, NCOA2, ARHGAP35, NNT) and their hypoxic regulation in U87 glioma cells for evaluation of their possible significance in the control of the glioma growth. METHODS: The expression of NR3C1,SGK1,SGK3, NCOA1, NCOA2, ARHGAP35, and NNT 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 quantitative polymerase chain reaction. RESULTS: Inhibition of IRE1 signaling enzyme function up-regulates the expression of NR3C1, SGK1, NCOA1, NCOA2, ARHGAP35, and NNT genes in U87 glioma cells in comparison with the control glioma cells, with more significant changes for NR3C1, SGK1, and NNT genes. At the same time, the expression of SGK3 gene is strongly down-regulated in glioma cells upon inhibition of IRE1. We have also shown that hypoxia increases the expression of NR3C1, SGK1, NCOA2, ARHGAP35, and NNT genes but decreases SGK3 and NCOA1 genes expression in control glioma cells. Moreover, the inhibition of both enzymatic activities (kinase and endoribonuclease) of IRE1 in U87 glioma cells enhances the eff ect of hypoxia on the expression of SGK1, SGK3, and NNT genes, but decreases the sensitivity of NR3C1 gene to hypoxic condition. Furthermore, the expression of NCOA1 gene is resistant to hypoxia in control glioma cells, but NCOA2 and ARHGAP35 genes are resistant to this condition in glioma cells without functional activity of IRE1 signaling enzyme. CONCLUSIONS: Results of this investigation demonstrate that inhibition of IRE1 signaling enzyme function affects the expression of NR3C1, SGK1, SGK3, NCOA1, NCOA2, ARHGAP35, and NNT genes in U87 glioma cells in gene specific manner and that all these genes are regulated by hypoxia preferentially through IRE1 signaling pathway of the endoplasmic reticulum stress.
Subject(s)
Brain Neoplasms/metabolism , Endoribonucleases/metabolism , Glioma/metabolism , Protein Serine-Threonine Kinases/metabolism , Receptors, Glucocorticoid/metabolism , Signal Transduction , Brain Neoplasms/genetics , Cell Hypoxia , Cell Line, Tumor , Endoribonucleases/genetics , Gene Expression Regulation, Enzymologic , Gene Expression Regulation, Neoplastic , Gene Knockdown Techniques , Glioma/genetics , Humans , Protein Serine-Threonine Kinases/genetics , Receptors, Glucocorticoid/genetics , TransfectionABSTRACT
We have studied the effect of inhibition of IRE1 (inositol requiring enzyme 1), which is a central mediator of endoplasmic reticulum stress and a controller of cell proliferation and tumor growth, on hypoxic regulation of the expression of different proliferation related genes in U87 glioma cells. It was shown that hypoxia leads to up-regulation of the expression of IL13RA2, CD24, ING1, ING2, ENDOG, and POLG genes and to down-regulation of KRT18, TRAPPC3, TSFM, and MTIF2 genes at the mRNA level in control glioma cells. Changes for ING1 and CD24 genes were more significant. At the same time, inhibition of IRE1 modifies the effect of hypoxia on the expression of all studied genes. In particular, it increases sensitivity to hypoxia of the expression of IL13RA2, TRAPPC3, ENDOG, and PLOG genes and suppresses the effect of hypoxia on the expression of ING1 gene. Additionally, it eliminates hypoxic regulation of KRT18, CD24, ING2, TSFM, and MTIF2 genes expressions and introduces sensitivity to hypoxia of the expression of BET1 gene in glioma cells. The present study demonstrates that hypoxia, which often contributes to tumor growth, affects the expression of almost all studied genes. Additionally, inhibition of IRE1 can both enhance and suppress the hypoxic regulation of these gene expressions in a gene specific manner and thus possibly contributes to slower glioma growth, but several aspects of this regulation must be further clarified.
Subject(s)
Endoplasmic Reticulum Stress/genetics , Endoribonucleases/genetics , Gene Expression Regulation, Neoplastic , Neuroglia/metabolism , Protein Serine-Threonine Kinases/genetics , RNA, Messenger/genetics , Signal Transduction/genetics , CD24 Antigen/genetics , CD24 Antigen/metabolism , Cell Hypoxia , Cell Line, Tumor , Cell Proliferation , DNA Polymerase gamma/genetics , DNA Polymerase gamma/metabolism , Endodeoxyribonucleases/genetics , Endodeoxyribonucleases/metabolism , Endoribonucleases/antagonists & inhibitors , Endoribonucleases/metabolism , Eukaryotic Initiation Factors/genetics , Eukaryotic Initiation Factors/metabolism , Homeodomain Proteins/genetics , Homeodomain Proteins/metabolism , Humans , Inhibitor of Growth Protein 1/genetics , Inhibitor of Growth Protein 1/metabolism , Interleukin-13 Receptor alpha2 Subunit/genetics , Interleukin-13 Receptor alpha2 Subunit/metabolism , Keratin-18/genetics , Keratin-18/metabolism , Mitochondrial Proteins/genetics , Mitochondrial Proteins/metabolism , Neuroglia/pathology , Peptide Elongation Factors/genetics , Peptide Elongation Factors/metabolism , Protein Serine-Threonine Kinases/antagonists & inhibitors , Protein Serine-Threonine Kinases/metabolism , Qc-SNARE Proteins/genetics , Qc-SNARE Proteins/metabolism , RNA, Messenger/metabolism , Receptors, Cytoplasmic and Nuclear/genetics , Receptors, Cytoplasmic and Nuclear/metabolism , Tumor Suppressor Proteins/genetics , Tumor Suppressor Proteins/metabolism , Vesicular Transport Proteins/genetics , Vesicular Transport Proteins/metabolismABSTRACT
We have studied hypoxic regulation of the expression of genes encoded GADD (growth arrest and DNA damage) family proteins in U87 glioma cells in relation to inhibition of IRE1 (inositol requiring enzyme-1), which controls cell proliferation and tumor growth as a central mediator of endoplasmic reticulum stress. We have shown that hypoxia up-regulates the expression of GADD34, GADD45A, GADD45B, and GADD153 genes, which are related to cell proliferation and apoptosis, in control (transfected by empty vector) glioma cells in gene specific manner. At the same time, the expression level of EIF2AK 1 (eukaryotic translation initiation factor 2-alpha kinase 1) and AI FM1 (apoptosis inducing factor, mitochondria associated 1) genes in these cells is down-regulated upon hypoxic condition. It was also shown that inhibition of ÐRE1 signaling enzyme function in U87 glioma cells enhances the effect of hypoxia on these genes expression, except EIF2AK 1 and AI FM1 genes. Furthermore, the expression of all studied genes in ÐRE1 knockdown cells is significantly decreased upon normoxic condition, except GADD45B gene, which expression level is strongly up-regulated. Therefore, the expression level of genes encoding GADD34, GADD45A, GADD45B, GADD153, EIF2AK 1, and AI FM1 is affected by hypoxia and by inhibition of IRE1-mediated endoplasmic reticulum stress signaling in gene specific manner and correlates with suppression of glioma cell proliferation upon inhibition of the IRE1 enzyme function.
