prostaglandin-d2 and Neuroblastoma

Tumor-associated inflammation is a driving force in several adult cancers and intake of low-dose aspirin has proven to reduce cancer incidence. Little is known about tumor-associated inflammation in pediatric neoplasms and no in vivo data exists on the effectiveness of low-dose aspirin on established tumors. The present study employs the transgenic TH-MYCN mouse model for neuroblastoma (NB) to evaluate inflammatory patterns paralleling tumor growth in vivo and low-dose aspirin as a therapeutic option for high-risk NB. Spontaneously arising abdominal tumors were monitored for tumor-associated inflammation ex vivo at various stages of disease and homozygous mice received daily low-dose aspirin (10mg/kg) using oral gavage or no treatment, from 4.5 to 6 weeks of age. Using flow cytometry, a transition from an adaptive immune response predominated by CD8(+) T cell in early neoplastic lesions, towards enrichment in immature cells of the innate immune system, including myeloid-derived suppressor cells, dendritic cells and tumor-associated macrophages, was detected during tumor progression. An M1 to M2 transition of tumor-associated macrophages was demonstrated, paralleled by a deterioration of dendritic cell status. Treatment with low-dose aspirin to mice homozygous for the TH-MYCN transgene significantly reduced the tumor burden (P < 0.01), the presence of tumor-associated cells of the innate immune system (P < 0.01), as well as the intratumoral expression of transforming growth factor-β, thromboxane A2 (P < 0.05) and prostaglandin D2 (P < 0.01). In conclusion, tumor-associated inflammation appears as a potential therapeutic target in NB and low-dose aspirin reduces tumor burden in the TH-MYCN transgenic mouse model of NB, hence warranting further studies on aspirin in high-risk NB.

Topics: Animals; Aspirin; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Cytokines; Dendritic Cells; Disease Models, Animal; Disease Progression; Homozygote; Immunity, Innate; Inflammation; Macrophages; Mice; Mice, Transgenic; Neuroblastoma; Prostaglandin D2; Th2 Cells; Thromboxane A2; Transforming Growth Factor beta

Paraquat is a widely used herbicide that is structurally similar to the known dopaminergic neurotoxicant 1-methyl-4-phenyl-pyridine and acts as a potential etiologic factor for the development of Parkinson's disease. In this study, we investigated the protective roles of lipocalin-type prostaglandin (PG) D synthase (L-PGDS) against paraquat-mediated apoptosis of human neuronal SH-SY5Y cells. The treatment of SH-SY5Y cells with paraquat decreased the intracellular GSH level, and enhanced the cell death with elevation of the caspase activities. L-PGDS was expressed in SH-SY5Y cells, and its expression was enhanced with the peak at 2 h after the initiation of the treatment with paraquat. Inhibition of PGD₂ synthesis and exogenously added PGs showed no effects regarding the paraquat-mediated apoptosis. SiRNA-mediated suppression of L-PGDS expression in the paraquat-treated cells increased the cell death and caspase activities. Moreover, over-expression of L-PGDS suppressed the cell death and caspase activities in the paraquat-treated cells. The results of a promoter-luciferase assay demonstrated that paraquat-mediated elevation of L-PGDS gene expression occurred through the NF-κB element in the proximal promoter region of the L-PGDS gene in SH-SY5Y cells. These results indicate that L-PGDS protected against the apoptosis in the paraquat-treated SH-SY5Y cells through the up-regulation of L-PGDS expression via the NF-κB element. Thus, L-PGDS might potentially serve as an agent for prevention of human neurodegenerative diseases caused by oxidative stress and apoptosis.

Topics: Apoptosis; Cell Line, Tumor; Cell Survival; Chromatin Immunoprecipitation; Dose-Response Relationship, Drug; Enzyme Inhibitors; Gene Expression Regulation, Neoplastic; Glutathione; Humans; Intramolecular Oxidoreductases; L-Lactate Dehydrogenase; Lipocalins; Neuroblastoma; NF-kappa B; Paraquat; Prostaglandin D2; Protein Binding; RNA, Small Interfering; Statistics, Nonparametric

TDP-43 proteinopathy (amyotrophic lateral sclerosis and frontotemporal lobar degeneration with ubiquitin-positive inclusions) is a newly categorized group of neurodegenerative disorders characterized by abnormal accumulation and mislocalization of nuclear TDP-43 protein in the neuronal cytoplasm. 15-Deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)) is non-enzymatically produced from PGD(2) and plays roles in inflammation and oxidative stress responses. Indeed, 15d-PGJ(2) is up-regulated in the spinal motor neurons in amyotrophic lateral sclerosis. In this study, biochemical and immunocytochemical analyses showed that 15d-PGJ(2) affects the proteolysis, solubility, and subcellular localization of TDP-43, similar to alterations found in TDP-43 proteinopathy. Further studies revealed that a cyclopentenone ring containing an electrophilic carbon of 15d-PGJ(2) is likely to influence these phenomena. These findings suggest that 15d-PGJ(2) is an endogenous modifier of TDP-43 protein in TDP-43 proteinopathy.

