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Sample records for oligomers neuroblastoma damaged

  1. Neuroblastoma

    MedlinePlus

    ... Old Feeding Your 1- to 2-Year-Old Neuroblastoma KidsHealth > For Parents > Neuroblastoma Print A A A ... infancy, the chance of recovery is good. About Neuroblastoma Neuroblastoma most commonly starts in the tissue of ...

  2. Neuroblastoma

    MedlinePlus

    ... Old Feeding Your 1- to 2-Year-Old Neuroblastoma KidsHealth > For Parents > Neuroblastoma A A A What's ... infancy, the chance of recovery is good. About Neuroblastoma Neuroblastoma most commonly starts in the tissue of ...

  3. Neuroblastoma

    MedlinePlus

    Cancer - neuroblastoma ... Neuroblastoma can occur in many areas of the body. It develops from the tissues that form the ... pressure, digestion, and levels of certain hormones. Most neuroblastomas begin in the abdomen, in the adrenal gland, ...

  4. A Kinetic Model for Cell Damage Caused by Oligomer Formation.

    PubMed

    Hong, Liu; Huang, Ya-Jing; Yong, Wen-An

    2015-10-06

    It is well known that the formation of amyloid fiber may cause invertible damage to cells, although the underlying mechanism has not been fully understood. In this article, a microscopic model considering the detailed processes of amyloid formation and cell damage is constructed based on four simple assumptions, one of which is that cell damage is raised by oligomers rather than mature fibrils. By taking the maximum entropy principle, this microscopic model in the form of infinite mass-action equations together with two reaction-convection partial differential equations (PDEs) has been greatly coarse-grained into a macroscopic system consisting of only five ordinary differential equations (ODEs). With this simple model, the effects of primary nucleation, elongation, fragmentation, and protein and seeds concentration on amyloid formation and cell damage have been extensively explored and compared with experiments. We hope that our results will provide new insights into the quantitative linkage between amyloid formation and cell damage.

  5. SGO1 is involved in the DNA damage response in MYCN-amplified neuroblastoma cells

    PubMed Central

    Murakami-Tonami, Yuko; Ikeda, Haruna; Yamagishi, Ryota; Inayoshi, Mao; Inagaki, Shiho; Kishida, Satoshi; Komata, Yosuke; Jan Koster, J K; Takeuchi, Ichiro; Kondo, Yutaka; Maeda, Tohru; Sekido, Yoshitaka; Murakami, Hiroshi; Kadomatsu, Kenji

    2016-01-01

    Shugoshin 1 (SGO1) is required for accurate chromosome segregation during mitosis and meiosis; however, its other functions, especially at interphase, are not clearly understood. Here, we found that downregulation of SGO1 caused a synergistic phenotype in cells overexpressing MYCN. Downregulation of SGO1 impaired proliferation and induced DNA damage followed by a senescence-like phenotype only in MYCN-overexpressing neuroblastoma cells. In these cells, SGO1 knockdown induced DNA damage, even during interphase, and this effect was independent of cohesin. Furthermore, MYCN-promoted SGO1 transcription and SGO1 expression tended to be higher in MYCN- or MYC-overexpressing cancers. Together, these findings indicate that SGO1 plays a role in the DNA damage response in interphase. Therefore, we propose that SGO1 represents a potential molecular target for treatment of MYCN-amplified neuroblastoma. PMID:27539729

  6. Postsynaptic Receptors for Amyloid-β Oligomers as Mediators of Neuronal Damage in Alzheimer's Disease.

    PubMed

    Dinamarca, Margarita C; Ríos, Juvenal A; Inestrosa, Nibaldo C

    2012-01-01

    The neurotoxic effect of amyloid-β peptide (Aβ) over the central synapses has been described and is reflected in the decrease of some postsynaptic excitatory proteins, the alteration in the number and morphology of the dendritic spines, and a decrease in long-term potentiation. Many studies has been carried out to identify the putative Aβ receptors in neurons, and is still no clear why the Aβ oligomers only affect the excitatory synapses. Aβ oligomers bind to neurite and preferentially to the postsynaptic region, where the postsynaptic protein-95 (PSD-95) is present in the glutamatergic synapse, and interacts directly with the N-methyl-D-aspartate receptor (NMDAR) and neuroligin (NL). NL is a postsynaptic protein which binds to the presynaptic protein, neurexin to form a heterophilic adhesion complex, the disruption of this interaction affects the integrity of the synaptic contact. Structurally, NL has an extracellular domain homolog to acetylcholinesterase, the first synaptic protein that was found to interact with Aβ. In the present review we will document the interaction between Aβ and the extracellular domain of NL-1 at the excitatory synapse, as well as the interaction with other postsynaptic components, including the glutamatergic receptors (NMDA and mGluR5), the prion protein, the neurotrophin receptor, and the α7-nicotinic acetylcholine receptor. We conclude that several Aβ oligomers receptors exist at the excitatory synapse, which could be the responsible for the neurotoxic effect described for the Aβ oligomers. The characterization of the interaction between Aβ receptors and Aβ oligomers could help to understand the source of the neurologic damage observed in the brain of the Alzheimer's disease patients.

  7. Visualization of co-localization in Aβ42-administered neuroblastoma cells reveals lysosome damage and autophagosome accumulation related to cell death.

    PubMed

    Soura, Violetta; Stewart-Parker, Maris; Williams, Thomas L; Ratnayaka, Arjuna; Atherton, Joe; Gorringe, Kirsti; Tuffin, Jack; Darwent, Elisabeth; Rambaran, Roma; Klein, William; Lacor, Pascale; Staras, Kevin; Thorpe, Julian; Serpell, Louise C

    2012-01-15

    Aβ42 [amyloid-β peptide-(1-42)] plays a central role in Alzheimer's disease and is known to have a detrimental effect on neuronal cell function and survival when assembled into an oligomeric form. In the present study we show that administration of freshly prepared Aβ42 oligomers to a neuroblastoma (SH-SY5Y) cell line results in a reduction in survival, and that Aβ42 enters the cells prior to cell death. Immunoconfocal and immunogold electron microscopy reveal the path of the Aβ42 with time through the endosomal system and shows that it accumulates in lysosomes. A 24 h incubation with Aβ results in cells that have damaged lysosomes showing signs of enzyme leakage, accumulate autophagic vacuoles and exhibit severely disrupted nuclei. Endogenous Aβ is evident in the cells and the results of the present study suggest that the addition of Aβ oligomers disrupts a crucial balance in Aβ conformation and concentration inside neuronal cells, resulting in catastrophic effects on cellular function and, ultimately, in cell death.

  8. α-Synuclein Oligomers Stabilize Pre-Existing Defects in Supported Bilayers and Propagate Membrane Damage in a Fractal-Like Pattern.

    PubMed

    Chaudhary, Himanshu; Iyer, Aditya; Subramaniam, Vinod; Claessens, Mireille M A E

    2016-11-15

    Phospholipid vesicles are commonly used to get insights into the mechanism by which oligomers of amyloidogenic proteins damage membranes. Oligomers of the protein α-synuclein (αS) are thought to create pores in phospholipid vesicles containing a high amount of anionic phospholipids but fail to damage vesicle membranes at low surface charge densities. The current understanding of how αS oligomers damage the membranes is thus incomplete. This incomplete understanding may, in part, result from the choice of model membrane systems. The use of free-standing membranes such as vesicles may interfere with the unraveling of some damage mechanisms because the line tension at the edge of a membrane defect or pore ensures defect closure. Here, we have used supported lipid bilayers (SLBs) of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine/1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-l-serine (POPC/POPS) to study the membrane damage caused by αS oligomers. Although αS oligomers were not able to initiate the disruption of POPC/POPS vesicles or intact SLBs, oligomers did stabilize and enlarge pre-existing SLB defects. The increased exposure of lipid acyl chains at the edges of defects very likely facilitates membrane-oligomer interactions, resulting in the growth of fractal domains devoid of lipids. Concomitant with the appearance of the fractal membrane damage patterns, lipids appear in solution, directly implicating αS oligomers in the observed lipid extraction. The growth of the membrane damage patterns is not limited by the binding of lipids to the oligomer. The analysis of the shape and growth of the lipid-free domains suggests the involvement of an oligomer-dependent diffusion-limited extraction mechanism. The observed αS oligomer-induced propagation of membrane defects offers new insights into the mechanisms by which αS oligomers can contribute to the loss in membrane integrity.

  9. Morroniside protects SK-N-SH human neuroblastoma cells against H2O2-induced damage

    PubMed Central

    Zhang, Jing-Xing; Wang, Rui; Xi, Jin; Shen, Lin; Zhu, An-You; Qi, Qi; Wang, Qi-Yi; Zhang, Lun-Jun; Wang, Feng-Chao; Lü, He-Zuo; Hu, Jian-Guo

    2017-01-01

    Oxidative stress-induced cell injury has been linked to the pathogenesis of neurodegenerative disorders such as spinal cord injury, Parkinson's disease, and multiple sclerosis. Morroniside is an antioxidant derived from the Chinese herb Shan-Zhu-Yu. The present study investigated the neuroprotective effect of morroniside against hydrogen peroxide (H2O2)-induced cell death in SK-N-SH human neuroblastoma cells. H2O2 increased cell apoptosis, as determined by flow cytometry and Hoechst 33342 staining. This effect was reversed by pretreatment with morroniside at concentrations of 1–100 µM. The increase in intracellular reactive oxygen species (ROS) generation and lipid peroxidation induced by H2O2 was also abrogated by morroniside. H2O2 induced a reduction in mitochondrial membrane potential, increased caspase-3 activity, and caused downregulation of B cell lymphoma-2 (Bcl-2) and upregulation of Bcl-2-associated X protein (Bax) expression. These effects were blocked by morroniside pretreatment. Thus, morroniside protects human neuroblastoma cells against oxidative damage by inhibiting ROS production while suppressing Bax and stimulating Bcl-2 expression, thereby blocking mitochondrial-mediated apoptosis. These results indicate that morroniside has therapeutic potential for the prevention and treatment of neurodegenerative diseases. PMID:28204825

  10. Morroniside protects SK-N-SH human neuroblastoma cells against H2O2-induced damage.

    PubMed

    Zhang, Jing-Xing; Wang, Rui; Xi, Jin; Shen, Lin; Zhu, An-You; Qi, Qi; Wang, Qi-Yi; Zhang, Lun-Jun; Wang, Feng-Chao; Lü, He-Zuo; Hu, Jian-Guo

    2017-03-01

    Oxidative stress-induced cell injury has been linked to the pathogenesis of neurodegenerative disorders such as spinal cord injury, Parkinson's disease, and multiple sclerosis. Morroniside is an antioxidant derived from the Chinese herb Shan-Zhu-Yu. The present study investigated the neuroprotective effect of morroniside against hydrogen peroxide (H2O2)-induced cell death in SK-N-SH human neuroblastoma cells. H2O2 increased cell apoptosis, as determined by flow cytometry and Hoechst 33342 staining. This effect was reversed by pretreatment with morroniside at concentrations of 1-100 µM. The increase in intracellular reactive oxygen species (ROS) generation and lipid peroxidation induced by H2O2 was also abrogated by morroniside. H2O2 induced a reduction in mitochondrial membrane potential, increased caspase-3 activity, and caused downregulation of B cell lymphoma-2 (Bcl-2) and upregulation of Bcl-2-associated X protein (Bax) expression. These effects were blocked by morroniside pretreatment. Thus, morroniside protects human neuroblastoma cells against oxidative damage by inhibiting ROS production while suppressing Bax and stimulating Bcl-2 expression, thereby blocking mitochondrial-mediated apoptosis. These results indicate that morroniside has therapeutic potential for the prevention and treatment of neurodegenerative diseases.

  11. Postsynaptic Receptors for Amyloid-β Oligomers as Mediators of Neuronal Damage in Alzheimer’s Disease

    PubMed Central

    Dinamarca, Margarita C.; Ríos, Juvenal A.; Inestrosa, Nibaldo C.

    2012-01-01

    The neurotoxic effect of amyloid-β peptide (Aβ) over the central synapses has been described and is reflected in the decrease of some postsynaptic excitatory proteins, the alteration in the number and morphology of the dendritic spines, and a decrease in long-term potentiation. Many studies has been carried out to identify the putative Aβ receptors in neurons, and is still no clear why the Aβ oligomers only affect the excitatory synapses. Aβ oligomers bind to neurite and preferentially to the postsynaptic region, where the postsynaptic protein-95 (PSD-95) is present in the glutamatergic synapse, and interacts directly with the N-methyl-D-aspartate receptor (NMDAR) and neuroligin (NL). NL is a postsynaptic protein which binds to the presynaptic protein, neurexin to form a heterophilic adhesion complex, the disruption of this interaction affects the integrity of the synaptic contact. Structurally, NL has an extracellular domain homolog to acetylcholinesterase, the first synaptic protein that was found to interact with Aβ. In the present review we will document the interaction between Aβ and the extracellular domain of NL-1 at the excitatory synapse, as well as the interaction with other postsynaptic components, including the glutamatergic receptors (NMDA and mGluR5), the prion protein, the neurotrophin receptor, and the α7-nicotinic acetylcholine receptor. We conclude that several Aβ oligomers receptors exist at the excitatory synapse, which could be the responsible for the neurotoxic effect described for the Aβ oligomers. The characterization of the interaction between Aβ receptors and Aβ oligomers could help to understand the source of the neurologic damage observed in the brain of the Alzheimer’s disease patients. PMID:23267328

  12. Abnormal mitochondrial dynamics, mitochondrial loss and mutant huntingtin oligomers in Huntington's disease: implications for selective neuronal damage

    PubMed Central

    Shirendeb, Ulziibat; Reddy, Arubala P.; Manczak, Maria; Calkins, Marcus J.; Mao, Peizhong; Tagle, Danilo A.; Hemachandra Reddy, P.

    2011-01-01

    The purpose of our study was to determine the relationship between mutant huntingtin (Htt) and mitochondrial dynamics in the progression of Huntington's disease (HD). We measured the mRNA levels of electron transport chain genes, and mitochondrial structural genes, Drp1 (dynamin-related protein 1), Fis1 (fission 1), Mfn1 (mitofusin 1), Mfn2 (mitofusin 2), Opa1 (optric atrophy 1), Tomm40 (translocase of outermembrane 40) and CypD (cyclophilin D) in grade III and grade IV HD patients and controls. The mutant Htt oligomers and the mitochondrial structural proteins were quantified in the striatum and frontal cortex of HD patients. Changes in expressions of the electron transport chain genes were found in HD patients and may represent a compensatory response to mitochondrial damage caused by mutant Htt. Increased expression of Drp1 and Fis1 and decreased expression of Mfn1, Mfn2, Opa1 and Tomm40 were found in HD patients relative to the controls. CypD was upregulated in HD patients, and this upregulation increased as HD progressed. Significantly increased immunoreactivity of 8-hydroxy-guanosine was found in the cortical specimens from stage III and IV HD patients relative to controls, suggesting increased oxidative DNA damage in HD patients. In contrast, significantly decreased immunoreactivities of cytochrome oxidase 1 and cytochrome b were found in HD patients relative to controls, indicating a loss of mitochondrial function in HD patients. Immunoblotting analysis revealed 15, 25 and 50 kDa mutant Htt oligomers in the brain specimens of HD patients. All oligomeric forms of mutant Htt were significantly increased in the cortical tissues of HD patients, and mutant Htt oligomers were found in the nucleus and in mitochondria. The increase in Drp1, Fis1 and CypD and the decrease in Mfn1 and Mfn2 may be responsible for abnormal mitochondrial dynamics that we found in the cortex of HD patients, and may contribute to neuronal damage in HD patients. The presence of mutant Htt

  13. Abnormal mitochondrial dynamics, mitochondrial loss and mutant huntingtin oligomers in Huntington's disease: implications for selective neuronal damage.

    PubMed

    Shirendeb, Ulziibat; Reddy, Arubala P; Manczak, Maria; Calkins, Marcus J; Mao, Peizhong; Tagle, Danilo A; Reddy, P Hemachandra

    2011-04-01

    The purpose of our study was to determine the relationship between mutant huntingtin (Htt) and mitochondrial dynamics in the progression of Huntington's disease (HD). We measured the mRNA levels of electron transport chain genes, and mitochondrial structural genes, Drp1 (dynamin-related protein 1), Fis1 (fission 1), Mfn1 (mitofusin 1), Mfn2 (mitofusin 2), Opa1 (optric atrophy 1), Tomm40 (translocase of outermembrane 40) and CypD (cyclophilin D) in grade III and grade IV HD patients and controls. The mutant Htt oligomers and the mitochondrial structural proteins were quantified in the striatum and frontal cortex of HD patients. Changes in expressions of the electron transport chain genes were found in HD patients and may represent a compensatory response to mitochondrial damage caused by mutant Htt. Increased expression of Drp1 and Fis1 and decreased expression of Mfn1, Mfn2, Opa1 and Tomm40 were found in HD patients relative to the controls. CypD was upregulated in HD patients, and this upregulation increased as HD progressed. Significantly increased immunoreactivity of 8-hydroxy-guanosine was found in the cortical specimens from stage III and IV HD patients relative to controls, suggesting increased oxidative DNA damage in HD patients. In contrast, significantly decreased immunoreactivities of cytochrome oxidase 1 and cytochrome b were found in HD patients relative to controls, indicating a loss of mitochondrial function in HD patients. Immunoblotting analysis revealed 15, 25 and 50 kDa mutant Htt oligomers in the brain specimens of HD patients. All oligomeric forms of mutant Htt were significantly increased in the cortical tissues of HD patients, and mutant Htt oligomers were found in the nucleus and in mitochondria. The increase in Drp1, Fis1 and CypD and the decrease in Mfn1 and Mfn2 may be responsible for abnormal mitochondrial dynamics that we found in the cortex of HD patients, and may contribute to neuronal damage in HD patients. The presence of mutant Htt

  14. Genotoxic and anti-genotoxic effects of esculin and its oligomer fractions against mitomycin C-induced DNA damages in mice.

    PubMed

    Mokdad Bzeouich, Imen; Mustapha, Nadia; Maatouk, Mouna; Ghedira, Kamel; Ghoul, Mohamed; Chekir-Ghedira, Leila

    2016-12-01

    Mitomycin C is one of the most effective chemotherapeutic drugs against various solid tumors. However, despite its wide spectrum of clinical benefits, this agent is capable of inducing various types of genotoxicity. In this study, we investigated the effect of esculin and its oligomer fractions (E1, E2 and E3) against mitomycin C induced genotoxicity in liver and kidney cells isolated from Balb/C mice using the comet assay. Esculin and its oligomer fractions were not genotoxic at the tested doses (20 mg/kg and 40 mg/kg b.w). A significant decrease in DNA damages was observed, suggesting a protective role of esculin and its oligomer fractions against the genotoxicity induced by mitomycin C on liver and kidney cells. Moreover, esculin and its oligomer fractions did not induce an increase of malondialdehyde levels.

  15. Cellulose-Derived Oligomers Act as Damage-Associated Molecular Patterns and Trigger Defense-Like Responses.

    PubMed

    Souza, Clarice de Azevedo; Li, Shundai; Lin, Andrew Z; Boutrot, Freddy; Grossmann, Guido; Zipfel, Cyril; Somerville, Shauna C

    2017-04-01

    The plant cell wall, often the site of initial encounters between plants and their microbial pathogens, is composed of a complex mixture of cellulose, hemicellulose, and pectin polysaccharides as well as proteins. The concept of damage-associated molecular patterns (DAMPs) was proposed to describe plant elicitors like oligogalacturonides (OGs), which can be derived by the breakdown of the pectin homogalacturon by pectinases. OGs act via many of the same signaling steps as pathogen- or microbe-associated molecular patterns (PAMPs) to elicit defenses and provide protection against pathogens. Given both the complexity of the plant cell wall and the fact that many pathogens secrete a wide range of cell wall-degrading enzymes, we reasoned that the breakdown products of other cell wall polymers may be similarly biologically active as elicitors and may help to reinforce the perception of danger by plant cells. Our results indicate that oligomers derived from cellulose are perceived as signal molecules in Arabidopsis (Arabidopsis thaliana), triggering a signaling cascade that shares some similarities to responses to well-known elicitors such as chitooligomers and OGs. However, in contrast to other known PAMPs/DAMPs, cellobiose stimulates neither detectable reactive oxygen species production nor callose deposition. Confirming our idea that both PAMPs and DAMPs are likely to cooccur at infection sites, cotreatments of cellobiose with flg22 or chitooligomers led to synergistic increases in gene expression. Thus, the perception of cellulose-derived oligomers may participate in cell wall integrity surveillance and represents an additional layer of signaling following plant cell wall breakdown during cell wall remodeling or pathogen attack.

  16. What Is Neuroblastoma?

    MedlinePlus

    ... Research and Treatment? Neuroblastoma About Neuroblastoma What Is Neuroblastoma? Cancer starts when cells in the body begin ... see the section, Signs and Symptoms of Neuroblastoma ). Neuroblastomas Neuroblastomas are cancers that start in early nerve ...

  17. How Is Neuroblastoma Diagnosed?

    MedlinePlus

    ... Neuroblastoma Early Detection, Diagnosis, and Staging How Is Neuroblastoma Diagnosed? Neuroblastomas are usually found when a child ... Ask Your Child’s Doctor About Neuroblastoma? More In Neuroblastoma About Neuroblastoma Causes, Risk Factors, and Prevention Early ...

  18. Effects of Cisplatin in Neuroblastoma Rat Cells: Damage to Cellular Organelles

    PubMed Central

    Santin, Giada; Scietti, Luigi; Veneroni, Paola; Barni, Sergio; Bernocchi, Graziella; Bottone, Maria Grazia

    2012-01-01

    Cisplatin (cisPt) is a chemotherapy agent used as a treatment for several types of cancer. The main cytotoxic effect of cisplatin is generally accepted to be DNA damage. Recently, the mechanism by which cisPt generates the cascade of events involved in the apoptotic process has been demonstrated. In particular it has been shown that some organelles are cisPt target and are involved in cell death. This paper aims to describe the morphological and functional changes of the Golgi apparatus and lysosomes during apoptosis induced in neuronal rat cells (B50) by cisplatin. The results obtained show that the cellular organelles are the target of cisPt, so their damage can induce cell death. PMID:22505928

  19. Neuroblastoma Screening

    MedlinePlus

    ... is the most common type of cancer in infants. The number of new cases of neuroblastoma is ... credited as the source. Please note that blog posts that are written by individuals from outside the ...

  20. Phytochemical Ginkgolide B Attenuates Amyloid-β1-42 Induced Oxidative Damage and Altered Cellular Responses in Human Neuroblastoma SH-SY5Y Cells.

    PubMed

    Gill, Iqbal; Kaur, Sukhchain; Kaur, Navrattan; Dhiman, Monisha; Mantha, Anil K

    2017-02-20

    Oxidative stress is an upsurge in reactive oxygen/nitrogen species (ROS/RNS), which aggravates damage to cellular components viz. lipids, proteins, and nucleic acids resulting in impaired cellular functions and neurological pathologies including Alzheimer's disease (AD). In the present study, we have examined amyloid-β (Aβ)-induced oxidative stress responses, a major cause for AD, in the undifferentiated and differentiated human neuroblastoma SH-SY5Y cells. Aβ1 - 42-induced oxidative damage was evaluated on lipids by lipid peroxidation; proteins by protein carbonyls; antioxidant status by SOD and GSH enzyme activities; and DNA and RNA damage levels by evaluating the number of AP sites and 8-oxo-G base damages produced. In addition, the neuro-protective role of the phytochemical ginkgolide B (GB) in countering Aβ1 - 42-induced oxidative stress was assessed. We report that the differentiated cells are highly vulnerable to Aβ1 - 42-induced oxidative stress events as exerted by the deposition of Aβ in AD. Results of the current study suggest that the pre-treatment of GB, followed by Aβ1 - 42 treatment for 24 h, displayed neuro-protective potential, which countered Aβ1 - 42-induced oxidative stress responses in both undifferentiated and differentiated SH-SY5Y neuronal cells by: 1) hampering production of ROS and RNS; 2) reducing lipid peroxidation; 3) decreasing protein carbonyl content; 4) restoring antioxidant activities of SOD and GSH enzymes; and 5) maintaining genome integrity by reducing the oxidative DNA and RNA base damages. In conclusion, Aβ1 - 42 induces oxidative damage to the cellular biomolecules, which are associated with AD pathology, and are protected by the pre-treatment of GB against Aβ-toxicity. Taken together, this study advocates for phytochemical-based therapeutic interventions against AD.

  1. Genetics Home Reference: neuroblastoma

    MedlinePlus

    ... Help Me Understand Genetics Home Health Conditions neuroblastoma neuroblastoma Enable Javascript to view the expand/collapse boxes. Download PDF Open All Close All Description Neuroblastoma is a type of cancer that most often ...

  2. Protective Effects of Bacopa Monnieri on Hydrogen Peroxide and Staurosporine: Induced Damage of Human Neuroblastoma SH-SY5Y Cells.

    PubMed

    Łojewski, Maciej; Pomierny, Bartosz; Muszyńska, Bożena; Krzyżanowska, Weronika; Budziszewska, Bogusława; Szewczyk, Agnieszka

    2016-02-01

    Many herbs, and recently their biomass from in vitro cultures, are essential for the treatment of diseases. The aim of this study was to determine the optimal growth of Bacopa monnieri (water hyssop) in an in vitro culture and to examine if extracts of the B. monnieri biomass from the in vitro culture would affect hydrogen peroxide- and staurosporine-induced injury of the human neuroblastoma SH-SY5Y cell line. It has been found that B. monnieri at concentrations of 25, 50, and 100 µg/mL inhibited both hydrogen peroxide-induced efflux of lactate dehydrogenase from damaged cells to culture medium and increased cell viability determined by an MTT assay. Moreover, B. monnieri at concentrations of 10, 25, and 50 µg/mL decreased staurosporine-induced activity of an executive apoptotic enzyme-caspase-3 and protected mitochondrial membrane potential. The obtained data indicate that the biomass from the in vitro culture of B. monnieri prevented SH-SY5Y cell damage related to oxidative stress and had the ability to inhibit the apoptotic process. Thus, this study supports the traditional use of B. monnieri as a neuroprotective therapy, and further in vivo studies on the effects of this preparation on morphology and function of nerve cells could lead to its wider application.

  3. Effects of antidepressants on DSP4/CPT-induced DNA damage response in neuroblastoma SH-SY5Y cells

    PubMed Central

    Wang, Yan; Hilton, Benjamin A.; Cui, Kui; Zhu, Meng-Yang

    2015-01-01

    DNA damage is a form of cell stress and injury. Increased systemic DNA damage is related to the pathogenic development of neurodegenerative diseases. Depression occurs in a relatively high percentage of patients suffering from degenerative diseases, for whom antidepressants are often used to relieve depressive symptoms. However, few studies have attempted to elucidate why different groups of antidepressants have similar effects on relieving symptoms of depression. Previously, we demonstrated that neurotoxins N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP4)- and camptothecin (CPT)-induced the DNA damage response in SH-SY5Y cells, and DSP4 caused cell cycle arrest which was predominately in the S-phase. The present study shows that CPT treatment also resulted in similar cell cycle arrest. Some classic antidepressants could reduce the DNA damage response induced by DSP4 or CPT in SH-SY5Y cells. Cell viability examination demonstrated that both DSP4 and CPT caused cell death, which was prevented by spontaneous administration of some tested antidepressants. Flow cytometric analysis demonstrated that a majority of the tested antidepressants protect cells from being arrested in S-phase. These results suggest that blocking the DNA damage response may be an important pharmacologic characteristic of antidepressants. Exploring the underlying mechanisms may allow for advances in the effort to improve therapeutic strategies for depression appearing in degenerative and psychiatric diseases. PMID:26038195

  4. Olfactory neuroblastoma

    SciTech Connect

    O'Connor, T.A.; McLean, P.; Juillard, G.J.; Parker, R.G.

    1989-06-15

    Fifteen patients with olfactory neuroblastoma were treated during the 17-year period of 1969 to 1986. Data was analyzed with respect to age at presentation, sex, presenting signs and symptoms, stage, and results of treatment. Age ranged from 4 to 67 years with the median age being 27 years. Median follow-up was 8 years. Local control was achieved in nine of nine patients or 100% with successful surgical resection, i.e., minimal residual disease, followed by postoperative radiation therapy (45 to 65 Gy) was employed. There were no distant failures when the primary site was controlled. Regional lymph node metastases were infrequent: only 13% (two of 15 patients) presented with positive nodes. Three of four patients treated initially with surgery alone had a local recurrence, two of which were successfully salvaged by combined therapy. There were four patients treated with radiation therapy alone: three had persistent disease after radiation therapy, and one patient was controlled with 65 Gy. Olfactory neuroblastoma has a propensity to recur locally when treated with surgery alone. The authors' experience suggests excellent local control can be achieved with surgery immediately followed by radiation therapy. Thus the authors recommend planned combined treatment for all resectable lesions.

  5. Do We Know What Causes Neuroblastoma?

    MedlinePlus

    ... Factors, and Prevention Do We Know What Causes Neuroblastoma? The causes of most neuroblastomas are not known. ... Causes Neuroblastoma? Can Neuroblastoma Be Prevented? More In Neuroblastoma About Neuroblastoma Causes, Risk Factors, and Prevention Early ...

  6. What Are the Key Statistics about Neuroblastoma?

    MedlinePlus

    ... About Neuroblastoma What Are the Key Statistics About Neuroblastoma? Neuroblastoma is by far the most common cancer ... New in Neuroblastoma Research and Treatment? More In Neuroblastoma About Neuroblastoma Causes, Risk Factors, and Prevention Early ...

  7. Clearance of Damaged Mitochondria Through PINK1 Stabilization by JNK and ERK MAPK Signaling in Chlorpyrifos-Treated Neuroblastoma Cells.