Subject(s)
Cell Cycle Proteins/genetics , Endoplasmic Reticulum Stress/genetics , Endoribonucleases/genetics , Gene Expression Regulation, Neoplastic , Neuroglia/metabolism , Nuclear Proteins/genetics , Protein Phosphatase 1/genetics , Protein Serine-Threonine Kinases/genetics , Antigens, Differentiation/genetics , Antigens, Differentiation/metabolism , Apoptosis/genetics , Apoptosis Inducing Factor/genetics , Apoptosis Inducing Factor/metabolism , Cell Cycle Proteins/metabolism , Cell Hypoxia , Cell Line, Tumor , Cell Proliferation , Endoribonucleases/deficiency , Gene Knockdown Techniques , Humans , Neuroglia/pathology , Nuclear Proteins/metabolism , Plasmids/chemistry , Plasmids/metabolism , Protein Phosphatase 1/metabolism , Protein Serine-Threonine Kinases/deficiency , Signal Transduction , Transcription Factor CHOP/genetics , Transcription Factor CHOP/metabolism , Transfection , eIF-2 Kinase/genetics , eIF-2 Kinase/metabolismABSTRACT
We have studied the effect of hypoxia on the expression of nuclear genes encoding mitochondrial proteins in U87 glioma cells under the inhibition of IRE1 (inositol requiring enzyme-1), which controls cell proliferation and tumor growth as a central mediator of endoplasmic reticulum stress. It was shown that hypoxia down-regulated gene expression of malate dehydrogenase 2 (MDH2), malic enzyme 2 (ME2), mitochondrial aspartate aminotransferase (GOT2), and subunit B of succinate dehydrogenase (SDHB) in control (transfected by empty vector) glioma cells in a gene specific manner. At the same time, the expression level of mitochondrial NADP+-dependent isocitrate dehydrogenase 2 (IDH2) and subunit D of succinate dehydrogenase (SDHD) genes in these cells does not significantly change in hypoxic conditions. It was also shown that the inhibition of ÐRE1 signaling enzyme function in U87 glioma cells decreases the effect of hypoxia on the expression of ME2, GOT2, and SDHB genes and introduces the sensitivity of IDH2 gene to hypoxia. Furthermore, the expression of all studied genes depends on IRE1-mediated endoplasmic reticulum stress signaling in gene specific manner, because ÐRE1 knockdown significantly decreases their expression in normoxic conditions, except for IDH2 gene, which expression level is strongly up-regulated. Therefore, changes in the expression level of nuclear genes encoding ME2, MDH2, IDH2, SDHB, SDHD, and GOT2 proteins possibly reflect metabolic reprogramming of mitochondria by hypoxia and IRE1-mediated endoplasmic reticulum stress signaling and correlate with suppression of glioma cell proliferation under inhibition of the IRE1 enzyme function.