Topics: Aged; Aged, 80 and over; Amyotrophic Lateral Sclerosis; Cell Line; Cyclopentanes; Cytoplasm; DNA-Binding Proteins; Female; Gene Expression Regulation; Humans; Immunologic Factors; Male; Middle Aged; Neuroblastoma; Prostaglandin D2; Spinal Cord; Subcellular Fractions

A proteomic approach was used to identify 15-deoxy-Delta12,14-prostaglandin J2 (15d-PGJ2) protein targets in human neuroblastoma SH-SY5Y cells. By using biotinylated 15d-PGJ2, beta-actin was found as the major adducted protein; at least 12 proteins were also identified as minor biotin-positive spots, falling in different functional classes, including glycolytic enzymes (enolase and lactate dehydrogenase), redox enzymes (biliverdin reductase), and a eukaryotic regulatory protein (14-3-3gamma). 15d-PGJ2 induced marked morphological changes in the actin filament network and in particular promoted F-actin depolymerization as confirmed by Western blot analysis. By using a mass spectrometric approach, we found that 15d-PGJ2 reacts with isolated G-actin in a 1:1 stoichiometric ratio and selectively binds the Cys374 site through a Michael adduction mechanism. Computational studies showed that the covalent binding of 15d-PGJ2 induces a significant unfolding of actin structure and in particular that 15d-PGJ2 distorts the actin subdomains 2 and 4, which define the nucleotide binding sites impeding the nucleotide exchange. The functional effect of 15d-PGJ2 on G-actin was studied by polymerization measurement: in the presence of 15d-PGJ2, a lower amount of F-actin forms, as followed by the increase in pyrenyl-actin fluorescence intensity, as the major effect of increasing 15d-PGJ2 concentrations occurs on the maximum extent of actin polymerization, whereas it is negligible on the initial rate of reaction. In summary, the results here reported give an insight into the role of 15d-PGJ2 as a cytotoxic compound in neuronal cell dysfunction. Actin is the main protein cellular target of 15d-PGJ2, which specifically binds through a Michael adduction to Cys374, leading to a protein conformational change that can explain the disruption of the actin cytoskeleton, F-actin depolymerization, and impairment of G-actin polymerization.

Topics: Actins; Binding Sites; Computational Biology; Cytoskeleton; Drug Delivery Systems; Humans; Mass Spectrometry; Models, Molecular; Neuroblastoma; Prostaglandin D2; Tumor Cells, Cultured

Many neurodegenerative disorders are characterized by two pathological hallmarks: progressive loss of neurons and occurrence of inclusion bodies containing ubiquitinated proteins. Inflammation may be critical to neurodegeneration associated with ubiquitin-protein aggregates. We previously showed that prostaglandin J2 (PGJ2), one of the endogenous products of inflammation, induces neuronal death and the accumulation of ubiquitinated proteins into distinct aggregates. We now report that temporal microarray analysis of human neuroblastoma SK-N-SH revealed that PGJ2 triggered a "repair" response including increased expression of heat shock, protein folding, stress response, detoxification and cysteine metabolism genes. PGJ2 also decreased expression of cell growth/maintenance genes and increased expression of apoptotic genes. Over time pro-death responses prevailed over pro-survival responses, leading to cellular demise. Furthermore, PGJ2 increased the expression of proteasome and other ubiquitin-proteasome pathway genes. This increase failed to overcome PGJ2 inhibition of 26 S proteasome activity. Ubiquitinated proteins are degraded by the 26 S proteasome, shown here to be the most active proteasomal form in SK-N-SH cells. We demonstrate that PGJ2 impairs 26 S proteasome assembly, which is an ATP-dependent process. PGJ2 perturbs mitochondrial function, which could be critical to the observed 26 S proteasome disassembly, suggesting a cross-talk between mitochondrial and proteasomal impairment. In conclusion neurotoxic products of inflammation, such as PGJ2, may play a role in neurodegenerative disorders associated with the aggregation of ubiquitinated proteins by impairing 26 S proteasome activity and inducing a chain of events that culminates in neuronal cell death. Temporal characterization of these events is relevant to understanding the underlying mechanisms and to identifying potential early biomarkers.

Topics: Biomarkers; Cell Line, Tumor; Cell Survival; DNA Repair; Gene Expression Regulation, Neoplastic; Humans; Inflammation; Neuroblastoma; Neurons; Oligonucleotide Array Sequence Analysis; Prostaglandin D2; Proteasome Endopeptidase Complex; Reverse Transcriptase Polymerase Chain Reaction

PPARgamma (peroxisome proliferator-activated receptor gamma) is a ligand-activated transcription factor that responds to 15dPGJ2 (15-deoxy-Delta12,14-prostglandin J2). 15dPGJ2, in vitro, halts neuroblastoma cell growth, but reported mechanisms vary. Here we evaluated the modulatory effects of endogenous serum lipid mitogens upon the extent of 15dPGJ2-induced growth inhibition and on the precise cellular responses of neuroblastoma cells to PPARgamma activation. We show that 15dPGJ2 specifically inhibited cell growth in both complete and delipidated media. 15dPGJ2-induced growth inhibition was accompanied by decreased cell viability, although the effect was far more marked in delipidated medium than in complete medium. Incubation with 15dPGJ2 in complete medium resulted in cytoplasmic changes characteristic of type II programmed cell death (autophagy), while prior serum lipid removal resulted in cell death via an apoptotic mechanism. These distinct, serum lipid-dependent cellular responses to 15dPGJ2 were accompanied by increases in the expression of a reporter gene construct containing a PPAR response element of 2.3-fold in complete medium, but of 4.8-fold in delipidated medium. Restoration of the serum lysolipid LPA (lysophosphatidic acid) to cells in delipidated medium reduced 15dPGJ2-mediated PPARgamma activation, growth inhibition and cell death; following addition of S1P (sphingosine 1-phosphate), decreases were apparent but more marginal. Further, while the effects of LPA in delipidated medium were mediated through a G(i)/phosphoinositide 3-kinase/MAPK (mitogen-activated protein kinase) pathway, those of S1P did not involve the MAPK component. These data suggest that the serum lysolipid LPA modulates the degree of PPARgamma activation and the precise cellular response to 15dPGJ2 via activation of a G(i)/phosphoinositide 3-kinase/MAPK pathway.