    PubMed

    Park, Jae Hyeon; Ko, Juyeon; Park, Yun Sun; Park, Jungyun; Hwang, Jungwook; Koh, Hyun Chul

    2017-04-01

    Mitochondrial quality control and clearance of damaged mitochondria through mitophagy are important cellular activities. Studies have shown that PTEN-induced putative protein kinase 1 (PINK1) and Parkin play central roles in triggering mitophagy; however, little is known regarding the mechanism by which PINK1 modulates mitophagy in response to reactive oxygen species (ROS)-induced stress. In this study, chlorpyrifos (CPF)-induced ROS caused mitochondrial damage and subsequent engulfing of mitochondria in double-membrane autophagic vesicles, indicating that clearance of damaged mitochondria is due to mitophagy. CPF treatment resulted in PINK1 stabilization on the outer mitochondrial membrane and subsequently increased Parkin recruitment from the cytosol to the abnormal mitochondria. We found that PINK1 physically interacts with Parkin in the mitochondria of CPF-treated cells. Furthermore, a knockdown of PINK1 strongly inhibited the LC3-II protein level by blocking Parkin recruitment. This indicates that CPF-induced mitophagy is due to PINK1 stabilization in mitochondria. We observed that PINK1 stabilization was selectively regulated by ROS-mediated c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase 1/2 (ERK1/2) signaling activation but not p38 signaling. In the mitochondria of CPF-exposed cells, pretreatment with specific inhibitors of JNK and ERK1/2 significantly decreased PINK1 stabilization and Parkin recruitment and blocked the LC3-II protein level. Specifically, JNK and ERK1/2 inhibition also dramatically blocked the interaction between PINK1 and Parkin. Our results demonstrated that PINK1 regulation plays a critical role in CPF-induced mitophagy. The simple interpretation of these results is that JNK and ERK1/2 signaling regulates PINK1/Parkin-dependent mitophagy in the mitochondria of CPF-treated cells. Overall, this study proposes a novel molecular regulatory mechanism of PINK1 stabilization under CPF exposure.

  8. Phenylethynyl terminated imide oligomers

    NASA Technical Reports Server (NTRS)

    Hergenrother, Paul M. (Inventor); Bryant, Robert G. (Inventor); Jensen, Brian J. (Inventor); Havens, Stephen J. (Inventor)

    1995-01-01

    Four phenylethynyl amine compounds - 3 and 4-aminophenoxy-4'-phenylethynylbenzophenone, and 3 and 4-amino-4'-phenylethynylbenzophenone - were readily prepared and were used to endcap imide oligomers. Phenylethynyl-terminated amide acid oligomers and phenylethynyl-terminated imide oligomers with various molecular weights and compositions were prepared and characterized. These oligomers were cured at 300 to 400 C to provide crosslinked polyimides with excellent solvent resistance, high strength and modulus, and good high temperature properties. Adhesive panels, composites, films, and moldings from these phenylethynyl terminated imide oligomers gave excellent mechanical performance.

  9. Ferulic Acid Regulates the Nrf2/Heme Oxygenase-1 System and Counteracts Trimethyltin-Induced Neuronal Damage in the Human Neuroblastoma Cell Line SH-SY5Y

    PubMed Central

    Catino, Stefania; Paciello, Fabiola; Miceli, Fiorella; Rolesi, Rolando; Troiani, Diana; Calabrese, Vittorio; Santangelo, Rosaria; Mancuso, Cesare

    2016-01-01

    Over the past years, several lines of evidence have pointed out the efficacy of ferulic acid (FA) in counteracting oxidative stress elicited by β-amyloid or free radical initiators, based on the ability of this natural antioxidant to up-regulate the heme oxygenase-1 (HO-1) and biliverdin reductase (BVR) system. However, scarce results can be found in literature regarding the cytoprotective effects of FA in case of damage caused by neurotoxicants. The aim of this work is to investigate the mechanisms through which FA exerts neuroprotection in SH-SY5Y neuroblastoma cells exposed to the neurotoxin trimethyltin (TMT). FA (1–10 μM for 6 h) dose-dependently increased both basal and TMT (10 μM for 24 h)-induced HO-1 expression in SH-SY5Y cells by fostering the nuclear translocation of the transcriptional activator Nrf2. In particular, the co-treatment of FA (10 μM) with TMT was also responsible for the nuclear translocation of HO-1 in an attempt to further increase cell stress response in SH-SY5Y cells. In addition to HO-1, FA (1–10 μM for 6 h) dose-dependently increased the basal expression of BVR. The antioxidant and neuroprotective features of FA, through the increase of HO activity, were supported by the evidence that FA inhibited TMT (10 μM)-induced lipid peroxidation (evaluated by detecting 4-hydroxy-nonenal) and DNA fragmentation in SH-SY5Y cells and that this antioxidant effect was reversed by the HO inhibitor Zinc-protoporphyrin-IX (5 μM). Among the by-products of the HO/BVR system, carbon monoxide (CORM-2, 50 nM) and bilirubin (BR, 50 nM) significantly inhibited TMT-induced superoxide anion formation in SH-SY5Y cells. All together, these results corroborate the neuroprotective effect of FA through the up-regulation of the HO-1/BVR system, via carbon monoxide and BR formation, and provide the first evidence on the role of HO-1/Nrf2 axis in FA-related enhancement of cell stress response in human neurons. PMID:26779023

  10. Neuroblastoma: A neurochemical approach

    SciTech Connect

    Schor, N.F. )

    1991-07-01

    Neuroblastoma is among the most common malignancies of childhood. Despite greatly improved therapy for some pediatric tumors, the prognosis for children with metastatic neuroblastoma has not changed significantly in the past 10 years. With conventional chemotherapy, radiation therapy, and surgery, children with metastatic neuroblastoma have a 20% long-term survival rate. The authors describe here approaches to neuroblastoma that target its neuronal characteristics. On the one hand, the neurotransmitter receptors on the surface of the neuroblastoma cells and, on the other hand, specific isozymes that distinguish neuroblastoma cells from their normal counterparts are the focus of these experimental therapies. In the former case, specificity for tumor cells is effected by (1) selective protection of normal neuronal elements from toxicity, or (2) selective potentiation of toxicity for neural tumor cells. It is hoped that these strategies will be generalizable to other neural crest-derived tumors. 32 references.

  11. Pathogenesis of Abeta oligomers in synaptic failure.

    PubMed

    Sivanesan, Senthilkumar; Tan, Aaron; Rajadas, Jayakumar

    2013-03-01

    The soluble Abeta oligomers in brain are highly correlated with memory related synaptic dysfunctions in Alzheimer's disease (AD). However, more recent studies implicate the involvement of Abeta dimers and trimers in memory related AD pathology. Apparently, Abeta oligomers can bind with cellular prion protein at the membrane receptors, forming annular amyloid pores and membrane ion channels to induce aberrant spine cytoskeletal changes. Hence synapse targeting of Abeta oligomers involves activation of many receptors such as N-Methyl-D-aspartate (NMDA), alpha-amino-3- hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), nicotinic acetylcholine (nAChRs), p75 neurotrophin (p75NTR) following aberrant clustering of metabotropic glutamate receptors (mGluR5) leading to neuronal loss and LTP failure. In particular, NMDA and AMPA receptor activation by soluble amyloid oligomers involves calcium mediated mitochondrial dysfunction, decreased Ca((2+))/calmodulin-dependent protein kinase II (CaMKII) levels at the synapses accompanying dramatic loss of synaptic proteins such as postsynaptic density-95 (PSD-95), dynamin-1 and synaptophysin. This kind of receptor-Abeta oligomer interaction might eventually affect the neuronal membrane integrity by altering dielectric barrier, various synaptic proteins, spine morphology and density and P/Q calcium currents that might provoke a cascade of events leading to neuronal loss and memory failure. In this review, we try to explain in detail the various possible mechanisms that connect Abeta oligomers with synapse damage and memory failure.

  12. Advances in neuroblastoma research

    SciTech Connect

    Evans, A.E.; D'Angio, G.J.; Seeger, R.C.

    1985-01-01

    This book contains over 50 papers. Some of the titles are: Studies on the expression of the amplified domain in human neuroblastoma cells; Comparison studies of oncogenes in retinoblastoma and neuroblastoma; Chromosome abnormalities, gene amplification and tumor progression; and Peripheral neuroepithelioma: Genetic analysis of tumor derived cell lines.

  13. Real-time investigation of cytochrome c release profiles in living neuronal cells undergoing amyloid beta oligomer-induced apoptosis

    NASA Astrophysics Data System (ADS)

    Lee, Jae Young; Park, Younggeun; Pun, San; Lee, Sung Sik; Lo, Joe F.; Lee, Luke P.

    2015-06-01

    Intracellular Cyt c release profiles in living human neuroblastoma undergoing amyloid β oligomer (AβO)-induced apoptosis, as a model Alzheimer's disease-associated pathogenic molecule, were analysed in a real-time manner using plasmon resonance energy transfer (PRET)-based spectroscopy.Intracellular Cyt c release profiles in living human neuroblastoma undergoing amyloid β oligomer (AβO)-induced apoptosis, as a model Alzheimer's disease-associated pathogenic molecule, were analysed in a real-time manner using plasmon resonance energy transfer (PRET)-based spectroscopy. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr02390d

  14. What's New in Neuroblastoma Research and Treatment?

    MedlinePlus

    ... Neuroblastoma Research and Treatment? Neuroblastoma About Neuroblastoma What’s New in Neuroblastoma Research and Treatment? Important research into ... cells different from normal cells may lead to new approaches to treating this disease. Newer drugs that ...

  15. Drugs Approved for Neuroblastoma

    Cancer.gov

    This page lists cancer drugs approved by the Food and Drug Administration (FDA) for neuroblastoma. The list includes generic names and brand names. The drug names link to NCI's Cancer Drug Information summaries.

  16. Immune Therapies for Neuroblastoma

    PubMed Central

    Navid, Fariba; Armstrong, Michael; Barfield, Raymond C.

    2009-01-01

    Neuroblastoma, a solid tumor arising from developing cells of the sympathetic nervous system, is the most common extracranial tumor in children. The prognosis for high-risk neuroblastoma remains poor with conventional treatment, and new approaches are therefore being explored to treat this disease. One such alternative therapy that holds promise is immune therapy. We review here the recent advances in 4 types of immune therapy – cytokine, vaccine, antibody, and cellular therapy – to treat neuroblastoma. We present preclinical research and clinical trials on several promising candidates such as IL-12, dendritic cell vaccines, anti-GD2 antibodies, and allogeneic hematopoietic stem cell transplant. An optimal treatment plan for neuroblastoma will most likely involve multimodal approaches and combinations of immune therapies. PMID:19342881

  17. Purified high molecular weight synthetic Aβ(1-42) and biological Aβ oligomers are equipotent in rapidly inducing MTT formazan exocytosis.

    PubMed

    Weidner, Adam M; Housley, Molly; Murphy, M Paul; Levine, Harry

    2011-06-15

    Synthetic soluble Aβ oligomers are often used as a surrogate for biologic material in a number of model systems. We compared the activity of Aβ oligomers (synthetic and cell culture media derived) on the human SH-SY5Y neuroblastoma and C2C12 mouse myoblast cell lines in a novel, modified MTT assay. Separating oligomers from monomeric peptide by size exclusion chromatography produced effects at peptide concentrations approaching physiologic levels (10-100 nM). Purified oligomers, but not monomers or fibrils, elicited an increase of a detergent-insoluble form of MTT formazan within 2h as opposed to a control toxin (H(2)O(2)). This effect was comparable for biological and synthetic peptide in both cell types. Monomeric Aβ attenuated the effect of soluble oligomers. This study suggests that the activities of biological and synthetic oligomers are indistinguishable during early stages of Aβ oligomer-cell interaction.

  18. Effects of enhancing mitochondrial oxidative phosphorylation with reducing equivalents and ubiquinone on 1-methyl-4-phenylpyridinium toxicity and complex I-IV damage in neuroblastoma cells.

    PubMed

    Mazzio, Elizabeth A; Soliman, Karam F A

    2004-03-15

    The effects of increasing mitochondrial oxidative phosphorylation (OXPHOS), by enhancing electron transport chain components, were evaluated on 1-methyl-4-phenylpyridinium (MPP+) toxicity in brain neuroblastoma cells. Although glucose is a direct energy source, ultimately nicotinamide and flavin reducing equivalents fuel ATP produced through OXPHOS. The findings indicate that cell respiration/mitochondrial O(2) consumption (MOC) (in cells not treated with MPP+) is not controlled by the supply of glucose, coenzyme Q(10) (Co-Q(10)), NADH+, NAD or nicotinic acid. In contrast, MOC in whole cells is highly regulated by the supply of flavins: riboflavin, flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN), where cell respiration reached up to 410% of controls. In isolated mitochondria, FAD and FMN drastically increased complex I rate of reaction (1300%) and (450%), respectively, having no effects on complex II or III. MPP+ reduced MOC in whole cells in a dose-dependent manner. In isolated mitochondria, MPP+ exerted mild inhibition at complex I, negligible effects on complexes II-III, and extensive inhibition of complex IV. Kinetic analysis of complex I revealed that MPP+ was competitive with NADH, and partially reversible by FAD and FMN. Co-Q(10) potentiated complex II ( approximately 200%), but not complex I or III. Despite positive influence of flavins and Co-Q(10) on complexes I-II function, neither protected against MPP+ toxicity, indicating inhibition of complex IV as the predominant target. The nicotinamides and glucose prevented MPP+ toxicity by fueling anaerobic glycolysis, evident by accumulation of lactate in the absence of MOC. The data also define a clear anomaly of neuroblastoma, indicating a preference for anaerobic conditions, and an adverse response to aerobic. An increase in CO(2), CO(2)/O(2) ratio, mitochondrial inhibition or O(2) deprivation was not directly toxic, but activated metabolism through glycolysis prompting depletion of glucose

  19. Monofunctional hyperbranched ethylene oligomers.

    PubMed

    Wiedemann, Thomas; Voit, Gregor; Tchernook, Alexandra; Roesle, Philipp; Göttker-Schnetmann, Inigo; Mecking, Stefan

    2014-02-05

    The neutral κ(2)N,O-salicylaldiminato Ni(II) complexes [κ(2)N,O-{(2,6-(3',5'-R2C6H3)2C6H3-N═C(H)-(3,5-I2-2-O-C6H2)}]NiCH3(pyridine)] (1a-pyr, R = Me; 1b-pyr, R = Et; 1c-pyr, R = iPr) convert ethylene to hyperbranched low-molecular-weight oligomers (Mn ca. 1000 g mol(-1)) with high productivities. While all three catalysts are capable of generating hyperbranched structures, branching densities decrease significantly with the nature of the remote substituent along Me > Et > iPr and oligomer molecular weights increase. Consequently, only 1a-pyr forms hyperbranched structures over a wide range of reaction conditions (ethylene pressure 5-30 atm and 20-70 °C). An in situ catalyst system achieves similar activities and identical highly branched oligomer microstructures, eliminating the bottleneck given by the preparation and isolation of Ni-Me catalyst precursor species. Selective introduction of one primary carboxylic acid ester functional group per highly branched oligoethylene molecule was achieved by isomerizing ethoxycarbonylation and alternatively cross metathesis with ethyl acrylate followed by hydrogenation. The latter approach results in complete functionalization and no essential loss of branched oligomer material and molecular weight, as the reacting double bonds are close to a chain end. Reduction yielded a monoalcohol-functionalized oligomer. Introduction of one reactive epoxide group per branched oligomer occurs completely and selectively under mild conditions. All reaction steps involved in oligomerization and monofunctionalization are efficient and readily scalable.

  20. Damage to fuel cell membranes. Reaction of HO* with an oligomer of poly(sodium styrene sulfonate) and subsequent reaction with O(2).

    PubMed

    Dockheer, Sindy M; Gubler, Lorenz; Bounds, Patricia L; Domazou, Anastasia S; Scherer, Günther G; Wokaun, Alexander; Koppenol, Willem H

    2010-10-07

    An understanding of the reactivity of oligomeric compounds that model fuel cell membrane materials under oxidative-stress conditions that mimic the fuel cell operating environment can identify material weaknesses and yield valuable insights into how a polymer might be modified to improve oxidative stability. The reaction of HO˙ radicals with a polymer electrolyte fuel cell membrane represents an initiation step for irreversible membrane oxidation. By means of pulse radiolysis, we measured k = (9.5 ± 0.6) × 10(9) M(-1) s(-1) for the reaction of HO˙ with poly(sodium styrene sulfonate), PSSS, with an average molecular weight of 1100 Da (PSSS-1100) in aqueous solution at room temperature. In the initial reaction of HO˙ with the oligomer (90 ± 10)% react by addition to form hydroxycyclohexadienyl radicals, while the remaining abstract a hydrogen to yield benzyl radicals. The hydroxycyclohexadienyl radicals react reversibly with dioxygen to form the corresponding peroxyl radicals; the second-order rate constant for the forward reaction is k(f) = (3.0 ± 0.5) × 10(7) M(-1) s(-1), and for the back reaction, we derive an upper limit for the rate constant k(r) of (4.5 ± 0.9) × 10(3) s(-1). These data place a lower bound on the equilibrium constant K of (7 ± 2) × 10(3) M(-1) at 295 K, which allows us to calculate a lower limit of the Gibbs energy for the reaction, (-21.7 ± 0.8) kJ mol(-1). At pH 1, the hydroxycyclohexadienyl radicals decay with an overall first-order rate constant k of (6 ± 1) × 10(3) s(-1) to yield benzyl radicals. The second-order rate constant for reaction of dioxygen with benzyl radicals of PSSS-1100 is k = (2-5) × 10(8) M(-1) s(-1). We discuss hydrogen abstraction from PSSS-1100 in terms of the bond dissociation energy, and relate these to relevant electrode potentials. We propose a reaction mechanism for the decay of hydroxycyclohexadienyl radicals and subsequent reaction steps.

  1. MEIS homeobox genes in neuroblastoma.

    PubMed

    Geerts, Dirk; Revet, Ingrid; Jorritsma, Gerda; Schilderink, Nathalie; Versteeg, Rogier

    2005-10-18

    The common pediatric tumor neuroblastoma originates from primitive neural crest-derived precursor cells of the peripheral nervous system. Neuroblastoma especially affects very young children, and can already be present at birth. Its early onset and cellular origin predict the involvement of developmental control genes in neuroblastoma etiology. These genes are indispensable for the tight regulation of normal embryonic development but as a consequence cause cancer and congenital diseases upon mutation or aberrant expression. To date however, the connotation of these genes in neuroblastoma pathogenesis is scant. This review recapitulates data on the MEIS homeobox control genes in cancer and focuses on neuroblastoma.

  2. Acquired resistance to oxaliplatin is not directly associated with increased resistance to DNA damage in SK-N-ASrOXALI4000, a newly established oxaliplatin-resistant sub-line of the neuroblastoma cell line SK-N-AS

    PubMed Central

    Saintas, Emily; Abrahams, Liam; Ahmad, Gulshan T.; Ajakaiye, Anu-Oluwa M.; AlHumaidi, Abdulaziz S. H. A. M.; Ashmore-Harris, Candice; Clark, Iain; Dura, Usha K.; Fixmer, Carine N.; Ike-Morris, Chinedu; Mato Prado, Mireia; Mccullough, Danielle; Mishra, Shishir; Schöler, Katia M. U.; Timur, Husne; Williamson, Maxwell D. C.; Alatsatianos, Markella; Bahsoun, Basma; Blackburn, Edith; Hogwood, Catherine E.; Lithgow, Pamela E.; Rowe, Michelle; Yiangou, Lyto; Rothweiler, Florian; Cinatl, Jindrich; Zehner, Richard; Baines, Anthony J.; Garrett, Michelle D.; Gourlay, Campbell W.; Griffin, Darren K.; Gullick, William J.; Hargreaves, Emma; Howard, Mark J.; Lloyd, Daniel R.; Rossman, Jeremy S.; Smales, C. Mark; Tsaousis, Anastasios D.; von der Haar, Tobias; Wass, Mark N.

    2017-01-01

    The formation of acquired drug resistance is a major reason for the failure of anti-cancer therapies after initial response. Here, we introduce a novel model of acquired oxaliplatin resistance, a sub-line of the non-MYCN-amplified neuroblastoma cell line SK-N-AS that was adapted to growth in the presence of 4000 ng/mL oxaliplatin (SK-N-ASrOXALI4000). SK-N-ASrOXALI4000 cells displayed enhanced chromosomal aberrations compared to SK-N-AS, as indicated by 24-chromosome fluorescence in situ hybridisation. Moreover, SK-N-ASrOXALI4000 cells were resistant not only to oxaliplatin but also to the two other commonly used anti-cancer platinum agents cisplatin and carboplatin. SK-N-ASrOXALI4000 cells exhibited a stable resistance phenotype that was not affected by culturing the cells for 10 weeks in the absence of oxaliplatin. Interestingly, SK-N-ASrOXALI4000 cells showed no cross resistance to gemcitabine and increased sensitivity to doxorubicin and UVC radiation, alternative treatments that like platinum drugs target DNA integrity. Notably, UVC-induced DNA damage is thought to be predominantly repaired by nucleotide excision repair and nucleotide excision repair has been described as the main oxaliplatin-induced DNA damage repair system. SK-N-ASrOXALI4000 cells were also more sensitive to lysis by influenza A virus, a candidate for oncolytic therapy, than SK-N-AS cells. In conclusion, we introduce a novel oxaliplatin resistance model. The oxaliplatin resistance mechanisms in SK-N-ASrOXALI4000 cells appear to be complex and not to directly depend on enhanced DNA repair capacity. Models of oxaliplatin resistance are of particular relevance since research on platinum drugs has so far predominantly focused on cisplatin and carboplatin. PMID:28192521

  3. Acquired resistance to oxaliplatin is not directly associated with increased resistance to DNA damage in SK-N-ASrOXALI4000, a newly established oxaliplatin-resistant sub-line of the neuroblastoma cell line SK-N-AS.

    PubMed

    Saintas, Emily; Abrahams, Liam; Ahmad, Gulshan T; Ajakaiye, Anu-Oluwa M; AlHumaidi, Abdulaziz S H A M; Ashmore-Harris, Candice; Clark, Iain; Dura, Usha K; Fixmer, Carine N; Ike-Morris, Chinedu; Mato Prado, Mireia; Mccullough, Danielle; Mishra, Shishir; Schöler, Katia M U; Timur, Husne; Williamson, Maxwell D C; Alatsatianos, Markella; Bahsoun, Basma; Blackburn, Edith; Hogwood, Catherine E; Lithgow, Pamela E; Rowe, Michelle; Yiangou, Lyto; Rothweiler, Florian; Cinatl, Jindrich; Zehner, Richard; Baines, Anthony J; Garrett, Michelle D; Gourlay, Campbell W; Griffin, Darren K; Gullick, William J; Hargreaves, Emma; Howard, Mark J; Lloyd, Daniel R; Rossman, Jeremy S; Smales, C Mark; Tsaousis, Anastasios D; von der Haar, Tobias; Wass, Mark N; Michaelis, Martin

    2017-01-01

    The formation of acquired drug resistance is a major reason for the failure of anti-cancer therapies after initial response. Here, we introduce a novel model of acquired oxaliplatin resistance, a sub-line of the non-MYCN-amplified neuroblastoma cell line SK-N-AS that was adapted to growth in the presence of 4000 ng/mL oxaliplatin (SK-N-ASrOXALI4000). SK-N-ASrOXALI4000 cells displayed enhanced chromosomal aberrations compared to SK-N-AS, as indicated by 24-chromosome fluorescence in situ hybridisation. Moreover, SK-N-ASrOXALI4000 cells were resistant not only to oxaliplatin but also to the two other commonly used anti-cancer platinum agents cisplatin and carboplatin. SK-N-ASrOXALI4000 cells exhibited a stable resistance phenotype that was not affected by culturing the cells for 10 weeks in the absence of oxaliplatin. Interestingly, SK-N-ASrOXALI4000 cells showed no cross resistance to gemcitabine and increased sensitivity to doxorubicin and UVC radiation, alternative treatments that like platinum drugs target DNA integrity. Notably, UVC-induced DNA damage is thought to be predominantly repaired by nucleotide excision repair and nucleotide excision repair has been described as the main oxaliplatin-induced DNA damage repair system. SK-N-ASrOXALI4000 cells were also more sensitive to lysis by influenza A virus, a candidate for oncolytic therapy, than SK-N-AS cells. In conclusion, we introduce a novel oxaliplatin resistance model. The oxaliplatin resistance mechanisms in SK-N-ASrOXALI4000 cells appear to be complex and not to directly depend on enhanced DNA repair capacity. Models of oxaliplatin resistance are of particular relevance since research on platinum drugs has so far predominantly focused on cisplatin and carboplatin.

  4. Recent Advances in Neuroblastoma

    PubMed Central

    Finklestein, Jerry Z.; Gilchrist, Gerald S.

    1972-01-01

    Neuroblastoma is one of the commoner tumors of infancy and childhood. There is great variation in the histological picture and even within one tumor. One unique feature is the apparently high rate of spontaneous regression, particularly during the first year of life. There is also a tendency for neuroblastoma to mature to the more benign ganglioneuroma and recent in vitro studies suggest that a serum factor may influence this process. Approximately 90 percent of patients with neuroblastoma excrete abnormally high quantities of various catecholamines, thus providing a useful diagnostic tool and a means for evaluating the effect of therapy. Treatment requires a multidisciplinary team approach involving a surgeon, radiotherapist and chemotherapist. Prognosis is influenced by a number of host factors and the most important of these seem to be the patient's age at diagnosis and the extent of the disease, although some children with widespread disease appear to have a particularly good prognosis. It is difficult to evaluate the influence of chemotherapy on survival in patients with neuroblastoma but it has not been of great significance. The unique biologic characteristics of this tumor require further study in the hope of providing more effective therapy. PMID:4622580

  5. Phenylethynyl terminated reactive oligomer

    NASA Technical Reports Server (NTRS)

    Bryant, Robert G. (Inventor); Jensen, Brian J. (Inventor); Hergenrother, Paul M. (Inventor)

    1995-01-01

    A composition of matter having the general structure: ##STR1## (wherein X is F, Cl, or NO.sub.2, and Y is CO, SO.sub.2 or C(CF.sub.3).sub.2) is employed to terminate a nucleophilic reagent, resulting in the exclusive production of phenylethynyl terminated reactive oligomers which display unique thermal characteristics. A reactive diluent having the general structure: ##STR2## (wherein R is any aliphatic or aromatic moiety) is employed to decrease the melt viscosity of a phenylethynyl terminated reactive oligomer and to subsequently react therewith to provide a thermosetting material of enhanced density. These materials have features which make them attractive candidates for use as composite matrices and adhesives.

  6. Pediatrics: diagnosis of neuroblastoma.

    PubMed

    Sharp, Susan E; Gelfand, Michael J; Shulkin, Barry L

    2011-09-01

    Neuroblastoma is the most common pediatric extracranial soft-tissue tumor, accounting for approximately 8% of childhood malignancies. Its prognosis is widely variable, ranging from spontaneous regression to fatal disease despite multimodality therapy. Multiple imaging and clinical tests are needed to accurately assess patient risk with risk groups based on disease stage, patient age, and biological tumor factors. Approximately 60% of patients with neuroblastoma have metastatic disease, most commonly involving bone marrow or cortical bone. Metaiodobenzylguanidine (mIBG) scintigraphy plays an important role in the assessment of neuroblastoma, allowing whole-body disease assessment. mIBG is used to define extent of disease at diagnosis, assess disease response during therapy, and detect residual and recurrent disease during follow-up. mIBG is highly sensitive and specific for neuroblastoma, concentrating in >90% of tumors. mIBG was initially labeled with (131)I, but (123)I-mIBG yields higher quality images at a lower patient radiation dose. (123)I-mIBG (AdreView; GE Healthcare, Arlington Heights, IL) was approved for clinical use in children by the Food and Drug Administration in 2008 and is now commercially available throughout the United States. The use of single-photon emission computed tomography and single-photon emission computed tomography/computed tomography in (123)I-mIBG imaging has improved certainty of lesion detection and localization. Fluorodeoxyglucose positron-emission tomography has recently been compared with mIBG and found to be most useful in neuroblastomas which fail to or weakly accumulate mIBG.

  7. Monoclonal antibodies and neuroblastoma

    SciTech Connect

    Miraldi, F. )

    1989-10-01

    Several antineuroblastoma monoclonal antibodies (MoAbs) have been described and two have been used in radioimmunoimaging and radioimmunotherapy in patients. MoAb 3F8 is a murine IgG3 antibody specific for the ganglioside GD2. Radioiodine-labeled 3F8 has been shown to specifically target human neuroblastoma in patients, and radioimmunoimaging with this agent has provided consistently high uptakes with tumor-to-background ratios of greater than or equal to 10:1. Radioimmunotherapy has been attempted with both MoAb 3F8 and MoAb UJ13A, and although encouraging results have been obtained, dosimetry data and tissue dose response information for these agents is lacking, which impedes the development of such therapy. 124I, a positron emitter, can be used with 3F8 in positron emission tomography (PET) scanning to provide dosimetry information for radioimmunotherapy. The tumor radiation dose response from radiolabeled MoAb also can be followed with PET images with fluorodeoxyglucose (FDG) scanning of neuroblastoma tumors. Results to date indicate that radioimmunoimaging has clinical use in the diagnosis of neuroblastoma and the potential for radioimmunotherapy for this cancer remains high.48 references.