Subject(s)
Cell Nucleus/genetics , Endoplasmic Reticulum Stress/genetics , Endoribonucleases/genetics , Gene Expression Regulation, Neoplastic , Mitochondria/genetics , Neuroglia/enzymology , Protein Serine-Threonine Kinases/genetics , Aspartate Aminotransferases/genetics , Aspartate Aminotransferases/metabolism , Cell Hypoxia , Cell Line, Tumor , Cell Nucleus/enzymology , Cell Proliferation , Endoribonucleases/deficiency , Humans , Isocitrate Dehydrogenase/genetics , Isocitrate Dehydrogenase/metabolism , Malate Dehydrogenase/genetics , Malate Dehydrogenase/metabolism , Mitochondria/enzymology , Mitochondrial Proteins/genetics , Mitochondrial Proteins/metabolism , Neuroglia/pathology , Nuclear Proteins/genetics , Nuclear Proteins/metabolism , Protein Serine-Threonine Kinases/deficiency , Protein Transport , Signal Transduction , Succinate Dehydrogenase/genetics , Succinate Dehydrogenase/metabolismABSTRACT
We have studied gene expression of insulin-like growth factor binding proteins in U87 glioma cells upon glutamine deprivation depending on the inhibition of IRE1 (inositol requiring enzyme-1), a central mediator of endoplasmic reticulum stress. We have shown that exposure of control glioma cells upon glutamine deprivation leads to down-regulation of NOV/IGFBP9, WISP1 and WISP2 gene expressions and up-regulation of CYR61/IGFBP10 gene expression at the mRNA level. At the same time, the expression of IGFBP6 and IGFBP7 genes in control glioma cells was resistant to glutamine deprivation. It was also shown that the inhibition of IRE1 modifies the effect of glutamine deprivation on the expression of all studied genes. Thus, the inhibition of IRE1 signaling enzyme enhances the effect of glutamine deprivation on the expression of CYR61 and WISP1 genes and suppresses effect of the deprivation on WISP2 gene expression in glioma cells. Moreover, the inhibition of IRE1 introduces sensitivity of the expression of IGFBP6 and IGFBP7 genes to glutamine deprivation and removes this sensitivity to NOV gene. We have also demonstrated that the expression of all studied genes in glioma cells growing with glutamine is regulated by IRE1 signaling enzyme, because the inhibition of IRE1 significantly down-regulates IGFBP6 and NOV genes and up-regulates IGFBP7, CYR61, WISP1, and WISP2 genes as compared to control glioma cells. The present study demonstrates that glutamine deprivation condition affects most studied IGFBP and WISP gene expressions in relation to IRE1 signaling enzyme function and possibly contributes to slower glioma cell proliferation upon inhibition of IRE1.
Subject(s)
CCN Intercellular Signaling Proteins/genetics , Endoribonucleases/genetics , Gene Expression Regulation, Neoplastic , Glutamine/deficiency , Insulin-Like Growth Factor Binding Protein 6/genetics , Neuroglia/enzymology , Protein Serine-Threonine Kinases/genetics , Proto-Oncogene Proteins/genetics , CCN Intercellular Signaling Proteins/metabolism , Cell Line, Tumor , Cell Proliferation , Cysteine-Rich Protein 61/genetics , Cysteine-Rich Protein 61/metabolism , Endoribonucleases/deficiency , Humans , Insulin-Like Growth Factor Binding Protein 6/metabolism , Insulin-Like Growth Factor Binding Proteins/genetics , Insulin-Like Growth Factor Binding Proteins/metabolism , Nephroblastoma Overexpressed Protein/genetics , Nephroblastoma Overexpressed Protein/metabolism , Neuroglia/pathology , Protein Serine-Threonine Kinases/deficiency , Proto-Oncogene Proteins/metabolism , Repressor Proteins/genetics , Repressor Proteins/metabolism , Signal TransductionABSTRACT
Tumor necrosis factor (TNF) superfamily receptors and TNF apoptosis inducing ligands play an important role in the realization of TNF function and control tumor growth. The TNF-related pathways are controlled by endoplasmic reticulum stress signaling, which has a crucial role in the control of cell proliferation and tumor growth. Furthermore, the inhibition of IRE1 (inositol requiring enzyme-1), which is a central mediator of endoplasmic reticulum stress sand mainly responsible for cell proliferation and apoptosis, leads to suppression of tumor growth through specific changes in the expression of genes encoding transcription factors, tumor suppressors, angiogenesis and apoptosis related proteins, including TNF superfamily receptors and TNF apoptosis inducing ligands. Therefore, changes in the expression level of TNF-related genes encoding TNF superfamily receptors and apoptosis inducing ligands possibly reflect metabolic reprogramming of cancer cells upon inhibition of IRE1-mediated endoplasmic reticulum stress signaling and correlate with suppression of glioma cell proliferation.
Subject(s)
Apoptosis/genetics , Brain Neoplasms/genetics , Endoribonucleases/genetics , Gene Expression Regulation, Neoplastic , Glioma/genetics , Protein Serine-Threonine Kinases/genetics , Receptors, TNF-Related Apoptosis-Inducing Ligand/genetics , Apoptosis Regulatory Proteins/genetics , Apoptosis Regulatory Proteins/metabolism , Brain Neoplasms/metabolism , Brain Neoplasms/pathology , Cell Line, Tumor , Cell Proliferation , Endoplasmic Reticulum Stress/genetics , Endoribonucleases/deficiency , Glioma/metabolism , Glioma/pathology , Humans , Protein Serine-Threonine Kinases/deficiency , Receptors, TNF-Related Apoptosis-Inducing Ligand/metabolism , Signal Transduction , Transcription Factors/genetics , Transcription Factors/metabolism , Tumor Suppressor Proteins/genetics , Tumor Suppressor Proteins/metabolismABSTRACT
We investigated the impact of IRE1/ERN1 (inositol requiring enzyme 1/endoplasmic reticulum to nucleus signaling 1) knockdown on hypoxic regulation of the expression of a subset of proliferation and migration-related genes in U87 glioma cells. It was shown that hypoxia leads to up-regulation of the expression of MEST and SNAI2, to down-regulation of MYBL1, TCF8 and GTF2F2 genes at the mRNA level in control glioma cells. At the same time hypoxia did not affect the expression of TCF3 and GTF2B transcription factor genes. In turn, inhibition of IRE1 modified the effect of hypoxia on the expression of all studied genes, except MYBL1 and GTF2B. For instance, IRE1 knockdown decreased sensitivity to hypoxia of the expression of MEST, TCF8 and SNAI2 genes and increased sensitivity to hypoxia of GTF2F2 expression. At the same time, IRE1 inhibition introduced sensitivity to hypoxia of the expression of TCF3 gene in glioma cells. The present study demonstrated that the inhibition of IRE1 in glioma cells affected the hypoxic regulation of the expression of studied genes in various directions, though hypoxic conditions did not abolish the effect of IRE1 inhibition on the expression of respective genes. To the contrary, in case of SNAI2, GTF2F2 and MEST hypoxic conditions magnified the effect of IRE1 inhibition on the expression of respective genes in glioma cells.
