UMLS:C0027819 - FACTA Search

Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Target Concepts:

Query: UMLS:C0027819 (neuroblastoma)
27,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A biologically active fusion protein comprising a short hydrophilic leader peptide fused to the N-terminus of rat CNTF was generated using commercially available materials. The coding region for rat CNTF was sub-cloned into the pFLAG-1 vector and transfected into the JM 109 strain of E. coli. The transfected cells expressed high levels of the fusion protein (FLAG-CNTF) following induction by isopropyl beta-D-thiogalactoside (IPTG). FLAG-CNTF is expressed as insoluble material that was resolubilized by extraction with guanidine hydrochloride and purified by immuno-affinity chromatography. Analysis of the purified material by reverse phase HPLC and Western blot analysis indicated that FLAG-CNTF was composed of two closely related species that are greater than 99% pure after affinity chromatography. The purified FLAG-CNTF migrated as a 27 KD doublet on SDS polyacrylamide gel electrophoresis. Both bands of the doublet were shown to contain the FLAG peptide and CNTF by Western blot analysis, and amino acid sequence analysis demonstrated a single amino acid sequence corresponding to FLAG peptide and the N-terminus of CNTF. The purified fusion protein was tested for biological activity using the IMR-32 human neuroblastoma cell line. Treatment of IMR-32 cells with FLAG-CNTF increased the level of choline acetyltransferase (ChAT) in these cells 2-3-fold over that of control cells in a dose dependent manner. A direct comparison of the effects of FLAG-CNTF and recombinant human CNTF on IMR-32 ChAT activity showed that both factors exhibited similar potencies.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Preparation and affinity purification of a novel, biologically active, CNTF fusion protein. 807 97

Patterned substrates offer the promise of controlled positioning and directional guidance of growing neurites. Therefore, they could be useful for constructing small neuronal networks with defined geometry in vitro. We have fabricated chemically patterned substrates using self-assembled monolayer films with a lithographic mask technique and demonstrated the feasibility for geometrically patterning neuroblastoma cells in culture. N-octadecyltrichlorosilane (OTS) was chemically bonded to glass and fused silica substrates, rendering the surface hydrophobic and non-adhesive to cells. Using surface analysis techniques, we have confirmed that OTS films were true monolayers and can be photocleaved from the surface by deep UV irradiation. An adhesive pattern of n-(2-aminoethyl-3-aminopropyl)trimethoxysilane was formed on a selectively irradiated OTS surface via a deep UV lithographic procedure. The chemically patterned surface was then seeded with SK-N-SH human neuroblastoma cells, and cellular attachment and growth were monitored by optical microscopy. The use of 2-dimensional substrates supported the containment and growth of neuroblastoma cells within the pattern for at least 15 days in culture. These chemical patterns may also be useful in controlled arrangements of hearts cells or muscle cells on prosthetic implant devices.
...
PMID:Containment and growth of neuroblastoma cells on chemically patterned substrates. 810 5

Six novel alkaloids that contain a fused tetracyclic pyrido[2,3,4-kl]acridine ring system were purified recently from the Red Sea purple tunicate Eudistoma sp. Evaluation of the effects of these alkaloids on cultured neuroblastoma and fibroblast cells revealed that they possess potent growth regulatory properties, and affect cell shape and adhesion. In mouse neuroblastoma cells, the Eudistoma alkaloids inhibited cell proliferation and induced a process of differentiation during which the cells flattened onto the surface, increased considerably in size, and extended long neurites. In hamster fibroblasts the alkaloids slowed down cell multiplication, and caused an exceptional cell flattening or elongation. In a virus-transformed derivative of the hamster fibroblasts the alkaloids restored many aspects of normal cell growth and morphology. In addition, several of the alkaloids mimicked the effects of cAMP analogs on two well-characterized cAMP-mediated processes involved in hepatic glucose metabolism--inhibition of pyruvate kinase (PK) activity and induction of mRNA for phosphoenolpyruvate carboxykinase (PEPCK). All these effects suggest that the Eudistoma alkaloids may act on the cAMP signaling system. However, a single application of these compounds was sufficient to completely block cell multiplication and to induce and sustain differentiation and "reverse transformation". Furthermore, these effects were not readily reversible following removal of the drugs. In contrast, a single application of agents that mimic or elevate cAMP induced a transient response that waned with time in culture, and the effects induced by constant elevation of cAMP reverse rapidly following drug removal. We propose that the Eudistoma alkaloids cause growth inhibition, differentiation, and reverse transformation by modifying the activity state of proteins that are involved in the regulation of cell shape and adhesion and serve as a target for the cAMP and/or other second messenger systems.
...
PMID:Novel marine alkaloids from the tunicate Eudistoma sp. are potent regulators of cellular growth and differentiation and affect cAMP-mediated processes. 825 59