  8. Effects of YM155 on survivin levels and viability in neuroblastoma cells with acquired drug resistance

    PubMed Central

    Voges, Yvonne; Michaelis, Martin; Rothweiler, Florian; Schaller, Torsten; Schneider, Constanze; Politt, Katharina; Mernberger, Marco; Nist, Andrea; Stiewe, Thorsten; Wass, Mark N; Rödel, Franz; Cinatl, Jindrich

    2016-01-01

    Resistance formation after initial therapy response (acquired resistance) is common in high-risk neuroblastoma patients. YM155 is a drug candidate that was introduced as a survivin suppressant. This mechanism was later challenged, and DNA damage induction and Mcl-1 depletion were suggested instead. Here we investigated the efficacy and mechanism of action of YM155 in neuroblastoma cells with acquired drug resistance. The efficacy of YM155 was determined in neuroblastoma cell lines and their sublines with acquired resistance to clinically relevant drugs. Survivin levels, Mcl-1 levels, and DNA damage formation were determined in response to YM155. RNAi-mediated depletion of survivin, Mcl-1, and p53 was performed to investigate their roles during YM155 treatment. Clinical YM155 concentrations affected the viability of drug-resistant neuroblastoma cells through survivin depletion and p53 activation. MDM2 inhibitor-induced p53 activation further enhanced YM155 activity. Loss of p53 function generally affected anti-neuroblastoma approaches targeting survivin. Upregulation of ABCB1 (causes YM155 efflux) and downregulation of SLC35F2 (causes YM155 uptake) mediated YM155-specific resistance. YM155-adapted cells displayed increased ABCB1 levels, decreased SLC35F2 levels, and a p53 mutation. YM155-adapted neuroblastoma cells were also characterized by decreased sensitivity to RNAi-mediated survivin depletion, further confirming survivin as a critical YM155 target in neuroblastoma. In conclusion, YM155 targets survivin in neuroblastoma. Furthermore, survivin is a promising therapeutic target for p53 wild-type neuroblastomas after resistance acquisition (neuroblastomas are rarely p53-mutated), potentially in combination with p53 activators. In addition, we show that the adaptation of cancer cells to molecular-targeted anticancer drugs is an effective strategy to elucidate a drug's mechanism of action. PMID:27735941

  9. Lack of Associations between XPC Gene Polymorphisms and Neuroblastoma Susceptibility in a Chinese Population

    PubMed Central

    Zheng, Jintao; Zhang, Ruizhong; Zhu, Jinhong; Wang, Fenghua; Yang, Tianyou

    2016-01-01

    Neuroblastoma is one of the most malignant solid tumors in infants and young children. No more than 40% of neuroblastoma patients can survive for longer than five years after it has been diagnosed. XPC protein is a pivotal factor that recognizes DNA damage and starts up the nucleotide excision repair (NER) in mammalian cells. This makes up the first group to defend against the cancer. Previous studies have identified that XPC gene polymorphisms were associated with various types of cancer. However, the associations between XPC gene polymorphisms and neuroblastoma risk have not yet been studied. We investigated the associations between three XPC gene polymorphisms (rs2228001 A>C, rs2228000 C>T, and rs2229090 G>C) and neuroblastoma risk with 256 neuroblastoma patients and 531 healthy controls in a Chinese Han population. Odds ratios and 95% confidence intervals were used to access the association between these three polymorphisms and neuroblastoma risk. No significant association was detected between these three polymorphisms and neuroblastoma risk in the overall analysis as well as in the stratification analysis. These results suggest that none of these three polymorphisms may be associated with the risk of neuroblastoma in the Chinese Han population. PMID:27847809

  10. Ataxia-telangiectasia mutated (ATM) silencing promotes neuroblastoma progression through a MYCN independent mechanism.

    PubMed

    Mandriota, Stefano J; Valentijn, Linda J; Lesne, Laurence; Betts, David R; Marino, Denis; Boudal-Khoshbeen, Mary; London, Wendy B; Rougemont, Anne-Laure; Attiyeh, Edward F; Maris, John M; Hogarty, Michael D; Koster, Jan; Molenaar, Jan J; Versteeg, Rogier; Ansari, Marc; Gumy-Pause, Fabienne

    2015-07-30

    Neuroblastoma, a childhood cancer with highly heterogeneous biology and clinical behavior, is characterized by genomic aberrations including amplification of MYCN. Hemizygous deletion of chromosome 11q is a well-established, independent marker of poor prognosis. While 11q22-q23 is the most frequently deleted region, the neuroblastoma tumor suppressor in this region remains to be identified. Chromosome bands 11q22-q23 contain ATM, a cell cycle checkpoint kinase and tumor suppressor playing a pivotal role in the DNA damage response. Here, we report that haploinsufficiency of ATM in neuroblastoma correlates with lower ATM expression, event-free survival, and overall survival. ATM loss occurs in high stage neuroblastoma without MYCN amplification. In SK-N-SH, CLB-Ga and GI-ME-N human neuroblastoma cells, stable ATM silencing promotes neuroblastoma progression in soft agar assays, and in subcutaneous xenografts in nude mice. This effect is dependent on the extent of ATM silencing and does not appear to involve MYCN. Our findings identify ATM as a potential haploinsufficient neuroblastoma tumor suppressor, whose inactivation mirrors the increased aggressiveness associated with 11q deletion in neuroblastoma.

  11. Lack of Associations between XPC Gene Polymorphisms and Neuroblastoma Susceptibility in a Chinese Population.

    PubMed

    Zheng, Jintao; Zhang, Ruizhong; Zhu, Jinhong; Wang, Fenghua; Yang, Tianyou; He, Jing; Xia, Huimin

    2016-01-01

    Neuroblastoma is one of the most malignant solid tumors in infants and young children. No more than 40% of neuroblastoma patients can survive for longer than five years after it has been diagnosed. XPC protein is a pivotal factor that recognizes DNA damage and starts up the nucleotide excision repair (NER) in mammalian cells. This makes up the first group to defend against the cancer. Previous studies have identified that XPC gene polymorphisms were associated with various types of cancer. However, the associations between XPC gene polymorphisms and neuroblastoma risk have not yet been studied. We investigated the associations between three XPC gene polymorphisms (rs2228001 A>C, rs2228000 C>T, and rs2229090 G>C) and neuroblastoma risk with 256 neuroblastoma patients and 531 healthy controls in a Chinese Han population. Odds ratios and 95% confidence intervals were used to access the association between these three polymorphisms and neuroblastoma risk. No significant association was detected between these three polymorphisms and neuroblastoma risk in the overall analysis as well as in the stratification analysis. These results suggest that none of these three polymorphisms may be associated with the risk of neuroblastoma in the Chinese Han population.

  12. Long noncoding RNAs and neuroblastoma

    PubMed Central

    Pandey, Gaurav Kumar; Kanduri, Chandrasekhar

    2015-01-01

    Neuroblastoma is a disease that affects infants and despite intense multimodal therapy, high-risk patients have low survival rates (<50%). In recent years long noncoding RNAs (lncRNAs) have become the cutting edge of cancer research with inroads made in understanding their roles in multiple cancer types, including prostate and breast cancers. The roles of lncRNAs in neuroblastoma have just begun to be elucidated. This review summarises where we are with regards to lncRNAs in neuroblastoma. The known mechanistic roles of lncRNAs during neuroblastoma pathogenesis are discussed, as well as the relationship between lncRNA expression and the differentiation capacity of neuroblastoma cells. We speculate about the use of some of these lncRNAs, such as those mapping to the 6p22 hotspot, as biomarkers for neuroblastoma prognosis and treatment. This novel way of thinking about both neuroblastoma and lncRNAs brings a new perspective to the prognosis and treatment of high-risk patients. PMID:26087192

  13. Long noncoding RNAs and neuroblastoma.

    PubMed

    Pandey, Gaurav Kumar; Kanduri, Chandrasekhar

    2015-07-30

    Neuroblastoma is a disease that affects infants and despite intense multimodal therapy, high-risk patients have low survival rates (<50%). In recent years long noncoding RNAs (lncRNAs) have become the cutting edge of cancer research with inroads made in understanding their roles in multiple cancer types, including prostate and breast cancers. The roles of lncRNAs in neuroblastoma have just begun to be elucidated. This review summarises where we are with regards to lncRNAs in neuroblastoma. The known mechanistic roles of lncRNAs during neuroblastoma pathogenesis are discussed, as well as the relationship between lncRNA expression and the differentiation capacity of neuroblastoma cells. We speculate about the use of some of these lncRNAs, such as those mapping to the 6p22 hotspot, as biomarkers for neuroblastoma prognosis and treatment. This novel way of thinking about both neuroblastoma and lncRNAs brings a new perspective to the prognosis and treatment of high-risk patients.

  14. Direct observation of single amyloid-β(1-40) oligomers on live cells: binding and growth at physiological concentrations.

    PubMed

    Johnson, Robin D; Schauerte, Joseph A; Wisser, Kathleen C; Gafni, Ari; Steel, Duncan G

    2011-01-01

    Understanding how amyloid-β peptide interacts with living cells on a molecular level is critical to development of targeted treatments for Alzheimer's disease. Evidence that oligomeric Aβ interacts with neuronal cell membranes has been provided, but the mechanism by which membrane binding occurs and the exact stoichiometry of the neurotoxic aggregates remain elusive. Physiologically relevant experimentation is hindered by the high Aβ concentrations required for most biochemical analyses, the metastable nature of Aβ aggregates, and the complex variety of Aβ species present under physiological conditions. Here we use single molecule microscopy to overcome these challenges, presenting direct optical evidence that small Aβ(1-40) oligomers bind to living neuroblastoma cells at physiological Aβ concentrations. Single particle fluorescence intensity measurements indicate that cell-bound Aβ species range in size from monomers to hexamers and greater, with the majority of bound oligomers falling in the dimer-to-tetramer range. Furthermore, while low-molecular weight oligomeric species do form in solution, the membrane-bound oligomer size distribution is shifted towards larger aggregates, indicating either that bound Aβ oligomers can rapidly increase in size or that these oligomers cluster at specific sites on the membrane. Calcium indicator studies demonstrate that small oligomer binding at physiological concentrations induces only mild, sporadic calcium leakage. These findings support the hypothesis that small oligomers are the primary Aβ species that interact with neurons at physiological concentrations.

  15. Prefibrillar transthyretin oligomers and cold stored native tetrameric transthyretin are cytotoxic in cell culture

    SciTech Connect

    Soergjerd, Karin; Klingstedt, Therese; Lindgren, Mikael; Kagedal, Katarina; Hammarstroem, Per

    2008-12-26

    Recent studies suggest that soluble, oligomeric species, which are intermediates in the fibril formation process in amyloid disease, might be the key species in amyloid pathogenesis. Soluble oligomers of human wild type transthyretin (TTR) were produced to elucidate oligomer properties. Employing ThT fluorescence, time-resolved fluorescence anisotropy of pyrene-labeled TTR, chemical cross-linking, and electron microscopy we demonstrated that early formed soluble oligomers (within minutes) from A-state TTR comprised on the average 20-30 TTR monomers. When administered to neuroblastoma cells these early oligomers proved highly cytotoxic and induced apoptosis after 48 h of incubation. More mature fibrils (>24 h of fibrillation) were non-toxic. Surprisingly, we also found that native tetrameric TTR, when purified and stored under cold conditions (4 deg. C) was highly cytotoxic. The effect could be partially restored by increasing the temperature of the protein. The cytotoxic effects of native tetrameric TTR likely stems from a hitherto unexplored low temperature induced rearrangement of the tetramer conformation that possibly is related to the conformation of misfolded TTR in amyloigogenic oligomers.

  16. Quantitative analysis of co-oligomer formation by amyloid-beta peptide isoforms

    NASA Astrophysics Data System (ADS)

    Iljina, Marija; Garcia, Gonzalo A.; Dear, Alexander J.; Flint, Jennie; Narayan, Priyanka; Michaels, Thomas C. T.; Dobson, Christopher M.; Frenkel, Daan; Knowles, Tuomas P. J.; Klenerman, David

    2016-06-01

    Multiple isoforms of aggregation-prone proteins are present under physiological conditions and have the propensity to assemble into co-oligomers with different properties from self-oligomers, but this process has not been quantitatively studied to date. We have investigated the amyloid-β (Aβ) peptide, associated with Alzheimer’s disease, and the aggregation of its two major isoforms, Aβ40 and Aβ42, using a statistical mechanical modelling approach in combination with in vitro single-molecule fluorescence measurements. We find that at low concentrations of Aβ, corresponding to its physiological abundance, there is little free energy penalty in forming co-oligomers, suggesting that the formation of both self-oligomers and co-oligomers is possible under these conditions. Our model is used to predict the oligomer concentration and size at physiological concentrations of Aβ and suggests the mechanisms by which the ratio of Aβ42 to Aβ40 can affect cell toxicity. An increased ratio of Aβ42 to Aβ40 raises the fraction of oligomers containing Aβ42, which can increase the hydrophobicity of the oligomers and thus promote deleterious binding to the cell membrane and increase neuronal damage. Our results suggest that co-oligomers are a common form of aggregate when Aβ isoforms are present in solution and may potentially play a significant role in Alzheimer’s disease.

  17. Neuroblastoma: diagnostic imaging and staging

    SciTech Connect

    Stark, D.D.; Moss, A.A.; Brasch, R.C.; deLorimier, A.A.; Albin, A.R.; London, D.A.; Gooding, C.A.

    1983-07-01

    Results of computed tomography (CT), scintigraphy, excretory urography, and other imaging tests used to diagnose and stage 38 cases of neuroblastoma prior to treatment were reviewed. Findings of these examinations were correlated with clinical data, laboratory data, results of biopsy, and surgical findings. CT was the most sensitive single test (100%) for the detection and delineation of the primary tumor. Calcifications that suggested the histologic diagnosis of neuroblastoma were present in 79% of the cases. Rim calcifications, the most specific pattern for neuroblastoma, were identified in 29% of all cases. CT alone accurately staged 82% of cases; when complemented by bone marrow biopsy, staging accuracy was 97%. CT alone was more accurate than any combination of imaging tests that excluded CT. An algorithm using CT is presented for the diagnosis and staging of neuroblastoma at reduced cost and with increased efficiency.

  18. Wnt-5a occludes Aβ oligomer-induced depression of glutamatergic transmission in hippocampal neurons

    PubMed Central

    2010-01-01

    Background Soluble amyloid-β (Aβ;) oligomers have been recognized to be early and key intermediates in Alzheimer's disease (AD)-related synaptic dysfunction. Aβ oligomers block hippocampal long-term potentiation (LTP) and impair rodent spatial memory. Wnt signaling plays an important role in neural development, including synaptic differentiation. Results We report here that the Wnt signaling activation prevents the synaptic damage triggered by Aβ oligomers. Electrophysiological analysis of Schaffer collaterals-CA1 glutamatergic synaptic transmission in hippocampal slices indicates that Wnt-5a increases the amplitude of field excitatory postsynaptic potentials (fEPSP) and both AMPA and NMDA components of the excitatory postsynaptic currents (EPSCs), without modifying the paired pulse facilitation (PPF). Conversely, in the presence of Aβ oligomers the fEPSP and EPSCs amplitude decreased without modification of the PPF, while the postsynaptic scaffold protein (PSD-95) decreased as well. Co-perfusion of hippocampal slices with Wnt-5a and Aβ oligomers occludes against the synaptic depression of EPSCs as well as the reduction of PSD-95 clusters induced by Aβ oligomers in neuronal cultures. Taken together these results indicate that Wnt-5a and Aβ oligomers inversely modulate postsynaptic components. Conclusion These results indicate that post-synaptic damage induced by Aβ oligomers in hippocampal neurons is prevented by non-canonical Wnt pathway activation. PMID:20205789

  19. Targeting tachykinin receptors in neuroblastoma

    PubMed Central

    Szymansky, Annabell; Seiler, Marleen; Althoff, Kristina; Beckers, Anneleen; Speleman, Frank; Schäfers, Simon; De Preter, Katleen; Astrahanseff, Kathy; Struck, Joachim; Schramm, Alexander; Eggert, Angelika; Bergmann, Andreas; Schulte, Johannes H.

    2017-01-01

    Neuroblastoma is the most common extracranial tumor in children. Despite aggressive multimodal treatment, high-risk neuroblastoma remains a clinical challenge with survival rates below 50%. Adding targeted drugs to first-line therapy regimens is a promising approach to improve survival in these patients. TACR1 activation by substance P has been reported to be mitogenic in cancer cell lines. Tachykinin receptor (TACR1) antagonists are approved for clinical use as an antiemetic remedy since 2003. Tachykinin receptor inhibition has recently been shown to effectively reduce growth of several tumor types. Here, we report that neuroblastoma cell lines express TACR1, and that targeting TACR1 activity significantly reduced cell viability and induced apoptosis in neuroblastoma cell lines. Gene expression profiling revealed that TACR1 inhibition repressed E2F2 and induced TP53 signaling. Treating mice harboring established neuroblastoma xenograft tumors with Aprepitant also significantly reduced tumor burden. Thus, we provide evidence that the targeted inhibition of tachykinin receptor signaling shows therapeutic efficacy in preclinical models for high-risk neuroblastoma. PMID:27888795

  20. Self-propagative replication of Aβ oligomers suggests potential transmissibility in Alzheimer disease.

    PubMed

    Kumar, Amit; Pate, Kayla M; Moss, Melissa A; Dean, Dexter N; Rangachari, Vijayaraghavan

    2014-01-01

    The aggregation of amyloid-β (Aβ) peptide and its deposition in parts of the brain form the central processes in the etiology of Alzheimer disease (AD). The low-molecular weight oligomers of Aβ aggregates (2 to 30 mers) are known to be the primary neurotoxic agents whose mechanisms of cellular toxicity and synaptic dysfunction have received substantial attention in the recent years. However, how these toxic agents proliferate and induce widespread amyloid deposition throughout the brain, and what mechanism is involved in the amplification and propagation of toxic oligomer species, are far from clear. Emerging evidence based on transgenic mice models indicates a transmissible nature of Aβ aggregates and implicates a prion-like mechanism of oligomer propagation, which manifests as the dissemination and proliferation of Aβ toxicity. Despite accumulating evidence in support of a transmissible nature of Aβ aggregates, a clear, molecular-level understanding of this intriguing mechanism is lacking. Recently, we reported the characterization of unique replicating oligomers of Aβ42 (12-24 mers) in vitro called Large Fatty Acid-derived Oligomers (LFAOs) (Kumar et al., 2012, J. Biol. Chem). In the current report, we establish that LFAOs possess physiological activity by activating NF-κB in human neuroblastoma cells, and determine the experimental parameters that control the efficiency of LFAO replication by self-propagation. These findings constitute the first detailed report on monomer - oligomer lateral propagation reactions that may constitute potential mechanism governing transmissibility among Aβ oligomers. These data support the previous reports on transmissible mechanisms observed in transgenic animal models.

  1. Neuroblastoma in Children: Just Diagnosed Information

    MedlinePlus

    ... Other Press Room Employment Feedback Contact Select Page Neuroblastoma in Children – Just Diagnosed Home > Cancer Resources > Types ... Diagnosed Just Diagnosed In Treatment After Treatment Diagnosing Neuroblastoma Depending on the location of the tumor and ...

  2. Autologous antibodies that bind neuroblastoma cells.

    PubMed

    Sun, Yujing; Sholler, Giselle S; Shukla, Girja S; Pero, Stephanie C; Carman, Chelsea L; Zhao, Ping; Krag, David N

    2015-11-01

    Antibody therapy of neuroblastoma is promising and our goal is to derive antibodies from patients with neuroblastoma for developing new therapeutic antibodies. The feasibility of using residual bone marrow obtained for clinical indications as a source of tumor cells and a source of antibodies was assessed. From marrow samples, neuroblastoma cells were recovered, grown in cell culture and also implanted into mice to create xenografts. Mononuclear cells from the marrow were used as a source to generate phage display antibody libraries and also hybridomas. Growth of neuroblastoma patient cells was possible both in vitro and as xenografts. Antibodies from the phage libraries and from the monoclonal hybridomas bound autologous neuroblastoma cells with some selectivity. It appears feasible to recover neuroblastoma cells from residual marrow specimens and to generate human antibodies that bind autologous neuroblastoma cells. Expansion of this approach is underway to collect more specimens, optimize methods to generate antibodies, and to evaluate the bioactivity of neuroblastoma-binding antibodies.

  3. Improve T Cell Therapy in Neuroblastoma

    DTIC Science & Technology

    2014-07-01

    AD_________________ Award Number: W81XWH-10-1-0425 TITLE: Improve T Cell Therapy in Neuroblastoma ...2014 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Improve T Cell Therapy in Neuroblastoma 5b. GRANT NUMBER W81XWH-10-1-0425 5c. PROGRAM...AVAILABILITY STATEMENT Approved for Public Release; Distribution Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Neuroblastoma (NB) is

  4. Environment-Mediated Drug Resistance in Neuroblastoma

    DTIC Science & Technology

    2014-10-01

    Neuroblastoma PRINCIPAL INVESTIGATOR: Yves A. DeClerck CONTRACTING ORGANIZATION... Neuroblastoma 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-12-1-0571 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) DE CLERCK, YVES 5d. PROJECT...experiments have demonstrated that monocytes collaborate with MSC in inducing STAT3-dependent drug resistance in neuroblastoma . Further

  5. Overcoming the Mechanism of Radioresistance in Neuroblastoma

    DTIC Science & Technology

    2014-06-01

    of Radioresistance in Neuroblastoma PRINCIPAL INVESTIGATOR: Brian Marples PhD CONTRACTING ORGANIZATION: William Beaumont Hospital Inc...COVERED 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Overcoming the Mechanism of Radioresistance in Neuroblastoma 5b. GRANT NUMBER 5c. PROGRAM...for highly aggressive advanced-stage neuroblastoma remains poor despite a multidisciplinary approach involving aggressive surgery, chemotherapy and

  6. Neuroblastoma and Its Zebrafish Model.

    PubMed

    Zhu, Shizhen; Thomas Look, A

    2016-01-01

    Neuroblastoma, an important developmental tumor arising in the peripheral sympathetic nervous system (PSNS), accounts for approximately 10 % of all cancer-related deaths in children. Recent genomic analyses have identified a spectrum of genetic alterations in this tumor. Amplification of the MYCN oncogene is found in 20 % of cases and is often accompanied by mutational activation of the ALK (anaplastic lymphoma kinase) gene, suggesting their cooperation in tumor initiation and spread. Understanding how complex genetic changes function together in oncogenesis has been a continuing and daunting task in cancer research. This challenge was addressed in neuroblastoma by generating a transgenic zebrafish model that overexpresses human MYCN and activated ALK in the PSNS, leading to tumors that closely resemble human neuroblastoma and new opportunities to probe the mechanisms that underlie the pathogenesis of this tumor. For example, coexpression of activated ALK with MYCN in this model triples the penetrance of neuroblastoma and markedly accelerates tumor onset, demonstrating the interaction of these modified genes in tumor development. Further, MYCN overexpression induces adrenal sympathetic neuroblast hyperplasia, blocks chromaffin cell differentiation, and ultimately triggers a developmentally-timed apoptotic response in the hyperplastic sympathoadrenal cells. In the context of MYCN overexpression, activated ALK provides prosurvival signals that block this apoptotic response, allowing continued expansion and oncogenic transformation of hyperplastic neuroblasts, thus promoting progression to neuroblastoma. This application of the zebrafish model illustrates its value in rational assessment of the multigenic changes that define neuroblastoma pathogenesis and points the way to future studies to identify novel targets for therapeutic intervention.

  7. Differential Aminoacylase Expression in Neuroblastoma

    PubMed Central

    Long, Patrick M.; Stradecki, Holly M.; Minturn, Jane E.; Wesley, Umadevi V.; Jaworski, Diane M.

    2012-01-01

    Neuroblastoma, a cancer of the sympathetic nervous system, is the most common extracranial solid tumor in children. MYCN amplification and increased BDNF/TrkB signaling are features of high-risk tumors; yet, only ~25% of malignant tumors display these features. Thus, the identification of additional biomarkers and therapeutic targets is essential. Since aminoacylase 1 (ACY1), an amino acid deacetylase, is a putative tumor suppressor in small cell lung and renal cell carcinomas, we investigated whether it or the other family members aspartoacylase (ASPA, aminoacylase 2) or aminoacylase 3 (ACY3) could serve a similar function in neuroblastoma. Aminoacylase expression was examined in TrkB-positive, MYCN-amplified (SMS-KCNR and SK-N-BE) and TrkB-negative, non-MYCN amplified (SK-N-AS, SK-N-SH, SH-SY5Y, and SH-EP) neuroblastoma cell lines. Each aminoacylase exhibited distinct spatial localization (i.e., cytosolic ACY1, membrane-associated ASPA, and nuclear ACY3). When SK-N-SH cells were treated with neural differentiation agents (e.g., retinoic acid, cAMP) in media containing 10% serum ACY1 was the only aminoacylase whose expression was up-regulated. ASPA was primarily expressed in SH-EP cells of a glial sublineage. ACY3 was more highly expressed in the TrkB-positive, MYCN-amplified lines. All three aminoacylases were expressed in normal human adrenal gland, a common site of neuroblastoma origin, but only ACY1 and ACY3 displayed detectable expression in primary neuroblastoma tumor. Bioinformatics data mining of Kaplan-Meier survival revealed that high ACY3 expression is correlated with poor prognosis; while, low expression of ACY1 or ASPA is correlated with poor prognosis. These data suggest that aminoacylase expression is dysregulated in neuroblastoma. PMID:21128244

  8. [Biochemical studies on familial neuroblastoma].

    PubMed

    Plöchl, E

    1978-01-01

    According to the two-mutation model of neuroblastoma several investigations were performed in order to find the gene carrier in a family with familial neuroblastoma. The results of these former studies are as follows: 1. Neither chromosomal analyses of the peripheral blood nor the examinations of catecholamines nor of cystathionine in the urine could mark the first step to neuroblastoma. 2. Since cystathioniuria was not only seen in blood-relations but also in relatives by marriage and since vitamin B6 deficiency was revealed, cystathioninuria was interpreted as secondary to vitamin B6 deficiency. In this study the normal values of cystathioninuria and vitamin B6 supply were examined. Furthermore the effect of oral vitamin B6 loading on cystathioninuria and oxaluria in familial neuroblastoma was investigated and the vitamin B6 supply in the neighbours of the family was analysed. The results permitted the following conclusions: 1. In 46 of 58 children and adults cystathioninuria was found in an immeasurable range by column chromatography. Only in 12 persons it could be measured quantitatively. With the exception of 6 explanable elevations no value exceeded 20 mumol/24 hr. These results show that the acceptance of the limiting value of 20 mumol/24 hr for increased cystathioninuria is justified. 2. Vitamine B6 deficiency was found in two of 7 patients. In one child this could be explained by the underlying disease. This finding supports the suggestion that vitamine B6 deficiency can relative frequently observed. 3. The examinations of cystathioninuria and oxaluria before and after loading with vitamine B6 showed different results. Whereas oxaluria decreased after loading cystathioninuria was not surely influenced. 4. The neighbours of the members with familial neuroblastoma showed mostly a reduced vitamine B6 supply. This fact could be an indication of exogenous reason of vitamine B6 deficiency in familial neuroblastoma.

  9. [Neuroblastoma presenting as obstructive jaundice].

    PubMed

    García de Andoin Barandiaran, N; Lassaletta Atienza, A; Scaglione Ríos, C; Contra Martín, T; Madero López, L

    2006-01-01

    Obstructive jaundice as a presentation of abdominal tumors in childhood is extremely rare. To date, only 4 cases of neuroblastoma causing obstructive jaundice at diagnosis have been reported in children. We report a 4-year-old boy who presented to the emergency department with abdominal pain, jaundice, choluria and acholia. A diagnosis of unresectable, nonmetastatic neuroblastoma was made. Chemotherapy reduced the size of the tumor and relieved the symptoms of obstructive jaundice without the need for decompressive surgery. Abdominal tumors should be included in the differential diagnoses of obstructive jaundice in childhood.

  10. Alzheimer's disease-type neuronal tau hyperphosphorylation induced by Aβ oligomers

    PubMed Central

    De Felice, Fernanda G.; Wu, Diana; Lambert, Mary P.; Fernandez, Sara J.; Velasco, Pauline T.; Lacor, Pascale N.; Bigio, Eileen H.; Jerecic, Jasna; Acton, Paul J.; Shughrue, Paul J.; Chen-Dodson, Elizabeth; Kinney, Gene G.; Klein, William L.