Topics: Cell Death; Cell Growth Processes; Cell Line, Tumor; Humans; Ligands; Lipid Metabolism; Lipids; Lysophospholipids; Neuroblastoma; PPAR gamma; Prostaglandin D2

Neuroblastoma (NB) is a phenotypically heterogeneous tumor, displaying cells of neuronal, melanocytic, or glial/schwannian lineage. This cellular heterogeneity is also present in vitro, where cells of neuroblastic (N)- or stromal (S)-type may be identified. Ligands of peroxisome proliferator-activated receptor gamma (PPARgamma) have been shown to inhibit growth in different tumor cell lines. The purpose of this study was to determine PPARgamma expression and the response to its ligands in NB cell lines with different phenotypes. We used eight NB cell lines with N-, mixed, and S-phenotype. PPARgamma expression was found in all NB cell lines, regardless of their phenotype. Mutational analysis and transactivation assays showed that PPARgamma is not mutated and remains functional in NB cells. Two PPARgamma ligands, 15-deoxy-delta12,14-prostaglandin J2 (PGJ2) and rosiglitazone, inhibited growth of all cell lines, with PGJ, being the most potent agent. PGJ2, but not rosiglitazone, induced arrest of the cells in the G2/M phase as well as apoptosis. The sensitivity to the two ligands appeared to be more related to the phenotype than PPARgamma expression, with the S-type cells being less sensitive than the N-type, partly because of their lower capability of undergoing apoptosis. No synergistic effect on growth inhibition was observed when all cell lines were co-treated with 9-cis retinoic acid (9-cis RA) and rosiglitazone. Our data indicate that PPARgamma expression and function are maintained in phenotipically different NB cell lines. Activation of PPARgamma by its synthetic ligands might have a therapeutic role in advanced NB.

Topics: Antineoplastic Agents; Apoptosis; Cell Cycle; Gene Expression Regulation, Neoplastic; Humans; Ligands; Neuroblastoma; Phenotype; PPAR gamma; Prostaglandin D2; Prostaglandins, Synthetic; Tumor Cells, Cultured

We have previously shown that a prostaglandin D(2) metabolite, 15-deoxy-delta(12,14)-prostaglandin J(2) (15d-PGJ(2)), is the potent inducer of intracellular oxidative stress on human neuroblastoma SH-SY5Y cells [Kondo, M., Oya-Ito, T., Kumagai, T., Osawa, T., and Uchida, K. (2001) Cyclopentenone prostaglandins as potential inducers of intracellular oxidative stress. J. Biol. Chem. 276, 12076-12083.]. In the present study, to investigate the correlation between the redox regulation and the 15d-PGJ(2)-induced oxidative stress and to establish the cellular mechanism for protection against the endogenous electrophile, we analyzed S-oxidized proteins using biotinylated cysteine as a molecular probe. In addition, the reversible regulation of protein function by S-oxidation/thiolation was characterized in vitro. When human neuroblastoma SH-SY5Y cells were exposed to 15d-PGJ(2), followed by treatment with biotinylated cysteine, 26 proteins, including glycolytic enzymes, cytoskeletal proteins, redox enzymes, and stress proteins, were identified as substrates for reversible cysteine-targeted oxidation. To investigate the regulatory mechanism of protein function by S-oxidation/thiolation, the binding of a low molecular weight thiol (glutathione) to a glycolytic enzyme alpha-enolase was characterized. Treatment of alpha-enolase with the thiol oxidant diamide in the presence of glutathione in vitro resulted in the binding of glutathione to the protein and concomitant loss of the enzymatic activity, whereas the glutathiolation and inactivation of alpha-enolase were fully reversed by dithiothreitol. Mass spectrometric analysis of the tryptic fragments from native and oxidized alpha-enolase identified two cysteine residues, Cys-118 and Cys-388, as the S-oxidation sites, which may play a role in the regulation of the biological activities of the protein and may be regulated by a reversible S-oxidation/thiolation reaction. These results suggest that cysteine-targeted oxidation/thiolation plays a critical role in the regulation of protein function under conditions of electrophile-induced oxidative stress.