The ret proto-oncogene (proto-ret) encodes a receptor type tyrosine kinase with a cadherin-related sequence in the extracellular domain. To investigate whether the proto-Ret protein functions as a cell adhesion molecule like cadherins, we transfected the human proto-ret gene fused to the SV40 promoter or cytomegalovirus (CMV) promoter into mouse L cells in which cadherins are not expressed. Three transfectants with high levels of expression of the proto-Ret proteins were obtained. The proto-Ret proteins were expressed as 150 kDa and 170 kDa glycoproteins in transfectants as observed in human neuroblastoma cells. Cell fractionation experiments revealed that the 170 kDa protein but not the 150 kDa protein was detected predominantly in the plasma membrane fraction, indicating that the 170 kDa protein represents the mature glycosylated form of the proto-Ret protein present on the cell surface. Both 150 kDa and 170 kDa proto-Ret proteins showed tyrosine kinase activity in immunocomplex kinase assay. It is known that cadherins have Ca(2+)-dependent homophilic binding activity and are resistant to trypsinization in the presence of Ca2+. When L cells expressing the proto-Ret proteins were treated with trypsin in the presence of Ca2+, the 170 kDa protein was resistant to its digestion. On the other hand, it was completely digested in the presence of EGTA, suggesting the possibility that the proto-Ret protein interacts with Ca2+ like cadherins. However, the transfectants did not show clear adhesive properties in cell aggregation assays.
...
PMID:Characterization of the ret proto-oncogene products expressed in mouse L cells. 841 95

An IgM human monoclonal antibody (HuMAb) SK1 was generated from mesenteric nodal lymphocytes of a colon cancer patient that were fused with a human B-lymphoblastoid cell line SHFP-1. The reactivities of HuMAb SK1 to various human cell lines were screened by cell enzyme linked immunosorbent assay and immunocytochemical staining. The HuMAb SK1 reacted strongly with all 11 human carcinoma cell lines that were tested and had no detectable binding with noncarcinoma cell lines of the following origins: fibroblast; fetal lung; melanoma; soft tissue sarcoma; neuroblastoma; and glioblastoma. Carcinoma preferred reactivity of HuMAb SK1 was further confirmed by immunoperoxidase staining of a large number of frozen tissues, both malignant and benign. The antigen SK1 (AgSK1) in human carcinoma detected by immunoperoxidase staining was also identified biochemically as a sialoglycoprotein that migrated at M(r) 42,000 with an isoelectric point (pI) of approximately 5.9. A preferential staining by HuMAb SK1 was seen among colorectal, gastric, pancreatic, and lung cancers. Competitive inhibition study in solid-phase immunoassay suggested that the HuMAb SK1 did not cross-react with other antibodies specific for CEA, CA 19-9, and TAG 72. The AgSK1 appears to be a novel carcinoma associated antigen which may be a useful tumor marker in cancer diagnosis and treatment.
...
PMID:AgSK1, a novel carcinoma associated antigen. 843 57

