Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P20366 (substance P)
 21,176 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the presence of substance P (SP; 10 microM), serotonin (5-HT; 1 microM) triggered a cation permeability in cells of the hybridoma (mouse neuroblastoma x rat glioma) clone NG 108-15 that could be assessed by measuring the cell capacity to accumulate [14C]guanidinium for 10-15 min at 37 degrees C. In addition to 5-HT (EC50 0.33 microM), the potent 5-HT3 receptor agonists 2-methyl-serotonin, phenylbiguanide, and m-chlorophenylbiguanide, and quipazine, markedly increased [14C]guanidinium uptake in NG 108-15 cells exposed to 10 microM SP. In contrast, 5-HT3 receptor antagonists prevented the effect of 5-HT. The correlation (r = 0.97) between the potencies of 16 different ligands to mimic or prevent the effects of 5-HT on [14C]guanidinium uptake, on the one hand, and to displace [3H]zacopride specifically bound to 5-HT3 receptors on NG 108-15 cells, on the other hand, clearly demonstrated that [14C]guanidinium uptake was directly controlled by 5-HT3 receptors. Various compounds such as inorganic cations (La3+, Mn2+, Ba2+, Ni2+, and Zn2+), D-tubocurarine, and memantine inhibited [14C]guanidinium uptake in NG 108-15 cells exposed to 5-HT and SP, as expected from their noncompetitive antagonistic properties at 5-HT3 receptors. However, ethanol (100 nM), which has been reported to potentiate the electrophysiological response to 5-HT3 receptor stimulation, prevented the effects of 5-HT plus SP on [14C]guanidinium uptake. The cooperative effect of SP on this 5-HT3-evoked response resulted neither from an interaction of the peptide with the 5-HT3 receptor binding site nor from a possible direct activation of G proteins in NG 108-15 cells. Among SP derivatives, [D-Pro9]SP, a compound inactive at the various neurokinin receptor classes, was the most potent to mimic the stimulatory effect of SP on [14C]guanidinium uptake in NG 108-15 cells exposed to 5-HT. Although the cellular mechanisms involved deserve further investigations, the 5-HT-evoked [14C]guanidinium uptake appears to be a rapid and reliable response for assessing the functional state of 5-HT3 receptors in NG 108-15 cells.
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PMID:Characteristics of [14C]guanidinium accumulation in NG 108-15 cells exposed to serotonin 5-HT3 receptor ligands and substance P. 768 66

In C6-2B rat glioma cells, agonist-stimulated cAMP accumulation is potently inhibited after the stimulation of endogenous bradykinin receptors or stably transfected substance K receptors, coupled to phosphatidylinositol hydrolysis. In the present report, pharmacological tools were used to selectively stimulate either protein kinase C or Ca2+, the two final effectors activated upon phosphatidylinositol hydrolysis, and their role in the inhibition of the C6-2B cell cAMP signaling pathway was investigated. Activation of protein kinase C by an acute treatment with phorbol 12-myristate 13-acetate or L-alpha-1-oleoyl-2-acetyl-sn-3-glycerol did not reduce, but rather enhanced, the cAMP accumulation elicited by forskolin, a direct activator of adenylyl cyclase [ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1]. This effect was antagonized by the protein kinase inhibitor H-7 and mimicked by the protein phosphatase inhibitor okadaic acid. Thapsigargin, a selective microsomal Ca(2+)-ATPase inhibitor, evoked a sustained increase in the intracellular free Ca2+ concentration, with an EC50 of 24.8 +/- 4.3 nM, and inhibited the cAMP accumulation induced by the beta-adrenergic receptor agonist isoproterenol with comparable potency (IC50 = 19.3 +/- 0.2 nM), strongly suggesting a causal relationship between the two phenomena. The inhibition by thapsigargin of isoproterenol- or forskolin-stimulated cAMP accumulation was not affected by pertussis toxin or down-regulation or inhibition of protein kinase C. Dantrolene, a blocker of Ca2+ release from intracellular stores, antagonized 1) the Ca2+ transient in response to thapsigargin and substance K and 2) the inhibitory effect of these compounds on isoproterenol- or forskolin-induced cAMP accumulation. Moreover, sequestration of intracellular Ca2+ with the cell-permeable Ca2+ chelator ethylene glycol bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid acetoxymethyl ester abolished the cAMP inhibition mediated by thapsigargin. Finally, isoproterenol- or forskolin-stimulated adenylyl cyclase activity in digitonin-permeabilized cells was not affected by either thapsigargin or substance K. These data provide compelling evidence that increases in intracellular free Ca2+ concentration without activation of protein kinase C suffice and are responsible for the inhibition of cAMP accumulation in C6-2B cells.
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PMID:Ca2+ inhibition of beta-adrenergic receptor- and forskolin-stimulated cAMP accumulation in C6-2B rat glioma cells is independent of protein kinase C. 838 3