Topics: Binding Sites; Biotinylation; Cell Line, Tumor; Cysteine; Glutathione; Glutathione Disulfide; Humans; Neuroblastoma; Oxidation-Reduction; Oxidative Stress; Phosphopyruvate Hydratase; Prostaglandin D2; Proteins; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Sulfhydryl Compounds

Neuroblastoma is a childhood cancer, which spontaneously regresses. This has led to a search for agents that mimic this process. We show that both natural and synthetic ligands of PPARgamma (peroxisome-proliferator-activated receptor gamma) inhibit the growth of neuroblastoma cells in vitro. The degree of PPAR activation was attenuated however in the presence of the retinoblastoma protein. Addition of trichostatin A, a histone deacetylase inhibitor, abolished retinoblastoma protein repression of PPAR activity. Moreover, enhanced growth inhibition was observed when neuroblastoma cells were treated with a PPARgamma ligand and a histone deacetylase inhibitor, suggesting a combination therapy to treat neuroblastoma might prove more effective than using either agent alone.

Topics: Carboxy-Lyases; Cell Line, Tumor; Dose-Response Relationship, Drug; Enzyme Inhibitors; Genes, Reporter; Histones; Humans; Hydroxamic Acids; Ligands; Neuroblastoma; PPAR gamma; Prostaglandin D2; Retinoblastoma Protein; Thiazolidinediones; Time Factors; Transcription, Genetic; Transfection

Peroxisome proliferator-activated receptor-gamma (PPAR-gamma) ligands have been demonstrated to inhibit growth of several cancer cells. Here, we investigated whether one of the PPAR-gamma ligands, 15-deoxy-Delta12,14-prostaglandin J2 (15-deoxy-PGJ2) inhibits cell growth of two human neuroblastoma cells (SK-N-SH and SK-N-MC) in a PPAR-gamma-dependent manner. PPAR-gamma was expressed in these cells, and 15-deoxy-PGJ2 increased expression, DNA binding activity, and transcriptional activity of PPAR-gamma. 15-Deoxy-PGJ2 also inhibited cell growth in time- and dose-dependent manners in both cells. Cells were arrested in G2/M phase after 15-deoxy-PGJ2 treatment with concomitant increase in the expression of G2/M phase regulatory protein cyclin B1 but decrease in the expression of cdk2, cdk4, cyclin A, cyclin D1, cyclin E, and cdc25C. Conversely, related to the growth inhibitory effect, 15-deoxy-PGJ2 increased the induction of apoptosis in a dose-dependent manner. Consistent with the induction of apoptosis, 15-deoxy-PGJ2 increased the expression of proapoptotic proteins caspase 3, caspase 9, and Bax but down-regulated antiapoptotic protein Bcl-2. 15-Deoxy-PGJ2 also activated extracellular signal-regulated kinase (ERK) 2. In addition, mitogen-activated protein kinase kinase (MEK) 1/2 inhibitor PD98059 (2'-amino-3'-methoxyflavone) decreased 15-deoxy-PGJ2-induced ERK2 activation, and expression of PPAR-gamma, capase-3, and cyclin B1. Moreover, MEK1/2 inhibitor PD98059 significantly prevented against the 15-deoxy-PGJ2-induced cell growth inhibition. We also found that PPAR-gamma antagonist GW9662 (2-chloro-5-nitro-N-phenylbenzamide) reversed the 15-deoxy-PGJ2-induced cell growth inhibition, PPAR-gamma expression, and activation of ERK2. These results demonstrate that 15-deoxy-PGJ2 inhibits growth of human neuroblastoma cells via the induction of apoptosis in a PPAR-gamma-dependent manner through activation of ERK pathway and suggest that 15-deoxy-PGJ2 may have promising application as a therapeutic agent for neuroblastoma.

Topics: Anilides; Apoptosis; Caspase 3; Caspases; Cell Division; Cyclin B; Cyclin B1; Drug Interactions; G2 Phase; Humans; Immunohistochemistry; Immunologic Factors; Mitogen-Activated Protein Kinases; Mitosis; Neuroblastoma; NF-kappa B; Organic Chemicals; Prostaglandin D2; Receptors, Cytoplasmic and Nuclear; Signal Transduction; Transcription Factors; Tumor Cells, Cultured

Prostaglandin D(2) (PGD(2)), a major cyclooxygenase product in a variety of tissues and cells, readily undergoes dehydration to yield the bioactive cyclopentenone-type PGs of the J(2)-series, such as 15-deoxy-Delta(12,14)-PGJ(2) (15d-PGJ(2)). The observation that the level of 15d-PGJ(2) increased in the tissue cells from patients with sporadic amyotrophic lateral sclerosis suggested that the formation of 15d-PGJ(2) may be closely associated with neuronal cell death during chronic inflammatory processes. In vitro experiments using SH-SY5Y human neuroblastoma cells revealed that 15d-PGJ(2) induced apoptotic cell death. An oligonucleotide microarray analysis demonstrated that, in addition to the heat shock-responsive and redox-responsive genes, the p53-responsive genes, such as gadd45, cyclin G1, and cathepsin D, were significantly up-regulated in the cells treated with 15d-PGJ(2). Indeed, the 15d-PGJ(2) induced accumulation and phosphorylation of p53, which was accompanied by a preferential redistribution of the p53 protein in the nuclei of the cells and by a time-dependent increase in p53 DNA binding activity, suggesting that p53 accumulated in response to the treatment with 15d-PGJ(2) was functional. The 15d-PGJ(2)-induced accumulation of p53 resulted in the activation of a death-inducing caspase cascade mediated by Fas and the Fas ligand.