Subject(s)
Endoplasmic Reticulum Stress/genetics , Endoribonucleases/genetics , Gene Expression Regulation, Neoplastic , Neuroglia/metabolism , Protein Serine-Threonine Kinases/genetics , RNA, Messenger/genetics , Basic Helix-Loop-Helix Transcription Factors/genetics , Basic Helix-Loop-Helix Transcription Factors/metabolism , Cell Hypoxia , Cell Line, Tumor , Cell Movement , Cell Proliferation , Endoribonucleases/deficiency , Gene Knockdown Techniques , Humans , Neuroglia/pathology , Protein Serine-Threonine Kinases/deficiency , Proteins/genetics , Proteins/metabolism , Proto-Oncogene Proteins/genetics , Proto-Oncogene Proteins/metabolism , RNA, Messenger/metabolism , Signal Transduction , Snail Family Transcription Factors/genetics , Snail Family Transcription Factors/metabolism , TATA-Box Binding Protein/genetics , TATA-Box Binding Protein/metabolism , Trans-Activators/genetics , Trans-Activators/metabolism , Transcription Factors, TFII/genetics , Transcription Factors, TFII/metabolismABSTRACT
Glycolysis and glutaminolysis as well as endoplasmic reticulum stress are required for tumor progression suggests through regulation of the cell cycle. Inhibition of ERN1/IRE1 (endoplasmic reticulum to nucleus signaling 1/inositol requiring enzyme 1), a central mediator of endoplasmic reticulum stress, significantly suppresses glioma cell proliferation and tumor growth as well as modifies sensitivity gene expressions to glucose and glutamine deprivation. We have studied the expression of genes encoded transcription factors such as E2F8 (E2F transcription factor 8), EPAS1 (endothelial PAS domain protein 1), HOXC6 (homeobox C6), TBX3 (T-box 3), TBX2 (T-box 2), GTF2F2 (general transcription factor IIF), GTF2B (general transcription factor IIB), MAZ (MYC-associated zinc finger protein, purine-binding transcription factor), SNAI2 (snail family zinc finger 2), TCF3 (transcription factor 3), and TCF8/ZEB1 (zinc finger E-box binding homeobox 1)in U87 glioma cells upon glucose and glutamine deprivation in relation to inhibition of IRE1.We demonstrated that glutamine deprivation leads to up-regulation of the expression of EPAS1, TBX3, GTF2B, and MAZ genes and down-regulation of E2F8, GTF2F2, TCF8, and TBX2 genes in control glioma cells.At the same time, glucose deprivation enhances the expression of EPAS1 and GTF2B genes and decreases of E2F8, HOXC6, TCF3, and TBX2 genes in these glioma cells. Inhibition of IRE1 by dnIRE1 significantly modifies the expression most of studied genes with different magnitude. Present study demonstrates that fine-tuning of the expression of proliferation related transcription factor genes depends upon glucose and glutamine deprivation in IRE1-dependent manner and possibly contributes to slower tumor growth after inhibition of IRE1.
Subject(s)
Endoplasmic Reticulum Stress/genetics , Endoribonucleases/genetics , Gene Expression Regulation, Neoplastic , Glucose/deficiency , Glutamine/deficiency , Neuroglia/metabolism , Protein Serine-Threonine Kinases/genetics , Basic Helix-Loop-Helix Transcription Factors/genetics , Basic Helix-Loop-Helix Transcription Factors/metabolism , Cell Cycle/genetics , Cell Hypoxia , Cell Line, Tumor , Cell Movement , Cell Proliferation , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Endoribonucleases/deficiency , Gene Knockdown Techniques , Homeodomain Proteins/genetics , Homeodomain Proteins/metabolism , Humans , Neuroglia/pathology , Protein Serine-Threonine Kinases/deficiency , Repressor Proteins/genetics , Repressor Proteins/metabolism , Signal Transduction , Snail Family Transcription Factors/genetics , Snail Family Transcription Factors/metabolism , T-Box Domain Proteins/genetics , T-Box Domain Proteins/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism , Transcription Factors, TFII/genetics , Transcription Factors, TFII/metabolism , Zinc Finger E-box-Binding Homeobox 1/genetics , Zinc Finger E-box-Binding Homeobox 1/metabolismABSTRACT
Obesity and its metabolic complications are one of the most profound public health problems and result from interactions between genes and environmental. The development of obesity is tightly connected with dysregulation of intrinsic gene expression mechanisms controlling majority of metabolic processes, which are essential for regulation many physiological functions, including insulin sensitivity, cellular proliferation and angiogenesis. Our objective was to evaluate if expression of angiogenesis related genes VEGF-A, CYR61, PDGFC, FGF1, FGF2, FGFR2, FGFRL1, E2F8, BAI2, HIF1A, and EPAS1 at mRNA level in adipose tissue could participate in the development of obesity and metabolic complications. We have shown that expression level of VEGF-A, PDGFC, FGF2, and FGFRL1 genes is decreased in adipose tissue of obese men with normal glucose tolerance (NGT) versus a group of control subjects. At the same time, in this group of obese individuals a significant up-regulation of CYR61, FGF1, FGFR2, E2F8, BAI2, and HIF1A gene expressions was observed. Impaired glucose tolerance (IGT) in obese patients associates with down-regulation of CYR61 and FGFR2 mRNA and up-regulations of E2F8, FGF1, FGF2, VEGF-A and its splice variant 189 mRNA expressions in adipose tissue versus obese (NGT) individuals. Thus, our data demonstrate that the expression of almost all studied genes is affected in subcutaneous adipose tissue of obese individuals with NGT and that glucose intolerance is associated with gene-specific changes in the expression of E2F8, FGF1, FGF2, VEGF-A, CYR61 and FGFR2 mRNAs. The data presented here provides evidence that VEGF-A, CYR61, PDGFC, FGF1, FGF2, FGFR2, FGFRL1, E2F8, BAI2, and HIF1A genes are possibly involved in the development of obesity and its complications.