The effects of neuromedin B (NMB) on C6 glioma cells were investigated. NMB bound with high affinity (IC50 = 1 nM) to C6 cells whereas BN and GRP were less potent (IC50 = 40 and 100 nM). NMB (1 nM) elevated cytosolic Ca2+ in individual C6 cells and the increase in cytosolic Ca2+ was reversed by 1 microM [D-Arg1, D-Pro2,D-Trp7.9,Leu11]substance P [APTTL]SP, a broad spectrum antagonist. NMB stimulated [3H]arachidonic acid release from C6 cells and the increase in [3H]arachidonic acid release was reversed [APTTL]SP. NMB increased transiently c-fos gene expression in C6 cells. NMB increased the number of C6 colonies in soft agar and the increase in growth caused by NMB was reversed by [APTTL]SP. These data suggest that NMB receptors may regulate the proliferation of C6 cells.
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PMID:Neuromedin B stimulates arachidonic acid release, c-fos gene expression, and the growth of C6 glioma cells. 853 98

Changes in intracellular calcium concentration are important in mediating a wide variety of physiological responses. Recently there has been renewed interest in the use of aequorin, a protein from jellyfish that emits light when calcium is bound, to measure calcium levels in cells. We have loaded populations of cells from the human glioma line, U373MG, with aequorin. Lysis of aequorin-loaded but not control cells with detergent resulted in a luminescence signal that was dependent on extracellular calcium. Aequorin-loaded cells responded to substance P, histamine, or the calcium ionophore, ionomycin, with an increase in luminescence. Signals in response to detergent, ionomycin, or substance P could be detected up to 48 h after cells were loaded with aequorin. Other neurokinin-1 agonists but not agonists at neurokinin-2 or neurokinin-3 receptors produced luminescence signals. Neurokinin-1 antagonists inhibited the substance P-induced signal. The aequorin-loading procedure worked well with U373MG cells but not with AR42J, CHO, IMR-90, or WI-38 cells.
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PMID:Measurement of intracellular calcium in cell populations loaded with aequorin: neurokinin-1 responses in U373MG cells. 866 May 4

1. The whole-cell patch-clamp technique was used to investigate the actions of substance P and other agonists at neurokinin (NK) receptors on voltage-gated K+ and Ca+ channel currents in undifferentiated mouse neuroblastoma x rat glioma NG 108-15 cells. 2. Both substance P (0.3-30 microM) and the NK1 receptor selective agonist GR73632 (10 nM-10 microM) caused concentration-dependent inhibition of K+ currents. GR64349 and senktide (agonists at NK2 and NK3 receptors respectively) also inhibited K+ currents, but only at concentrations which were several orders of magnitude greater than GR73632, suggesting that current inhibition was mediated via NK1 receptors. 3. Substance P and GR73632 were without effect on residual K+ currents recorded in the presence of extracellular Co2+ (4 mM) to abolish the Ca(2+)-sensitive component (IKca) of the K+ current. Ca2+ channel currents, recorded with either Ba2+ or Ca2+ as charge carrier, were unaffected by NK1, NK2 and NK3 receptor ligands. 4. Iontophoretic application of GR73632 produced a current-dependent reduction of K+ currents. In the presence of the non-peptide NK1 antagonists, CP-99,994 and RP67580, and the peptide antagonist, GR82334, the current-response relationship was reversibly shifted to the right. This indicates that the response is mediated by NK1 receptors. 5. Our results indicate that activation of NK1 receptors leads to the selective inhibition of IKca in undifferentiated NG 108-15 cells.
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PMID:Inhibition of Ca(2+)-sensitive K+ currents in NG 108-15 cells by substance P and related tachykinins. 888 15

Cells from primary cultures of four glioblastomas (GB), three low-grade astrocytomas (A), and four low-grade oligodendrogliomas (O) were tested for the presence of neuroligand receptors linked to Ca2+ signalling by calcium imaging. Cells of days 3 to 21 in culture were incubated with 5 microM fluo-3-acetomethylester in a bath solution and stimulated with 0.1 mM ATP, 0.01 mM angiotensin II, bradykinin, histamine, norepinephrine, serotonin, and substance P for 15 s, with 0.01 mM glutamate and 50 mM K+ for 30 s. Changes in the Ca2+ concentration were measured with a confocal laser scanning microscope. In all glioma subtypes, the majority of cells showed Ca2+ responses after application of histamine (60% of cells tested in GB, 67% in A, 86% in O), bradykinin (66% in GB, 29% in A, 55% in O) and ATP (48% in GB, 70% in A, 47% in O). The other stimuli induced Ca2+ transients in a smaller proportion (between 33% and 2%) of the cells. Our study demonstrates that histamine, bradykinin and ATP are potent inducers of [Ca2+]i signals in gliomas.
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PMID:Neuroligand-triggered calcium signalling in cultured human glioma cells. 920 6

In human astrocytoma cell lines, substance P (SP) stimulated interleukin (IL)-8, IL-6, granulocyte macrophage colony-stimulating factor and leukemia inhibitory factor protein secretion. These SP effects were blocked by a specific NK1 tachykinin receptor antagonist. Further, SP stimulation increased the half-life of IL-6 and IL-8 messenger RNAs, suggesting that the synthesis of these cytokines is also regulated post-transcriptionally. SP-induced cytokine release was inhibited by staurosporine and phorbol 12-myristate 13-acetate desensitization suggesting protein kinase C involvement. The demonstration that SP affects cytokine production in glioma cells might be of relevance for the biology of such tumors.
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PMID:Substance P induces secretion of immunomodulatory cytokines by human astrocytoma cells. 952 14