    2008-01-01

    Alzheimer’s disease (AD) is characterized by presence of extracellular fibrillar Aβ in amyloid plaques, intraneuronal neurofibrillary tangles consisting of aggregated hyperphosphorylated tau and elevated brain levels of soluble Aβ oligomers (ADDLs). A major question is how these disparate facets of AD pathology are mechanistically related. Here we show that, independent of the presence of fibrils, ADDLs stimulate tau phosphorylation in mature cultures of hippocampal neurons and in neuroblastoma cells at epitopes characteristically hyperphosphorylated in AD. A monoclonal antibody that targets ADDLs blocked their attachment to synaptic binding sites and prevented tau hyperphosphorylation. Tau phosphorylation was blocked by the Src family tyrosine kinase inhibitor, 4-amino-5-(4-chlorophenyl)-7(t-butyl)pyrazol(3,4-D)pyramide (PP1), and by the phosphatidylinositol-3-kinase inhibitor LY294002. Significantly, tau hyperphosphorylation was also induced by a soluble aqueous extract containing Aβ oligomers from AD brains, but not by an extract from non-AD brains. Aβ oligomers have been increasingly implicated as the main neurotoxins in AD, and the current results provide a unifying mechanism in which oligomer activity is directly linked to tau hyperphosphorylation in AD pathology. PMID:17403556

  11. Targeting Cancer with Antisense Oligomers

    SciTech Connect

    Hnatowich, DJ

    2008-10-28

    With financial assistance from the Department of Energy, we have shown definitively that radiolabeled antisense DNAs and other oligomers will accumulate in target cancer cells in vitro and in vivo by an antisense mechanism. We have also shown that the number of mRNA targets for our antisense oligomers in the cancer cell types that we have investigated so far is sufficient to provide and antisense image and/or radiotherapy of cancer in mice. These studies have been reported in about 10 publications. However our observation over the past several years has shown that radiolabeled antisense oligomers administered intravenously in their native and naked form will accumulate and be retained in target xenografts by an antisense mechanism but will also accumulate at high levels in normal organs such as liver, spleen and kidneys. We have investigated unsuccessfully several commercially available vectors. Thus the use of radiolabeled antisense oligomers for the imaging of cancer must await novel approaches to delivery. This laboratory has therefore pursued two new paths, optical imaging of tumor and Auger radiotherapy. We are developing a novel method of optical imaging tumor using antisense oligomers with a fluorophore is administered while hybridized with a shorter complementary oligomer with an inhibitor. In culture and in tumored mice that the duplex remains intact and thus nonfluorescent until it encounters its target mRNA at which time it dissociates and the antisense oligomer binds along with its fluorophore to the target. Simultaneous with the above, we have also observed, as have others, that antisense oligomers migrate rapidly and quantitatively to the nucleus upon crossing cell membranes. The Auger electron radiotherapy path results from this observation since the nuclear migration properties could be used effectively to bring and to retain in the nucleus an Auger emitting radionuclide such as 111In or 125I bound to the antisense oligomer. Since the object becomes

  12. Imide Oligomers Containing Pendent and Terminal Phenylethynyl Groups-2

    NASA Technical Reports Server (NTRS)

    Connell, J. W.; Smith, J. G., Jr.; Hergenrother, P. M.

    1998-01-01

    As part of a program to develop high-performance/high-temperature structural resins for aeronautical applications, imide oligomers containing pendent and terminal phenylethynyl groups were prepared, characterized and the cured resins evaluated as composite matrices. The oligomers were prepared at a calculated number-average molecular weight of 5000 g/mol and contained 15-20 mol% pendent phenylethynyl groups. In previous work, an oligomer containing pendent and terminal phenylethynyl groups exhibited a high glass transition temperature (approximately 313 C), and laminates therefrom exhibited high compressive properties, but processability, fracture toughness, microcrack resistance and damage tolerance were less than desired. In an attempt to improve these deficiencies, modifications in the oligomeric backbone involving the incorporation of 1,3-bis(3-aminophenoxy)benzene were investigated as a means of improving processability and toughness without detracting from the high glass transition temperature and high compressive properties. The amide acid oligomeric solutions were prepared in N-methyl-2-pyrrolidinone and were subsequently processed into imide powder, thin films, adhesive tape and carbon fiber prepreg. Neat resin plaques were fabricated from imide powder by compression moulding. The maximum processing pressure was 1.4 MPa and the cure temperature ranged from 350 to 371 C for 1 h for the mouldings, adhesives, films and composites. The properties of the 1,3-bis(3-aniinophenoxy)benzene modified cured imide oligomers containing pendent and terminal phenylethynyl groups are compared with those of previously prepared oligomers containing pendent and terminal phenylethynyl groups of similar composition and molecular weight.

  13. Yi-Zhi-Fang-Dai Formula Protects against Aβ1–42 Oligomer Induced Cell Damage via Increasing Hsp70 and Grp78 Expression in SH-SY5Y Cells

    PubMed Central

    Liu, Lumei; Wan, Wenbin; Chen, Wenjing; Chan, Yuanjin; Shen, Qi

    2016-01-01

    Yi-Zhi-Fang-Dai formula (YZFDF) is an experiential prescription used to cure dementia cases like Alzheimer's disease (AD). In this study, the main effective compounds of YZFDF have been identified from this formula, and the neuroprotective effect against Aβ1–42 oligomer of YZFDF has been tested in SH-SY5Y cells. Our results showed that YZFDF could increase cell viability and could attenuate endothelial reticula- (ER-) mediated apoptosis. Evidence indicated that protein folding and endothelial reticula stress (ERS) played an important role in the AD pathological mechanism. We further explored the expression of Hsp70, an important molecular chaperon facilitating the folding of other proteins, and Grp78, the marker protein of ERS in SH-SY5Y cells. Data told us that YZFDF pretreatment could influence the mRNA and protein expression of these two proteins. At last, we also found that YZFDF pretreatment could activate Akt in SH-SY5Y cells. All these above indicate that YZFDF could be a potent therapeutic candidate for AD treatment. PMID:27829867

  14. Environment-Mediated Drug Resistance in Neuroblastoma

    DTIC Science & Technology

    2013-10-01

    Neuroblastoma PRINCIPAL INVESTIGATOR: Yves A. DeClerck, MD CONTRACTING ORGANIZATION: Children’s Hospital Los Angeles Los Angeles, CA...3. DATES COVERED 30September2012 – 29September2013 4. TITLE AND SUBTITLE Environment-Mediated Drug Resistance in Neuroblastoma 5a. CONTRACT...demonstrating that interleukin-6 protects neuroblastoma cells from drug-induced apoptosis via activation of signal transduction and activator of

  15. HOXC9-Induced Differentiation in Neuroblastoma Development

    DTIC Science & Technology

    2013-10-01

    Award Number: W81XWH-12-1-0613 TITLE: HOXC9-Induced Differentiation in Neuroblastoma Development...3. DATES COVERED (From - To) 09/30/2012 – 09/29/2013 4. TITLE AND SUBTITLE HOXC9-­‐Induced  Differentiation  in   Neuroblastoma ...determining the differentiation states of neuroblastoma tumors, with higher levels of HOXC9 promoting differentiation. At the cellular level, HOXC9

  16. Overcoming the Mechanism of Radioresistance in Neuroblastoma

    DTIC Science & Technology

    2013-10-01

    Radioresistance in Neuroblastoma PRINCIPAL INVESTIGATOR: Brian Marples, Ph.D. CONTRACTING ORGANIZATION: William Beaumont Hospital Inc Royal Oak, MI... Neuroblastoma 5b. GRANT NUMBER W81XWH-12-1-0355 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER Brian Marples, PhD 5e. TASK NUMBER...13. SUPPLEMENTARY NOTES 14. ABSTRACT Patient survival for highly aggressive advanced-stage neuroblastoma remains poor despite a

  17. PrPSc-Specific Antibodies with the Ability to Immunodetect Prion Oligomers

    PubMed Central

    Tayebi, Mourad; Jones, Daryl Rhys; Taylor, William Alexander; Stileman, Benjamin Frederick; Chapman, Charlotte; Zhao, Deming; David, Monique

    2011-01-01

    The development of antibodies with binding capacity towards soluble oligomeric forms of PrPSc recognised in the aggregation process in early stage of the disease would be of paramount importance in diagnosing prion diseases before extensive neuropathology has ensued. As blood transfusion appears to be efficient in the transmission of the infectious prion agent, there is an urgent need to develop reagents that would specifically recognize oligomeric forms of the abnormally folded prion protein, PrPSc. To that end, we show that anti-PrP monoclonal antibodies (called PRIOC mAbs) derived from mice immunised with native PrP-coated microbeads are able to immunodetect oligomers/multimers of PrPSc. Oligomer-specific immunoreactivity displayed by these PRIOC mAbs was demonstrated as large aggregates of immunoreactive deposits in prion-permissive neuroblastoma cell lines but not in equivalent non-infected or prn-p0/0 cell lines. In contrast, an anti-monomer PrP antibody displayed diffuse immunoreactivity restricted to the cell membrane. Furthermore, our PRIOC mAbs did not display any binding with monomeric recombinant and cellular prion proteins but strongly detected PrPSc oligomers as shown by a newly developed sensitive and specific ELISA. Finally, PrioC antibodies were also able to bind soluble oligomers formed of Aβ and α-synuclein. These findings demonstrate the potential use of anti-prion antibodies that bind PrPSc oligomers, recognised in early stage of the disease, for the diagnosis of prion diseases in blood and other body fluids. PMID:21625515

  18. Paraneoplastic syndromes in olfactory neuroblastoma

    PubMed Central

    Gabrych, Anna; Czapiewski, Piotr; Sworczak, Krzysztof

    2015-01-01

    Olfactory neuroblastoma (ONB) is a rare malignant neoplasm of sinonasal tract, derived from olfactory epithelium. Unilateral nasal obstruction, epistaxis, sinusitis, and headaches are common symptoms. Olfactory neuroblastoma shows neuroendocrine differentiation and similarly to other neuroendocrine tumors can produce several types of peptic substances and hormones. Excess production of these substances can be responsible for different types of endocrinological paraneoplastic syndromes (PNS). Moreover, besides endocrinological, in ONB may also occur neurological PNS, caused by immune cross-reactivity between tumor and normal host tissues in the nervous system. Paraneoplastic syndromes in ONB include: syndrome of inappropriate ADH secretion (SIADH), ectopic ACTH syndrome (EAS), humoral hypercalcemia of malignancy (HHM), hypertension due to catecholamine secretion by tumor, opsoclonus-myoclonus-ataxia (OMA) and paraneoplastic cerebellar degeneration. Paraneoplastic syndromes in ONB tend to have atypical features, therefore diagnosis may be difficult. In this review, we described initial symptoms, patterns of presentation, treatment and outcome of paraneoplastic syndromes in ONB, reported in the literature. PMID:26199564

  19. Depletion of TFAP2E attenuates adriamycin-mediated apoptosis in human neuroblastoma cells.

    PubMed

    Hoshi, Reina; Watanabe, Yosuke; Ishizuka, Yoshiaki; Hirano, Takayuki; Nagasaki-Maeoka, Eri; Yoshizawa, Shinsuke; Uekusa, Shota; Kawashima, Hiroyuki; Ohashi, Kensuke; Sugito, Kiminobu; Fukuda, Noboru; Nagase, Hiroki; Soma, Masayoshi; Ozaki, Toshinori; Koshinaga, Tsugumichi; Fujiwara, Kyoko

    2017-04-01

    Neuroblastoma is a childhood malignancy originating from the sympathetic nervous system and accounts for approximately 15% of all pediatric cancer-related deaths. To newly identify gene(s) implicated in the progression of neuroblastoma, we investigated aberrantly methylated genomic regions in mouse skin tumors. Previously, we reported that TFAP2E, a member of activator protein-2 transcription factor family, is highly methylated within its intron and its expression is strongly suppressed in mouse skin tumors compared with the normal skin. In the present study, we analyzed public data of neuroblastoma patients and found that lower expression levels of TFAP2E are significantly associated with a shorter survival. The data indicate that TFAP2E acts as a tumor suppressor of neuroblastoma. Consistent with this notion, TFAP2E-depleted neuroblastoma NB1 and NB9 cells displayed a substantial resistance to DNA damage arising from adriamycin (ADR), cisplatin (CDDP) and ionizing radiation (IR). Silencing of TFAP2E caused a reduced ADR-induced proteolytic cleavage of caspase-3 and PARP. Of note, compared with the untransfected control cells, ADR-mediated stimulation of CDK inhibitor p21WAF1 was markedly upregulated in TFAP2E‑knocked down cells. Therefore, our present findings strongly suggest that TFAP2E has a pivotal role in the regulation of DNA damage response in NB cells through the induction of p21WAF1.

  20. [Cervical neuroblastoma in an infant].

    PubMed

    Arvai, Krisztina; Tóth, Judit; Németh, Tamás; Kiss, Csongor; Molnár, Péter; Oláh, Eva

    2004-01-01

    The case of a one-month-old patient admitted to the Department of Pediatrics (Medical and Health Science Center, Debrecen University) because of respiratory distress caused by a cervical mass compressing the upper respiratory pathways is presented. The mass could only be partially removed, the histological diagnosis proved to be neuroblastoma (SBCT: "small blue cell tumor"). Despite the fact that the DNA index of tumor cells (ploidy measurements) and the age of the patient suggested a favourable prognosis, the tumor continued to grow and metastases appeared. Because of symptoms of compression exerted on the respiratory system by the tumor, chemotherapy had to be applied. Since a standard OPEC/OJEC chemotherapeutic protocol proved to be not entirely effective and a residual tumor was still present, retinoic acid and interferon treatment was introduced. Presently, 4 years after the diagnosis, the patient is in complete remission and can be considered to be cured. The case presented here demonstrates that despite the favorable prognosis of the majority of infant neuroblastomas, in some cases the anatomic location of the tumor, leading to disturbance of vital functions, may serve as indication of chemotherapy. Our experience also proved the efficacy of retinoic acid and interferon treatment in relapsed neuroblastoma.

  1. Counterion condensation on heparin oligomers.

    PubMed

    Minsky, Burcu Baykal; Atmuri, Anand; Kaltashov, Igor A; Dubin, Paul L

    2013-04-08

    The electropherogram of native heparin shows a broad distribution of mobilities μ, which truncates abruptly at a notably high μ = 4.7 × 10(-4) cm(2) V(-1) s(-1). This highly skewed mobility distribution is also found for the 20-saccharide chain, which shows from mass spectrometry a more uniform (symmetrical) with respect to sulfation level. Since a partially degraded heparin exhibits oligomer peaks with μ> 5 × 10(-4) cm(2) V(-1) s(-1) (appearing to escape the limitation of the mobility value for native heparin), we examined the electrophoretic behavior of chain-length monodisperse heparin oligomers. Their mobilities varied inversely with the logarithm of the contour length, L, for L from 3 to 10 nm and reached an asymptotic limit for L > 20 nm. The generality of this effect was indicated by similar behavior for oligomers of poly(styrene sulfonate). A recent theory of polyelectrolyte end effects (Manning, G. S. Macromolecules2008, 41, 6217-6227), in which chain termini exhibit reduced counterion condensation was found to quantitatively account for these results. A qualitative explanation for the anomalously high value of μ of native heparin, 10-20% higher than those seen for synthetic polyelectrolytes of higher linear charge density, is suggested on the basis of similar junction effects (Manning, G. S. Macromolecules2008, 41, 6217-6227), which reduce counterion condensation at the interfaces of regions of high and low sulfation. We suggest that these effects should be considered in models for the biofunctionality of the regulated high and low sulfation (NS/NA) domains of heparan sulfate.

  2. Aβ1-42 monomers or oligomers have different effects on autophagy and apoptosis.

    PubMed

    Guglielmotto, Michela; Monteleone, Debora; Piras, Antonio; Valsecchi, Valeria; Tropiano, Marta; Ariano, Stefania; Fornaro, Michele; Vercelli, Alessandro; Puyal, Julien; Arancio, Ottavio; Tabaton, Massimo; Tamagno, Elena

    2014-10-01

    The role of autophagy and its relationship with apoptosis in Alzheimer disease (AD) pathogenesis is poorly understood. Disruption of autophagy leads to buildup of incompletely digested substrates, amyloid-β (Aβ) peptide accumulation in vacuoles and cell death. Aβ, in turn, has been found to affect autophagy. Thus, Aβ might be part of a loop in which it is both the substrate of altered autophagy and its cause. Given the relevance of different soluble forms of Aβ1-42 in AD, we have investigated whether monomers and oligomers of the peptide have a differential role in causing altered autophagy and cell death. Using differentiated SK-N-BE neuroblastoma cells, we found that monomers hamper the formation of the autophagic BCL2-BECN1/Beclin 1 complex and activate the MAPK8/JNK1-MAPK9/JNK2 pathway phosphorylating BCL2. Monomers also inhibit apoptosis and allow autophagy with intracellular accumulation of autophagosomes and elevation of levels of BECN1 and LC3-II, resulting in an inhibition of substrate degradation due to an inhibitory action on lysosomal activity. Oligomers, in turn, favor the formation of the BCL2-BECN1 complex favoring apoptosis. In addition, they cause a less profound increase in BECN1 and LC3-II levels than monomers without affecting the autophagic flux. Thus, data presented in this work show a link for autophagy and apoptosis with monomers and oligomers, respectively. These studies are likely to help the design of novel disease modifying therapies.

  3. Advances in the translational genomics of neuroblastoma

    PubMed Central

    Bosse, Kristopher R.; Maris, John M.

    2015-01-01

    Neuroblastoma is an embryonal malignancy that commonly affects young children and is remarkably heterogenous in its malignant potential. Recently, the genetic basis of neuroblastoma has come into focus, which has catalyzed not only a more comprehensive understanding of neuroblastoma tumorigenesis, but has also revealed novel oncogenic vulnerabilities that are being leveraged therapeutically. Neuroblastoma is a model pediatric solid tumor in its use of recurrent genomic alterations, such as high-level MYCN amplification, for risk stratification. Given the relative paucity of recurrent activating somatic point mutations or gene fusions in primary neuroblastoma tumors studied at initial diagnosis, innovative treatment approaches beyond small molecules targeting mutated or dysregulated kinases will be required moving forward to achieve noticeable improvements in overall patient survival. However, the clonally acquired, oncogenic aberrations in relapsed neuroblastomas are currently being defined and may offer an opportunity to improve patient outcomes with molecularly targeted therapy directed towards aberrantly regulated pathways in relapsed disease. This review will summarize the current state of knowledge of neuroblastoma genetics and genomics, highlighting the improved prognostication and potential therapeutic opportunities that have arisen from recent advances in understanding germline predisposition, recurrent segmental chromosomal alterations, somatic point mutations and translocations, and clonal evolution in relapsed neuroblastoma. PMID:26539795

  4. Sublethal irradiation promotes invasiveness of neuroblastoma cells

    SciTech Connect

    Schweigerer, Lothar; Rave-Fraenk, Margret; Schmidberger, Heinz; Hecht, Monica . E-mail: monica.hecht@med.uni-goettingen.de

    2005-05-13

    Neuroblastoma is the most frequent extracranial solid tumour of childhood. Despite multiple clinical efforts, clinical outcome has remained poor. Neuroblastoma is considered to be radiosensitive, but some clinical studies including the German trial NB90 failed to show a clinical benefit of radiation therapy. The mechanisms underlying this apparent discrepancy are still unclear. We have therefore investigated the effects of radiation on neuroblastoma cell behaviour in vitro. We show that sublethal doses of irradiation up-regulated the expression of the hepatocyte growth factor (HGF) and its receptor c-Met in some neuroblastoma cell lines. The increase in HGF/c-Met expression was correlated with enhanced invasiveness and activation of proteases degrading the extracellular matrix. Thus, irradiation at sublethal doses may promote the metastatic dissemination of neuroblastoma cells through activating the HGF/c-Met pathway and triggering matrix degradation.

  5. Absorption enhancing effects of chitosan oligomers on the intestinal absorption of low molecular weight heparin in rats.

    PubMed

    Zhang, Hailong; Mi, Jie; Huo, Yayu; Huang, Xiaoyan; Xing, Jianfeng; Yamamoto, Akira; Gao, Yang

    2014-05-15

    Absorption enhancing effects of chitosan oligomers with different type and varying concentration on the intestinal absorption of low molecular weight heparin (LMWH) were examined by an in situ closed loop method in different intestinal sections of rats. Chitosan hexamer with the optimal concentration of 0.5% (w/v) showed the highest absorption enhancing ability both in the small intestine and large intestine. The membrane toxicities of chitosan oligomers were evaluated by morphological observation and determining the biological markers including amount of protein and activity of lactate dehydrogenase (LDH) released from intestinal epithelium cells. There was no obvious change both in levels of protein and LDH and morphology in the intestinal membrane between control and various chitosan oligomers groups, suggesting that chitosan oligomers did not induce any significant membrane damage to the intestinal epithelium. In addition, zeta potentials became less negative and amount of free LMWH gradually decreased when various chitosan oligomers were added to LMWH solution, revealing that electrostatic interaction between positively charged chitosan oligomers and negative LMWH was included in the absorption enhancing mechanism of chitosan oligomers. In conclusion, chitosan oligomers, especially chitosan hexamer, are safe and efficient absorption enhancers and can be used promisingly to improve oral absorption of LMWH.

  6. Human neuroblastoma cultures for biorobotics.

    PubMed

    Ferrández, J M; Lorente, V; de Santos, D; Cuadra, J M; de la Paz, F; Alvarez, J R; Fernández, E

    2011-01-01

    This paper introduces a new biorobotic system using human neuroblastoma cultures and centre of area learning for basic robotic guidance. Multielectrode Arrays Setups have been designed for direct culturing neural cells over silicon or glass substrates, providing the capability to stimulate and record simultaneously populations of neural cells. The main objective of this work will be to control a robot using this biological neuroprocessor and a new simple centre of area learning scheme. The final system could be applied for testing how chemicals affect the behaviour of the robot or to establish the basis for new hybrid optogenetic neuroprostheses based on stimulating optically genetic-modified neurons.

  7. PARP inhibitors enhance replication stress and cause mitotic catastrophe in MYCN-dependent neuroblastoma.

    PubMed

    Colicchia, V; Petroni, M; Guarguaglini, G; Sardina, F; Sahún-Roncero, M; Carbonari, M; Ricci, B; Heil, C; Capalbo, C; Belardinilli, F; Coppa, A; Peruzzi, G; Screpanti, I; Lavia, P; Gulino, A; Giannini, G

    2017-04-10

    High-risk and MYCN-amplified neuroblastomas are among the most aggressive pediatric tumors. Despite intense multimodality therapies, about 50% of these patients succumb to their disease, making the search for effective therapies an absolute priority. Due to the important functions of poly (ADP-ribose) polymerases, PARP inhibitors have entered the clinical settings for cancer treatment and are being exploited in a variety of preclinical studies and clinical trials. PARP inhibitors based combination schemes have also been tested in neuroblastoma preclinical models with encouraging results. However, the expression of PARP enzymes in human neuroblastoma and the biological consequences of their inhibition remained largely unexplored. Here, we show that high PARP1 and PARP2 expression is significantly associated with high-risk neuroblastoma cases and poor survival, highlighting its previously unrecognized prognostic value for human neuroblastoma. In vitro, PARP1 and 2 are abundant in MYCN amplified and MYCN-overexpressing cells. In this context, PARP inhibitors with high 'PARP trapping' potency, such as olaparib or talazoparib, yield DNA damage and cell death preceded by intense signs of replication stress. Notwithstanding the activation of a CHK1-CDC25A replication stress response, PARP-inhibited MYCN amplified and overexpressing cells fail to sustain a prolonged checkpoint and progress through mitosis in the presence of damaged DNA, eventually undergoing mitotic catastrophe. CHK1-targeted inhibition of the replication stress checkpoint exacerbated this phenotype. These data highlight a novel route for cell death induction by PARP inhibitors and support their introduction, together with CHK1 inhibitors, in therapeutic approaches for neuroblastomas with high MYC(N) activity.Oncogene advance online publication, 10 April 2017; doi:10.1038/onc.2017.40.

  8. Butyrylcholinesterase as a Blood Biomarker in Neuroblastoma.

    PubMed

    Coulter, Don W; Boettner, Angela D; Kortylewicz, Zbigniew P; Enke, Stephen P; Luther, Jake A; Verma, Vivek; Baranowska-Kortylewicz, Janina

    2017-04-03

    Blood-based biomarkers are important in the detection of the disease and in the assessment of responses to therapy. In this study, butyrylcholinesterase was evaluated as a potential biomarker in newly diagnosed neuroblastoma (NB) patients at diagnosis and longitudinally during treatment. Plasma butyrylcholinesterase activities in age-matched and sex-matched children were used as controls. Pretreatment butyrylcholinesterase levels in NB subjects are on an average 2 times lower than butyrylcholinesterase levels in healthy subjects. Significantly, butyrylcholinesterase activities are ∼40% lower in MYCN-amplified as compared with nonamplified disease. As the course of chemotherapy progresses, butyrylcholinesterase activities recover and normalize to control values. The evident response to treatment indicates that plasma butyrylcholinesterase is a good biomarker of tumor response to therapy. Depressed butyrylcholinesterase levels in NB subjects are not caused by hepatic deficits suggesting a specific role for butyrylcholinesterase in NB. Further examination of the mechanism of altered butyrylcholinesterase production require an animal model that best approximates human condition. Studies in mice show that murine NB allografts significantly reduce butyrylcholinesterase activity in plasma. This finding correlates with changes observed in NB patients. In contrast, human NB xenografts produce the opposite effect, that is, butyrylcholinesterase plasma levels rise as the xenograft size increases. In the absence of any liver damage, dissimilarities between butyrylcholinesterase production in murine and human NB models suggest species-specific signaling pathways. This disparity also suggests that human NB xenograft mouse models do not approximate the human disease.

  9. Cytopathogenicity of Naegleria for cultured neuroblastoma cells

    SciTech Connect

    Fulford, D.E.

    1985-01-01

    The cytopathic activity of live Naegleria amoebae and cell-free lysates of Naegleria for B-103 rat neuroblastoma cells was investigated using a /sup 51/Cr release assay. Live amoebae and cell-free lysates of N. fowleri, N. australiensis, N. lovaniensis, and N. gruberi all induced sufficient damage to radiolabeled B-103 cells to cause a significant release of chromium. The cytotoxic activity present in the cell-free lysates of N. fowleri can be recovered in the supernatant fluid following centrifugation at 100,000xg and precipitation of the 100,000xg supernatant fluid with ammonium sulfate. Initial characterization of the cytotoxic factor indicates that it is a heat labile, pH sensitive, soluble protein. The cytotoxic activity is abolished by either extraction, unaffected by repeated freeze-thawing, and is not sensitive to inhibitors of proteolytic enzymes. Phospholipase A activity was detected in the cytotoxic ammonium sulfate precipitable material, suggesting that this enzyme activity may have a role in the cytotoxic activity of the cell-free lysates.

  10. Antidepressants modulate intracellular amyloid peptide species in N2a neuroblastoma cells.

    PubMed

    Aboukhatwa, Marwa; Luo, Yuan

    2011-01-01

    It is estimated that 30%-50% of Alzheimer's disease (AD) patients are diagnosed with major or minor depression. Research that addresses the relationship between these two diseases will benefit patients who suffer from depression comorbid with AD and allow further understanding of the neuroanatomy of depression. A clinical study showed that the use of the antidepressant fluoxetin concomitantly with the FDA-approved AD drug rivastigmine provided an improvement in the daily activities and the overall functioning in the patients with cognitive impairment. In an attempt to understand the underlying mechanism for the antidepressant's beneficial effect in AD patients, we evaluated the effects of different classes of antidepressants on the amyloid-β peptide (Aβ) species in N2a neuroblastoma cells overexpressing amyloid-β protein precursor. The effect of increasing antidepressant concentrations on the intracellular and secreted Aβ species is investigated by Western blotting. The tested antidepressants include fluoxetine, paroxetine, maprotiline, and imipramine. Fluoxetine and paroxetine at 10 μM significantly decreased the intracellular level of Aβ oligomers and increased the level of Aβ monomers. However, imipramine and maprotiline increased the intracellular amount of Aβ monomers without affecting Aβ oligomers. Based on these results, it is possible that fluoxetine and paroxetine could be beneficial to AD patients via reducing the level of the cytotoxic oligomers and keeping the Aβ peptide in the monomeric form. These data could explain some of the beneficial effects of antidepressants in AD patients observed in clinical studies.

  11. Neuroblastoma: A Tough Nut to Crack.

    PubMed

    Speleman, Frank; Park, Julie R; Henderson, Tara O

    2016-01-01

    Neuroblastoma, an embryonal tumor arising from neural crest-derived progenitor cells, is the most common solid tumor in childhood, with more than 700 cases diagnosed per year in the United States. In the past several decades, significant advances have been made in the treatment of neuroblastoma. Treatment advances reflect improved understanding of the biology of neuroblastoma. Although amplification of MYCN was discovered in the early 1980s, our understanding of neuroblastoma oncogenesis has advanced in the last decade as a result of high-throughput genomic analysis, exome and whole-genome sequencing, genome-wide association studies, and synthetic lethal drug screens. Our refined understanding of neuroblastoma biology and genetics is reflected in improved prognostic stratification and appropriate tailoring of therapy in recent clinical trials. Moreover, for high-risk neuroblastoma, a disease that was uniformly fatal 3 decades ago, recent clinical trials incorporating autologous hematopoietic transplant and immunotherapy utilizing anti-GD2 antibody plus cytokines have shown improved event-free and overall survival. These advances have resulted in a growing population of long-term survivors of neuroblastoma. Examination of the late effects and second malignant neoplasms (SMNs) in both older generations of survivors and more recently treated survivors will inform both design of future trials and surveillance guidelines for long-term follow-up. As a consequence of advances in understanding of the biology of neuroblastoma, successful clinical trials, and refined understanding of the late effects and SMNs of survivors, the promise of precision medicine is becoming a reality for patients with neuroblastoma.

  12. Chitosan oligomers as potential and safe absorption enhancers for improving the pulmonary absorption of interferon-alpha in rats.

    PubMed

    Yamada, Keigo; Odomi, Masaaki; Okada, Naoki; Fujita, Takuya; Yamamoto, Akira

    2005-11-01

    Effects of chitosan oligomers on pulmonary absorption of interferon-alpha (IFN) were examined by means of an in vivo pulmonary absorption experiment. Chitosan oligomers used in this study were chitosan dimer, tetramer, hexamer, and water-soluble (WS) chitosan. A significant increase in serum IFN concentrations was observed after intratracheal administration of IFN with these oligomers. Of these chitosan oligomers, 0.5% w/v chitosan hexamer appeared to be more effective in enhancing the pulmonary absorption of IFN than other oligomers at the same concentration, and the AUC value of IFN with chitosan hexamer increased 2.6-fold as compared with the control. On the other hand, chitosan polymers, which have relatively high molecular weights (22-96 kDa), were not effective in enhancing the pulmonary absorption of IFN due to their low solubility in water. Additionally, the effect of different concentrations (0.1%-1% w/v) of chitosan hexamer on the pulmonary absorption of IFN was studied. Of these different concentrations of chitosan hexamers, the highest AUC value of IFN was obtained in the presence of 0.5% w/v chitosan hexamer. Furthermore, chitosan oligomers did not cause any membrane damage to the rat pulmonary tissues, as determined by leakage of protein and lactate dehydrogenase (LDH) in bronchoalveolar lavage (BAL) fluid. Therefore, these findings indicated that the use of chitosan oligomers would be a promising approach for improving of the pulmonary absorption of biologically active peptides including IFN.

