Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027819 (neuroblastoma)
 27,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have demonstrated that the mouse neuroblastoma N18Tg2 cell line and several clones of hybrid ND cells (ND7, ND9 and ND21), derived from the fusion of neonatal rat sensory neurons with that neuroblastoma, show immunostaining to protein gene product 9.5, neuropeptide Y, C-flanking peptide of neuropeptide Y, tyrosine hydroxylase and chromogranins. Synaptophysin could only be detected in ND cells. Immunoreactivities to substance P, calcitonin gene-related peptide, galanin and somatostatin could not be detected in any of these cell lines. After three days of incubation in a differentiation medium, cell processes of various lengths were observed both in neuroblastoma and ND cell cultures. In ND7 cells there was also a redistribution of neuropeptide Y and its C-flanking peptide to the tips of cell processes. The differentiation of cell processes was also accompanied by the appearance of immunostaining to rat chromogranins in their tips. In contrast, synaptophysin expression was found mainly in cell bodies. Neuropeptide Y, its C-flanking peptide and chromogranins have been associated with secretory granules, whereas synaptophysin is a marker for small synaptic-like vesicles. Therefore, our morphological findings further support and expand the view that these markers are primarily associated with different subcellular structures. Moreover, they indicate that the regulated secretory pathway associated with chromogranins is segregated into nerve processes at an early stage of differentiation, when the synaptophysin-associated pathway is not yet mature. ND7 cells thus provide a useful model system for studying changes in the distribution of neuropeptides, cytoskeletal elements and proteins associated with cell secretion during neuronal differentiation.
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PMID:Intracellular redistribution of neuropeptides and secretory proteins during differentiation of neuronal cell lines. 134 12

D-myo-Inositol-1,2,6-trisphosphate (PP56) is a novel experimental drug which is structurally related to the intracellular second messenger IP3. Among other pharmacological effects, PP56 has been shown to antagonize neuropeptide Y (NPY) induced vasoconstriction with a high degree of specificity. We examined the effects of i.c.v. PP56 on locomotor activity and food intake in rats, and on the hypoactivity and hyperphagia induced by NPY. In the open field, PP56 given alone increased locomotor activity by up to 85%. It did not prevent NPY induced hypoactivity to any extent. PP56 given alone did not affect food intake except for a small increase after the highest dose tested (200 nmol). When NPY was given after pretreatment with PP56, NPY induced hyperphagia was significantly reduced. A similar effect, however, was seen with regard to the hyperphagia produced by another orexigenic peptide, galanin. PP56 did not affect the binding of 125I-NPY to brain membranes in vitro, or to cells of two different neuroblastoma cell lines which selectively express NPY Y1 or Y2 receptors. In summary, PP56 acted as a locomotor stimulant per se. Only one of the two tested central effects of NPY could be antagonized by PP56, and then only partially and in a non-specific manner. The central effects of PP56 do not seem to be produced at the level of NPY receptors.
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PMID:Effects of intracerebroventricular D-myo-inositol-1,2,6-trisphosphate (PP56), a proposed neuropeptide Y (NPY) antagonist, on locomotor activity, food intake, central effects of NPY and NPY-receptor binding. 166 39

Galanin, a novel neuropeptide/hypothalamic hormone originally identified and isolated by virtue of its carboxy-terminal amide group, has recently been shown to have a diverse range of biological activities, including potent effects on the secretion of insulin and growth hormone. The physiological role of galanin remains unclear, with different effects being observed when porcine and rat galanin have been used in various animal model systems and in human studies. Molecular cloning of cDNA encoding human galanin and galanin mRNA associated peptide (GMAP) from both pituitary and neuroblastoma sources has revealed a unique and unexpected structure. In contrast to porcine, bovine and rodent galanin, human galanin lacks a carboxy-terminal amide. By analogy to other neurohormones, the absence of carboxy-terminal amidation would be expected to have significant effects on functional properties such as affinity for different receptor subtypes and physiological half life, and may be responsible for the species specificity observed in the action of galanin.
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PMID:Human galanin: molecular cloning reveals a unique structure. 171 39

