RESUMO
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.
Assuntos
Estresse do Retículo Endoplasmático/genética , Endorribonucleases/genética , Regulação Neoplásica da Expressão Gênica , Neuroglia/metabolismo , Via de Pentose Fosfato/genética , Proteínas Serina-Treonina Quinases/genética , Aldose-Cetose Isomerases/genética , Aldose-Cetose Isomerases/metabolismo , Hidrolases de Éster Carboxílico/genética , Hidrolases de Éster Carboxílico/metabolismo , Hipóxia Celular , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Endorribonucleases/deficiência , Técnicas de Silenciamento de Genes , Glucose-6-Fosfato Isomerase/genética , Glucose-6-Fosfato Isomerase/metabolismo , Glucosefosfato Desidrogenase/genética , Glucosefosfato Desidrogenase/metabolismo , Humanos , Neuroglia/patologia , Proteínas Serina-Treonina Quinases/deficiência , Transdução de Sinais , Transaldolase/genética , Transaldolase/metabolismo , Transcetolase/genética , Transcetolase/metabolismoRESUMO
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.
Assuntos
Endorribonucleases/genética , Regulação Neoplásica da Expressão Gênica/genética , Glioblastoma/genética , Proteínas Serina-Treonina Quinases/genética , Hipóxia Tumoral/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas de Transporte de Cátions/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Proteínas de Ligação a DNA/genética , Estresse do Retículo Endoplasmático , Glioma/genética , Humanos , Proteínas de Membrana/genética , Proteínas Mitocondriais/genética , Proteínas de Neoplasias/genética , Proteínas Nucleares/genética , Proteína 1 de Interação com Receptor Nuclear , Receptores de Estrogênio/genética , Receptores de Progesterona/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais , Fatores de Transcrição/genética , Proteínas com Motivo Tripartido , Ubiquitina-Proteína Ligases , Receptor ERRalfa Relacionado ao EstrogênioRESUMO
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.
Assuntos
Neoplasias Encefálicas/metabolismo , Endorribonucleases/metabolismo , Glioma/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Receptores de Glucocorticoides/metabolismo , Transdução de Sinais , Neoplasias Encefálicas/genética , Hipóxia Celular , Linhagem Celular Tumoral , Endorribonucleases/genética , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Glioma/genética , Humanos , Proteínas Serina-Treonina Quinases/genética , Receptores de Glucocorticoides/genética , TransfecçãoRESUMO
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.
Assuntos
Estresse do Retículo Endoplasmático/genética , Endorribonucleases/genética , Regulação Neoplásica da Expressão Gênica , Glucose/deficiência , Glutamina/deficiência , Neuroglia/metabolismo , Proteínas Serina-Treonina Quinases/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Ciclo Celular/genética , Hipóxia Celular , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Endorribonucleases/deficiência , Técnicas de Silenciamento de Genes , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Neuroglia/patologia , Proteínas Serina-Treonina Quinases/deficiência , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Transdução de Sinais , Fatores de Transcrição da Família Snail/genética , Fatores de Transcrição da Família Snail/metabolismo , Proteínas com Domínio T/genética , Proteínas com Domínio T/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Fatores de Transcrição TFII/genética , Fatores de Transcrição TFII/metabolismo , Homeobox 1 de Ligação a E-box em Dedo de Zinco/genética , Homeobox 1 de Ligação a E-box em Dedo de Zinco/metabolismoRESUMO
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.