Subject(s)
Gene Expression Regulation , Glucose Intolerance/genetics , Glucose/metabolism , Neovascularization, Pathologic/genetics , Obesity/genetics , Subcutaneous Fat/metabolism , Adult , Basic Helix-Loop-Helix Transcription Factors/genetics , Basic Helix-Loop-Helix Transcription Factors/metabolism , Case-Control Studies , Cysteine-Rich Protein 61/genetics , Cysteine-Rich Protein 61/metabolism , Fibroblast Growth Factor 1/genetics , Fibroblast Growth Factor 1/metabolism , Fibroblast Growth Factor 2/genetics , Fibroblast Growth Factor 2/metabolism , Glucose Intolerance/metabolism , Glucose Intolerance/pathology , Glucose Tolerance Test , Humans , Hypoxia-Inducible Factor 1, alpha Subunit/genetics , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Insulin/metabolism , Insulin Resistance , Lymphokines/genetics , Lymphokines/metabolism , Male , Middle Aged , Neovascularization, Pathologic/metabolism , Neovascularization, Pathologic/pathology , Nerve Tissue Proteins/genetics , Nerve Tissue Proteins/metabolism , Obesity/metabolism , Obesity/pathology , Platelet-Derived Growth Factor/genetics , Platelet-Derived Growth Factor/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Receptor, Fibroblast Growth Factor, Type 2/genetics , Receptor, Fibroblast Growth Factor, Type 2/metabolism , Receptor, Fibroblast Growth Factor, Type 5/genetics , Receptor, Fibroblast Growth Factor, Type 5/metabolism , Repressor Proteins/genetics , Repressor Proteins/metabolism , Signal Transduction , Subcutaneous Fat/blood supply , Subcutaneous Fat/pathology , Vascular Endothelial Growth Factor A/genetics , Vascular Endothelial Growth Factor A/metabolismABSTRACT
OBJECTIVE: The aim of the present study was to investigate the effect of inhibition of endoplasmic reticulum stress signaling mediated by IRE1/ERN1 (inositol-requiring enzyme 1/endoplasmic reticulum to nucleus signaling 1) on the expression of genes encoding different groups of insulin-like growth binding proteins (IGFBP6 and IGFBP7) and CCN family (IGFBP8/CTGF/CCN2, IGFBP9/NOV/CCN3, IGFBP10/CYR61/CCN1, WISP1/CCN4, and WISP2/CCN5) and its sensitivity to glucose deprivation in U87 glioma cells. METHODS: The expression of IGFBP6, IGFBP7, IGFBP8, IGFBP9, IGFBP10, WISP1, and WISP2 genes was studied by qPCR in control U87 glioma cells (wild-type) and its subline with IRE1 signaling enzyme loss of function upon glucose deprivation. RESULTS: The expression of IGFBP8, IGFBP9, and WISP2 genes was up-regulated in control glioma cells upon glucose deprivation with most significant changes for IGFBP9 gene. At the same time, the expression of IGFBP6, IGFBP10, and WISP1 genes was resistant to glucose deprivation in these glioma cells, but the IGFBP7 gene expression was down-regulated. The inhibition of both enzymatic activities (kinase and endoribonuclease) of IRE1 in glioma cells modified the sensitivity of most studied gene expressions to glucose deprivation condition: introduced sensitivity of IGFBP10 and WISP1 genes to glucose deprivation, enhanced the effect of this deprivation on IGFBP7 and IGFBP9 gene expressions, and reduced this effect on WISP2 gene and induced suppressive effect of glucose deprivation on the expression of IGFBP8 gene. Furthermore, the inhibition of IRE1 strongly affected the expression of all studied genes in glioma cells upon regular growing condition in gene specific manner: up-regulated the expression levels of IGFBP7, IGFBP8, IGFBP10, WISP1, and WISP2 genes and down-regulated the IGFBP6 and IGFBP9 genes. CONCLUSIONS: The data of this investigation demonstrate that the expression of IGFBP7, IGFBP8, IGFBP9, and WISP2 genes are sensitive to glucose deprivation in U87 glioma cells and that inhibition of IRE1 signaling enzyme function may significantly affect the expression of all studied genes in the presence of glucose as well as modify the effect of glucose deprivation on the expression of most studied genes. These data also show that proteins encoded by these genes may participate in the regulation of metabolic and proliferative processes via IGF/INS receptors and possibly other signaling pathways as well, via IRE1 signaling, which is a central mediator of the unfolded protein response and an important component of the tumor growth and metabolic diseases.