Secretogranin II is an acidic secretory protein with a widespread distribution in secretory granules of neuronal and endocrine cells. The secretogranin II gene contains, like other members of the granin family, a cAMP response element (CRE) in its upstream region. To investigate the functional significance of this motif, intracellular cAMP levels were increased in a neuronal cell line derived from the septal region of the brain and the level of secretogranin II gene expression was analysed. It was found that increased cAMP levels did, in fact, induce secretogranin II gene expression. To analyse the cis-acting sequence responsible for this induction, a hybrid gene containing the upstream region of the mouse secretogranin II gene fused to beta-globin as a reporter was constructed. Transfection analysis revealed that cAMP-induced transcription of the secretogranin II promoter/beta-globin gene in septal and insulinoma cells. DNA-protein binding assays showed that recombinant CRE-binding protein (CREB), produced in bacteria or human cells, bound in a sequence-specific manner to the secretogranin II promoter CRE. Moreover, deletion mutagenesis revealed that the CRE motif is a bifunctional genetic regulatory element in that it mediates basal as well as cAMP-stimulated transcription. Interestingly, cAMP had no effect upon secretogranin II gene transcription in PC12 and neuroblastoma cells. An increase in the intracellular cAMP concentration activated a GAL4-CREB fusion protein upon transcription in neuroblastoma cells indicating the integrity of the cAMP signaling pathway to the nucleus. Basal as well as cAMP-stimulated transcription, directed from the secretogranin II promoter was, however, impaired in insulinoma cells by overexpression of CREB-2, a negative-acting CRE-binding protein. These results indicate that competitive effects are likely to occur between CRE-bound transcriptional activators and repressors. We conclude that cAMP-stimulated induction of secretogranin II gene transcription is mediated by the CRE motif in a cell-type-specific manner, and is likely to depend on the balance between positive and negative CRE-binding proteins in a particular cell type.
...
PMID:Identification of a functional cAMP response element in the secretogranin II gene. 861 62

Secretogranin II (SgII) is a member of the granin family of secretory proteins, which are selectively expressed in neuroendocrine cells. As a first step in understanding the molecular basis for cell type-specific expression of SgII, we isolated a 12-kb clone from a rat genomic library that contained the entire rat SgII coding region, the transcription initiation site, and approximately 3 kb of 5'-flanking region. Within 75 bp of the transcription start site (+1) we located a TATA box and a consensus cAMP responsive element. Within the 5'-flanking region, a number of potential cis-acting elements were identified, including 2 Pit-1 binding sites, 15 E box motifs, and near-perfect matches for AP-1 and AP-2 sites. To demonstrate cell type-specific expression the rat SgII gene, a plasmid containing 2.6 kb of the 5'-flanking region of the SgII gene fused to the luciferase reporter gene (p2774Luc) was transfected into rat pheochromocytoma PC-12 cells, rat pituitary GH4C1 (GH) cells, human BE(2)-M17 (M17) neuroblastoma cells, and mouse fibroblast NIH/3T3 cells. The promoter activity was 6- to 36-fold higher in neuroendocrine cells than in NIH/ 3T3 cells. Progressive deletions in the 5'-flanking region to 61 bp upstream of the start site (p223Luc) had no effect on promoter activity in PC-12 cells. On the other hand, a 5'-deletion in the SgII promoter to -1032 increased promoter activity 3.8-fold in GH cells. This level of expression was maintained when the SgII promoter was further truncated to -189, whereas truncation to -61 resulted in a 2.6-fold reduction in promoter activity. These results suggest that the sequence between -61 and +162 bp is sufficient for SgII promoter activity in PC-12 cells. However, other elements in the 5'-flanking region contribute to both positive and negative regulation of the rat SgII gene in GH cells.
...
PMID:Cell-specific expression of the rat secretogranin II promoter. 875 52