Assuntos
Regulação da Expressão Gênica , Intolerância à Glucose/genética , Glucose/metabolismo , Neovascularização Patológica/genética , Obesidade/genética , Gordura Subcutânea/metabolismo , Adulto , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Estudos de Casos e Controles , Proteína Rica em Cisteína 61/genética , Proteína Rica em Cisteína 61/metabolismo , Fator 1 de Crescimento de Fibroblastos/genética , Fator 1 de Crescimento de Fibroblastos/metabolismo , Fator 2 de Crescimento de Fibroblastos/genética , Fator 2 de Crescimento de Fibroblastos/metabolismo , Intolerância à Glucose/metabolismo , Intolerância à Glucose/patologia , Teste de Tolerância a Glucose , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Insulina/metabolismo , Resistência à Insulina , Linfocinas/genética , Linfocinas/metabolismo , Masculino , Pessoa de Meia-Idade , Neovascularização Patológica/metabolismo , Neovascularização Patológica/patologia , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Obesidade/metabolismo , Obesidade/patologia , Fator de Crescimento Derivado de Plaquetas/genética , Fator de Crescimento Derivado de Plaquetas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/genética , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/metabolismo , Receptor Tipo 5 de Fator de Crescimento de Fibroblastos/genética , Receptor Tipo 5 de Fator de Crescimento de Fibroblastos/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Transdução de Sinais , Gordura Subcutânea/irrigação sanguínea , Gordura Subcutânea/patologia , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
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.
Assuntos
Estresse do Retículo Endoplasmático/genética , Endorribonucleases/genética , Regulação Neoplásica da Expressão Gênica , Neuroglia/metabolismo , Proteínas Serina-Treonina Quinases/genética , RNA Mensageiro/genética , Transdução de Sinais/genética , Antígeno CD24/genética , Antígeno CD24/metabolismo , Hipóxia Celular , Linhagem Celular Tumoral , Proliferação de Células , DNA Polimerase gama/genética , DNA Polimerase gama/metabolismo , Endodesoxirribonucleases/genética , Endodesoxirribonucleases/metabolismo , Endorribonucleases/antagonistas & inibidores , Endorribonucleases/metabolismo , Fatores de Iniciação em Eucariotos/genética , Fatores de Iniciação em Eucariotos/metabolismo , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Proteína 1 Inibidora do Crescimento/genética , Proteína 1 Inibidora do Crescimento/metabolismo , Subunidade alfa2 de Receptor de Interleucina-13/genética , Subunidade alfa2 de Receptor de Interleucina-13/metabolismo , Queratina-18/genética , Queratina-18/metabolismo , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Neuroglia/patologia , Fatores de Alongamento de Peptídeos/genética , Fatores de Alongamento de Peptídeos/metabolismo , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Qc-SNARE/genética , Proteínas Qc-SNARE/metabolismo , RNA Mensageiro/metabolismo , Receptores Citoplasmáticos e Nucleares/genética , Receptores Citoplasmáticos e Nucleares/metabolismo , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo , Proteínas de Transporte Vesicular/genética , Proteínas de Transporte Vesicular/metabolismoRESUMO
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.
Assuntos
Proteínas de Ciclo Celular/genética , Estresse do Retículo Endoplasmático/genética , Endorribonucleases/genética , Regulação Neoplásica da Expressão Gênica , Neuroglia/metabolismo , Proteínas Nucleares/genética , Proteína Fosfatase 1/genética , Proteínas Serina-Treonina Quinases/genética , Antígenos de Diferenciação/genética , Antígenos de Diferenciação/metabolismo , Apoptose/genética , Fator de Indução de Apoptose/genética , Fator de Indução de Apoptose/metabolismo , Proteínas de Ciclo Celular/metabolismo , Hipóxia Celular , Linhagem Celular Tumoral , Proliferação de Células , Endorribonucleases/deficiência , Técnicas de Silenciamento de Genes , Humanos , Neuroglia/patologia , Proteínas Nucleares/metabolismo , Plasmídeos/química , Plasmídeos/metabolismo , Proteína Fosfatase 1/metabolismo , Proteínas Serina-Treonina Quinases/deficiência , Transdução de Sinais , Fator de Transcrição CHOP/genética , Fator de Transcrição CHOP/metabolismo , Transfecção , eIF-2 Quinase/genética , eIF-2 Quinase/metabolismoRESUMO
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.