  13. Olfactory neuroblastoma: A case report

    PubMed Central

    USLU, GONCA HANEDAN; CANYILMAZ, EMINE; ZENGIN, AHMET YASAR; MUNGAN, SEVDEGUL; YONEY, ADNAN; BAHADIR, OSMAN; GOCMEZ, HUSEYIN

    2015-01-01

    Olfactory neuroblastoma (ON) is a rare type of malignant neoplasm originating from the olfactory neuroepithelial cells of the nasal cavity. ON is also known as esthesioneuroblastoma or neuroendocrine carcinoma. The malignancy accounts for <3% of tumors originating in the nasal cavity. Through the nasal cavity, ON may infiltrate the sinuses, the orbit and the cranium. The tumor is characterized by a pattern of slow growth and local recurrences. Treatment options are surgical excision or surgery combined with a radiotherapy (RT) and/or chemotherapy combination treatment. The present study reports the case of a 69-year-old patient with a mass in the nasal cavity who was treated by combined surgical excision and RT. The literature for ON and the treatment of the tumor are also discussed. PMID:26788185

  14. Radiolabeled Metaiodobenzylguanidine for the Treatment of Neuroblastoma

    PubMed Central

    DuBois, Steven G.; Matthay, Katherine K.

    2008-01-01

    Introduction Neuroblastoma is the most common pediatric extracranial solid cancer. This tumor is characterized by metaiodobenzylguanidine (MIBG) avidity in 90% of cases, prompting the use of radiolabeled MIBG for targeted radiotherapy in these tumors. Methods The available English language literature was reviewed for original research investigating in vitro, in vivo, and clinical applications of radiolabeled MIBG for neuroblastoma. Results MIBG is actively transported into neuroblastoma cells by the norepinephrine transporter. Preclinical studies demonstrate substantial activity of radiolabeled MIBG in neuroblastoma models, with 131I-MIBG showing enhanced activity in larger tumors compared to 125I-MIBG. Clinical studies of 131I-MIBG in patients with relapsed or refractory neuroblastoma have identified myelosuppression as the main dose-limiting toxicity, necessitating stem cell reinfusion at higher doses. Most studies report a response rate of 30–40% with 131I-MIBG in this population. More recent studies have focused on the use of 131I-MIBG in combination with chemotherapy or myeloablative regimens. Conclusions 131I-MIBG is an active agent for the treatment of patients with neuroblastoma. Future studies will need to define the optimal role of this targeted radiopharmaceutical in the therapy of this disease. PMID:18707633

  15. Nanopore formation in neuroblastoma cells following ultrashort electric pulse exposure

    NASA Astrophysics Data System (ADS)

    Roth, Caleb C.; Payne, Jason A.; Wilmink, Gerald J.; Ibey, Bennett L.

    2011-03-01

    Ultrashort or nanosecond electrical pulses (USEP) cause repairable damage to the plasma membranes of cells through formation of nanopores. These nanopores are able to pass small ions such as sodium, calcium, and potassium, but remain impermeable to larger molecules like trypan blue and propidium iodide. What remains uncertain is whether generation of nanopores by ultrashort electrical pulses can inhibit action potentials in excitable cells. In this paper, we explored the sensitivity of excitable cells to USEP using Calcium Green AM 1 ester fluorescence to measure calcium uptake indicative of nanopore formation in the plasma membrane. We determined the threshold for nanopore formation in neuroblastoma cells for three pulse parameters (amplitude, pulse width, and pulse number). Measurement of such thresholds will guide future studies to determine if USEP can inhibit action potentials without causing irreversible membrane damage.

  16. Marrow-Derived Antibody Library for Treatment of Neuroblastoma

    DTIC Science & Technology

    2013-09-01

    Treatment of Neuroblastoma PRINCIPAL INVESTIGATOR: Giselle Sholler CONTRACTING...Treatment of Neuroblastoma 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-12-1-0332 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Giselle Sholler...Release; Distribution Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Neuroblastoma (NB) is the most common solid tumor in children

  17. Studies of the Tumor Microenvironment in Pathogenesis of Neuroblastoma

    DTIC Science & Technology

    2013-07-01

    of Neuroblastoma PRINCIPAL INVESTIGATOR: Shahab Asgharzadeh, M D CONTRACTING ORGANIZATION: Children’s Hospital Los Angeles Los Angeles...2012 - 30 June 2013 4. TITLE AND SUBTITLE Studies of the Tumor Microenvironment in Pathogenesis of Neuroblastoma 5a. CONTRACT NUMBER 5b...NOTES 14. ABSTRACT The NBL-Tag neuroblastoma tumors were assessed for presence of macrophages and their role in promoting tumor growth

  18. Identifying microRNAs that Regulate Neuroblastoma Cell Differentiation

    DTIC Science & Technology

    2014-09-01

    AD_________________ Award Number: W81XWH-13-1-0241 TITLE: Identifying that Regulate Neuroblastoma ...Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT We identified 14 microRNA candidates that induce neuroblastoma cell differentiation based on a high...content screening of neurite outgrowth — the morphological differentiation marker of neuroblastoma cells. We further validated that the identified

  19. [Anesthetic management of an infant with giant abdominal neuroblastoma].

    PubMed

    Gómez-Ríos, Manuel Ángel; Nuño, Federico Curt; Barreto-Calvo, Purísima

    Neuroblastoma is the most common, non-central nervous system tumor of childhood. It has the potential to synthesize catecholamines. However, the presences of hypertension are uncommon. We report the perioperative management of a 15-month-old infant with giant abdominal neuroblastoma who presented severe hypertension. The pathophysiological alterations of neuroblastoma are reviewed and perioperative management presented.

  20. Anesthetic management of an infant with giant abdominal neuroblastoma.

    PubMed

    Gómez-Ríos, Manuel Ángel; Nuño, Federico Curt; Barreto-Calvo, Purísima

    Neuroblastoma is the most common, non-central nervous system tumor of childhood. It has the potential to synthesize catecholamines. However, the presences of hypertension are uncommon. We report the perioperative management of a 15-month-old infant with giant abdominal neuroblastoma who presented severe hypertension. The pathophysiological alterations of neuroblastoma are reviewed and perioperative management presented.

  1. Diagnosis and treatment of neuroblastoma using metaiodobenzylguanidine

    SciTech Connect

    Edeling, C.J.; Frederiksen, P.B.; Kamper, J.; Jeppesen, P.

    1987-08-01

    Neuroblastoma is a lethal and not uncommon tumor in childhood. Early detection and display of the spread of the tumor is highly desirable for proper treatment. Nine children suspected of having neuroblastomas were examined by I-131 metaiodobenzylguanidine (I-131 MIBG) imaging. In two recent studies I-123 metaiodobenzylguanidine (I-123 MIBG) was used. A primary adrenal neuroblastoma was correctly identified in three cases. In two patients additional tumor sites were found. In one patient, who was in complete remission, no pathologic accumulation of I-131 MIBG was found. I-131 MIBG images were also normal in four patients with other types of neoplastic diseases. A boy with multiple metastases was treated with 100 mCi of I-131 MIBG. He developed transient gastrointestinal illness and there was no regression of the tumor deposits. In one girl with a large adrenal neuroblastoma high uptake of I-131 MIBG was observed. She received two therapy doses of I-131 MIBG (35 mCi and 75 mCi) with curative intention giving a total absorbed dose in the tumor of approximately 76 Gy. In spite of high retention of radioactivity in the tumor, regression did not occur, but her general condition was improved. In the present study, images of superior quality were obtained with I-123 MIBG imaging. It is concluded that imaging using I-131 MIBG or I-123 MIBG should be used in both the initial evaluation and the follow-up of children with neuroblastoma.

  2. Autologous cord blood transplantation for metastatic neuroblastoma.

    PubMed

    Ning, Botao; Cheuk, Daniel Ka-Leung; Chiang, Alan Kwok-Shing; Lee, Pamela Pui-Wah; Ha, Shau-Yin; Chan, Godfrey Chi-Fung

    2016-03-01

    Auto-SCT is a common approach for metastatic neuroblastoma with the intention to rescue hematopoiesis after megadose chemotherapy. PBSC or BM is the usual stem cell source for auto-SCT. Auto-CBT for neuroblastoma has very rarely been performed. Currently, case reports are available for two patients only. We performed 13 auto-SCTs for high-risk neuroblastoma from 2007 to 2013, including four cases of metastatic neuroblastoma aged 11-64 months treated with auto-CBT. All four patients had partial or CR to upfront treatments before auto-CBT. Nucleated cell dose and CD34+ cell dose infused were 2.8-8.7 × 10(7) /kg and 0.36-3.9 × 10(5) /kg, respectively. Post-thawed viability was 57-76%. Neutrophil engraftment (>0.5 × 10(9) /L) occurred at 15-33 days, while platelet engraftment occurred at 31-43 days (>20 × 10(9) /L) and 33-65 days (>50 × 10(9) /L) post-transplant, respectively. There was no severe acute or chronic complication. Three patients survived for 1.9-7.7 yr without evidence of recurrence. One patient relapsed at 16 months post-transplant and died of progressive disease. Cord blood may be a feasible alternative stem cell source for auto-SCT in patients with stage 4 neuroblastoma, and outcomes may be improved compared to autologous PBSC or BM transplants.

  3. The epidemiology of neuroblastoma: a review.

    PubMed

    Heck, Julia E; Ritz, Beate; Hung, Rayjean J; Hashibe, Mia; Boffetta, Paolo

    2009-03-01

    Neuroblastoma is the most common tumour in children less than 1 year of age. The goal of this review was to summarise the existing epidemiological research on risk factors for neuroblastoma. A comprehensive search of the literature was undertaken using PubMed for epidemiological studies on neuroblastoma risk factors. We ascertained 47 articles which examined the risk factors. Ten studies employed population-based case-control designs; six were hospital-based case-control studies; two were cohort studies; and five employed ecological designs. Studies ranged in size from 42 to 538 cases. Three studies showed evidence of an increased risk of disease with use of alcohol during pregnancy (OR range 1.1, 12.0). Protective effects were seen with maternal vitamin intake during pregnancy (OR range 0.5, 0.7) in two studies, while risk of disease increased with maternal intake of diuretics (OR range 1.2, 5.8) in three studies. Three studies reported a decrease in risk for children with a history of allergic disease prior to neuroblastoma diagnosis (OR range 0.2, 0.4). The rarity of neuroblastoma makes this disease particularly challenging to study epidemiologically. We review the methodological limitations of prior research and make suggestions for further areas of study.

  4. The TP53 gene rs1042522 C>G polymorphism and neuroblastoma risk in Chinese children.

    PubMed

    He, Jing; Wang, Fenghua; Zhu, Jinhong; Zhang, Zhuorong; Zou, Yan; Zhang, Ruizhong; Yang, Tianyou; Xia, Huimin

    2017-03-08

    TP53, a tumor suppressor gene, plays a critical role in cell cycle control, apoptosis, and DNA damage repair. Previous studies have indicated that the TP53 gene Arg72Pro (rs1042522 C>G) polymorphism is associated with susceptibility to various types of cancer. We evaluated the association of the TP53 gene rs1042522 C>G polymorphism with neuroblastoma susceptibility in a hospital-based study among the Chinese Han population. Enrolled were 256 patients and 531 controls. Odds ratios (ORs) and 95% confidence intervals (CIs) generated using logistic regression models were used to determine the strength of the association of interest. No association was detected between rs1042522 C>G polymorphism and neuroblastoma risk. In our stratification analysis of age, gender, sites of origin, and clinical stages, we observed that subjects with rs1042522 CG/GG genotypes had a lower risk of developing neuroblastoma in the mediastinum (Adjusted OR=0.52, 95% CI=0.33-0.82, P=0.005) than those carrying the CC genotype. These results indicate that TP53 gene rs1042522 C>G polymorphism may exert a weak and site-specific effect on neuroblastoma risk in Southern Chinese children and warrant further confirmation.

  5. Lipid raft disruption protects mature neurons against amyloid oligomer toxicity.

    PubMed

    Malchiodi-Albedi, Fiorella; Contrusciere, Valentina; Raggi, Carla; Fecchi, Katia; Rainaldi, Gabriella; Paradisi, Silvia; Matteucci, Andrea; Santini, Maria Teresa; Sargiacomo, Massimo; Frank, Claudio; Gaudiano, Maria Cristina; Diociaiuti, Marco

    2010-04-01

    A specific neuronal vulnerability to amyloid protein toxicity may account for brain susceptibility to protein misfolding diseases. To investigate this issue, we compared the effects induced by oligomers from salmon calcitonin (sCTOs), a neurotoxic amyloid protein, on cells of different histogenesis: mature and immature primary hippocampal neurons, primary astrocytes, MG63 osteoblasts and NIH-3T3 fibroblasts. In mature neurons, sCTOs increased apoptosis and induced neuritic and synaptic damages similar to those caused by amyloid beta oligomers. Immature neurons and the other cell types showed no cytotoxicity. sCTOs caused cytosolic Ca(2+) rise in mature, but not in immature neurons and the other cell types. Comparison of plasma membrane lipid composition showed that mature neurons had the highest content in lipid rafts, suggesting a key role for them in neuronal vulnerability to sCTOs. Consistently, depletion in gangliosides protected against sCTO toxicity. We hypothesize that the high content in lipid rafts makes mature neurons especially vulnerable to amyloid proteins, as compared to other cell types; this may help explain why the brain is a target organ for amyloid-related diseases.

  6. Lactic acid oligomers (OLAs) as prodrug moieties.

    PubMed

    Kruse, J; Lachmann, B; Lauer, R; Eppacher, S; Noe, C R

    2013-02-01

    In this paper we propose the use of lactic acid oligomers (OLAs) as prodrug moieties. Two synthetic approaches are presented, on the one hand a non selective oligomerisation of lactic acid and on the other hand a block synthesis to tetramers of lactic acid. Dimers of lactic acid were investigated with respect to their plasma stability and their adsorption to albumine. Ibuprofen was chosen as the first drug for OLAylation. The ester 19 of LA(1)-ibuprofen was evaluated with respect to the degradation to human plasma and the adsorption to albumine. All results indicate that lactic acid oligomers are promising prodrug moieties.

  7. Improve T Cell Therapy in Neuroblastoma

    DTIC Science & Technology

    2015-09-01

    antibodies and T-cell immune responses elicited by tumor vaccine , we have combined the beneficial effects of both humoral and cell-mediated components of...the anti-neuroblastoma activity of CTLs expressing the GD2-specific CAR in two xenograft mouse models of neuroblastoma. Figure 1: Vaccination with...K562-derived whole-cell vaccine expressing CMV-pp65, CD40L and OX40L enhances antitumor effects of CAR-CMV- CTLs in vivo. Panel A. NOG/SCID/γc

  8. PHOX2B Is Associated with Neuroblastoma Cell Differentiation.

    PubMed

    Yang, Liqun; Ke, Xiao-Xue; Xuan, Fan; Tan, Juan; Hou, Jianbing; Wang, Mei; Cui, Hongjuan; Zhang, Yundong

    2016-03-01

    Neuroblastoma is a common pediatric malignancy that accounts for ∼15% of tumor-related deaths in children. The tumor is generally believed to originate from neural crest cells during early sympathetic neurogenesis. As the degree of neuroblastoma differentiation has been correlated with clinical outcome, clarifying the molecular mechanisms that drive neuroblastoma progression and differentiation is important for increasing the survival of these patients. In a previous study, the authors identified paired-like homeobox 2b (PHOX2B) as a key mediator of neuroblastoma pathogenesis in a TH-MYCN mouse model. In the present study, they aimed to define whether PHOX2B is also associated with proliferation and differentiation of human neuroblastoma cells. PHOX2B expression in neuroblastoma cells was evaluated by immunoblot analyses, and the effects of PHOX2B on the proliferation of neuroblastoma cells in vitro were determined using clonogenic and sphere formation assays. Xenograft experiments in NOD/SCID mice were used to examine the in vivo response to PHOX2B knockdown. Their data demonstrated that PHOX2B acts as a prognostic marker in neuroblastoma and that retinoic acid-induced neuronal differentiation downregulates PHOX2B expression, thereby suppressing the self-renewal capacity of neuroblastoma cells and inhibiting tumorigenicity. These findings confirmed that PHOX2B is a key regulator of neuroblastoma differentiation and stemness maintenance and indicated that PHOX2B might serve as a potential therapeutic target in neuroblastoma patients.

  9. Tau Oligomers Associate with Inflammation in the Brain and Retina of Tauopathy Mice and in Neurodegenerative Diseases

    PubMed Central

    Nilson, Ashley N.; English, Kelsey C.; Gerson, Julia E.; Barton Whittle, T.; Nicolas Crain, C.; Xue, Judy; Sengupta, Urmi; Castillo-Carranza, Diana L.; Zhang, Wenbo; Gupta, Praveena; Kayed, Rakez

    2016-01-01

    It is well-established that inflammation plays an important role in Alzheimer’s disease (AD) and frontotemporal lobar dementia (FTLD). Inflammation and synapse loss occur in disease prior to the formation of larger aggregates, but the contribution of tau to inflammation has not yet been thoroughly investigated. Tau pathologically aggregates to form large fibrillar structures known as tangles. However, evidence suggests that smaller soluble aggregates, called oligomers, are the most toxic species and form prior to tangles. Furthermore, tau oligomers can spread to neighboring cells and between anatomically connected brain regions. In addition, recent evidence suggests that inspecting the retina may be a window to brain pathology. We hypothesized that there is a relationship between tau oligomers and inflammation, which are hallmarks of early disease. We conducted immunofluorescence and biochemical analyses on tauopathy mice, FTLD, and AD subjects. We showed that oligomers co-localize with astrocytes, microglia, and HMGB1, a pro-inflammatory cytokine. Additionally, we show that tau oligomers are present in the retina and are associated with inflammatory cells suggesting that the retina may be a valid non-invasive biomarker for brain pathology. These results suggest that there may be a toxic relationship between tau oligomers and inflammation. Therefore, the ability of tau oligomers to spread may initiate a feed-forward cycle in which tau oligomers induce inflammation, leading to neuronal damage, and thus more inflammation. Further mechanistic studies are warranted in order to understand this relationship, which may have critical implications for improving the treatment of tauopathies. PMID:27716675

  10. Designing Surface-Confined Coordination Oligomers

    SciTech Connect

    Altman, M.; Rachamim, M; Ichiki, T; Iron, M; Evmenenko, G; Dutta, P; van der Boom, M

    2010-01-01

    HOMO-LUMO engineering of coordination-based oligomers covalently bound to silicon or glass has been achieved by the use of a partially fluorinated chromophore (see graphic). The experimental and computationally derived physical chemical properties of these assemblies are compared to their non-fluorinated analogues.

  11. Glucosamine oligomers: 1. Preparation and characterization.

    PubMed

    Domard, A; Cartier, N

    1989-10-01

    Hydrolysis of chitosan in hot concentrated HCl led to chito-oligosaccharides [beta-(1----4) linked 2-amino-2-deoxy-D-glucose]. The time dependence of the distribution was studied. A convenient choice of the conditions for steric exclusion chromatography of these hydrolysates allowed the separation of the first 15 oligomers and of fractions up to DP = 40.

  12. Genetic Discoveries and Treatment Advances in Neuroblastoma

    PubMed Central

    Bagatell, Rochelle; Cohn, Susan L.

    2016-01-01

    Purpose of review Major advances in our understanding of the genetic basis of neuroblastoma and the role somatic alterations play in driving tumor growth have led to improvements in risk-stratified therapy and have provided the rationale for targeted therapies. In this review, we highlight current risk-based treatment approaches and discuss the opportunities and challenges of translating recent genomic discoveries into the clinic. Recent Findings Significant progress in the treatment of neuroblastoma has been realized using risk-based treatment strategies. Outcome has improved for all patients, including those classified as high-risk, although survival remains poor for this cohort. Integration of whole-genome DNA copy number and comprehensive molecular profiles into neuroblastoma classification systems will allow more precise prognostication and refined treatment assignment. Promising treatments that include targeted systemic radiotherapy, pathway-targeted small molecules, and therapy targeted at cell surface molecules are being evaluated in clinical trials, and recent genomic discoveries in relapsed tumor samples have led to the identification of new actionable mutations. Summary The integration of refined treatment stratification based on whole-genome profiles with therapeutics that target the molecular drivers of malignant behavior in neuroblastoma has the potential to dramatically improve survival with decreased toxicity. PMID:26576010

  13. Monoclonal Antibody Therapy for Advanced Neuroblastoma

    Cancer.gov

    NCI is sponsoring two clinical trials of a monoclonal antibody called ch14.18, in combination with other drugs, to see if the antibody may be helpful for children or young adults (up to age 21) with relapsed or refractory neuroblastoma.

  14. Capping of Aβ42 Oligomers by Small Molecule Inhibitors

    PubMed Central

    2015-01-01

    Aβ42 peptides associate into soluble oligomers and protofibrils in the process of forming the amyloid fibrils associated with Alzheimer’s disease. The oligomers have been reported to be more toxic to neurons than fibrils, and have been targeted by a wide range of small molecule and peptide inhibitors. With single touch atomic force microscopy (AFM), we show that monomeric Aβ42 forms two distinct types of oligomers, low molecular weight (MW) oligomers with heights of 1–2 nm and high MW oligomers with heights of 3–5 nm. In both cases, the oligomers are disc-shaped with diameters of ∼10–15 nm. The similar diameters suggest that the low MW species stack to form the high MW oligomers. The ability of Aβ42 inhibitors to interact with these oligomers is probed using atomic force microscopy and NMR spectroscopy. We show that curcumin and resveratrol bind to the N-terminus (residues 5–20) of Aβ42 monomers and cap the height of the oligomers that are formed at 1–2 nm. A second class of inhibitors, which includes sulindac sulfide and indomethacin, exhibit very weak interactions across the Aβ42 sequence and do not block the formation of the high MW oligomers. The correlation between N-terminal interactions and capping of the height of the Aβ oligomers provides insights into the mechanism of inhibition and the pathway of Aβ aggregation. PMID:25422864

  15. The Effect of Molecular Weight on the Composite Properties of Cured Phenylethynyl Terminated Imide Oligomers

    NASA Technical Reports Server (NTRS)

    Smith, J. G., Jr.; Connell, J. W.; Hergenrother, P. M.

    1997-01-01

    As part of a program to develop high temperature/high performance structural resins for aeronautical applications, imide oligomers containing terminal phenylethynyl groups with calculated number average molecular weights of 1250, 2500 and 5000 g/mol were prepared, characterized, and evaluated as adhesives and composite matrix resins. The goal of this work was to develop resin systems that are processable using conventional processing equipment into void free composites that exhibit high mechanical properties with long term high temperature durability, and are not affected by exposure to common aircraft fluids. The imide oligomers containing terminal phenylethynyl groups were fabricated into titanium adhesive specimens and IM-7 carbon fiber laminates under 0.1 - 1.4 MPa for 1 hr at 350-371 C. The lower molecular weight oligomers exhibited higher cured Tg, better processability, and better retention of mechanical properties at elevated temperature without significantly sacrificing toughness or damage tolerance than the higher molecular weight oligomer. The neat resin, adhesive and composite properties of the cured polymers will be presented.

  16. DOPAL derived alpha-synuclein oligomers impair synaptic vesicles physiological function

    PubMed Central

    Plotegher, N.; Berti, G.; Ferrari, E.; Tessari, I.; Zanetti, M.; Lunelli, L.; Greggio, E.; Bisaglia, M.; Veronesi, M.; Girotto, S.; Dalla Serra, M.; Perego, C.; Casella, L.; Bubacco, L.

    2017-01-01

    Parkinson’s disease is a neurodegenerative disorder characterized by the death of dopaminergic neurons and by accumulation of alpha-synuclein (aS) aggregates in the surviving neurons. The dopamine catabolite 3,4-dihydroxyphenylacetaldehyde (DOPAL) is a highly reactive and toxic molecule that leads to aS oligomerization by covalent modifications to lysine residues. Here we show that DOPAL-induced aS oligomer formation in neurons is associated with damage of synaptic vesicles, and with alterations in the synaptic vesicles pools. To investigate the molecular mechanism that leads to synaptic impairment, we first aimed to characterize the biochemical and biophysical properties of the aS-DOPAL oligomers; heterogeneous ensembles of macromolecules able to permeabilise cholesterol-containing lipid membranes. aS-DOPAL oligomers can induce dopamine leak in an in vitro model of synaptic vesicles and in cellular models. The dopamine released, after conversion to DOPAL in the cytoplasm, could trigger a noxious cycle that further fuels the formation of aS-DOPAL oligomers, inducing neurodegeneration. PMID:28084443

  17. Monte Carlo Simulation of Endlinking Oligomers

    NASA Technical Reports Server (NTRS)

    Hinkley, Jeffrey A.; Young, Jennifer A.

    1998-01-01

    This report describes initial efforts to model the endlinking reaction of phenylethynyl-terminated oligomers. Several different molecular weights were simulated using the Bond Fluctuation Monte Carlo technique on a 20 x 20 x 20 unit lattice with periodic boundary conditions. After a monodisperse "melt" was equilibrated, chain ends were linked whenever they came within the allowed bond distance. Ends remained reactive throughout, so that multiple links were permitted. Even under these very liberal crosslinking assumptions, geometrical factors limited the degree of crosslinking. Average crosslink functionalities were 2.3 to 2.6; surprisingly, they did not depend strongly on the chain length. These results agreed well with the degrees of crosslinking inferred from experiment in a cured phenylethynyl-terminated polyimide oligomer.

  18. Cure Chemistry of Phenylethynyl Terminated Oligomers

    NASA Technical Reports Server (NTRS)

    Wood, Karen H.; Orwoll, Robert A.; Young, Philip R.; Jensen, Brian J.; McNair, Harold M.

    1997-01-01

    The ability to process high performance polymers into quality, void-free composites has been significantly advanced using oligomers terminated with reactive groups which cure or crosslink at elevated temperature without the evolution of volatile byproducts. Several matrix resin systems of considerable interest to the aerospace community utilize phenylethynyl-terminated imide (PETI) technology to achieve this advantage. The present paper addresses the cure chemistry of PETI oligomers. The thermal cure of a low molecular weight model compound was studied using a variety of analytical techniques including differential scanning calorimetry, Fourier transform infrared spectroscopy, and liquid chromatography-mass spectroscopy. The studies indicate an extremely complex cure process. Many stable products were isolated and this paper reports current work on identification of those products. The intent of this research is to provide fundamental insight into the molecular structure of the cured PETI engineering materials so that performance and durability can be more fully assessed.

  19. Oligomer functionalized nanotubes and composites formed therewith

    DOEpatents

    Zettl, Alexander K; Sainsbury, Toby; Frechet, Jean M.J.

    2014-03-18

    Disclosed herein is a sequential functionalization methodology for the covalent modification of nanotubes with between one and four repeat units of a polymer. Covalent attachment of oligomer units to the surface of nanotubes results in oligomer units forming an organic sheath around the nanotubes, polymer-functionalized-nanotubes (P-NTs). P-NTs possess chemical functionality identical to that of the functionalizing polymer, and thus provide nanoscale scaffolds which may be readily dispersed within a monomer solution and participate in the polymerization reaction to form a polymer-nanotube/polymer composite. Formation of polymer in the presence of P-NTs leads to a uniform dispersion of nanotubes within the polymer matrix, in contrast to aggregated masses of nanotubes in the case of pristine-NTs. The covalent attachment of oligomeric units to the surface of nanotubes represents the formation of a functional nanoscale building block which can be readily dispersed and integrated within the polymer to form a novel composite material.

  20. Interaction of arginine oligomer with model membrane

    SciTech Connect

    Yi, Dandan . E-mail: yi_dandan@yahoo.com.cn; Guoming, Li; Gao, Li; Wei, Liang

    2007-08-10

    Short oligomers of arginine (R8) have been shown to cross readily a variety of biological barriers. A hypothesis was put forward that inverted micelles form in biological membranes in the presence of arginine oligomer peptides, facilitating their transfer through the membranes. In order to define the role of peptide-lipid interaction in this mechanism, we prepared liposomes as the model membrane to study the ability of R8 inducing calcein release from liposomes, the fusion of liposomes, R8 binding to liposomes and membrane disturbing activity of the bound R8. The results show that R8 binding to liposome membrane depends on lipid compositions, negative surface charge density and interior water phase pH values of liposomes. R8 has no activity to induce the leakage of calcein from liposomes or improve liposome fusion. R8 does not permeabilize through the membrane spontaneously. These peptides delivering drugs through membranes may depend on receptors and energy.

  1. Ethynyl terminated ester oligomers and polymers therefrom

    NASA Technical Reports Server (NTRS)

    Hergenrother, Paul M. (Inventor); hesives and composite matrices. (Inventor)

    1987-01-01

    A new class of ethynyl-terminated oligomers and the process for preparing same are disclosed. Upon the application of heat, with or without a catalyst, the ethynyl groups react to provide crosslinking and chain extension to increase the polymer use temperature and improve the polymer solvent resistance. These improved polyesters are potentially useful in packaging, magnetic tapes, capacitors, industrial belting, protective coatings, structural adhesives and composite matrices.

