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)

Retinoic acid (RA) treatment of SH-SY5Y neuroblastoma cells results in activation of phosphatidylinositol-3-kinase (PI3K) signaling pathway, and this activation is required for RA-induced differentiation. Here we show that RA activates PI3K and ERK1/2 MAPK signaling pathways through a rapid, nongenomic mechanism that does not require new gene transcription or newly synthesized proteins. Activation of PI3K by RA appears to involve the classical nuclear receptor, retinoic acid receptor (RAR), on the basis of the pharmacological profile of the activation, loss, and gain of function experiments with mouse embryo fibroblast-RAR(alpha beta gamma)(L-/L-) null cells, and the physical association between liganded RAR and PI3K activity. The association of RAR with the two subunits of PI3K was differentially regulated by the ligand. Immunoprecipitation experiments performed in SH-SY5Y cells showed stable association between RARalpha and p85, the regulatory subunit of PI3K, independently of the presence of RA. In contrast, ligand administration increased the association of p110, the catalytic subunit of PI3K, to this complex. The intracellular localization of RAR proved to be relevant for PI3K activation. A chimerical RAR fusing c-Src myristylation domain to the N terminus of RARalpha (Myr-RARalpha) was targeted to plasma membrane. Transfection of Myr-RARalpha to mouse embryo fibroblast-RAR(alpha beta gamma)(L-/L-) null cells and COS-7 cells results in strong activation of the PI3K signaling pathway, although both in the absence as well in the presence of RA. Our results support a mechanism in which ligand binding to RAR would play a major role in the assembly and intracellular location of a signaling complex involving RAR and the subunits of PI3K.
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PMID:Rapid, nongenomic actions of retinoic acid on phosphatidylinositol-3-kinase signaling pathway mediated by the retinoic acid receptor. 1759 18

In the non-amyloidogenic pathway the alpha-secretase cleaves the amyloid precursor protein (APP) within the sequence of Abeta-peptides and precludes their formation. In addition, alpha-secretase cleavage releases an N-terminal extracellular domain with neurotrophic and neuroprotective properties. The disintegrin metalloproteinase ADAM10 has been shown to act as alpha-secretase in vivo, to prevent amyloid plaque formation and hippocampal defects in an Alzheimer disease mouse model. An increase in alpha-secretase activity therefore is an attractive strategy for treatment of AD and may be achieved by modulating selective signalling pathways. Functional characterization of the human ADAM10 promoter showed that it contains several binding elements for transcription factors which are regulated by extracellular ligands. Retinoic acid (RA) was identified as an inducer of human ADAM10 promoter activity. In human neuroblastoma cell lines RA treatment upregulated the expression of both the alpha-secretase ADAM10 and its substrates APP and the related APP-like-protein 2 (APLP2), and led to an enhanced secretion of their extracellular domains. Furthermore, G protein-coupled receptors (GPCRs) localized in brain areas affected by AD were investigated. Activation of the PAC1 receptor by the neuropeptide PACAP was identified as an approach for upregulation of the alpha-secretase pathway.
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PMID:Alpha-secretase as a therapeutic target. 1790 44

Neuroblastoma is one of the most common cancers in children. Neuroblastoma differentiation is linked to the presence of the promyelocytic leukemia (PML) protein. Retinoic acid, a powerful differentiation-inducer in vitro, is a potent agent for the treatment of neuroblastoma. Using two different human neuroblastoma cell lines, SH-SY5Y and LA-N-5, we show here that PML protein leads to the formation of nuclear bodies (PML-NB) after only 1 h of retinoic acid treatment and that this formation is mediated by the extracellular signal-regulated kinase (ERK) pathway. Inhibition of protein kinase C also leads to formation of PML-NB via the ERK pathway. Both sumoylation and phosphorylation of PML in an ERK-dependent pathway are also required for formation of PML-NB. Finally, we show that PML-NB formation in neuroblastoma cells is associated with neurite outgrowth. These results support the proposal that the formation of PML-NB is correlated with the differentiation of neuroblastoma cells.
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PMID:Promyelocytic leukemia-nuclear body formation is an early event leading to retinoic acid-induced differentiation of neuroblastoma cells. 1798 32