Assuntos
Núcleo Celular/genética , Estresse do Retículo Endoplasmático/genética , Endorribonucleases/genética , Regulação Neoplásica da Expressão Gênica , Mitocôndrias/genética , Neuroglia/enzimologia , Proteínas Serina-Treonina Quinases/genética , Aspartato Aminotransferases/genética , Aspartato Aminotransferases/metabolismo , Hipóxia Celular , Linhagem Celular Tumoral , Núcleo Celular/enzimologia , Proliferação de Células , Endorribonucleases/deficiência , Humanos , Isocitrato Desidrogenase/genética , Isocitrato Desidrogenase/metabolismo , Malato Desidrogenase/genética , Malato Desidrogenase/metabolismo , Mitocôndrias/enzimologia , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Neuroglia/patologia , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas Serina-Treonina Quinases/deficiência , Transporte Proteico , Transdução de Sinais , Succinato Desidrogenase/genética , Succinato Desidrogenase/metabolismoRESUMO
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.
Assuntos
Apoptose/genética , Neoplasias Encefálicas/genética , Endorribonucleases/genética , Regulação Neoplásica da Expressão Gênica , Glioma/genética , Proteínas Serina-Treonina Quinases/genética , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/genética , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Proliferação de Células , Estresse do Retículo Endoplasmático/genética , Endorribonucleases/deficiência , Glioma/metabolismo , Glioma/patologia , Humanos , Proteínas Serina-Treonina Quinases/deficiência , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Transdução de Sinais , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismoRESUMO
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.
Assuntos
Estresse do Retículo Endoplasmático/genética , Endorribonucleases/genética , Regulação Neoplásica da Expressão Gênica , Glucose/deficiência , Proteínas Serina-Treonina Quinases/genética , RNA Mensageiro/genética , Fator de Necrose Tumoral alfa/genética , Proteínas Adaptadoras de Transdução de Sinal , Ligante CD27/genética , Ligante CD27/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Endorribonucleases/deficiência , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Neuroglia/metabolismo , Neuroglia/patologia , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Osteoprotegerina/genética , Osteoprotegerina/metabolismo , Proteínas Serina-Treonina Quinases/deficiência , Proteínas/genética , Proteínas/metabolismo , RNA Mensageiro/metabolismo , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/genética , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Receptores do Fator de Necrose Tumoral/genética , Receptores do Fator de Necrose Tumoral/metabolismo , Receptores Tipo I de Fatores de Necrose Tumoral/genética , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo , Transdução de Sinais , Proteína de Domínio de Morte Associada a Receptor de TNF/genética , Proteína de Domínio de Morte Associada a Receptor de TNF/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Receptores Chamariz do Fator de Necrose Tumoral/genética , Receptores Chamariz do Fator de Necrose Tumoral/metabolismo , Proteína 3 Induzida por Fator de Necrose Tumoral alfa , Fator de Necrose Tumoral alfa/metabolismoRESUMO
We studied the expression mRNA of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-2 (PFKFB-2) in the rat lung and kidney in experimental diabetes mellitus. For investigation we select two isoforms of PFKFB-2 with different C-terminus. The level of the expression of both PFKFB-2 mRNA isoforms is decreased in the kidney and lung in rats with experimental diabetes mellitus respect to the control animals. Moreover, four new alternative splice variants of PFKFB-2 mRNA were identified in the rat kidney. These splice variants of PFKFB-2 mRNA have different inserts and/or deletions in 6-phosphofructo-2-kinase as well as in fructose-2,6-bisphosphatase part of PFKFB-2. Three alternative splice variants cannot encode active 6-phosphofructo-2-kinase as a result of deletion of two catalytic domains (E and F). They encode fructose-2,6-bisphosphatase. It was shown that these alternative splice variants express in the kidney and lung and that this expression changes in rats with experimental diabetes mellitus with respect to the control animals. The results of this investigation clearly demonstrated that diabetes mellitus significantly affects the expression and alternative splicing of PFKFB-2 in the kidney and lungs and showed the complexity of regulatory mechanisms of glucose metabolism in this disease.