Topics: Adult; Aged; Apoptosis; Female; Flow Cytometry; Gene Expression Regulation; Genes, p53; Humans; Immunologic Factors; Male; Middle Aged; Motor Neuron Disease; Motor Neurons; Neuroblastoma; Neurons; Oligonucleotide Array Sequence Analysis; Prostaglandin D2; Tumor Cells, Cultured; Tumor Suppressor Protein p53

Although considerable research has shown a role for peroxisome proliferator-activated receptors (PPAR) in adipose differentiation and in the regulation of inflammation, little is known about its possible functions in neurons. We investigated the role of PPARgamma in primary cultures of cortical neurons and human neuroblastoma SH-SYSY cells. Incubation of cortical neurons with the specific PPARgamma ligand 15-Deoxy-delta12,14-prostaglandin J2 (15d-PGJ2) induced morphological changes including neurite degeneration and nuclear condensation that were consistent with neurons dying by apoptosis. The morphological changes associated with incubation of cortical neurons with 15d-PGJ2 were prevented following pretreatment of neurons with the general caspase inhibitor, Z-VAD. These results highlight a novel role for PPARgamma in neurons and suggest that unwarranted activation of PPARgamma may contribute to the neuronal apoptosis associated with certain neurodegenerative disorders including Alzheimer's disease (AD).

Topics: Animals; Apoptosis; Cerebral Cortex; Humans; Immunologic Factors; Neuroblastoma; Neurons; Poly(ADP-ribose) Polymerases; Prostaglandin D2; Rats; Rats, Sprague-Dawley; Receptors, Cytoplasmic and Nuclear; Transcription Factors; Tumor Cells, Cultured

The aim of these studies was to compare the effects of several prostaglandin agonists on adenylyl cyclase activity in embryonic bovine tracheal (EBTr) cells, transformed human nonpigmented ciliary epithelial (NPE) cells and National Cancer Bank (NCB-20) cells. These cell types have been shown to express DP, EP2 and IP prostaglandin (PG) receptors, respectively. Cyclic AMP (cAMP) generation was measured by manual and semi-automated radioimmunoassay (RIA) techniques. ZK118182 (EC50 = 10-27 nM), PGE2 (EC50 = 21-27 nM) and PGI2 (EC50 = 3.5-4 nM) had the highest potency at the DP, EP2 and IP receptors, respectively. A plot of potency (EC50) values generated with both techniques showed a high degree of correlation for all three receptors. These studies provide further characterization of prostanoid receptor functional responses in three cell types and demonstrate the advantages of a semi-automated RIA method for the analysis of the second messenger cAMP.

Topics: Animals; Cattle; Cells, Cultured; Cyclic AMP; Epoprostenol; Ganglia, Sympathetic; Humans; Hybridomas; Iodine Radioisotopes; Mice; Neuroblastoma; Prostaglandin D2; Radioimmunoassay; Receptors, Epoprostenol; Receptors, Immunologic; Receptors, Prostaglandin; Receptors, Prostaglandin E; Robotics; Trachea; Tumor Cells, Cultured

Using a human neuroblastoma cell line GOTO, the effects of delta 12-prostaglandin (PG) J2 on the modulation of cell cycle progression and protein synthesis were examined in comparison with those caused by heat shock (HS). delta 12-PGJ2 induced G1 arrest, the peak of which was obtained at 24 h and continued for 72 h. HS was found to induce G1 arrest earlier than delta 12-PGJ2. Furthermore, sequential HS could maintain G1 arrest. delta 12-PGJ2 induced the synthesis of several heat shock proteins (HSPs) in a manner similar to HS. Using immunoblot analysis, HSP72 was detected prior to inducing G1 arrest and accumulated during the subsequent 72h. The content of HSP72 induced by HS also correlated well with the induction, release, and maintenance of G1 arrest. In addition, both delta 12-PGJ2 and HS induced HSP72 mRNA and simultaneously suppressed N-myc mRNA expression. These results suggest that delta 12-PGJ2 and HS regulate cell cycle progression of GOTO cells via similar mechanisms.

Topics: Blotting, Northern; Cell Cycle; Cell Line; DNA, Neoplasm; Flow Cytometry; G1 Phase; Genes, myc; Heat-Shock Proteins; Hot Temperature; Humans; Kinetics; Neoplasm Proteins; Neuroblastoma; Prostaglandin D2; RNA, Messenger

Effects of cyclopentenone prostaglandins, delta 12-prostaglandin (PG) J2 and PGA2 on the expression of N-myc in relation to the effects on cell cycle progression were investigated using human neuroblastoma cell line GOTO. Both PGs suppressed N-myc expression within several hours prior to inducing G1 arrest. The N-myc suppression with delta 12-PGJ2 was continued but with PGA2 it was gradually released, followed by the release of G1 arrest. These results suggest that delta 12-PGJ2 and PGA2 inhibit cell cycle progression in strong association with N-myc suppression and delta 12-PGJ2 is more potent and has a longer effect than PGA2.