Galanin (GAL) is a biologically active neuropeptide that has been suggested to play a role in stress-induced inhibition of insulin secretion, in dementia of the Alzheimer's type, and in the regulation of growth hormone secretion. We report here the isolation of a bovine genomic clone containing more than 5-kb 5'-flanking sequences. Partial sequence analysis of the genomic clone revealed an atypical TATA-box in the promoter (ATAAATA) and several consensus sequences that typically bind transcription factors, including those that bind NF kappa B, Sp1, and AP-2. Primer extension and RNase protection analyses revealed that transcription is initiated at two sites, 28 and 31 bp, respectively, downstream from the TATA-box. To locate functionally active regulatory elements on the GAL gene, we first identified a neural crest-derived human neuroblastoma cell line, SK-N-SH subclone SH-SY5Y, that expressed easily detectable levels of endogenous GAL mRNA. We then constructed plasmids containing various lengths of bovine GAL 5'-flanking sequences and the first exon fused to a reporter plasmid encoding luciferase. Transfection of these plasmids into the SH-SY5Y cells and analysis by transient expression indicated that 131 bp of 5' gene sequence was sufficient to obtain maximal basal expression. Further, expression was suppressed 16-fold when 5 kb were included, suggesting the presence of a distal repressor element(s). In another set of experiments, we found that GAL mRNA levels could be induced more than 10-fold by 20-hr treatment with phorbol 12-myristate 13-acetate (PMA). In cells transfected with the same plasmids, luciferase activity was also induced by PMA, but the degree of induction did not significantly differ among the deletion constructions (varying from six- to eight-fold), suggesting that elements conferring PMA induction and/or RNA stabilization may be located within 131 bp of the transcriptional start site, in the first exon, or on gene sequences not studied here.
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PMID:Primary sequence and functional analysis of the bovine galanin gene promoter in human neuroblastoma cells. 752 Jul 3

Expression of the human galanin gene was analysed using a 3.5-kb DNA fragment comprising the 5'-flanking sequence of the gene. This sequence contains a TATA box (ATATATA) preceded by numerous potential binding sites for transcription factors such as SP1, AP2, and NF kappa B. Three half-palindromic estrogen response elements (EREs, GGTCA) are also found at positions -1,162, -361, and -122 bp relative to the transcription start site. To localize functionally important portions of the promoter region, several shorter fragments of the galanin 5'-flanking region were placed upstream from the chloramphenicol acetyltransferase (CAT) reporter gene. In transient transfection assays, all constructs demonstrated substantial transcriptional activity in both rat glioma/mouse neuroblastoma hybrid cells (NG108-15) and Chinese hamster ovary (CHO-K1) cells. Comparison of the basal expression levels of the different constructs suggests the presence of a negative modulator between positions -1,891 and -207. When cotransfected into NG108-15 cells with the human estrogen receptor cDNA, estrogen did not induce transcription of the human galanin gene at physiological levels of estrogen receptor, although transcription was induced up to 30-fold in the presence of high levels of receptor.
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PMID:Characterization of the 5'-flanking region of the human preprogalanin gene. 753 7

The stabilities of vasoactive intestinal polypeptide (VIP) and galanin mRNAs were examined in a human neuroblastoma cell line (NBFL) treated with agents that alter second-messenger pathways. VIP and galanin mRNA stabilities were estimated by the decay of steady-state levels of transcripts following transcriptional arrest with actinomycin D or 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB). In the presence of actinomycin D, phorbol ester treatment stabilized VIP mRNA while treatment with adenylate cyclase activators, calcium ionophore, or CNTF did not. In the presence of DRB, VIP mRNA was not stabilized in phorbol ester-treated cells but instead was stabilized in cells treated with adenylate cyclase activators. With either transcriptional inhibitor, stability of galanin mRNA was not significantly altered. The difference in the behavior of VIP mRNA in the presence of actinomycin D and DRB may result from their different mechanisms of action-actinomycin D intercalates into nucleic acids while DRB is a kinase inhibitor. Using an assay for RNA stability that did not require transcriptional inhibitors, an in vitro transcribed VIP RNA fragment was relatively stable in extracts from phorbol ester-treated cells. Although treatment with phorbol ester alone resulted in stabilization of VIP mRNA, treatment with a combination of phorbol ester and adenylate cyclase activator, calcium ionophore, or CNTF did not-implying a complex interaction of these second-messenger pathways in the regulation of RNA stability.
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PMID:Regulation of vasoactive intestinal polypeptide and galanin mRNA stabilities. 880 17

The diverse biological functions of galanin are mediated via membrane bound high-affinity receptors. In order to identify and characterize potential galanin receptor subtypes, we have examined the specific 125I-galanin binding to the CHP-212 human neuroblastoma cell line. The galanin receptors expressed in CHP-212 cells, like GALR1 have high affinity for galanin (Kd = 0.07 nM) and the potency for inhibition of 125I-galanin binding by galanin peptides parallels that of hGALR1 expressed in a stable CHO cell line. We confirmed that GALR1 is expressed in these cells by RT-PCR. We further determined the tissue expression patterns of hGALR1 which is expressed in a variety of human tissues at a very low level, with the highest levels seen in heart, small intestine and prostate. A species of approximately 70 kDa is recognized by antisera specific for hGALR1 by Western blot analysis and should allow future measurements of receptor protein expression.
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PMID:Pharmacological characterization and tissue distribution of the human and rat GALR1 receptors. 916 41