  2. New Acetylene-Terminated Quinoxaline Oligomers

    DTIC Science & Technology

    1982-03-01

    diketone . In this work, we tried other bases, but potassium t-butoxide and lithium t- butoxide gave unsatisfactory results. Synthesis of acetone adduct...the most expensive ingredient. We have previously been able to improve the synthesis of the bisglyoxals needed for these adhesives,2 and are now...general method of synthesis which have been developed is to first condense the quinoxallne oligomer with glyoxal end groups. 2 r ),-CO--CO-Ar--CO--C&O--j

  3. Identifying microRNAs that Regulate Neuroblastoma Cell Differentiation

    DTIC Science & Technology

    2015-10-01

    Award Number: W81XWH-13-1-0241 TITLE: Identifying that Regulate Neuroblastoma Cell Differentiation PRINCIPAL INVESTIGATOR: Dr. Liqin Du...inducing miRNA, miR- 449a. We examined the differentiation-inducing function of miR-449a in multiple neuroblastoma cell lines. We have demonstrated that...miR-449a functions as an inducer of cell differentiation in neuroblastoma cell lines with distinct genetic backgrounds, including the MYCN

  4. Neuroblastoma treatment in the post-genomic era.

    PubMed

    Esposito, Maria Rosaria; Aveic, Sanja; Seydel, Anke; Tonini, Gian Paolo

    2017-02-08

    Neuroblastoma is an embryonic malignancy of early childhood originating from neural crest cells and showing heterogeneous biological, morphological, genetic and clinical characteristics. The correct stratification of neuroblastoma patients within risk groups (low, intermediate, high and ultra-high) is critical for the adequate treatment of the patients.High-throughput technologies in the Omics disciplines are leading to significant insights into the molecular pathogenesis of neuroblastoma. Nonetheless, further study of Omics data is necessary to better characterise neuroblastoma tumour biology. In the present review, we report an update of compounds that are used in preclinical tests and/or in Phase I-II trials for neuroblastoma. Furthermore, we recapitulate a number of compounds targeting proteins associated to neuroblastoma: MYCN (direct and indirect inhibitors) and downstream targets, Trk, ALK and its downstream signalling pathways. In particular, for the latter, given the frequency of ALK gene deregulation in neuroblastoma patients, we discuss on second-generation ALK inhibitors in preclinical or clinical phases developed for the treatment of neuroblastoma patients resistant to crizotinib.We summarise how Omics drive clinical trials for neuroblastoma treatment and how much the research of biological targets is useful for personalised medicine. Finally, we give an overview of the most recent druggable targets selected by Omics investigation and discuss how the Omics results can provide us additional advantages for overcoming tumour drug resistance.

  5. Didymin: an orally active citrus flavonoid for targeting neuroblastoma.

    PubMed

    Singhal, Sharad S; Singhal, Sulabh; Singhal, Preeti; Singhal, Jyotsana; Horne, David; Awasthi, Sanjay

    2017-02-08

    Neuroblastoma, a rapidly growing yet treatment responsive cancer, is the third most common cancer of children and the most common solid tumor in infants. Unfortunately, neuroblastoma that has lost p53 function often has a highly treatment-resistant phenotype leading to tragic outcomes. In the context of neuroblastoma, the functions of p53 and MYCN (which is amplified in ~25% of neuroblastomas) are integrally linked because they are mutually transcriptionally regulated, and because they together regulate the catalytic activity of RNA polymerases. Didymin is a citrus-derived natural compound that kills p53 wild-type as well as drug-resistant p53-mutant neuroblastoma cells in culture. In addition, orally administered didymin causes regression of neuroblastoma xenografts in mouse models, without toxicity to non-malignant cells, neural tissues, or neural stem cells. RKIP is a Raf-inhibitory protein that regulates MYCN activation, is transcriptionally upregulated by didymin, and appears to play a key role in the anti-neuroblastoma actions of didymin. In this review, we discuss how didymin overcomes drug-resistance in p53-mutant neuroblastoma through RKIP-mediated inhibition of MYCN and its effects on GRK2, PKCs, Let-7 micro-RNA, and clathrin-dependent endocytosis by Raf-dependent and -independent mechanisms. In addition, we will discuss studies supporting potential clinical impact and translation of didymin as a low cost, safe, and effective oral agent that could change the current treatment paradigm for refractory neuroblastoma.

  6. Neonatal Sacrococcygeal Neuroblastoma Mimicking a Teratoma

    PubMed Central

    Lugo-Vicente, Humberto; Correa-Rivas, María; Bouet, Kary; Reyes Bou, Zayhara; Suleiman, Mohammed

    2017-01-01

    We reported the first case of a congenital intrapelvic presacral neuroblastoma in Puerto Rico managed in the early neonatal period. The preoperative diagnosis was a sacrococcygeal teratoma Altman stage IV classification. This case confirms the importance of a comprehensive physical examination and observation of low-risk newborn infants with a history of adequate prenatal care and an unremarkable fetal ultrasonogram during pregnancy. PMID:28116200

  7. [Unusual presentation of scurvy mimicking a neuroblastoma].

    PubMed

    Rethore, S; Leblond, P; Thebaud, E; Sonna, M; Legrand, C; Rocourt, N; Defachelles, A-S

    2011-01-01

    Scurvy, a disease related to ascorbic acid deficiency, remains rare in industrial countries. Ascorbic acid is a vitamin that intervenes most notably in the synthesis of collagen and catecholamines. We report the case of a 2-year-old boy hospitalized in a pediatric oncology unit because of an unusual presentation of scurvy revealed by pain and a significant increase in urinary catecholamine levels, raising fear of a neuroblastoma.

  8. HOXC9-Induced Differentiation in Neuroblastoma Development

    DTIC Science & Technology

    2014-10-01

    within the serine-glycine synthesis pathway were significantly enriched (Fig. 2A), including phosphoglycerate dehydrogenase (PHGDH), phosphoserine...one-carbon units for purine synthesis [11, 15-17]. Our findings provide the first line of direct evidence for increased activation of this biosynthetic...obtained evidence for selective activation of the serine- glycine synthesis pathway in mouse neuroblastoma stem cells. These findings provide the

  9. Action of HMGB1 on miR-221/222 cluster in neuroblastoma cell lines

    PubMed Central

    Mari, Emanuela; Zicari, Alessandra; Fico, Flavia; Massimi, Isabella; Martina, Lolli; Mardente, Stefania

    2016-01-01

    microRNA (miR/miRNA) are small non-coding RNAs that control gene expression at the post-transcriptional level by targeting mRNAs. Aberrant expression of miRNAs is often observed in different types of cancer. Specific miRNAs function as tumor suppressors or oncogenes and interfere with various aspects of carcinogenesis, including differentiation, proliferation and invasion. Upregulation of miRNAs 221 and 222 has been shown to induce a malignant phenotype in numerous human cancers via inhibition of phosphatase and tensin homolog (PTEN) expression. Neuroblastoma is the most common extracranial solid malignancy in children, which is characterized by cellular heterogeneity that corresponds to different clinical outcomes. The different cellular phenotypes are associated with different gene mutations and miRs that control genetic and epigenetic factors. For this reason miRs are considered a potential therapeutic target in neuroblastoma. The aim of the present study was to investigate the mechanisms by which extracellular high mobility group box 1 (HMGB1) promotes cell growth in neuroblastoma. SK-N-BE(2) and SH-SY5Y neuroblastoma derived cell lines were transfected with the antisense oligonucleotides, anti-miR-221 and −222, followed by treatment with HMGB1 to investigate the expression of the oncosuppressor PTEN. In this study, it was demonstrated that HMGB1, which is released by damaged cells and tumor cells, upregulates miR-221/222 oncogenic clusters in the two human neuroblastoma derived cell lines. The results revealed that the oncogenic cluster miRs 221/222 were more highly expressed by the most undifferentiated cell line [SK-N-BE(2)] compared with the the less tumorigenic cell line (SH-SY5Y) and that exogenous HMGB1 increases this expression. In addition, HMGB1 modulates PTEN expression via miR-221/222, as demonstrated by transiently blocking miR-221/222 with anti-sense oligonucleotides. These results may lead to the development of novel therapeutic strategies for

  10. Action of HMGB1 on miR-221/222 cluster in neuroblastoma cell lines.

    PubMed

    Mari, Emanuela; Zicari, Alessandra; Fico, Flavia; Massimi, Isabella; Martina, Lolli; Mardente, Stefania

    2016-09-01

    microRNA (miR/miRNA) are small non-coding RNAs that control gene expression at the post-transcriptional level by targeting mRNAs. Aberrant expression of miRNAs is often observed in different types of cancer. Specific miRNAs function as tumor suppressors or oncogenes and interfere with various aspects of carcinogenesis, including differentiation, proliferation and invasion. Upregulation of miRNAs 221 and 222 has been shown to induce a malignant phenotype in numerous human cancers via inhibition of phosphatase and tensin homolog (PTEN) expression. Neuroblastoma is the most common extracranial solid malignancy in children, which is characterized by cellular heterogeneity that corresponds to different clinical outcomes. The different cellular phenotypes are associated with different gene mutations and miRs that control genetic and epigenetic factors. For this reason miRs are considered a potential therapeutic target in neuroblastoma. The aim of the present study was to investigate the mechanisms by which extracellular high mobility group box 1 (HMGB1) promotes cell growth in neuroblastoma. SK-N-BE(2) and SH-SY5Y neuroblastoma derived cell lines were transfected with the antisense oligonucleotides, anti-miR-221 and -222, followed by treatment with HMGB1 to investigate the expression of the oncosuppressor PTEN. In this study, it was demonstrated that HMGB1, which is released by damaged cells and tumor cells, upregulates miR-221/222 oncogenic clusters in the two human neuroblastoma derived cell lines. The results revealed that the oncogenic cluster miRs 221/222 were more highly expressed by the most undifferentiated cell line [SK-N-BE(2)] compared with the the less tumorigenic cell line (SH-SY5Y) and that exogenous HMGB1 increases this expression. In addition, HMGB1 modulates PTEN expression via miR-221/222, as demonstrated by transiently blocking miR-221/222 with anti-sense oligonucleotides. These results may lead to the development of novel therapeutic strategies for

  11. Structural studies on HCN oligomers. [catalysts for prebiotic processes

    NASA Technical Reports Server (NTRS)

    Ferris, J. P.; Edelson, E. H.; Auyeung, J. M.; Joshi, P. C.

    1981-01-01

    NMR spectral studies on the HCN oligomers suggest the presence of carboxamide and urea groupings. The release of CO2, H2O, HCN, CH3CN, HCONH2 and pyridine on pyrolysis is consistent with the presence of these groupings as well as carboxylic acid groups. No basic primary amine groupings could be detected with fluorescamine. Hydrazinolysis of the HCN oligomers releases 10% of the amino acids normally released by acid hydrolysis. The oligomers give a positive biuret test but this is not due to the presence of peptide bonds. There is no conclusive evidence for the presence of peptide bonds in the HCN oligomers. No diglycine was detected on partial hydrolysis of the HCN oligomers at pH 8.5 suggesting that HCN oligomers were not a source of prebiotic peptides.

  12. Neuroblastoma with intracranial involvement: an ENSG Study.

    PubMed

    Shaw, P J; Eden, T

    1992-01-01

    We report the experience of the European Neuroblastoma Study Group (ENSG) with central nervous system (CNS) involvement of neuroblastoma. Among this series of intensively treated patients, CNS neuroblastoma was diagnosed by computerised tomography (CT) scanning, rather than by autopsy. Cranial disease occurred in 5% of ENSG patients. Of 11 patients with intracranial disease, 4 had disease in the posterior fossa, a site rarely reported previously. Furthermore, 5 cases had CNS metastases at a time when there was no detectable disease elsewhere, rather than as part of extensive relapse. The pattern of disease we observed, at least for those with parenchymal disease, is in keeping with arterial spread. Although CT scanning is the optimal modality for identifying CNS disease, 2 cases had normal head CT scans prior to the onset of CNS disease. As most patients had symptoms of raised intracranial pressure (RICP) at the time the CNS disease was diagnosed, there does not seem to be any indication for routine CT scanning of the head at diagnosis, but this should be performed as soon as any symptoms or signs appear. With patients living longer with their disease, vigilance must be maintained during follow-up.

  13. Translational compensation of genomic instability in neuroblastoma

    PubMed Central

    Dassi, Erik; Greco, Valentina; Sidarovich, Viktoryia; Zuccotti, Paola; Arseni, Natalia; Scaruffi, Paola; Paolo Tonini, Gian; Quattrone, Alessandro

    2015-01-01

    Cancer-associated gene expression imbalances are conventionally studied at the genomic, epigenomic and transcriptomic levels. Given the relevance of translational control in determining cell phenotypes, we evaluated the translatome, i.e., the transcriptome engaged in translation, as a descriptor of the effects of genetic instability in cancer. We performed this evaluation in high-risk neuroblastomas, which are characterized by a low frequency of point mutations or known cancer-driving genes and by the presence of several segmental chromosomal aberrations that produce gene-copy imbalances that guide aggressiveness. We thus integrated genome, transcriptome, translatome and miRome profiles in a representative panel of high-risk neuroblastoma cell lines. We identified a number of genes whose genomic imbalance was corrected by compensatory adaptations in translational efficiency. The transcriptomic level of these genes was predictive of poor prognosis in more than half of cases, and the genomic imbalances found in their loci were shared by 27 other tumor types. This homeostatic process is also not limited to copy number-altered genes, as we showed the translational stoichiometric rebalance of histone genes. We suggest that the translational buffering of fluctuations in these dose-sensitive transcripts is a potential driving process of neuroblastoma evolution. PMID:26399178

  14. DNA sequence similarity recognition by hybridization to short oligomers

    DOEpatents

    Milosavljevic, Aleksandar

    1999-01-01

    Methods are disclosed for the comparison of nucleic acid sequences. Data is generated by hybridizing sets of oligomers with target nucleic acids. The data thus generated is manipulated simultaneously with respect to both (i) matching between oligomers and (ii) matching between oligomers and putative reference sequences available in databases. Using data compression methods to manipulate this mutual information, sequences for the target can be constructed.

  15. Nuclear FOXO3 predicts adverse clinical outcome and promotes tumor angiogenesis in neuroblastoma

    PubMed Central

    Salvador, Christina; Meister, Bernhard; Kiechl-Kohlendorfer, Ursula; Müller, Thomas; Geiger, Kathrin; Sergi, Consolato; Obexer, Petra; Ausserlechner, Michael J.

    2016-01-01

    Neuroblastoma is the most frequent, extracranial solid tumor in children with still poor prognosis in stage IV disease. In this study, we analyzed FOXO3-phosphorylation and cellular localization in tumor biopsies and determined the function of this homeostasis regulator in vitro and in vivo. FOXO3-phosphorylation at threonine-32 (T32) and nuclear localization in biopsies significantly correlated with stage IV disease. DNA-damaging drugs induced nuclear accumulation of FOXO3, which was associated with elevated T32-phosphorylation in stage IV-derived neuroblastoma cells, thereby reflecting the in situ results. In contrast, hypoxic conditions repressed PKB-activity and caused dephosphorylation of FOXO3 in both, stroma-like SH-EP and high-stage-derived STA-NB15 cells. The activation of an ectopically-expressed FOXO3 in these cells reduced viability at normoxia, but promoted growth at hypoxic conditions and elevated VEGF-C-expression. In chorioallantoic membrane (CAM) assays STA-NB15 tumors with ectopic FOXO3 showed increased micro-vessel formation and, when xenografted into nude mice, a gene-dosage-dependent effect of FOXO3 in high-stage STA-NB15 cells became evident: low-level activation increased tumor-vascularization, whereas hyper-activation repressed tumor growth. The combined data suggest that, depending on the mode and intensity of activation, cellular FOXO3 acts as a homeostasis regulator promoting tumor growth at hypoxic conditions and tumor angiogenesis in high-stage neuroblastoma. PMID:27769056

  16. Amyloid β-protein oligomers and Alzheimer’s disease

    PubMed Central

    2013-01-01

    The oligomer cascade hypothesis, which states that oligomers are the initiating pathologic agents in Alzheimer’s disease, has all but supplanted the amyloid cascade hypothesis, which suggested that fibers were the key etiologic agents in Alzheimer’s disease. We review here the results of in vivo, in vitro and in silico studies of amyloid β-protein oligomers, and discuss important caveats that should be considered in the evaluation of these results. This article is divided into four sections that mirror the main approaches used in the field to better understand oligomers: (1) attempts to locate and examine oligomers in vivo in situ; that is, without removing these species from their environment; (2) studies involving oligomers extracted from human or animal tissues and the subsequent characterization of their properties ex vivo; (3) studies of oligomers that have been produced synthetically and studied using a reductionist approach in relatively simple in vitro biophysical systems; and (4) computational studies of oligomers in silico. These multiple orthogonal approaches have revealed much about the molecular and cell biology of amyloid β-protein. However, as informative as these approaches have been, the amyloid β-protein oligomer system remains enigmatic. PMID:24289820

  17. Polyetherurethane oligomers with aldehyde groups as additives for lubricating oils

    SciTech Connect

    Nikolaev, V.N.; Abramov, E.G.; Tenyushev, A.I.

    1995-01-01

    Polyetherurethane oligomers with aldehyde groups, which we synthesized from polyoxypropylene diols (molecular weight 500, 1000, 1500, 2000, or 3000) with toluene diisocyanate and salicylaldehyde, are of interest as additives for lubricating oils. The effects of these oligomers on the service properties and physicochemical characteristics of lubricating oils were investigated by methods prreviously described. As the lube base stocks we used castor oil, a polyoxypropylene diol and a polyethoxysiloxane. The oligomers are readily soluble in organic solvents and in the lube base stocks, and their solutions are stable during storage and use. We found that the optimal concentration of oligomers is 5%, providing the best lubricating properties, in particular the best antiwear properties.

  18. Functional characterization of a new p53 mutant generated by homozygous deletion in a neuroblastoma cell line

    SciTech Connect

    Nakamura, Yohko; Ozaki, Toshinori; Niizuma, Hidetaka; Ohira, Miki; Kamijo, Takehiko; Nakagawara, Akira . E-mail: akiranak@chiba-cc.jp

    2007-03-23

    p53 is a key modulator of a variety of cellular stresses. In human neuroblastomas, p53 is rarely mutated and aberrantly expressed in cytoplasm. In this study, we have identified a novel p53 mutant lacking its COOH-terminal region in neuroblastoma SK-N-AS cells. p53 accumulated in response to cisplatin (CDDP) and thereby promoting apoptosis in neuroblastoma SH-SY5Y cells bearing wild-type p53, whereas SK-N-AS cells did not undergo apoptosis. We found another p53 (p53{delta}C) lacking a part of oligomerization domain and nuclear localization signals in SK-N-AS cells. p53{delta}C was expressed largely in cytoplasm and lost the transactivation function. Furthermore, a 3'-part of the p53 locus was homozygously deleted in SK-N-AS cells. Thus, our present findings suggest that p53 plays an important role in the DNA-damage response in certain neuroblastoma cells and it seems to be important to search for p53 mutations outside DNA-binding domain.

  19. Macrocyclic 2,7-Anthrylene Oligomers.

    PubMed

    Yamamoto, Yuta; Wakamatsu, Kan; Iwanaga, Tetsuo; Sato, Hiroyasu; Toyota, Shinji

    2016-05-06

    A macrocyclic compound consisting of six 2,7-anthrylene units was successfully synthesized by Ni-mediated coupling of the corresponding dibromo precursor as a novel π-conjugated compound. This compound was sufficiently stable and soluble in organic solvents due to the presence of mesityl groups. X-ray analysis showed that the molecule had a nonplanar and hexagonal wheel-shaped framework of approximately S6 symmetry. The dynamic process between two S6 structures was observed by using the dynamic NMR technique, the barrier being 58 kJ mol(-1) . The spectroscopic properties of the hexamer were compared with those of analogous linear oligomers.

  20. Anharmonic Vibrational Dynamics of DNA Oligomers

    NASA Astrophysics Data System (ADS)

    Kühn, O.; Došlić, N.; Krishnan, G. M.; Fidder, H.; Heyne, K.

    Combining two-color infared pump-probe spectroscopy and anharmonic force field calculations we characterize the anharmonic coupling patterns between fingerprint modes and the hydrogen-bonded symmetric vNH2 stretching vibration in adenine-thymine dA20-dT20 DNA oligomers. Specifically, it is shown that the anharmonic coupling between the δNH2 bending and the vC4=O4 stretching vibration, both absorbing around 1665 cm-1, can be used to assign the vNH2 fundamental transition at 3215 cm-1 despite the broad background absorption of water.

  1. Dye-mediated photosensitization of murine neuroblastoma cells

    SciTech Connect

    Sieber, F.; Sieber-Blum, M.

    1986-04-01

    The purpose of this study was to determine if photosensitization mediated by the fluorescent dye, merocyanine 540, could be used to preferentially kill murine neuroblastoma cells in simulated autologous remission marrow grafts. Simultaneous exposure of Neuro 2a or NB41A3 neuroblastoma cells to merocyanine 540 and white light reduced the concentration of in vitro-clonogenic tumor cells 50,000-fold. By contrast, the same treatment had little effect on the graft's ability to rescue lethally irradiated syngeneic hosts. Lethally irradiated C57BL/6J X A/J F1 mice transplanted with photosensitized mixtures of neuroblastoma cells and normal marrow cells (1:100 or 1:10) survived without developing neuroblastomas. It is conceivable that merocyanine 540-mediated photosensitization will prove useful for the extracorporeal purging of residual neuroblastoma cells from human autologous remission marrow grafts.

  2. International consensus for neuroblastoma molecular diagnostics: report from the International Neuroblastoma Risk Group (INRG) Biology Committee.

    PubMed

    Ambros, P F; Ambros, I M; Brodeur, G M; Haber, M; Khan, J; Nakagawara, A; Schleiermacher, G; Speleman, F; Spitz, R; London, W B; Cohn, S L; Pearson, A D J; Maris, J M

    2009-05-05

    Neuroblastoma serves as a paradigm for utilising tumour genomic data for determining patient prognosis and treatment allocation. However, before the establishment of the International Neuroblastoma Risk Group (INRG) Task Force in 2004, international consensus on markers, methodology, and data interpretation did not exist, compromising the reliability of decisive genetic markers and inhibiting translational research efforts. The objectives of the INRG Biology Committee were to identify highly prognostic genetic aberrations to be included in the new INRG risk classification schema and to develop precise definitions, decisive biomarkers, and technique standardisation. The review of the INRG database (n=8800 patients) by the INRG Task Force finally enabled the identification of the most significant neuroblastoma biomarkers. In addition, the Biology Committee compared the standard operating procedures of different cooperative groups to arrive at international consensus for methodology, nomenclature, and future directions. Consensus was reached to include MYCN status, 11q23 allelic status, and ploidy in the INRG classification system on the basis of an evidence-based review of the INRG database. Standardised operating procedures for analysing these genetic factors were adopted, and criteria for proper nomenclature were developed. Neuroblastoma treatment planning is highly dependant on tumour cell genomic features, and it is likely that a comprehensive panel of DNA-based biomarkers will be used in future risk assignment algorithms applying genome-wide techniques. Consensus on methodology and interpretation is essential for uniform INRG classification and will greatly facilitate international and cooperative clinical and translational research studies.

  3. Cooperative Switching in Nanofibers of Azobenzene Oligomers

    NASA Astrophysics Data System (ADS)

    Weber, Christopher; Liebig, Tobias; Gensler, Manuel; Zykov, Anton; Pithan, Linus; Rabe, Jürgen P.; Hecht, Stefan; Bléger, David; Kowarik, Stefan

    2016-05-01

    Next-generation molecular devices and machines demand the integration of molecular switches into hierarchical assemblies to amplify the response of the system from the molecular level to the meso- or macro-scale. Here, we demonstrate that multi-azobenzene oligomers can assemble to form robust supramolecular nanofibers in which they can be switched repeatedly between the E- and Z-configuration. While in isolated oligomers the azobenzene units undergo reversible photoisomerization independently, in the nanofibers they are coupled via intermolecular interactions and switch cooperatively as evidenced by unusual thermal and kinetic behavior. We find that the photoisomerization rate from the Z-isomer to the E-isomer depends on the fraction of Z-azobenzene in the nanofibers, and is increased by more than a factor of 4 in Z-rich fibers when compared to E-rich fibers. This demonstrates the great potential of coupling individual photochromic units for increasing their quantum efficiency in the solid state with potential relevance for actuation and sensing.

  4. Computing highly specific and mismatch tolerant oligomers efficiently.

    PubMed

    Yamada, Tomoyuki; Morishita, Shinichi

    2003-01-01

    The sequencing of the genomes of a variety of species and the growing databases containing expressed sequence tags (ESTs) and complementary DNAs (cDNAs) facilitate the design of highly specific oligomers for use as genomic markers, PCR primers, or DNA oligo microarrays. The first step in evaluating the specificity of short oligomers of about twenty units in length is to determine the frequencies at which the oligomers occur. However, for oligomers longer than about fifty units this is not efficient, as they usually have a frequency of only 1. A more suitable procedure is to consider the mismatch tolerance of an oligomer, that is, the minimum number of mismatches that allows a given oligomer to match a sub-sequence other than the target sequence anywhere in the genome or the EST database. However, calculating the exact value of mismatch tolerance is computationally costly and impractical. Therefore, we studied the problem of checking whether an oligomer meets the constraint that its mismatch tolerance is no less than a given threshold. Here, we present an efficient dynamic programming algorithm solution that utilizes suffix and height arrays. We demonstrated the effectiveness of this algorithm by efficiently computing a dense list of oligo-markers applicable to the human genome. Experimental results show that the algorithm runs faster than well-known Abrahamson's algorithm by orders of magnitude and is able to enumerate 63% to approximately 79% of qualified oligomers.

  5. Computing highly specific and noise-tolerant oligomers efficiently.

    PubMed

    Yamada, Tomoyuki; Morishita, Shinichi

    2004-03-01

    The sequencing of the genomes of a variety of species and the growing databases containing expressed sequence tags (ESTs) and complementary DNAs (cDNAs) facilitate the design of highly specific oligomers for use as genomic markers, PCR primers, or DNA oligo microarrays. The first step in evaluating the specificity of short oligomers of about 20 units in length is to determine the frequencies at which the oligomers occur. However, for oligomers longer than about fifty units this is not efficient, as they usually have a frequency of only 1. A more suitable procedure is to consider the mismatch tolerance of an oligomer, that is, the minimum number of mismatches that allows a given oligomer to match a substring other than the target sequence anywhere in the genome or the EST database. However, calculating the exact value of mismatch tolerance is computationally costly and impractical. Therefore, we studied the problem of checking whether an oligomer meets the constraint that its mismatch tolerance is no less than a given threshold. Here, we present an efficient dynamic programming algorithm solution that utilizes suffix and height arrays. We demonstrated the effectiveness of this algorithm by efficiently computing a dense list of numerous oligo-markers applicable to the human genome. Experimental results show that the algorithm runs faster than well-known Abrahamson's algorithm by orders of magnitude and is able to enumerate 65% approximately 76% of qualified oligomers.

  6. Management of Neuroblastoma: ICMR Consensus Document.

    PubMed

    Bansal, Deepak; Totadri, Sidharth; Chinnaswamy, Girish; Agarwala, Sandeep; Vora, Tushar; Arora, Brijesh; Prasad, Maya; Kapoor, Gauri; Radhakrishnan, Venkatraman; Laskar, Siddharth; Kaur, Tanvir; Rath, G K; Bakhshi, Sameer

    2017-04-03

    Neuroblastoma (NBL) is the most common extra-cranial solid tumor in childhood. High-risk NBL is considered challenging and has one of the least favourable outcomes amongst pediatric cancers. Primary tumor can arise anywhere along the sympathetic chain. Advanced disease at presentation is common. Diagnosis is established by tumor biopsy and elevated urinary catecholamines. Staging is performed using bone marrow and mIBG scan (FDG-PET/bone scan if mIBG unavailable or non-avid). Age, stage, histopathological grading, MYCN amplification and 11q aberration are important prognostic factors utilized in risk stratification. Low-risk disease including Stage 1 and asymptomatic Stage 2 disease has an excellent prognosis with non-mutilating surgery alone. Perinatal adrenal neuroblastoma may be managed with close observation alone. Intermediate-risk disease consisting largely of unresectable/symptomatic Stage 2/3 disease and infants with Stage 4 disease has good outcome with few cycles of chemotherapy followed by surgical resection. Paraspinal neuroblastomas with cord compression are treated emergently, typically with upfront chemotherapy. Asymptomatic Stage 4S disease may be followed closely without treatment. Organ dysfunction and age below 3 mo would warrant chemotherapy in 4S. High-risk disease includes older children with Stage 4 disease and MYCN amplified tumors. High-risk disease has a suboptimal outcome, though the survival is improving with multimodality therapy including autologous stem cell transplant and immunotherapy. Relapse after multimodality therapy is difficult to salvage. Late presentation, lack of transplant facility, malnutrition and treatment abandonment are additional hurdles for survival in India. The review provides a consensus document on management of NBL for developing countries, including India.

  7. Spinal deformity in children treated for neuroblastoma

    SciTech Connect

    Mayfield, J.K.; Riseborough, E.J.; Jaffe, N.; Nehme, M.E.

    1981-02-01

    Of seventy-four children who were treated at a mean age of seventeen months for neuroblastoma and survived more than five years, fifty-six had spinal deformity due either to the disease or to the treatment after a mean follow-up of 12.9 years. Of these fifty-six, 50 per cent had post-radiation scoliosis, and 16 per cent had post-radiation kyphosis, most frequently at the thoracolumbar junction, at the time of follow-up. Two kyphotic thoracolumbar curve patterns were identified: an angular kyphosis with a short radius of curvature and its apex at the twelfth thoracic and first lumbar vertebrae, and a thoracic kyphosis with a long radius of curvature that extended into the lumbar spine. The post-radiation deformity - both the scoliosis and the kyphosis - progressed with growth, the scoliosis at a rate of 1 degree per year and the kyphosis at a rate of 3 degrees per year. Epidural spread of the neuroblastoma was associated with most of the cases of severe scoliosis and kyphosis. The deformity was due either to the laminectomy or to the paraplegia acting in conjunction with the radiation. Eighteen per cent of 419 children with this malignant disease survived more than five years, and of the survivors, 20 per cent had spinal deformity severe enough to warrant treatment. The factors associated with the development of spinal deformity in patient treated for neuroblastoma were: orthovoltage radiation exceeding 3000 rads, asymmetrical radiation of the spine, thoracolumbar kyphosis, and epidural spread of the tumor.