Topics: Cell Cycle; Gene Expression Regulation; Genes, myc; Humans; Neuroblastoma; Prostaglandin D2; Prostaglandins A; Prostaglandins, Synthetic; Proto-Oncogene Proteins c-myc; RNA, Messenger; Suppression, Genetic; Tumor Cells, Cultured

The accumulation of inositol phosphates (IPs) in response to prostaglandins (PGs) was studied in NG108-15 cells preincubated with myo-[3H]inositol. As a positive control, bradykinin caused accumulation of IPs transiently at an early phase (within 1 min) and continuously during a late phase (15-60 min) of incubation in the cells. PGD2 and PGF2 alpha did not significantly cause the accumulation of IPs at an early phase but significantly stimulated inositol bisphosphate (IP2) and inositol monophosphate (IP) formation at late phase of incubation. The maximum stimulation was obtained at greater than 10(-7) M concentrations of these PGs, the levels being three-and twofold for IP2 and IP1, respectively. 9 alpha, 11 beta-PGF2 has a slight effect but PGE2 and the metabolites of PGD2 and PGF2 alpha have no effect up to 10(-6)M. The effects of PGD2 and PGF2 alpha were not additive, but the effect of each PG was additive to that of bradykinin at a late phase of incubation. Inositol 1-monophosphate was mainly identified in the stimulation by 10(-5) M PGD2 and 10(-5) M PGF2 alpha, whereas both inositol 1-monophosphate and inositol 4-monophosphate were produced in the stimulation by 10(5) M bradykinin. Depletion of extracellular Ca2+ diminished the stimulatory effect of PGD2 and PGF2 alpha and late-phase effect of bradykinin, but simple Ca2+ influx into the cells by high K+, ionomycin, or A23187 failed to cause such late-phase effects. These results suggest that PGD2 and PGF2 alpha specifically stimulate hydrolysis of inositol phospholipids.

Topics: Animals; Bradykinin; Calcium; Chromatography, High Pressure Liquid; Dinoprost; Dose-Response Relationship, Drug; Egtazic Acid; Glioma; Hybrid Cells; Inositol Phosphates; Isomerism; Neuroblastoma; Prostaglandin D2; Stimulation, Chemical; Time Factors; Tumor Cells, Cultured

Various prostaglandins (PGs) (10 nM-30 microM) were added to NG108-15 cells in culture, and changes in the levels of intracellular cyclic GMP and Ca2+ were investigated. Exposure of the cells to PGF2 alpha, PGD2, and PGE2 (10 microM) transiently increased the cyclic GMP content 7.5-, 3.9-, and 3.1-fold, respectively. Furthermore, the increased levels of cyclic GMP correlated well with the rise in cytosolic free Ca2+ concentrations induced by the PGs. Other PGs (10 microM), including metabolites and synthetic analogs, which had no effect on intracellular Ca2+, failed to increase the cyclic GMP content in the cells. When extracellular Ca2+ was depleted from the culture medium, the PG-induced increase in cyclic GMP level was almost completely abolished. In addition, treatment of the cells with quin 2 tetraacetoxymethyl ester dose-dependently inhibited the PG-induced cyclic GMP formation. The increase in cyclic GMP content caused by treatment of the cells with a high K+ level (50 mM) was completely blocked by voltage-dependent Ca2+ entry blockers, such as verapamil (10 microM), nifedipine (1 microM), and diltiazem (100 microM); however, the PG (10 microM)-induced increase in cyclic GMP content was not affected by such Ca2+ entry blockers. These findings indicate that PG-induced cyclic GMP formation may require the rise in intracellular Ca2+ level and that the voltage-dependent Ca2+ channels may not be involved in the PG-induced rise in Ca2+ content.

Topics: Aminoquinolines; Animals; Calcium; Cyclic GMP; Diltiazem; Dinoprost; Dinoprostone; Fluorescent Dyes; Glioma; Hybrid Cells; Kinetics; Mice; Neuroblastoma; Nifedipine; Potassium; Prostaglandin D2; Prostaglandins; Prostaglandins D; Prostaglandins E; Prostaglandins F; Rats; Tumor Cells, Cultured; Verapamil

To determine the role of adenosine 3'5'-cyclic monophosphate (cAMP) in the antineoplastic effect of prostaglandins (PGE1, PGE2, PGD2 and PGA1), we studied 2 cell lines of human neuroblastoma; i.e. GOTO and SK-N-DZ. PGE1 or E2 at 30 micrograms/ml and PGD2 or PGA1 at 5 micrograms/ml were cytotoxic to these neuroblastoma cells. In both cell lines, increase of intracellular cAMP was closely associated with E-type PGs cytotoxicity, however, in PGD2, or PGA1 cytotoxicity, cAMP increase was observed only in GOTO cells. Pretreatment of GOTO cells with 5 micrograms/ml PGE2 for 24 hr caused a desensitization of cAMP responses to PGE1, PGD2 or PGA1 only in association with a reduced cytotoxicity of PGE1. On the other hand, PGE2-pretreated SK-N-DZ cells resulted in a desensitization in response to PGE1, but not to other PGs, without affecting the cytotoxicity of these PGs. A decreased [3H]PGE1 binding similarly occurred in either the PGE2-pretreated GOTO or SK-N-DZ cells. However, cholera toxin- or forskolin-induced cAMP production was suppressed only in the pretreated GOTO cells. cAMP response by forskolin rather increased in the pretreated SK-N-DZ cells. These results indicate that antineoplastic effect of E type PGs mediates through cAMP, but not that of PGD2 and PGA1 and that PGE2 pretreatment may cause a down regulation of PGE1 receptor site in both cell lines. It is also suggested that PGE2 pretreatment results in a heterologous desensitization in GOTO and a homologous desensitization in SK-N-DZ cells.