Subject(s)
Brain Neoplasms/enzymology , Endoribonucleases/deficiency , Glioma/enzymology , Glucose/deficiency , Insulin-Like Growth Factor Binding Proteins/metabolism , Protein Serine-Threonine Kinases/deficiency , Brain Neoplasms/genetics , Brain Neoplasms/pathology , CCN Intercellular Signaling Proteins/genetics , CCN Intercellular Signaling Proteins/metabolism , Cell Line, Tumor , Endoribonucleases/genetics , Gene Expression Regulation, Neoplastic , Glioma/genetics , Glioma/pathology , Humans , Insulin-Like Growth Factor Binding Proteins/genetics , Protein Serine-Threonine Kinases/genetics , RNA, Messenger/metabolism , Repressor Proteins/genetics , Repressor Proteins/metabolism , Signal Transduction , TransfectionABSTRACT
Hypoxia as well as the endoplasmic reticulum stress are important factors of malignant tumor growth and control of the expression of genes, which regulate numerous metabolic processes and cell proliferation. Furthermore, blockade of ERN1 (endoplasmic reticulum to nucleus 1) suppresses cell proliferation and tumor growth. We studied the effect of hypoxia on the expression of genes encoding the transcription factors such as E2F8 (E2F transcription factor 8), EPAS1 (endothelial PAS domain protein 1), TBX3 (T-box 3), ATF3 (activating transcription factor 3), FOXF1 (forkhead box F), and HOXC6 (homeobox C6) in U87 glioma cells with and without ERN1 signaling enzyme function. We have established that hypoxia enhances the expression of HOXC6, E2F8, ATF3, and EPAS1 genes but does not change TBX3 and FOXF1 gene expression in glioma cells with ERNI function. At the same time, the expression level of all studied genes is strongly decreased, except for TBX3 gene, in glioma cells without ERN1 function. Moreover, the inhibition of ERN1 signaling enzyme function significantly modifies the effect of hypoxia on the expression of these transcription factor genes. removes or introduces this regulation as well as changes a direction or magnitude of hypoxic regulation. Present study demonstrates that fine-tuning of the expression of proliferation related genes depends upon hypoxia and ERN1-mediated endoplasmic reticulum stress signaling and correlates with slower proliferation rate of glioma cells without ERN1 function.
Subject(s)
Endoribonucleases/genetics , Gene Expression Regulation, Neoplastic/drug effects , Neuroglia/drug effects , Oxygen/pharmacology , Protein Serine-Threonine Kinases/genetics , Signal Transduction/drug effects , Activating Transcription Factor 3/genetics , Activating Transcription Factor 3/metabolism , Basic Helix-Loop-Helix Transcription Factors/genetics , Basic Helix-Loop-Helix Transcription Factors/metabolism , Cell Hypoxia/genetics , Cell Line, Tumor , Cell Proliferation , Endoplasmic Reticulum Stress/genetics , Endoribonucleases/antagonists & inhibitors , Endoribonucleases/metabolism , Forkhead Transcription Factors/genetics , Forkhead Transcription Factors/metabolism , Homeodomain Proteins/genetics , Homeodomain Proteins/metabolism , Humans , Neuroglia/metabolism , Neuroglia/pathology , Protein Serine-Threonine Kinases/antagonists & inhibitors , Protein Serine-Threonine Kinases/metabolism , RNA, Small Interfering/genetics , RNA, Small Interfering/metabolism , Repressor Proteins/genetics , Repressor Proteins/metabolism , T-Box Domain Proteins/genetics , T-Box Domain Proteins/metabolism , TransfectionABSTRACT
The development of obesity and its metabolic complications is associated with dysregulation of various intrinsic mechanisms, which control basic metabolic processes via changes in the expression of numerous regulatory genes. We studied the expression of the subset of genes, which responsible for control of cell growth and glucose metabolism, in blood cells of obese boys with normal and impaired insulin sensitivity as well as in normal (control) individuals. It was shown that obesity with normal insulin sensitivity enhances the expression of IRS1, RIPK2, IL13RA2, RSPO1, IQSEC, and CCN2 genes but decreases the expression level IRS2 and DNAJC15 genes in the blood cells as compared to control group. Insulin resistance in obese boys leads to up-regulation of IRS2, RSPO1, and DNAJC15 gene expressions as wells to down-regulation of IRS1 and RIPK2 genes in the blood cells versus obese patients with normal insulin sensitivity. Results of this study provide evidence that obesity affects the expression of the subset of genes related to cell growth and glucose metabolism in blood cells and that insulin resistance in obesity is associated with changes in the expression level of IRS1, IRS2, RIPK2, RSPO1, and DNA JC15 genes, which contribute to the development of insulin resistance and glucose intolerance and possibly reflect some changes in fat tissue.