The neuropeptide substance P (SP), by stimulating tachykinin NK1 receptors (NK1R), triggers a number of biological responses in human glioma cells which are potentially relevant for tumour growth. First, radioligand binding studies demonstrated the presence of tachykinin NK1R on SNB-19, DBTRG-05 MG and U373 MG, but not on U138 MG and MOG-G-GCM human glioma cell lines. Second, application of SP or neurokinin A (NKA) to NK1R+ glioma cell lines increased the secretion of interleukin 6 (IL-6) and potentiated IL-6 secretion induced by IL-1beta. SP also up-regulated the release of transforming growth factor beta1 (TGF-beta1) by the U373 MG glioma cell line. Third, SP induced new DNA synthesis and enhanced the proliferation rate of NK1R+, but not of NK1R- glioma cell lines. Also, NKA stimulated the proliferation and cytokine secretion in NK1R+ glioma cell lines. All the stimulant effects of SP/NKA on NK1R+ glioma cell lines were completely blocked by a specific tachykinin NK1R antagonist, MEN 11467. These data support the potential use of tachykinin NK1R antagonist for controlling the proliferative rate of human gliomas.
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PMID:Substance P activates responses correlated with tumour growth in human glioma cell lines bearing tachykinin NK1 receptors. 988 63

Protein kinase C (PKC) designates a family of kinases that regulate many essential functions including cell growth and differentiation. The tight regulation of PKC activity is crucial for maintaining normal cellular proliferation and excessive activity leads to abnormal or uncontrolled cell growth. Recent reports indicate that malignant glioma cell lines express 100 to 1000-fold higher PKC activity when compared to non-neoplastic astrocytes. This high activity correlates well with the proliferation of tumor cells in vitro. We recently reported on the anti-proliferative properties of selective PKC inhibitors on the growth of U-373MG human astrocytoma cell line, and their ability to block mitogen-activated protein (MAP) kinase pathway activated by substance P (SP) neuropeptide receptor signaling via a PKC-dependent mechanism. Therefore, inhibiting PKC activity by selective PKC inhibitors may present a promising approach for improving astroglial brain tumor therapy. For this purpose, we constructed a high throughput model cell system to evaluate the efficacy of PKC inhibitors. This system is based on the measurement of light production in U-373MG cells stably transfected with the luciferase reporter gene whose expression depends on the transcriptional activation of GAL4-Elk1 fusion protein by enzyme components of the MAP kinase pathway and the upstream activation of PKC (PKC activation-->MAP kinases-->GAL4-Elk1 phosphorylation-->luciferase expression-->luciferase activity). In brief, we have demonstrated that the PKC activator 12-O-tetradecanoyl phorbol 13-acetate (TPA)-induced luciferase activity in this cell system is mediated via the MAP kinase pathway and can be blocked in the presence of MEK1 selective inhibitors (PD 098059 or U0126). We also demonstrated that TPA-induced luciferase activity in U-373MG stable clones can be blocked by PKC inhibitors (CGP 41251, Go 6976, and GF 109203X) in a concentration dependent manner. In contrast, epidermal growth factor (EGF)-induced luciferase activity, which is independent of PKC activation (Ras-->Raf-1-->MEK1-->MAP kinases-->GAL4-Elk1 phosphorylation-->luciferase expression-->luciferase activity) can only be blocked using a selective EGF receptor inhibitor (AG 1478). In conclusion, we have constructed a model cell system for the high throughput screening and identification of PKC inhibitors potentially active against astrocytoma cells in culture.
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PMID:A high throughput system for the evaluation of protein kinase C inhibitors based on Elk1 transcriptional activation in human astrocytoma cells. 991 10

Astrocytes harbour functional receptors to many neurotransmitters, including substance P (SP), an undecapeptide belonging to the tachykinin family of peptide transmitters. SP activates malignant glial cells to induce cytokine release and proliferation, both responses being relevant for tumour progression. In tumours developed in nude mice transplanted subcutaneously (s.c.) to U373 MG human glioma cells, the presence of SP was observed at immunohistochemistry. Although the administration of exogenous SP did not significantly affect the size or development of U373 MG xenograft, a role of SP in supporting glioma progression in vivo was highlighted by the tumour growth inhibition induced by highly specific and selective human tachykinin NK1 receptor antagonists (MEN 11467 and MEN 11149). The anti-tumour activity of MEN 11467 was observed both with s.c. or intravenous treatments and was partially reverted by the concomitant administration of exogenous SP. Doxorubicin did not show any activity in controlling U373 MG growth in this in vivo model. A novel therapeutic approach to treat malignant gliomas with tachykinin NK1 receptor antagonists is suggested by these findings.
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PMID:Anti-tumour activity of tachykinin NK1 receptor antagonists on human glioma U373 MG xenograft. 1064 8


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