Inositol 1,4,5-trisphosphate receptor (IP3R) is an inositol 1,4,5-trisphosphate (InsP3)-gated Ca2+ release channel. Type 1 IP3R (IP3R1) is the neuronal member of the IP3R family in the CNS and is predominantly expressed in cerebellar Purkinje cells. To elucidate the molecular mechanisms responsible for coupling gene expression to neuronal InsP3/Ca2+ signaling, we have studied the structure and function of the 5'-flanking region of the mouse IP3R1 gene. The cloned 5'-flanking region has several sequences sharing identity with motifs for known transcriptional regulation. We have fused 5'-flanking regions 1N from -528 to +169 and 4N from -4,187 to +169 to a beta-galactosidase gene (lacZ) as a reporter marker and have characterized their in vivo gene expression. Both 1N and 4N fusion genes functioned as a strong promoter in a neuroblastoma-glioma hybrid cell line NG108-15. Moreover, both 1N and 4N transgenic mouse lines carrying these 1N and 4N fusion genes showed characteristic patterns of beta-galactosidase activity in the CNS that are almost consistent with that of the endogenous IP3R1 protein, thereby suggesting that the 1N region from -528 to +169 contains sequence elements responsible for regulating gene expression in neurons and for specifying predominant expression in cerebellar Purkinje cells.
...
PMID:Functional expression of the type 1 inositol 1,4,5-trisphosphate receptor promoter-lacZ fusion genes in transgenic mice. 878 3

Transcriptional regulation of the rat tyrosine hydroxylase (TH) gene by prostaglandin E2 (PGE2) was investigated in human neuroblastoma SK-N-BE(2)C cells. Prostaglandins increased intracellular cAMP in the presence of 3-isobutyl-1-methylxanthine (IBMX), a cAMP phosphodiesterase inhibitor. Among the prostaglandins tested for their cAMP raising property PGE2 was the most effective. The results suggest that the cells express adenylyl cyclase-linked prostanoid receptors that have a higher affinity for PGE2 than for any other naturally occurring prostaglandin. The treatment of cells with PGE2 increased the TH gene expression approximately 2-fold, even though the cAMP accumulation induced by PGE2 alone was almost negligible. Simultaneous treatment with PGE2 and IBMX enhanced the gene expression concomitantly with a marked accumulation of cAMP. Transient transfection assays with 5' upstream serially deleted constructs of the rat TH gene promoter region fused to the chloramphenicol acetyltransferase (CAT) gene revealed that a cAMP response element (CRE) located at -45 to -38 from the start of the TH gene was essential for the enhancement of TH gene expression by PGE2. Site-directed mutagenesis and specific deletion within the sequence of the CRE motif abolished the transcriptional enhancement by PGE2. In addition, a protein kinase A (PKA) inhibitor, H89, specifically blocked the PGE2 effect on TH gene expression. Northern blot analysis revealed that the increase in TH gene transcription with PGE2 is associated with an elevated TH mRNA level. Gel retardation and competition assays confirmed that the binding of nuclear factors to the CRE site was sequence specific and was augmented by PGE2. Our data indicate that PGE2 enhances transcription of the TH gene mediated by the CRE motif through the activation of PKA. They also suggest that the signal flow from the adenylyl cyclase-linked prostanoid receptor to the nucleus is efficient although cAMP accumulation is not prominent.
...
PMID:Transcriptional enhancement of tyrosine hydroxylase by prostaglandin E2 in SK-N-BE(2) C cells. 880 26

Class I HLA genes are expressed in almost all tissues, but expression is low or undetectable in many neuroblastomas. We analysed class I HLA methylation in normal tissues and in 28 neuroectodermal tumour cell lines. HLA-C is hypermethylated in normal adult tissues and 13 cell lines, while 15 cell lines show the hypomethylated phenotype. Hypomethylation of HLA-C strongly correlates with hemizygous deletion of a 9 cM interval on 1p35-36.1, suggesting that this region encodes a modifier of methylation for HLA-C. To test whether hypomethylation of class I HLA genes results from loss of a modifier gene, we fused a hypomethylating neuroblastoma cell line with a hypermethylating cell line. Methylation of class I HLA genes was induced in the hybrids. Furthermore, methylation of HLA-C, -E and -A genes, which are encoded in a 1.4 Mb region on 6p21, is correlated in most cell lines. Our results suggest that 1p35-36.1 encodes a modifier of methylation for class I HLA genes, that is deleted in many neuroblastomas.
...
PMID:A human modifier of methylation for class I HLA genes (MEMO-1) maps to chromosomal bands 1p35-36.1. 885 54

<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>