Subject(s)
Blood Cells/metabolism , Insulin Resistance , Obesity/genetics , Adolescent , Blood Cells/pathology , Blood Glucose/metabolism , Body Mass Index , Case-Control Studies , Connective Tissue Growth Factor/genetics , Connective Tissue Growth Factor/metabolism , Gene Expression Regulation , Guanine Nucleotide Exchange Factors/genetics , Guanine Nucleotide Exchange Factors/metabolism , HSP40 Heat-Shock Proteins/genetics , HSP40 Heat-Shock Proteins/metabolism , Humans , Insulin Receptor Substrate Proteins/genetics , Insulin Receptor Substrate Proteins/metabolism , Interleukin-13 Receptor alpha2 Subunit/genetics , Interleukin-13 Receptor alpha2 Subunit/metabolism , Male , Obesity/metabolism , Obesity/pathology , Receptor-Interacting Protein Serine-Threonine Kinase 2/genetics , Receptor-Interacting Protein Serine-Threonine Kinase 2/metabolism , Signal Transduction , Thrombospondins/genetics , Thrombospondins/metabolismABSTRACT
OBJECTIVE: The aim of the present study was to examine the association between the expression of insulin-like growth binding protein-1 and -2 (IGFBP1 and IGFBP2), insulin-like growth factor 2 mRNA binding protein 3/KH domain containing protein over-expressed in cancer (IGF2BP3/KOC1), and HtrA serine peptidase 1/serine protease with IGF-binding domain (HTRA1/PRSS11) genes and function of endoplasmic reticulum stress signaling mediated by ERN1 (endoplasmic reticulum to nucleus signaling 1) as well as the regulation of these genes by hypoxia in U87glioma cells. METHODS: The expression of IGFBP1, IGFBP2, IGF2BP3, and HTRA1 genes in U87 glioma cells and its subline with ERN1 signaling enzyme loss of function, were analyzed by qPCR. Cells underwent to hypoxia exposure (3% oxygen, 16 h). RESULTS: The blockade of both enzymatic activities (kinase and endoribonuclease) of ERN1 in glioma cells led to a significant down-regulation of the expression of IGFBP1, IGFBP2, and IGF2BP3 genes and strong up-regulation of HTRA1. At the same time, the inhibition of ERN1 endoribonuclease significantly increased the expression of IGFBP1, IGFBP2, and HTRA1 genes and did not affect the IGF2BP3 gene expression. Hypoxia up-regulated the expression of IGFBP1 and IGFBP2 genes in control glioma cells, with more significant changes in IGFBP1 gene. Furthermore, effect of hypoxia on these gene expressions was significantly lower in glioma cells without ERN1 signaling enzyme function. CONCLUSIONS: Results of this study demonstrate the dependence of insulin-like growth binding proteins as well as IGF2BP3 and HTRA1 gene expressions in U87 glioma cells on ERN1 signaling enzyme function and hypoxia, indicating its participation in the regulation of metabolic and proliferative processes via IGF/INS receptors, because endoplasmic reticulum stress is an important component of tumor growth and metabolic diseases.
Subject(s)
Brain Neoplasms/genetics , Endoplasmic Reticulum Stress/physiology , Endoribonucleases/physiology , Glioma/genetics , Insulin-Like Growth Factor Binding Proteins/genetics , Protein Serine-Threonine Kinases/physiology , Brain Neoplasms/metabolism , Cell Hypoxia/genetics , Cell Line, Tumor , Endoplasmic Reticulum Stress/genetics , Endoribonucleases/antagonists & inhibitors , Gene Expression Regulation, Neoplastic , Gene Knockdown Techniques , Glioma/metabolism , Humans , Insulin-Like Growth Factor Binding Proteins/metabolism , Protein Serine-Threonine Kinases/antagonists & inhibitors , Signal Transduction/geneticsABSTRACT
Inhibition of IRE1 (inositol requiring enzyme-1), the major signaling pathway of endoplasmic reticulm stress, significantly decreases glioma cell proliferation and tumor growth. We have studied the expression of TNFα-related genes and effect of glucose deprivation on these gene expressions in U87 glioma cells over-expressing dominant-negative IRE1 defective in both kinase and endonuclease (dn-IRE1) activity of IRE1 with hopes of elucidating its contribution to IRE1 mediated glioma growth. We have demonstrated that glucose deprivation condition leads to down-regulation of the expression of TNFRSF11B, TNFRSF1A, TNFRSF10D/TRAILR4, and LITAF genes and up-regulation of TNFRSF10B/TRAILR2/DR5 gene at the mRNA level in control glioma cells. At the same time, the expression of TNFRSF21/DR6, TNFAIP1, TNFAIP3, TRADD, and CD70/TNFSF7 genes in control glioma cells is resistant to glucose deprivation condition. The inhibition of IRE1 modifies the effect of glucose deprivation on LITAF, TNFRSF21, TNFRSF11B, and TRADD gene expressions and induces sensitivity to glucose deprivation condition the expression of TNFRSF10B, TNFRSF1A, and CD70 genes. We have also demonstrated that the expression of all studied genes is affected in glioma cells by inhibition of IRE1, except TNFRSF1A gene, as compared to control glioma cells. Moreover, the changes in the expression of TNFRSF1A, TNFRSF10D/TRAILR4, and LITAF genes induced by glucose deprivation condition have opposite orientation to that induced by inhibition of IRE1. The present study demonstrates that fine-tuning of the expression of TNFα-induced proteins and TNF receptor superfamily genes, which related to cell death and proliferation, is regulated by IRE1, an effector of endoplasmic reticulum stress, as well as depends on glucose deprivation in gene specific manner. Thus, the inhibition of kinase and endoribonuclease activity of IRE1 correlates with deregulation of TNFα-induced protein genes and TNF receptor superfamily genes in gene specific manner and thus slower the tumor growth.