Retinoic acid stimulates alpha-secretase processing of amyloid precursor protein (APP) and decreases beta-secretase cleavage that leads to amyloid-beta formation. Here, we investigated the effect of retinoic acid on the two putative alpha-secretases, the disintegrin metalloproteinases ADAM10 and TACE, and the beta-site cleaving enzyme BACE1, in human neuroblastoma SH-SY5Y cells. Western blot analysis showed that exposure to retinoic acid resulted in significantly increased levels of ADAM10 and TACE, suggesting that regulation of alpha-secretases causes the effects on APP processing. The presence of the phosphatidylinositol 3-kinase inhibitor LY 294002 selectively reduced the effect on ADAM10 protein levels but not on ADAM10 mRNA levels as determined by RT-PCR. On the other hand, the effect on TACE was shown to be dependent on protein kinase C, since it was completely blocked in the presence of the inhibitor bisindolylmaleimide XI. Our data indicate that different signalling pathways are involved in retinoic acid-induced up-regulation of the secretases.
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PMID:PI3-K- and PKC-dependent up-regulation of APP processing enzymes by retinoic acid. 1798 85

Understanding the interplay between intracellular signals initiated by multiple receptor tyrosine kinases (RTKs) to give the final cell phenotype is a major pharmacological challenge. Retinoic acid (RA)-treatment of neuroblastoma (NB) cells implicates activation of Ret and TrkB RTKs as critical step to induce cell differentiation. By studying the signaling interplay between TrkB and Ret as paradigmatic example, here we demonstrate the existence of a cross-talk mechanism between the two unrelated receptors that is needed to induce the cell differentiation. Indeed, we show that TrkB receptor promotes Ret phosphorylation by a mechanism that does not require GDNF. This reveals to be a key mechanism, since blocking either TrkB or Ret by small interfering RNA causes a failure in NB biochemical and morphological differentiation. Our results provide the first evidence that a functional transactivation between distinct tyrosine kinases receptors is required for an important physiological process.
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PMID:A cross-talk between TrkB and Ret tyrosine kinases receptors mediates neuroblastoma cells differentiation. 1828 98

Brain ischemia causes neuronal cell death by several mechanisms involving necrotic and apoptotic processes. The contributions of each process depend on conditions such as the severity and duration of ischemia, and the availability of ATP. We examined whether glucose affected the development of apoptosis after transient ischemia, and whether this was sensitive to caspase inhibition. Retinoic acid-differentiated SH-SY5Y human neuroblastoma cells were subjected to oxygen and glucose deprivation for 15 h followed by various periods of reoxygenation in either the presence or absence of glucose. Oxygen and glucose deprivation induced cell death in the hours following reoxygenation, as detected by propidium iodide staining. At the end of the period of oxygen and glucose deprivation, both cytochrome c and apoptosis-inducing factor translocated from mitochondria to cytosol. Reoxygenation in the presence of glucose accelerated cell death, and enhanced caspase-3 activity and apoptosis. The glucose-dependent increase in apoptosis was prevented by treatment with the caspase inhibitor zVAD-fmk, but not with calpeptin, a calpain inhibitor. Nevertheless, both zVAD-fmk and calpeptin decreased cell death in the glucose-treated group. ATP levels dropped dramatically after oxygen and glucose deprivation, but recovered steadily thereafter, and were significantly higher at 6 h of reoxygenation in the glucose-treated group. This indicates that energy recovery may promote the glucose-dependent cell death. We conclude that glucose favours the development of caspase-dependent apoptosis during reoxygenation following oxygen and glucose deprivation.
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PMID:Glucose promotes caspase-dependent delayed cell death after a transient episode of oxygen and glucose deprivation in SH-SY5Y cells. 1846 26

Neuroblastoma is a pediatric tumor which can spontaneously regress or differentiate into a benign tumor. MYCN oncogene amplification occurs in 22% of neuroblastomas and is associated with poor prognosis. Retinoic acid (RA), a molecule able to induce differentiation and to decrease MYCN expression, is used in the therapy of neuroblastomas. The neuropeptide vasoactive intestinal peptide (VIP) is known to control proliferation or differentiation of numerous cancer cells. In vitro, VIP induces differentiation of neuroblastoma cells. To determine whether VIP could modulate MYCN expression, we carried out real-time quantitative RT-PCR and Western immunoblot analyses in human neuroblastoma SH-SY5Y and IMR-32 cells. The results indicated that VIP reduced MYCN mRNA and protein expression, especially in the MYCN-amplified IMR-32 cells, with a maximal and transient decrease by approximately 50% after few hours of treatment with VIP at 10(-6) M. This effect was compared to that of RA at 10(-5) M, which induced a diminution of MYCN mRNA expression by approximately 25% after few days of treatment. This indicated that VIP and RA display complementary kinetics. Cotreatments showed that VIP and RA had synergistic effects on regulation of expression of MYCN proteins. VIP and RA cotreatments regulated also expression of two MYCN target genes, SKP2 and TP53INP1. These results suggest that VIP, in combination with RA may have a potential therapeutic benefit in neuroblastomas with MYCN amplification, a genetic abnormality associated with poor prognosis.
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PMID:Vasoactive intestinal peptide decreases MYCN expression and synergizes with retinoic acid in a human MYCN-amplified neuroblastoma cell line. 1894 72