Topics: Alprostadil; Cell Survival; Cholera Toxin; Colforsin; Cyclic AMP; Dinoprostone; Drug Resistance; Drug Screening Assays, Antitumor; Drug Synergism; Humans; Neuroblastoma; Prostaglandin D2; Prostaglandins; Prostaglandins A; Tumor Cells, Cultured

delta 12-prostaglandin(PG)J2 (7.5 micrograms/ml) significantly inhibited protein synthesis and cell growth in a human neuroblastoma cell line (NCG), decreasing these factors by 31.5% and 78.2% of the control values, respectively. Two protein synthesis inhibitors, cycloheximide (CHM) and emetine, exhibited a dose-dependent protective effect for neuroblastoma cells against delta 12-PGJ2 cytotoxicity. At a concentration of 15 micrograms/ml CHM, the number of viable cells increased from 21.8% to 36.7% of the control value (p less than 0.01). The sodium dodecyl sulfate-polyacrylamide gel analysis of [35S]methionine-incorporated proteins revealed an increased synthesis of 86k, 70k and 66k proteins in the delta 12-PGJ2-treated NCG cells under the condition that delta 12-PGJ2 exerts cytotoxicity. Of these proteins, the amount of 66k protein was particularly increased in cell cytosol; however, its synthesis did not occur when CHM prohibited the delta 12-PGJ2 cytotoxic effect. When emetine was used instead of CHM, similar results were obtained. These results strongly suggest that the 66k protein plays a critical role in the delta 12-PGJ2 cytotoxicity.

Topics: Cell Division; Cell Line; Cycloheximide; Electrophoresis, Polyacrylamide Gel; Emetine; Humans; Molecular Weight; Neoplasm Proteins; Neuroblastoma; Prostaglandin D2; Prostaglandins D

To determine the mechanism of the antineoplastic effect of PGD2, we studied the intracellular adenosine 3',5'-cyclic monophosphate (cAMP), cell growth and the kinetics of a human neuroblastoma (NCG line) in culture. Cells were maintained in RPMI 1640 with 10% FCS. cAMP level was determined for the cells, which were incubated for 10 min. with and without PGD2 (1 microgram/ml) in the presence of 100 microM papaverine. Growth inhibition was examined by counting viable cells after treatment with PGD2 (0-100 micrograms/ml) for 4 consecutive days starting at Day 4 after subculture. Effects on cell kinetics were examined for similarly treated cells by DNA cytofluorometry combined with 3H-thymidine autoradiography. In response to PGD2, the NCG line failed to increase its cAMP; however, cell growth was inhibited (IC50 13 micrograms/ml), accompanied by the marked decrease of S phase cells. The results indicate that PGD2 exerts its cytotoxic effect by a probable G1 block of the cell cycle and not through cAMP action.

Topics: Antineoplastic Agents; Cell Cycle; Cell Division; Cell Line; Cyclic AMP; DNA, Neoplasm; Drug Evaluation, Preclinical; Humans; Kinetics; Neuroblastoma; Prostaglandin D2; Prostaglandins D

To study the precise mechanism of cytotoxic activity of PGD2 or delta 12-PGJ2 (a biologically active metabolite of PGD2), we examined the effect of various compounds on PGD2 or delta 12-PGJ2 cytotoxicity, using a human neuroblastoma cell line (NCG). Cycloheximide (CHM) specifically protected PGD2 cytotoxicity on NCG cells. When delta 12-PGJ2 was tested, CHM exhibited a similar rescue effect. Puromycin, mitomycin C, and alpha-amanitin did not affect PGD2 or delta 12-PGJ2 cytotoxicity. Emetine showed a variable and no consistent rescue effect CHM may have been active at the primary site where PGD2 or delta 12-PGJ2 exerts its cytotoxicity. This is the first report indicating that CHM reduces the cytotoxicity induced by PGD2 or delta 12-PGJ2.

Topics: Amanitins; Cell Line; Cell Survival; Cycloheximide; Drug Interactions; Emetine; Humans; Mitomycin; Mitomycins; Neuroblastoma; Prostaglandin D2; Prostaglandins D; Puromycin

Topics: Abdominal Neoplasms; Alprostadil; Animals; Blood Coagulation Factors; Cell Differentiation; Cell Division; Cells, Cultured; Child; Child, Preschool; Cyclic AMP; Drug Evaluation; Drug Evaluation, Preclinical; Drug Therapy, Combination; Female; Humans; Male; Mice; Neuroblastoma; Papaverine; Platelet Activating Factor; Prostaglandin D2; Prostaglandins D; Prostaglandins E

The effect of prostaglandin (PG) D2 on neuronal functions was investigated in neuroblastoma X glioma NG108-15 hybrid cells. PGD2 caused a sustained increase in miniature end-plate potentials (MEPPs) recorded from cultured striated muscle cells which had formed junctions with NG108-15 cells. PGD2 initially hyperpolarized and then depolarized NG108-15 cells. The time course of depolarization fitted well to the facilitative phase of MEPPs. The same action on synaptic transmission and membrane potentials was detected with PGF2 alpha but not with PGE1. PGD2 (10(-4)M) produced a 3-fold increase of adenylate cyclase activity in NG108-15 cell homogenates through its receptors that are distinct from those of PGE1 and PGI2. These results show that PGD2 facilitates MEPP frequency from NG108-15 cells due to depolarization, and suggest that PGD2 may act as a physiological neuromodulator for synaptic transmission in vivo.