Subject(s)
Endoplasmic Reticulum Stress/genetics , Endoribonucleases/genetics , Gene Expression Regulation, Neoplastic , Glucose/deficiency , Protein Serine-Threonine Kinases/genetics , RNA, Messenger/genetics , Tumor Necrosis Factor-alpha/genetics , Adaptor Proteins, Signal Transducing , CD27 Ligand/genetics , CD27 Ligand/metabolism , Cell Line, Tumor , Cell Proliferation , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Endoribonucleases/deficiency , Humans , Intracellular Signaling Peptides and Proteins/genetics , Intracellular Signaling Peptides and Proteins/metabolism , Neuroglia/metabolism , Neuroglia/pathology , Nuclear Proteins/genetics , Nuclear Proteins/metabolism , Osteoprotegerin/genetics , Osteoprotegerin/metabolism , Protein Serine-Threonine Kinases/deficiency , Proteins/genetics , Proteins/metabolism , RNA, Messenger/metabolism , Receptors, TNF-Related Apoptosis-Inducing Ligand/genetics , Receptors, TNF-Related Apoptosis-Inducing Ligand/metabolism , Receptors, Tumor Necrosis Factor/genetics , Receptors, Tumor Necrosis Factor/metabolism , Receptors, Tumor Necrosis Factor, Type I/genetics , Receptors, Tumor Necrosis Factor, Type I/metabolism , Signal Transduction , TNF Receptor-Associated Death Domain Protein/genetics , TNF Receptor-Associated Death Domain Protein/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism , Tumor Necrosis Factor Decoy Receptors/genetics , Tumor Necrosis Factor Decoy Receptors/metabolism , Tumor Necrosis Factor alpha-Induced Protein 3 , Tumor Necrosis Factor-alpha/metabolismABSTRACT
We have studied hypoxic regulation of the expression of different insulin-like growth factor binding protein genes in U87 glioma cells in relation to inhibition of IRE1 (inositol requiring enzyme-1), a central mediator of endoplasmic reticulum stress, which controls cell proliferation and tumor growth. We have demonstrated that hypoxia leads to up-regulation of the expression of IGFBP6, IGFBP7, IGFBP10/CYR61, WISP1, and WISP2 genes and down-regulation--of IGFBP9/NOV gene at the mRNA level in control glioma cells, being more signifcant changes for IGFBP10/CYR61 and WISP2 genes. At the same time, inhibition of IRE1 modifies the effect of hypoxia on the expression of all studied genes: eliminates sensitivity to hypoxia the expression of IGFBP7 and IGFBP9/NOV genes, suppresses effect of hypoxia on IGFBP6, IGFBP10/CYR61, and WISP2 genes, and slightly enhances hypoxic regulation of WISP1 gene expression in glioma cells. We have also demonstrated that the expression of all studied genes in glioma cells is regulated by IRE1 signaling enzyme upon normoxic condition, because inhibition of IRE1 significantly up-regulates IGFBP7, IGFBP10/CYR61, WISP1, and WISP2 genes and down-regulates IGFBP6 and IGFBP9/NOV genes as compared to control glioma cells. The present study demonstrates that hypoxia, which contributes to tumor growth, affects all studied IGFBP and WISP gene expressions and that inhibition of IRE1 preferentially abolishes or suppresses the hypoxic regulation of these gene expressions and thus possibly contributes to slower glioma growth. Moreover, inhibition of IRE1, which correlates with suppression of cell proliferation and glioma growth, is down-regulated expression of pro-proliferative IGFBP genes, attesting to the fact that endoplasmic reticulum stress is a necessary component of malignant tumor growth.
Subject(s)
Endoplasmic Reticulum Stress/genetics , Endoribonucleases/genetics , Gene Expression Regulation, Neoplastic , Neuroglia/drug effects , Oxygen/pharmacology , Protein Serine-Threonine Kinases/genetics , RNA, Messenger/genetics , CCN Intercellular Signaling Proteins/genetics , CCN Intercellular Signaling Proteins/metabolism , Cell Hypoxia , Cell Line, Tumor , Cell Proliferation/drug effects , Cysteine-Rich Protein 61/genetics , Cysteine-Rich Protein 61/metabolism , Endoribonucleases/deficiency , Humans , Insulin-Like Growth Factor Binding Protein 6/genetics , Insulin-Like Growth Factor Binding Protein 6/metabolism , Insulin-Like Growth Factor Binding Proteins/genetics , Insulin-Like Growth Factor Binding Proteins/metabolism , Nephroblastoma Overexpressed Protein/genetics , Nephroblastoma Overexpressed Protein/metabolism , Neuroglia/metabolism , Neuroglia/pathology , Protein Serine-Threonine Kinases/deficiency , Proto-Oncogene Proteins/genetics , Proto-Oncogene Proteins/metabolism , RNA, Messenger/metabolism , Repressor Proteins/genetics , Repressor Proteins/metabolism , Signal TransductionABSTRACT
We studied the peculiarity of the expression of several key genes related to dysregulation of cell proliferation and surviving processes in pediatric glioma (glioblastoma multiforme) tissue from five children with age from 5 to 8 years as well a sin corresponding nonmalignant tissue counterparts as control from the same patients. RNA was isolated from glioma tissue and corresponding non-malignant tissue counterparts and PFKFB1, PFKFB2, PFKFB3, PFKFB4, HK2, NAMPT, TSPAN13, and HSPB8 gene expressions were studied by quantitative polymerase chain reaction. It was shown that the expression level of genes PFKFB1, PFKFB2, PFKFB3, PFKFB4, HK2, NAMPT, TSPAN13, and HSPB8 is increased in pediatric gliomas as compared to corresponding non-malignant tissue counterparts, but in different grade. More significant changes were demonstrated for PFKFB3, PFKFB4 HK2, NAMPT, TSPAN13, and HSPB8 genes. Thus, the changes in pediatric glioma tissues of the expression of PFKFB1, PFKFB2, PFKFB3, PFKFB4, HK2, NAMPT, TSPAN13, and HSPB8 genes, which control cell proliferation and apoptosis, possibly contribute to enhance the tumor growth, because these genes control cell proliferation and surviving.