A 6-year-old male diagnosed with extensive neuroblastoma was treated with chemotherapy, surgery, autotransplantation, and radiotherapy. He was then enrolled on a study to assess the monoclonal antibody Ch14.18 (anti-GD2) with 13 cis-retinoic acid. 13-cis-retinoic acid therapy caused severe bone pain and hypercalcemia. Bone scans showed multiple osteoblastic lesions suggesting recurrent disease however MIBG scans were negative. Serum markers of bone turnover were increased and the patient required pamidronate therapy to treat persistent hypercalcemia. Retinoic acid toxicity needs to be considered in the differential of painful osteoblastic lesions and/or hypercalcemia. MIBG scans can assist in differentiating from recurrent disease.
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PMID:Hypercalcemia and osteoblastic lesions induced by 13-Cis-retinoic acid mimicking relapsed neuroblastoma. 1949 17

The transcription factor Nrf2 has emerged as a master regulator of the endogenous antioxidant response, which is critical in defending cells against environmental insults and in maintaining intracellular redox balance. However, whether Nrf2 has any role in neuronal cell differentiation is largely unknown. In this report, we have examined the effects of Nrf2 on cell differentiation using a neuroblastoma cell line, SH-SY5Y. Retinoic acid (RA) and 12-O-tetradecanoylphorbol 13-acetate, two well-studied inducers of neuronal differentiation, are able to induce Nrf2 and its target gene NAD(P)H quinone oxidoreductase 1 in a dose- and time-dependent manner. RA-induced Nrf2 up-regulation is accompanied by neurite outgrowth and an induction of two neuronal differentiation markers, neurofilament-M and microtubule-associated protein 2. Overexpression of Nrf2 in SH-SY5Y cells promotes neuronal differentiation, whereas inhibition of endogenous Nrf2 expression inhibited neuronal differentiation. More remarkably, the positive role of Nrf2 in neuronal differentiation was verified ex vivo in primary neuron culture. Primary neurons isolated from Nrf2-null mice showed a retarded progress in differentiation, compared to those from wild-type mice. Collectively, our data demonstrate a novel role for Nrf2 in promoting neuronal cell differentiation, which will open new perspectives for therapeutic uses of Nrf2 activators in patients with neurodegenerative diseases.
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PMID:Nrf2 promotes neuronal cell differentiation. 1957 94

Retinoic acid (RA) signaling is mediated by the retinoic acid receptor (RAR), belonging to the nuclear hormone receptor superfamily. In addition to its classical transcriptional actions, RAR also mediates rapid transcription-independent (nongenomic) actions, consisting in the activation of signal transduction pathways, as the phosphatidyl-inositol-3-kinase or the ERK MAPK-signaling pathways. RA-induced rapid transcription-independent actions play a role in different physiological contexts. As an effort toward understanding the functions of those rapid actions on signaling elicited by RA, we have identified nuclear proteins the phosphorylation state of which is rapidly modified by RA treatment in neuroblastoma cells, using a proteomic approach. Our results show that RA treatment led to changes in the phosphorylation patterns in two families of proteins: 1) those related to chromatin dynamics in relation to transcriptional activation, and 2) those related to mRNA processing and, in particular, mRNA splicing. We show that treatment of neuroblastoma cells with RA leads to alteration of the regulation of pre-mRNA splicing and mRNA translation. Thus, our results underscore novel functions for the rapid signaling elicited by RAR in the regulation of mRNA processing. We conclude that RA activation of signaling pathways can indeed regulate mRNA processing as part of a cellular response orchestrated by the nuclear receptor RAR.
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PMID:Proteomic analysis of phosphorylated nuclear proteins underscores novel roles for rapid actions of retinoic acid in the regulation of mRNA splicing and translation. 1981 89


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