  8. Origin and diversification of a metabolic cycle in oligomer world.

    PubMed

    Nishio, Tomoaki; Narikiyo, Osamu

    2013-02-01

    Based on the oligomer-world hypothesis we propose an abstract model where the molecular recognition among oligomers is described in the shape space. The origin of life in the oligomer world is regarded as the establishment of a metabolic cycle in a primitive cell. The cycle is sustained by the molecular recognition. If an original cell acquires the ability of the replication of oligomers, the relationship among oligomers changes due to the poor fidelity of the replication. This change leads to the diversification of metabolic cycles. The selection among diverse cycles is the basis of the evolution. The evolvability is one of the essential characters of life. We demonstrate the origin and diversification of the metabolic cycle by the computer simulation of our model. Such a simulation is expected to be the simplified demonstration of what actually occurred in the primordial soup. Our model describes an analog era preceding the digital era based on the genetic code.

  9. Non-aqueous dispersion coatings based on crystalline oligomers

    SciTech Connect

    Jones, F.N.

    1993-12-31

    Amorphous oligomers and polymers are generally used in coatings; crystalline ones are avoided because of the difficulty of achieving homogeneous, defect-free films. However, dispersions of crystalline oligomers offer potential advantages of stability, useful application rheology, and excellent film properties. The authors describe non-aqueous dispersions of mixtures of crystalline and amorphous oligomers. An example is a dispersion of mixtures of crystalline (at ambient temperature) hydroxyl-functional oligomer of terephthalic acid and 1,6-hexanediol mixed with an amorphous hydroxyl-functional oligomer of terephthalic acid and glycidyl neodecanote. Microscopy, WAXD and DSC indicate that the dispersion particles are crystalline and have a diameter of 5 to 20 {mu}m. The dispersions are stable and are thixotropic. Coatings formulated with melamine and polyisocyanate resin crosslinkers form glossy, transparent film with excellent mechanical properties.

  10. Atomic View of a Toxic Amyloid Small Oligomer

    SciTech Connect

    Laganowsky, Arthur; Liu, Cong; Sawaya, Michael R.; Whitelegge, Julian P.; Park, Jiyong; Zhao, Minglei; Pensalfini, Anna; Soriaga, Angela B.; Landau, Meytal; Teng, Poh K.; Cascio, Duilio; Glabe, Charles; Eisenberg, David

    2012-04-30

    Amyloid diseases, including Alzheimer's, Parkinson's, and the prion conditions, are each associated with a particular protein in fibrillar form. These amyloid fibrils were long suspected to be the disease agents, but evidence suggests that smaller, often transient and polymorphic oligomers are the toxic entities. Here, we identify a segment of the amyloid-forming protein {alpha}{beta} crystallin, which forms an oligomeric complex exhibiting properties of other amyloid oligomers: {beta}-sheet-rich structure, cytotoxicity, and recognition by an oligomer-specific antibody. The x-ray-derived atomic structure of the oligomer reveals a cylindrical barrel, formed from six antiparallel protein strands, that we term a cylindrin. The cylindrin structure is compatible with a sequence segment from the {beta}-amyloid protein of Alzheimer's disease. Cylindrins offer models for the hitherto elusive structures of amyloid oligomers.

  11. Glucosamine oligomers: 4. Solid state-crystallization and sustained dissolution.

    PubMed

    Domard, A; Cartier, N

    1992-04-01

    When glucosamine oligomers are stored in the solid state they undergo a process of crystallization. The extent to which this occurs depends on whether the samples are isolated in the -NH3+ or -NH2 form, on the storage time, and on the degree of polymerization of the isolated oligomer. The allomorph obtained by this process seems to correspond to the so-called 'tendon-chitosan'. Dissolution of such aged oligomer samples gives rise to a process of dissociation of the associated chains in the crystal, leading to the establishment of a pseudo-equilibrium between single and associated oligomer chains and hence the simultaneous presence of the 'monomeric', 'dimeric', 'trimeric', etc., forms of the oligomer. The phenomenon cannot be attributed to a process of aggregation in solution. The effects of various parameters on this behaviour have been investigated.

  12. Alpha-Synuclein Oligomers Interact with Metal Ions to Induce Oxidative Stress and Neuronal Death in Parkinson's Disease

    PubMed Central

    Deas, Emma; Cremades, Nunilo; Angelova, Plamena R.; Ludtmann, Marthe H.R.; Yao, Zhi; Chen, Serene; Horrocks, Mathew H.; Banushi, Blerida; Little, Daniel; Devine, Michael J.; Gissen, Paul; Klenerman, David; Dobson, Christopher M.; Wood, Nicholas W.

    2016-01-01

    Abstract Aims: Protein aggregation and oxidative stress are both key pathogenic processes in Parkinson's disease, although the mechanism by which misfolded proteins induce oxidative stress and neuronal death remains unknown. In this study, we describe how aggregation of alpha-synuclein (α-S) from its monomeric form to its soluble oligomeric state results in aberrant free radical production and neuronal toxicity. Results: We first demonstrate excessive free radical production in a human induced pluripotent stem-derived α-S triplication model at basal levels and on application of picomolar doses of β-sheet-rich α-S oligomers. We probed the effects of different structural species of α-S in wild-type rat neuronal cultures and show that both oligomeric and fibrillar forms of α-S are capable of generating free radical production, but that only the oligomeric form results in reduction of endogenous glutathione and subsequent neuronal toxicity. We dissected the mechanism of oligomer-induced free radical production and found that it was interestingly independent of several known cellular enzymatic sources. Innovation: The oligomer-induced reactive oxygen species (ROS) production was entirely dependent on the presence of free metal ions as addition of metal chelators was able to block oligomer-induced ROS production and prevent oligomer-induced neuronal death. Conclusion: Our findings further support the causative role of soluble amyloid oligomers in triggering neurodegeneration and shed light into the mechanisms by which these species cause neuronal damage, which, we show here, can be amenable to modulation through the use of metal chelation. Antioxid. Redox Signal. 24, 376–391. PMID:26564470

  13. Remote orbital recurrence of olfactory neuroblastoma (esthesioneuroblastoma).

    PubMed

    Breazzano, Mark P; Lewis, James S; Chambless, Lola B; Rohde, Sarah L; Sobel, Rachel K

    2017-03-31

    Olfactory neuroblastoma is a rare and often locally aggressive malignancy that invades the orbit via local destruction. It is known to recur in a delayed fashion, particularly to the neck lymph nodes. This is a case of a 65-year-old gentleman who presents with recurrence in the orbit and a neck lymph node 19 years after treatment for his initial disease. This report describes the longest known interval in orbital recurrence and should alert the monitoring physician that extreme delays in recurrence can occur.

  14. Aβ40 Oligomers Identified as a Potential Biomarker for the Diagnosis of Alzheimer's Disease

    PubMed Central

    Wang, Xuemei; Magdangal, Erika; Salisbury, Cleo; Peretz, David; Zuckermann, Ronald N.; Connolly, Michael D.; Hansson, Oskar; Minthon, Lennart; Zetterberg, Henrik; Blennow, Kaj; Fedynyshyn, Joseph P.; Allauzen, Sophie

    2010-01-01

    Alzheimer's Disease (AD) is the most prevalent form of dementia worldwide, yet the development of therapeutics has been hampered by the absence of suitable biomarkers to diagnose the disease in its early stages prior to the formation of amyloid plaques and the occurrence of irreversible neuronal damage. Since oligomeric Aβ species have been implicated in the pathophysiology of AD, we reasoned that they may correlate with the onset of disease. As such, we have developed a novel misfolded protein assay for the detection of soluble oligomers composed of Aβ x-40 and x-42 peptide (hereafter Aβ40 and Aβ42) from cerebrospinal fluid (CSF). Preliminary validation of this assay with 36 clinical samples demonstrated the presence of aggregated Aβ40 in the CSF of AD patients. Together with measurements of total Aβ42, diagnostic sensitivity and specificity greater than 95% and 90%, respectively, were achieved. Although larger sample populations will be needed to confirm this diagnostic sensitivity, our studies demonstrate a sensitive method of detecting circulating Aβ40 oligomers from AD CSF and suggest that these oligomers could be a powerful new biomarker for the early detection of AD. PMID:21209907

  15. Intersectin 1 is required for neuroblastoma tumorigenesis

    PubMed Central

    Russo, Angela; O'Bryan, John P.

    2011-01-01

    Intersectin 1 (ITSN1) is a scaffold protein that regulates diverse cellular pathways including endocytosis and several signal transduction pathways including phosphotidylinositol 3-kinase, Class IIβ (PI3K-C2β). ITSN1's transforming potential in vitro suggests that this scaffold protein may be involved in human tumorigenesis. Herein, we demonstrate that ITSN1 is expressed in primary human neuroblastoma tumors and tumor cell lines and is necessary for their in vitro and in vivo tumorigenic properties. Silencing ITSN1 dramatically inhibits the anchorage independent growth of tumor cells in vitro and tumor formation in xenograft assays independent of MYCN status. Overexpression of the ITSN1 target, PI3K-C2β, rescues the soft agar growth of ITSN1-silenced cells demonstrating the importance of the ITSN1-PI3K-C2β pathway in NB tumorigenesis. These findings represent the first demonstration that the ITSN1-PI3K-C2β pathway plays a requisite role in human cancer, specifically neuroblastomas. PMID:22266851

  16. Neuroblastoma: MIBG Imaging and New Tracers.

    PubMed

    Pfluger, Thomas; Piccardo, Arnoldo

    2017-03-01

    Neuroblastoma is an embryonic tumor of the peripheral sympathetic nervous system, and is metastatic or otherwise high risk for relapse in nearly 50% of cases, with a long-term survival of <40%. Therefore, exact staging with radiological and nuclear medicine imaging methods is crucial for finding the adequate therapeutic choice. The tumor cells express the norepinephrine transporter, which makes metaiodobenzylguanidine (MIBG), an analogue of norepinephrine, an ideal tumor-specific agent for imaging. On the contrary, MIBG imaging has several disadvantages such as limited spatial resolution, limited sensitivity in small lesions, need for two or even more acquisition sessions, and a delay between the start of the examination and result. Most of these limitations can be overcome with positron emission tomography (PET) using different radiotracers. Furthermore, for operative or biopsy planning, a combination with morphological imaging methods is indispensable. This article would discuss the therapeutic strategy for primary and follow-up diagnosis in neuroblastoma using MIBG scintigraphy and different new PET tracers as well as multimodality imaging.

  17. Soluble Aβ oligomer production and toxicity

    PubMed Central

    Larson, Megan E.; Lesné, Sylvain E.

    2011-01-01

    For nearly 100 years following the first description of this neurological disorder by Dr. Alois Alzheimer, amyloid plaques and neurofibrillary tangles have been hypothesized to cause neuronal loss. With evidence that the extent of insoluble, deposited amyloid poorly correlated with cognitive impairment, research efforts focused on soluble forms of Aβ, also referred as Aβ oligomers. Following a decade of studies, soluble oligomeric forms of Aβ are now believed to induce the deleterious cascade(s) involved in the pathophysiology of Alzheimer’s disease. In this review, we will discuss our current understanding about endogenous oligomeric Aβ production, their relative toxicity in vivo and in vitro, and explore the potential future directions needed for the field. PMID:22121920

  18. Syndrome of inappropriate antidiuretic hormone secretion associated with olfactory neuroblastoma.

    PubMed

    Yumusakhuylu, Ali Cemal; Binnetoglu, Adem; Topuz, Muhammet Fatih; Bozkurtlar, Emine Baş; Baglam, Tekin; Sari, Murat

    2013-11-01

    This study reports a patient having olfactory neuroblastoma complicated by syndrome of inappropriate antidiuretic hormone secretion. Olfactory neuroblastoma is a rare tumor that begins in the olfactory membrane. Only 10 cases have been reported previously. Because of having nonspecific symptoms, most patients manifest at an advanced stage at the time of diagnosis. Olfactory neuroblastoma may show local invasion and/or distant metastasis. We demonstrated preoperatively clinical and biochemical parameters consistent with antidiuretic hormone syndrome turned to normal ranges after the treatment. Surgery, chemotherapy, and radiotherapy are the choices of treatment; among these, surgery is an indispensible treatment.

  19. Structural and functional properties of prefibrillar α-synuclein oligomers.

    PubMed

    Pieri, Laura; Madiona, Karine; Melki, Ronald

    2016-04-14

    The deposition of fibrillar alpha-synuclein (α-syn) within inclusions (Lewy bodies and Lewy neurites) in neurons and glial cells is a hallmark of synucleinopathies. α-syn populates a variety of assemblies ranging from prefibrillar oligomeric species to fibrils whose specific contribution to neurodegeneration is still unclear. Here, we compare the specific structural and biological properties of distinct soluble prefibrillar α-syn oligomers formed either spontaneously or in the presence of dopamine and glutaraldehyde. We show that both on-fibrillar assembly pathway and distinct dopamine-mediated and glutaraldehyde-cross-linked α-syn oligomers are only slightly effective in perturbing cell membrane integrity and inducing cytotoxicity, while mature fibrils exhibit the highest toxicity. In contrast to low-molecular weight and unstable oligomers, large stable α-syn oligomers seed the aggregation of soluble α-syn within reporter cells although to a lesser extent than mature α-syn fibrils. These oligomers appear elongated in shape. Our findings suggest that α-syn oligomers represent a continuum of species ranging from unstable low molecular weight particles to mature fibrils via stable elongated oligomers composed of more than 15 α-syn monomers that possess seeding capacity.

  20. Toxic species in amyloid disorders: Oligomers or mature fibrils

    PubMed Central

    Verma, Meenakshi; Vats, Abhishek; Taneja, Vibha

    2015-01-01

    Protein aggregation is the hallmark of several neurodegenerative disorders. These protein aggregation (fibrillization) disorders are also known as amyloid disorders. The mechanism of protein aggregation involves conformation switch of the native protein, oligomer formation leading to protofibrils and finally mature fibrils. Mature fibrils have long been considered as the cause of disease pathogenesis; however, recent evidences suggest oligomeric intermediates formed during fibrillization to be toxic. In this review, we have tried to address the ongoing debate for these toxic amyloid species. We did an extensive literature search and collated information from Pubmed (http://www.ncbi.nlm.nih.gov) and Google search using various permutations and combinations of the following keywords: Neurodegeneration, amyloid disorders, protein aggregation, fibrils, oligomers, toxicity, Alzheimer's Disease, Parkinson's Disease. We describe different instances showing the toxicity of mature fibrils as well as oligomers in Alzheimer's Disease and Parkinson's Disease. Distinct structural framework and morphology of amyloid oligomers suggests difference in toxic effect between oligomers and fibrils. We highlight the difference in structure and proposed toxicity pathways for fibrils and oligomers. We also highlight the evidences indicating that intermediary oligomeric species can act as potential diagnostic biomarker. Since the formation of these toxic species follow a common structural switch among various amyloid disorders, the protein aggregation events can be targeted for developing broad-range therapeutics. The therapeutic trials based on the understanding of different protein conformers (monomers, oligomers, protofibrils and fibrils) in amyloid cascade are also described. PMID:26019408

  1. A Generic Method for Design of Oligomer-Specific Antibodies

    PubMed Central

    Brännström, Kristoffer; Lindhagen-Persson, Malin; Gharibyan, Anna L.; Iakovleva, Irina; Vestling, Monika; Sellin, Mikael E.; Brännström, Thomas; Morozova-Roche, Ludmilla; Forsgren, Lars; Olofsson, Anders

    2014-01-01

    Antibodies that preferentially and specifically target pathological oligomeric protein and peptide assemblies, as opposed to their monomeric and amyloid counterparts, provide therapeutic and diagnostic opportunities for protein misfolding diseases. Unfortunately, the molecular properties associated with oligomer-specific antibodies are not well understood, and this limits targeted design and development. We present here a generic method that enables the design and optimisation of oligomer-specific antibodies. The method takes a two-step approach where discrimination between oligomers and fibrils is first accomplished through identification of cryptic epitopes exclusively buried within the structure of the fibrillar form. The second step discriminates between monomers and oligomers based on differences in avidity. We show here that a simple divalent mode of interaction, as within e.g. the IgG isotype, can increase the binding strength of the antibody up to 1500 times compared to its monovalent counterpart. We expose how the ability to bind oligomers is affected by the monovalent affinity and the turnover rate of the binding and, importantly, also how oligomer specificity is only valid within a specific concentration range. We provide an example of the method by creating and characterising a spectrum of different monoclonal antibodies against both the Aβ peptide and α-synuclein that are associated with Alzheimer's and Parkinson's diseases, respectively. The approach is however generic, does not require identification of oligomer-specific architectures, and is, in essence, applicable to all polypeptides that form oligomeric and fibrillar assemblies. PMID:24618582

  2. Structural and functional properties of prefibrillar α-synuclein oligomers

    PubMed Central

    Pieri, Laura; Madiona, Karine; Melki, Ronald

    2016-01-01

    The deposition of fibrillar alpha-synuclein (α-syn) within inclusions (Lewy bodies and Lewy neurites) in neurons and glial cells is a hallmark of synucleinopathies. α-syn populates a variety of assemblies ranging from prefibrillar oligomeric species to fibrils whose specific contribution to neurodegeneration is still unclear. Here, we compare the specific structural and biological properties of distinct soluble prefibrillar α-syn oligomers formed either spontaneously or in the presence of dopamine and glutaraldehyde. We show that both on-fibrillar assembly pathway and distinct dopamine-mediated and glutaraldehyde-cross-linked α-syn oligomers are only slightly effective in perturbing cell membrane integrity and inducing cytotoxicity, while mature fibrils exhibit the highest toxicity. In contrast to low-molecular weight and unstable oligomers, large stable α-syn oligomers seed the aggregation of soluble α-syn within reporter cells although to a lesser extent than mature α-syn fibrils. These oligomers appear elongated in shape. Our findings suggest that α-syn oligomers represent a continuum of species ranging from unstable low molecular weight particles to mature fibrils via stable elongated oligomers composed of more than 15 α-syn monomers that possess seeding capacity. PMID:27075649

  3. Elucidating molecular mass and shape of a neurotoxic Aβ oligomer.

    PubMed

    Sebollela, Adriano; Mustata, Gina-Mirela; Luo, Kevin; Velasco, Pauline T; Viola, Kirsten L; Cline, Erika N; Shekhawat, Gajendra S; Wilcox, Kyle C; Dravid, Vinayak P; Klein, William L

    2014-12-17

    Alzheimer's disease (AD), the most prevalent type of dementia, has been associated with the accumulation of amyloid β oligomers (AβOs) in the central nervous system. AβOs vary widely in size, ranging from dimers to larger than 100 kDa. Evidence indicates that not all oligomers are toxic, and there is yet no consensus on the size of the actual toxic oligomer. Here we used NU4, a conformation-dependent anti-AβO monoclonal antibody, to investigate size and shape of a toxic AβO assembly. By using size-exclusion chromatography and immuno-based detection, we isolated an AβO-NU4 complex amenable for biochemical and morphological studies. The apparent molecular mass of the NU4-targeted oligomer was 80 kDa. Atomic force microscopy imaging of the AβO-NU4 complex showed a size distribution centered at 5.37 nm, an increment of 1.5 nm compared to the size of AβOs (3.85 nm). This increment was compatible with the size of NU4 (1.3 nm), suggesting a 1:1 oligomer to NU4 ratio. NU4-reactive oligomers extracted from AD human brain concentrated in a molecular mass range similar to that found for in vitro prepared oligomers, supporting the relevance of the species herein studied. These results represent an important step toward understanding the connection between AβO size and toxicity.

  4. Pramipexole prevents neurotoxicity induced by oligomers of beta-amyloid.

    PubMed

    Uberti, Daniela; Bianchi, Irene; Olivari, Luca; Ferrari-Toninelli, Giulia; Canonico, PierLuigi; Memo, Maurizio

    2007-08-27

    Here we demonstrate that pramipexole, an antiparkinsonian dopamine receptor agonist drug, exerts neuroprotective effects against beta-amyloid neurotoxicity. Using a specific protocol to test individually oligomers, fibrils, or unaggregated amyloid beta-peptide, we found pramipexole able to protect cells against oligomers and fibrils. Unaggregated amyloid beta-peptide was found unable to cause cell death. Fibrils and oligomers were also found to produce elevated amount of free radicals, and this effect was prevented by pramipexole. We propose pramipexole may become in the future a coadjuvant in the treatment of neuropathologies, besides Parkinson's disease, where amyloid beta-peptide-mediated oxidative injury exerts a relevant role.

  5. The slowly aggregating salmon Calcitonin: a useful tool for the study of the amyloid oligomers structure and activity.

    PubMed

    Diociaiuti, Marco; Gaudiano, Maria Cristina; Malchiodi-Albedi, Fiorella

    2011-01-01

    Amyloid proteins of different aminoacidic composition share the tendency to misfold and aggregate in a similar way, following common aggregation steps. The process includes the formation of dimers, trimers, and low molecular weight prefibrillar oligomers, characterized by the typical morphology of globules less than 10 nm diameter. The globules spontaneously form linear or annular structures and, eventually, mature fibers. The rate of this process depends on characteristics intrinsic to the different proteins and to environmental conditions (i.e., pH, ionic strength, solvent composition, temperature). In the case of neurodegenerative diseases, it is now generally agreed that the pathogenic aggregates are not the mature fibrils, but the intermediate, soluble oligomers. However, the molecular mechanism by which these oligomers trigger neuronal damage is still unclear. In particular, it is not clear if there is a peculiar structure at the basis of the neurotoxic effect and how this structure interacts with neurons. This review will focus on the results we obtained using salmon Calcitonin, an amyloid protein characterized by a very slow aggregation rate, which allowed us to closely monitor the aggregation process. We used it as a tool to investigate the characteristics of amyloid oligomers formation and their interactions with neuronal cells. Our results indicate that small globules of about 6 nm could be the responsible for the neurotoxic effects. Moreover, our data suggest that the rich content in lipid rafts of neuronal cell plasma membrane may render neurons particularly vulnerable to the amyloid protein toxic effect.

  6. Binding affinity of amyloid oligomers to cellular membranes is a generic indicator of cellular dysfunction in protein misfolding diseases.

    PubMed

    Evangelisti, Elisa; Cascella, Roberta; Becatti, Matteo; Marrazza, Giovanna; Dobson, Christopher M; Chiti, Fabrizio; Stefani, Massimo; Cecchi, Cristina

    2016-09-13

    The conversion of peptides or proteins from their soluble native states into intractable amyloid deposits is associated with a wide range of human disorders. Misfolded protein oligomers formed during the process of aggregation have been identified as the primary pathogenic agents in many such conditions. Here, we show the existence of a quantitative relationship between the degree of binding to neuronal cells of different types of oligomers formed from a model protein, HypF-N, and the GM1 content of the plasma membranes. In addition, remarkably similar behavior is observed for oligomers of the Aβ42 peptide associated with Alzheimer's disease. Further analysis has revealed the existence of a linear correlation between the level of the influx of Ca(2+) across neuronal membranes that triggers cellular damage, and the fraction of oligomeric species bound to the membrane. Our findings indicate that the susceptibility of neuronal cells to different types of misfolded oligomeric assemblies is directly related to the extent of binding of such oligomers to the cellular membrane.

  7. Binding affinity of amyloid oligomers to cellular membranes is a generic indicator of cellular dysfunction in protein misfolding diseases

    PubMed Central

    Evangelisti, Elisa; Cascella, Roberta; Becatti, Matteo; Marrazza, Giovanna; Dobson, Christopher M.; Chiti, Fabrizio; Stefani, Massimo; Cecchi, Cristina

    2016-01-01

    The conversion of peptides or proteins from their soluble native states into intractable amyloid deposits is associated with a wide range of human disorders. Misfolded protein oligomers formed during the process of aggregation have been identified as the primary pathogenic agents in many such conditions. Here, we show the existence of a quantitative relationship between the degree of binding to neuronal cells of different types of oligomers formed from a model protein, HypF-N, and the GM1 content of the plasma membranes. In addition, remarkably similar behavior is observed for oligomers of the Aβ42 peptide associated with Alzheimer’s disease. Further analysis has revealed the existence of a linear correlation between the level of the influx of Ca2+ across neuronal membranes that triggers cellular damage, and the fraction of oligomeric species bound to the membrane. Our findings indicate that the susceptibility of neuronal cells to different types of misfolded oligomeric assemblies is directly related to the extent of binding of such oligomers to the cellular membrane. PMID:27619987

  8. Constitutional Ip36 deletion in a child with neuroblastoma

    SciTech Connect

    Biegel, J.A.; Zackai, E.H.; Scher, C.D.; Emanuel, B.S. Univ. of Pennsylvania, Philadelphia ); White, P.S.; Marshall, H.N.; Fujimori, Minoru; Brodeur, G.M. )

    1993-01-01

    The authors describe a child with dysmorphic features, as well as developmental and growth delay, who developed neuroblastoma at 5 mo of age. Cytogenetic analysis of blood lymphocytes revealed an interstitial deletion of 1p36.1 [r arrow] 1p36.2, which was apparent only with high-resolution banding. Molecular analysis with a collection of polymorphic DNA probes for 1p confirmed an interstitial deletion involving subbands of 1p36. Deletions of this region are a common finding in neuroblastoma cells from patients with advanced stages of disease. Therefore, these results (a) suggest that constitutional deletion of this region predisposed the patient to the development of neuroblastoma and (b) support the localization of a neuroblastoma tumor-suppressor locus to 1p36. 48 refs., 2 figs.

  9. Synchronous Ipsilateral Wilms’ Tumor and Neuroblastoma in an Infant

    PubMed Central

    Thakkar, Nirali Chirag; Sinha, Shalini

    2016-01-01

    Wilms’ tumor (WT) and neuroblastoma (NB), the two most common extra-cranial solid malignant tumors, are seldom seen together in the same patient. A 10-month girl presented with a right retroperitoneal mass. A preoperative diagnosis of Wilms’ tumor (WT) was made. She was given preoperative chemotherapy followed by surgery. At surgery a renal mass (WT) and a suprarenal mass (neuroblastoma – NB) were removed. She finally succumbed to metastatic NB in the postoperative period. PMID:26816675

  10. Scintigraphy of a neuroblastoma with I-131 meta-iodobenzylguanidine

    SciTech Connect

    Kimmig, B.; Brandeis, W.E.; Eisenhut, M.; Bubeck, B.; Hermann, H.J.; zum Winkel, K.

    1984-07-01

    Radioiodinated m-iodobenzylguanidine has been applied mainly for the diagnosis of pheochromocytoma and blastoma. In this paper the author shows that an ontogenetically related tumor, the neuroblastoma, is also scintigraphically visualized by its high uptake of I-131 MIBG. Because of the kinetic findings and the high uptake of more than 30% of the injected activity, it is likely that the neuroblastoma, by analogy with pheochromocytoma, is susceptible to specific radionuclide therapy.

  11. Scintigraphy of a neuroblastoma with I-131 meta-iodobenzylguanidine

    SciTech Connect

    Kimmig, B.; Brandeis, W.E.; Eisenhut, M.; Bubeck, B.; Hermann, H.J.; Zum Winkel, K.

    1984-07-01

    Radioiodinated m-iodobenzylguanidine has been applied mainly for the diagnosis of pheochromocytoma and blastoma. In this paper the authors show that an ontogenetically related tumor, the neuroblastoma, is also scintigraphically visualized by its high uptake of I-131 MIBG. Because of the kinetic findings and the high uptake of more than 30% of the injected activity, it is likely that the neuroblastoma, by analogy with pheochromocytoma, is susceptible to specific radionuclide therapy.

  12. Rapamycin induces the anti-apoptotic protein survivin in neuroblastoma.

    PubMed

    Samkari, Ayman; Cooper, Zachary A; Holloway, Michael P; Liu, Jiebin; Altura, Rachel A

    2012-01-01

    Neuroblastoma is the most common solid tumor of infancy, accounting for 15% of all cancer cell deaths in children. Expression of the anti-apoptotic protein survivin in these tumors correlates with poor prognostic features and resistance to therapy. The mammalian target of rapamycin (mTOR) protein is being explored as a potential therapeutic target in patients with this disease. The objective of this study was to test the hypothesis that rapamycin regulates survivin expression and function in neuroblastoma cells. To explore this hypothesis, we treated two different neuroblastoma lines (NB7, NB8) and a well-characterized control lung cancer cell line, A549, with varying doses of rapamycin (0.1-10μM) for serial time points (2-48 hours). RNA and protein expression levels were then evaluated by quantitative RT-PCR and western blotting, respectively. Cell proliferation and apoptosis were assayed by WST-1 and Annexin V. The results showed a rapamycin-dependent increase in survivin mRNA and protein levels in the neuroblastoma cell lines in a dose- and time-dependent fashion, while a decrease in these levels was observed in control cells. Rapamycin inhibited cell proliferation in both A549 and neuroblastoma cells however neuroblastoma cells had less apoptosis than A549 cells (9% vs. 20%). In summary, our results indicate that rapamycin induces expression of the anti-apoptotic protein survivin in neuroblastoma cells which may protect these cells from programmed cell death. Induction of survivin by rapamycin could therefore be a potential mechanism of neuroblastoma tumor cell resistance and rapamycin may not be an effective therapeutic agent for these tumors.