The expression of the neuropeptide galanin (GAL) is elevated in vivo upon nerve stimulation, injury, and in vitro by phorbol 12-myristate-13-acetate (PMA), suggesting that a signal pathway involving protein kinase C activation may be involved in GAL-gene activation. When plasmids containing a different length of the bovine GAL-promoter fused to luciferase were transfected into the human neuroblastoma cell line (SK-N-SH subclone SH-SY5Y), a PMA-responsive element was identified in the promoter-region -68 to -46 base pairs (bp). Co-transfection experiments with plasmids expressing cJun and cFos revealed that they could act alone, as well as synergistically with PMA to induce luciferase activity. Electrical mobility shift assays revealed that a cAMP response element (CRE)-like sequence (TGACGCGG; -59 to -52 bp) bound PMA-inducible nuclear proteins present in SH-SY5Y cells. These proteins appear to bind mainly as CRE-binding protein/activating-transcription-factor (CREB/ATF) and Jun/ATF heterodimers. In addition, an apparent PMA-inducible protein(s) not recognized by CREB/ATF and Jun antibodies bound to the CRE-like containing probe.
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PMID:Characterization of phorbolester-inducible human neuronal factors involved in trans-activation of the galanin gene. 960 91

Galanin (GAL) is a 29/30 amino acid residue neuropeptide that regulates a wide variety of neuroendocrine functions. Galanin is expressed in specific populations of neurons in the hypothalamus and other regions of the brain and in numerous peripheral sites. Previous studies in which galanin-reporter genes were transfected into neural crest-derived neuroblastoma and other tumor cells indicated that cell-specific galanin expression is controlled by gene elements on the 5' flanking sequence which enhance and restrict transcriptional activity. To determine how the gene sequences act in vivo, we first determined the distribution of endogenous galanin gene expression in normal mice. Galanin mRNA was detected in several parts of the central nervous system (CNS), and in several peripheral organs, including the pituitary, pancreas, small and large intestine, adrenal gland, lung, tongue, testes, ovary-fallopian tubes, and uterus, but not at detectable levels in the heart, liver, kidney, urinary bladder or skeletal muscle. We then created several lines of transgenic mice which contained either 5 or 0.131 kilobases (kb) of the bovine galanin gene 5' flanking sequence fused to the luciferase (luc) reporter gene (5GAL-luc vs. 0.1GAL-luc mice, respectively) and compared luciferase activity in these and other organs. In some regions of the CNS that expressed high amounts of galanin mRNA, such as the spinal cord, hypothalamus, thalamus, and medulla, transgene expression was significantly higher in 5GAL-luc vs. 0.1GAL-luc mice, whereas in certain other regions of the brain and in all peripheral organs, the ratio was strikingly reversed. It is concluded that 5 kb of flanking sequence contains elements that mediate basal transcriptional activity in certain parts of the CNS, but also contains sequences that restrict expression in many tissues. However, because the larger transgene was expressed at very low levels in some peripheral sites of high galanin expression such as the pituitary, pancreas, adrenal gland, and intestine, it is concluded that sequences on the 5 kb transgene are not sufficient to direct expression to these peripheral tissues in mice.
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PMID:Tissue-specific enhancement and restriction of galanin gene expression in transgenic mice by 5' flanking sequences. 975 22

We have developed a fluorescence-based mix and read method for the quantitative determination of receptor-ligand binding interactions. This method was used to determine IC(50) values for peptide ligands of two endogenous seven-transmembrane receptors that are expressed in cultured human cancer cells. Substance P, neurokinin A, and galanin were labeled with Cy5 and were shown to retain their native binding affinities. The cell-associated fluorescence was quantified using a fluorometric microvolume assay technology (FMAT) scanner that was designed to perform high-throughput screening assays in multiwell plates with no wash steps. The binding of fluorescently labeled substance P and neurokinin A was tested on the human astrocytoma cell line UC11 that expresses endogenous NK(1) receptor. Galanin binding was measured on endogenous galanin type 1 receptors in the Bowes neuroblastoma cell line. IC(50) values were determined for substance P, neurokinin A, and galanin and were found to correspond well with reported values from radioligand binding determinations. To demonstrate FMAT as instrumentation for high-throughput screening, it was utilized to successfully identify individual wells in a 96-well plate in which Cy5-substance P binding in UC11 cells was competed with unlabeled substance P. In addition, we developed a two-color multiplex assay in which cells individually expressing neuropeptide Y and substance P receptors were mixed in the same well. In this assay, the fluorescent ligands substance P and neuropeptide Y bound only to their respective cell types and binding was specifically competed. Therefore, two different seven-transmembrane receptor targets can be tested in one screen to minimize reagent consumption and increase throughput.
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PMID:Determination of ligand binding affinities for endogenous seven-transmembrane receptors using fluorometric microvolume assay technology. 1041 87


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