Topics: Adenylyl Cyclases; Alprostadil; Animals; Cell Line; Dinoprost; Epoprostenol; Glioma; Hybrid Cells; Kinetics; Membrane Potentials; Mice; Muscles; Neuroblastoma; Prostaglandin D2; Prostaglandins D; Prostaglandins E; Prostaglandins F; Rats; Synapses; Synaptic Transmission

Combination of dibutyryl adenosine 3', 5'-cyclic monophosphate or prostaglandin E1 (PGE1) and papaverine effectively induced differentiation of neuroblastoma in mice. Two cases of human neuroblastoma with stage III and IV were administered intraaortic PGE1 infusion combined with oral papaverine and conventional chemotherapy. There were no noticeable side effects and the treatment was effective in decreasing tumor size and promoting tumor maturation in the infused area. However, distant osseous metastases were developed in both cases, during and after the PGE1 administration. They survived 30 and 17 months, respectively, from the initiation of therapy. (Jpn J Cancer Chemother 10(9): 1936-1943, 1983) These results prompted us to study the metastatic potentials of neuroblastoma. In vitro studies demonstrated that cultured human neuroblastoma cells (NB-1, GOTO, SK-N-DZ, SJ-N-KP, SJ-N-CG and SK-N-FI) aggregate human platelets with maximum aggregation ranging from 28% to 51%. Addition of PGE1 or PGD2 to PRP effectively inhibited the tumor-cell-platelet interaction, with IC50 approximately 100 nM for PGE1 and 10 nM for PGD2, respectively. In addition, 50 microM PGE1 or PGD2, 5 microM PGI2 reversed neuroblastoma-induced platelet aggregation in 4 out of 5 cell lines were studied. These findings indicate a the possible role of PGs in effective inhibition of neuroblastoma metastases in vivo. However, two cell lines (SK-N-DZ and SJ-N-CG), which had been exposed to 8.5 microM PGE1 or PGD2 for 90 min and 72 hr, respectively, retained the platelet aggregating activity which was not significantly different from that of untreated cells. We conclude that clinical application of intraaortic PGE1 in the treatment of advanced neuroblastoma has advantage in potentiation of tumor cell kill and in inducing maturation. Administered PGE1 may exert its action in two ways: in preventing tumor metastasis or possibly in enhancing the metastatic potential of neuroblastoma cells. Further refinement of these modalities including other PGs such as PGD2 or PGI2 and more detailed studies on optimal PG administration to prevent metastasis should be evaluated in future.

Topics: Alprostadil; Cell Line; Cell Transformation, Neoplastic; Cells, Cultured; Humans; Infusions, Intra-Arterial; Neoplasm Metastasis; Neuroblastoma; Platelet Aggregation; Prostaglandin D2; Prostaglandins D; Prostaglandins E

The cytotoxic action of prostaglandin (PG) D2, E1 and F2 alpha was examined on human neuroblastoma cells (NB-1 cell line), and PGD2 was found to be the most effective. PGE1, thought to be the most effective among all PGs in the therapy of neuroblastoma, was much less effective than PGD2. PGF2 alpha did not show any inhibitory effect on the proliferation of NB-1 cells. When PGD2 was added, the cytoplasma became microscopically larger, then the cells gradually died off. PGD2 also exerted a dose-dependent inhibition of DNA and RNA syntheses. These results strongly suggest an antineoplastic activity of PGD2 for human neuroblastoma.

Topics: Alprostadil; Cell Division; Cell Line; Cell Survival; Dinoprost; DNA Replication; Humans; Kinetics; Neuroblastoma; Prostaglandin D2; Prostaglandins; Prostaglandins D; Prostaglandins E; Prostaglandins F; Structure-Activity Relationship; Transcription, Genetic

Addition to the culture medium of prostaglandin (PG) D2 resulted in the degeneration in a dose- and time-dependent manner of N18TG-2 cells cloned from mouse neuroblastoma. The ED50 for PGD2-induced cytotoxicity was about 10 microM. The degenerative changes were irreversible when the cells were exposed for more than 10 h. Scanning and transmission electron microscopic examination revealed that treatment with PGD2 resulted in appearance of numerous blebs of various sizes along the cell surface and also in destruction of surface membrane and of cytoplasmic organelles. Tumor weight of N18TG-2 neuroblastoma inoculated subcutaneously on the backs of A/J mice was about 35-70% less than that of controls after 14 days of single daily i.p. or s.c. injections of 0.5-1 mg/kg of PGD2. The results indicate that PGD2 has growth-inhibitory effects on mouse neuroblastoma cells in vitro and in vivo.

Topics: Animals; Cells, Cultured; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Female; In Vitro Techniques; Male; Mice; Mice, Inbred A; Microscopy, Electron; Microscopy, Electron, Scanning; Neoplasm Transplantation; Neoplasms, Experimental; Neuroblastoma; Prostaglandin D2; Prostaglandins; Prostaglandins D; Time Factors