  13. Natural Killer Cells to the Attack: Combination Therapy against Neuroblastoma.

    PubMed

    Zenarruzabeitia, Olatz; Vitallé, Joana; Astigarraga, Itziar; Borrego, Francisco

    2017-02-01

    TGFβ in the tumor microenvironment diminishes natural killer (NK) cell-mediated anti-disialoganglioside (anti-GD2) mAb elimination of neuroblastoma cells. Consequently, blockade of TGFβ signaling with galunisertib in combination with the anti-GD2 mAb dinutuximab plus adoptively transferred NK cells is a promising tool for the treatment of neuroblastoma. Clin Cancer Res; 23(3); 615-7. ©2016 AACRSee related article by Tran et al., p. 804.

  14. Congenital neuroblastoma in a neonate with isotretinoin embryopathy.

    PubMed

    Aguilar, Shiley; Louis, Chrystal; Hicks, John; Zage, Peter; Russell, Heidi

    2014-03-01

    We describe a neonate with isotretinoin embryopathy and an incidental finding of congenital neuroblastoma. Diffuse liver metastases led to the decision to provide oncologic therapy followed by tumor resection. Despite the possible need for chronic care related to the comorbidities of the isotretinoin embryopathy and oncologic management, the patient remains disease-free. Because of the uncertain etiology of neuroblastoma, it remains unclear whether exposure to isotretinoin during embryogenesis and fetal development had an oncogenic effect on this patient.

  15. Fractionated total body irradiation for metastatic neuroblastoma

    SciTech Connect

    Kun, L.E.; Casper, J.T.; Kline, R.W.; Piaskowski, V.D.

    1981-11-01

    Twelve patients over one year old with neuroblastoma (NBL) metastatic to bone and bone marrow entered a study of adjuvant low-dose, fractionated total body irradiation (TBI). Six children who achieved a ''complete clinical response'' following chemotherapy (cyclophosphamide and adriamycin) and surgical resection of the abdominal primary received TBI (10 rad/fraction to totals of 100-120 rad/10-12 fx/12-25 days). Two children received concurrent local irradiation for residual abdominal tumor. The intervals from cessation of chemotherapy to documented progression ranged from 2-16 months, not substatially different from patients receiving similar chemotherapy and surgery without TBI. Three additional children with progressive NBL received similar TBI (80-120 rad/8-12 fx) without objective response.

  16. Oligomer formation in the radiation-induced polymerization of styrene

    NASA Astrophysics Data System (ADS)

    Harayma, Hiroshi; Al-Sheikhly, Mohamad; Silverman, Joseph

    2003-12-01

    Analyses of the oligomers formed in radiation-induced polymerization of purified styrene were performed. The principal dimeric products were cis- and trans-diphenyl-cyclobutane with a relatively small amount of 1-phenyltetralin; the trimeric products were the optical isomers of 1-phenyl-4-[1'-phenylethyl-(1')]-tetralin in gamma-ray and 60 MeV proton irradiation. Oligomer formation increased with increasing dose, but more gradually than the linear formation of high polymer with dose. The yield was 0.25-3.1 μmol/J at low doses and decreased to an asymptotic value of 0.15 at higher doses. It appears that oligomers act as chain transfer agents during the polymerization reaction which would account for the observed decrease in molecular weight of the high polymer with increase in dose. Although the thermal and radiation-induced polymerization of styrene have different initiation steps, the oligomers produced by both reactions are similar in composition.

  17. Biomimetic peptoid oligomers as dual-action antifreeze agents

    PubMed Central

    Huang, Mia L.; Ehre, David; Jiang, Qi; Hu, Chunhua; Kirshenbaum, Kent; Ward, Michael D.

    2012-01-01

    The ability of natural peptides and proteins to influence the formation of inorganic crystalline materials has prompted the design of synthetic compounds for the regulation of crystal growth, including the freezing of water and growth of ice crystals. Despite their versatility and ease of structural modification, peptidomimetic oligomers have not yet been explored extensively as crystallization modulators. This report describes a library of synthetic N-substituted glycine peptoid oligomers that possess “dual-action” antifreeze activity as exemplified by ice crystal growth inhibition concomitant with melting temperature reduction. We investigated the structural features responsible for these phenomena and observed that peptoid antifreeze activities depend both on oligomer backbone structure and side chain chemical composition. These studies reveal the capability of peptoids to act as ice crystallization regulators, enabling the discovery of a unique and diverse family of synthetic oligomers with potential as antifreeze agents in food production and biomedicine. PMID:23169638

  18. HAUSP deubiquitinated and stabilizes N-Myc in neuroblastoma

    PubMed Central

    Tavana, Omid; Li, Dawei; Dai, Chao; Lopez, Gonzalo; Banerjee, Debarshi; Kon, Ning; Chen, Chao; Califano, Andrea; Yamashiro, Darrell J; Sun, Hongbin; Gu, Wei

    2016-01-01

    The MYCN protooncogene is amplified in a number of advanced-stage human tumors such as neuroblastomas. Like other members of Myc family proteins, N-Myc is a transcription factor and its stability and activity are tightly controlled by ubiquitination-dependent proteasome degradation1-4. Although numerous studies demonstrate that N-Myc acts as a driver of neuroblastoma tumorigenesis, therapies that directly suppress N-Myc activity in human tumors are limited. Here, we have identified the herpesvirus-associated ubiquitin-specific protease (HAUSP or USP75-7) as a regulator of N-Myc in neuroblastoma. HAUSP interacts with N-Myc, and HAUSP expression induces deubiquitination and subsequent stabilization of N-Myc. Conversely, RNAi-mediated knockdown of HAUSP in neuroblastoma cancer cell lines, or genetic ablation of Hausp in the mouse brain destabilizes N-Myc, which leads to inhibition of N-Myc function. Notably, HAUSP is more abundant in neuroblastoma patients with poorer prognosis and HAUSP expression significantly correlates with N-Myc transcriptional activity. Furthermore, small molecule inhibitors against HAUSP deubiquitinase activity significantly suppress the growth of MYCN-amplified human neuroblastoma cell lines in xenograft mouse models. Together, our findings demonstrate a crucial role of HAUSP in regulating N-Myc function in vivo and suggest that HAUSP inhibition is a potential therapy for MYCN-amplified tumors. PMID:27618649

  19. PHOX2B is a suppressor of neuroblastoma metastasis.

    PubMed

    Naftali, Osnat; Maman, Shelly; Meshel, Tsipi; Sagi-Assif, Orit; Ginat, Ravit; Witz, Isaac P

    2016-03-01

    Paired like homeobox 2B (PHOX2B) is a minimal residual disease (MRD) marker of neuroblastoma. The presence of MRD, also referred to as micro-metastases, is a powerful marker of poor prognosis in neuroblastoma. Lung metastasis is considered a terminal event in neuroblastoma. Lung micro-metastatic neuroblastoma (MicroNB) cells show high expression levels of PHOX2B and possess a less malignant and metastatic phenotype than lung macro metastatic neuroblastoma (MacroNB) cells, which hardly express PHOX2B. In vitro assays showed that PHOX2B knockdown in MicroNB cells did not affect cell viability; however it decreased the migratory capacity of the MicroNB-shPHOX2B cells. An orthotopic inoculation of MicroNB-shPHOX2B cells into the adrenal gland of nude mice resulted in significantly larger primary tumors and a heavier micro-metastatic load in the lungs and bone-marrow, than when control cells were inoculated. PHOX2B expression was found to be regulated by methylation. The PHOX2B promoter in MacroNB cells is significantly more methylated than in MicroNB cells. Demethylation assays using 5-azacytidine demonstrated that methylation can indeed inhibit PHOX2B transcription in MacroNB cells. These pre-clinical data strongly suggest that PHOX2B functions as a suppressor of neuroblastoma progression.

  20. Polysialic acid in human neuroblastoma cells

    SciTech Connect

    Livingston, B.D.; Jacobs, J.; Shaw, G.W.; Glick, M.C.; Troy, F.A.

    1987-05-01

    Prokaryotic-derived probes that specifically detect ..cap alpha..-2,8-linked polysialic acid (PSA) units on embryonic neural cell adhesion molecules (N-CAM) were used to show that membrane glycoproteins (GPs) from metastatic human neuroblastoma cells (CHP-134) also contain these unique carbohydrate moieties. This conclusion was based on the following evidence: (1) membranes from CHP-134 cells served as an exogenous acceptor of (/sup 14/C)NeuNAc units in an E. coli K1 sialyltransferase (ST) assay. The bacterial ST is specific for the transfer of (/sup 14/C)NeuNAc to exogenous acceptors containing at least 3 sialyl units (DP3); (2) in SDS-PAGE, the (/sup 14/C)NeuNAc-labeled CHP-134 membranes showed a major peak of radioactivity that was polydisperse. N-CAM shows a similar Mr heterogeneity; (3) treatment of the high Mr CHP-134 product with Endo-N-acetylneuraminidase (Endo-N) released the (/sup 14/C)NeuNAc label as a DP4. Endo-N is specific for hydrolysing ..cap alpha..-2,8-linked PSA chains containing a minimum of 5 sialyl residues; (4) treatment of the DP4 with sialidase converted the label to (/sup 14/C)NeuNAc, thus proving the tetramer contained sialic acid; (5) CHP-134 cells were labeled in vivo with (/sup 3/H)GlcN. A glycopeptide fraction representing ca. 1% of the (/sup 3/H)GlcN incorporated was isolated. Based on Endo-N sensitivity, this glycopeptide contained at least 15-20% of the (/sup 3/H)GlcN label as PSA. Endo-N digestion of the (/sup 3/H)-labeled glycopeptide released (/sup 3/H)-DP4. These results suggest that the surface expression of PSA-containing GPs may be important in neuroblastoma metastasis.

  1. Proton-Beam Therapy for Olfactory Neuroblastoma

    SciTech Connect

    Nishimura, Hideki . E-mail: westvill@med.kobe-u.ac.jp; Ogino, Takashi; Kawashima, Mitsuhiko; Nihei, Keiji; Arahira, Satoko; Onozawa, Masakatsu; Katsuta, Shoichi; Nishio, Teiji

    2007-07-01

    Purpose: To analyze the feasibility and efficacy of proton-beam therapy (PBT) for olfactory neuroblastoma (ONB) as a definitive treatment, by reviewing our preliminary experience. Olfactory neuroblastoma is a rare disease, and a standard treatment strategy has not been established. Radiation therapy for ONB is challenging because of the proximity of ONBs to critical organs. Proton-beam therapy can provide better dose distribution compared with X-ray irradiation because of its physical characteristics, and is deemed to be a feasible treatment modality. Methods and Materials: A retrospective review was performed on 14 patients who underwent PBT for ONB as definitive treatment at the National Cancer Center Hospital East (Kashiwa, Chiba, Japan) from November 1999 to February 2005. A total dose of PBT was 65 cobalt Gray equivalents (Gy{sub E}), with 2.5-Gy{sub E} once-daily fractionations. Results: The median follow-up period for surviving patients was 40 months. One patient died from disseminated disease. There were two persistent diseases, one of which was successfully salvaged with surgery. The 5-year overall survival rate was 93%, the 5-year local progression-free survival rate was 84%, and the 5-year relapse-free survival rate was 71%. Liquorrhea was observed in one patient with Kadish's stage C disease (widely destroying the skull base). Most patients experienced Grade 1 to 2 dermatitis in the acute phase. No other adverse events of Grade 3 or greater were observed according to the RTOG/EORTC acute and late morbidity scoring system. Conclusions: Our preliminary results of PBT for ONB achieved excellent local control and survival outcomes without serious adverse effects. Proton-beam therapy is considered a safe and effective modality that warrants further study.

  2. Identification and characterization of an aβ oligomer precipitating peptide that may be useful to explore gene therapeutic approaches to Alzheimer disease.

    PubMed

    Funke, Susanne Aileen; Liu, Hongmei; Sehl, Torsten; Bartnik, Dirk; Brener, Oleksandr; Nagel-Steger, Luitgard; Wiesehan, Katja; Willbold, Dieter

    2012-04-01

    A key feature of Alzheimer disease (AD) is the pathologic self-association of the amyloid-β (Aβ) peptide, leading to the formation of diffusible toxic Aβ oligomers and extracellular amyloid plaques. Next to extracellular Aβ, intraneuronal Aβ has important pathological functions in AD. Agents that specifically interfere with the oligomerization processes either outside or inside of neurons are highly desired for the elucidation of the pathologic mechanisms of AD and might even pave the way for new AD gene therapeutic approaches. Here, we characterize the Aβ binding peptide L3 and its influence on Aβ oligomerization in vitro. Preliminary studies in cell culture demonstrate that stably expressed L3 reduces cell toxicity of externally added Aβ in neuroblastoma cells.

  3. Natural killer cells facilitate PRAME-specific T-cell reactivity against neuroblastoma.

    PubMed

    Spel, Lotte; Boelens, Jaap-Jan; van der Steen, Dirk M; Blokland, Nina J G; van Noesel, Max M; Molenaar, Jan J; Heemskerk, Mirjam H M; Boes, Marianne; Nierkens, Stefan

    2015-11-03

    Neuroblastoma is the most common solid tumor in children with an estimated 5-year progression free survival of 20-40% in stage 4 disease. Neuroblastoma actively avoids recognition by natural killer (NK) cells and cytotoxic T lymphocytes (CTLs). Although immunotherapy has gained traction for neuroblastoma treatment, these immune escape mechanisms restrain clinical results. Therefore, we aimed to improve neuroblastoma immunogenicity to further the development of antigen-specific immunotherapy against neuroblastoma. We found that neuroblastoma cells significantly increase surface expression of MHC I upon exposure to active NK cells which thereby readily sensitize neuroblastoma cells for recognition by CTLs. We show that oncoprotein PRAME serves as an immunodominant antigen for neuroblastoma as NK-modulated neuroblastoma cells are recognized by PRAMESLLQHLIGL/A2-specific CTL clones. Furthermore, NK cells induce MHC I upregulation in neuroblastoma through contact-dependent secretion of IFNγ. Our results demonstrate remarkable plasticity in the peptide/MHC I surface expression of neuroblastoma cells, which is reversed when neuroblastoma cells experience innate immune attack by sensitized NK cells. These findings support the exploration of NK cells as adjuvant therapy to enforce neuroblastoma-specific CTL responses.

  4. Subdiffusion of proteins and oligomers on membranes

    NASA Astrophysics Data System (ADS)

    Lepzelter, David; Zaman, Muhammad

    2012-11-01

    Diffusion of proteins on lipid membranes plays a central role in cell signaling processes. From a mathematical perspective, most membrane diffusion processes are explained by the Saffman-Delbrück theory. However, recent studies have suggested a major limitation in the theoretical framework, the lack of complexity in the modeled lipid membrane. Lipid domains (sometimes termed membrane rafts) are known to slow protein diffusion, but there have been no quantitative theoretical examinations of how much diffusion is slowed in a general case. We provide an overall theoretical framework for confined-domain ("corralled") diffusion. Further, there have been multiple apparent contradictions of the basic conclusions of Saffman and Delbrück, each involving cases in which a single protein or an oligomer has multiple transmembrane regions passing through a lipid phase barrier. We present a set of corrections to the Saffman-Delbrück theory to account for these experimental observations. Our corrections are able to provide a quantitative explanation of numerous cellular signaling processes that have been considered beyond the scope of the Saffman-Delbrück theory, and may be extendable to other forms of subdiffusion.

  5. UBE4B Levels Are Correlated with Clinical Outcomes in Neuroblastoma Patients and with Altered Neuroblastoma Cell Proliferation and Sensitivity to EGFR Inhibitors

    PubMed Central

    Zage, Peter E.; Sirisaengtaksin, Natalie; Liu, Yin; Gireud, Monica; Brown, Brandon S.; Palla, Shana; Richards, Kristen N.; Hughes, Dennis P.M.; Bean, Andrew J.

    2012-01-01

    Background The UBE4B gene, located on chromosome 1p36, encodes a ubiquitin ligase that interacts with Hrs, a protein involved in EGFR trafficking, suggesting a link between EGFR trafficking and neuroblastoma pathogenesis. We have analyzed the roles of UBE4B in the outcomes of neuroblastoma patients and in neuroblastoma tumor cell proliferation, EGFR trafficking, and response to EGFR inhibition. Methods We examined the association of UBE4B expression with neuroblastoma patient survival using available microarray datasets. We measured UBE4B and EGFR protein levels in patient tumor samples and EGFR degradation rates in neuroblastoma cell lines and analyzed the effects of UBE4B on neuroblastoma tumor cell growth. The effects of the EGFR inhibitor cetuximab were examined in neuroblastoma cells expressing wild-type and mutant UBE4B. Results Low UBE4B gene expression is associated with poor outcomes in patients with neuroblastoma. UBE4B overexpression reduced neuroblastoma tumor cell proliferation, and UBE4B expression was inversely related to EGFR expression in patient tumor samples. EGFR degradation rates correlated with cellular UBE4B levels. Enhanced expression of catalytically active UBE4B resulted in reduced sensitivity to EGFR inhibition. Conclusions We have demonstrated associations between UBE4B expression and neuroblastoma patient outcomes and between UBE4B and EGFR expression in neuroblastoma tumor samples. Moreover, levels of UBE4B influenced neuroblastoma tumor cell proliferation, EGFR degradation, and response to EGFR inhibition. These results suggest UBE4B-mediated GFR trafficking may contribute to the poor prognosis of neuroblastoma tumors with 1p36 deletions, and that UBE4B expression may be a marker that can predict responses of neuroblastoma tumors to treatment. PMID:22990745

  6. Identification of GALNT14 as a novel neuroblastoma predisposition gene

    PubMed Central

    Chierici, Marco; Furlanello, Cesare; Conte, Massimo; Garaventa, Alberto; Croce, Michela; Ferrini, Silvano; Tonini, Gian Paolo; Longo, Luca

    2015-01-01

    Although several genes have been associated to neuroblastoma (NB) predisposition and aggressiveness, further genes are likely involved in the overall risk of developing this pediatric cancer. We thus carried out whole-exome sequencing on germline DNA from two affected second cousins and two unlinked healthy relatives from a large family with hereditary NB. Bioinformatics analysis revealed 6999 variations that were exclusively shared by the two familial NB cases. We then considered for further analysis all unknown or rare missense mutations, which involved 30 genes. Validation and analysis of these variants led to identify a GALNT14 mutation (c.802C > T) that properly segregated in the family and was predicted as functionally damaging by PolyPhen2 and SIFT. Screening of 8 additional NB families and 167 sporadic cases revealed this GALNT14 mutation in the tumors of two twins and in the germline of one sporadic NB patient. Moreover, a significant association between MYCN amplification and GALNT14 expression was observed in both NB patients and cell lines. Also, GALNT14 higher expression is associated with a worse OS in a public dataset of 88 NB samples (http://r2.amc.nl). GALNT14 is a member of the polypeptide N-acetylgalactosaminyl-transferase family and maps closely to ALK on 2p23.1, a region we previously discovered in linkage with NB in the family here considered. The aberrant function of GALNTs can result in altered glycoproteins that have been associated to the promotion of tumor aggressiveness in various cancers. Although rare, the recurrence of this mutation suggests GALNT14 as a novel gene potentially involved in NB predisposition. PMID:26309160

  7. Telomerase activation by genomic rearrangements in high-risk neuroblastoma.

    PubMed

    Peifer, Martin; Hertwig, Falk; Roels, Frederik; Dreidax, Daniel; Gartlgruber, Moritz; Menon, Roopika; Krämer, Andrea; Roncaioli, Justin L; Sand, Frederik; Heuckmann, Johannes M; Ikram, Fakhera; Schmidt, Rene; Ackermann, Sandra; Engesser, Anne; Kahlert, Yvonne; Vogel, Wenzel; Altmüller, Janine; Nürnberg, Peter; Thierry-Mieg, Jean; Thierry-Mieg, Danielle; Mariappan, Aruljothi; Heynck, Stefanie; Mariotti, Erika; Henrich, Kai-Oliver; Gloeckner, Christian; Bosco, Graziella; Leuschner, Ivo; Schweiger, Michal R; Savelyeva, Larissa; Watkins, Simon C; Shao, Chunxuan; Bell, Emma; Höfer, Thomas; Achter, Viktor; Lang, Ulrich; Theissen, Jessica; Volland, Ruth; Saadati, Maral; Eggert, Angelika; de Wilde, Bram; Berthold, Frank; Peng, Zhiyu; Zhao, Chen; Shi, Leming; Ortmann, Monika; Büttner, Reinhard; Perner, Sven; Hero, Barbara; Schramm, Alexander; Schulte, Johannes H; Herrmann, Carl; O'Sullivan, Roderick J; Westermann, Frank; Thomas, Roman K; Fischer, Matthias

    2015-10-29

    Neuroblastoma is a malignant paediatric tumour of the sympathetic nervous system. Roughly half of these tumours regress spontaneously or are cured by limited therapy. By contrast, high-risk neuroblastomas have an unfavourable clinical course despite intensive multimodal treatment, and their molecular basis has remained largely elusive. Here we have performed whole-genome sequencing of 56 neuroblastomas (high-risk, n = 39; low-risk, n = 17) and discovered recurrent genomic rearrangements affecting a chromosomal region at 5p15.33 proximal of the telomerase reverse transcriptase gene (TERT). These rearrangements occurred only in high-risk neuroblastomas (12/39, 31%) in a mutually exclusive fashion with MYCN amplifications and ATRX mutations, which are known genetic events in this tumour type. In an extended case series (n = 217), TERT rearrangements defined a subgroup of high-risk tumours with particularly poor outcome. Despite a large structural diversity of these rearrangements, they all induced massive transcriptional upregulation of TERT. In the remaining high-risk tumours, TERT expression was also elevated in MYCN-amplified tumours, whereas alternative lengthening of telomeres was present in neuroblastomas without TERT or MYCN alterations, suggesting that telomere lengthening represents a central mechanism defining this subtype. The 5p15.33 rearrangements juxtapose the TERT coding sequence to strong enhancer elements, resulting in massive chromatin remodelling and DNA methylation of the affected region. Supporting a functional role of TERT, neuroblastoma cell lines bearing rearrangements or amplified MYCN exhibited both upregulated TERT expression and enzymatic telomerase activity. In summary, our findings show that remodelling of the genomic context abrogates transcriptional silencing of TERT in high-risk neuroblastoma and places telomerase activation in the centre of transformation in a large fraction of these tumours.

  8. Correlation between the International Neuroblastoma Pathology Classification and genomic signature in neuroblastoma.

    PubMed

    Nakazawa, Atsuko; Haga, Chizuko; Ohira, Miki; Okita, Hajime; Kamijo, Takehiko; Nakagawara, Akira

    2015-06-01

    The International Neuroblastoma Pathology Classification (INPC) has a prognostic impact that distinguishes two categories of neuroblastoma: favorable histology (FH) and unfavorable histology (UH). We analyzed 92 cases of neuroblastoma with the INPC evaluation and genomic grouping to investigate the correlation between the INPC and genomic signature, together with their prognostic significance. The correlation of UH tumor and partial gains and/or losses (GGP), as well as the correlation of FH tumor and whole gains and/or losses (GGW), was statistically significant. Both UH and GGP were late-onset (median age at diagnosis was 36 and 48 months, respectively) and had poor prognosis (overall survival rate [OS], 43.1% and 42.4%, respectively). In contrast, both FH and GGW were early-onset (median age at diagnosis, 4 and 9.5 months, respectively) and had favorable prognosis (OS, 88.6% and 87.1%, respectively). Unfavorable histology and GGP had significantly inferior OS compared to FH and GGW. Overall survival was not significantly different among the genomic groups in FH; however, it was inferior in UH with GGP. In UH with a single copy MYCN, genomic subgroups GGP2s (both 1p and 11q losses) and GGP3s (partial 11q loss but not 1p loss) indicated significantly poor prognosis compared to GGP4s (no partial 1p and 11q loss). As INPC and MYCN amplification were found to be the most powerful prognostic biological factors, they should be included with genomic grouping as treatment stratification for patients with UH and single copy of MYCN.

  9. Functional Diversity of Isoamylase Oligomers: The ISA1 Homo-Oligomer Is Essential for Amylopectin Biosynthesis in Rice Endosperm1[W][OA

    PubMed Central

    Utsumi, Yoshinori; Utsumi, Chikako; Sawada, Takayuki; Fujita, Naoko; Nakamura, Yasunori

    2011-01-01

    Rice (Oryza sativa) endosperm has two isoamylase (ISA) oligomers, ISA1 homo-oligomer and ISA1-ISA2 hetero-oligomer. To examine their contribution to starch synthesis, expression of the ISA1 or ISA2 gene was differently regulated in various transgenic plants. Although suppression of ISA2 gene expression caused the endosperm to have only the homo-oligomer, no significant effects were detected on the starch phenotypes. In contrast, ISA2 overexpression led to endosperm having only the hetero-oligomer, and starch synthesis in the endosperm was drastically impaired, both quantitatively and qualitatively, because the starch was devoid of typical starch features, such as thermal and x-ray diffraction properties, and water-soluble highly branched maltodextrins were accumulated. In the ISA2 overexpressed line, about 60% to 70% of the ISA1-ISA2 hetero-oligomer was bound to starch, while the ISA homo- and hetero-oligomers from the wild type were mostly present in the soluble form at the early milking stage of the endosperm. Detailed analysis of the relative amounts of homo- and hetero-oligomers in various lines also led us to the conclusion that the ISA1 homo-oligomer is essential, but not the ISA1-ISA2 oligomer, for starch production in rice endosperm. The relative amounts of ISA1 and ISA2 proteins were shown to determine the ratio of both oligomers and the stoichiometry of both ISAs in the hetero-oligomer. It was noted when compared with the homo-oligomer that all the hetero-oligomers from rice endosperm and leaf and potato (Solanum tuberosum) tuber were much more stable at 40°C. This study provides substantial data on the structural and functional diversity of ISA oligomers between plant tissues and species. PMID:21436381

  10. Weightlessness influences the cytoskeleton and ROS level in SH-SY5Y neuroblastoma cells

    NASA Astrophysics Data System (ADS)

    Bo, Wang; Lina, Qu; Yingxian, Li; Qi, Li; Lei, Bi; Yinghui, Li

    During Spaceflight the nerve system of astronauts was obviously influenced To investigate how gravity effects nerve system the SH-SY5Y neuroblastoma cells were taken as research object By utilizing clinostat and parabolic flight for the model of gravity changing the level of reactive oxygen species was assayed in different time under simulated microgravity the cytomorphology and cytoskeleton of SH-SY5Y neuroblastoma cells were also observed after parabolic flight and clinostat by the conventional and the confocal laser scanning microscope The data showed that ROS level was enhanced and the cytoskeleton was damaged which microfilaments and microtubules were highly disorganized the cell shape was deteriorated under simulated microgravity indicating the relativity between the ROS level fluctuating and cytoskeleton changing It illuminates signal transduction disturbed by oxidative stress also regulates the cytoskeleton changing in SH-SY5Y cells The results suggest the cytoskeleton which is the receptor for sensing gravity was also regulated by cellular redox state which clues on the complexity of cell for self-adjusting to gravity changing

  11. Neuroblastoma patient-derived orthotopic xenografts retain metastatic patterns and geno- and phenotypes of patient tumours.

    PubMed

    Braekeveldt, Noémie; Wigerup, Caroline; Gisselsson, David; Mohlin, Sofie; Merselius, My; Beckman, Siv; Jonson, Tord; Börjesson, Anna; Backman, Torbjörn; Tadeo, Irene; Berbegall, Ana P; Ora, Ingrid; Navarro, Samuel; Noguera, Rosa; Påhlman, Sven; Bexell, Daniel

    2015-03-01

    Neuroblastoma is a childhood tumour with heterogeneous characteristics and children with metastatic disease often have a poor outcome. Here we describe the establishment of neuroblastoma patient-derived xenografts (PDXs) by orthotopic implantation of viably cryopreserved or fresh tumour explants of patients with high risk neuroblastoma into immunodeficient mice. In vivo tumour growth was monitored by magnetic resonance imaging and fluorodeoxyglucose-positron emission tomography. Neuroblastoma PDXs retained the undifferentiated histology and proliferative capacity of their corresponding patient tumours. The PDXs expressed neuroblastoma markers neural cell adhesion molecule, chromogranin A, synaptophysin and tyrosine hydroxylase. Whole genome genotyping array analyses demonstrated that PDXs retained patient-specific chromosomal aberrations such as MYCN amplification, deletion of 1p and gain of chromosome 17q. Thus, neuroblastoma PDXs recapitulate the hallmarks of high-risk neuroblastoma in patients. PDX-derived cells were cultured in serum-free medium where they formed free-floating neurospheres, expressed neuroblastoma gene markers MYCN, CHGA, TH, SYP and NPY, and retained tumour-initiating and metastatic capacity in vivo. PDXs showed much higher degree of infiltrative growth and distant metastasis as compared to neuroblastoma SK-N-BE(2)c cell line-derived orthotopic tumours. Importantly, the PDXs presented with bone marrow involvement, a clinical feature of aggressive neuroblastoma. Thus, neuroblastoma PDXs serve as clinically relevant models for studying and targeting high-risk metastatic neuroblastoma.

  12. In vitro synthesis and purification of PhIP-deoxyguanosine and PhIP-DNA oligomer covalent complexes

    SciTech Connect

    Freeman, J.

    1994-12-01

    2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a heterocyclic amine compound formed when meats are cooked at high temperatures. PhIP damages DNA by forming covalent complexes with DNA carcinogen. In an effort to understand how the binding of PhIP to DNA may cause cancer, it is important to characterize the structures of PhIP-damaged DNA molecules. Our HPLC data support fluorescence and {sup 32}P Post-labeling studies which indicate the formation of several species of 2{prime}deoxyguanosine-(dG) or oligodeoxynucleotide-PhIP adducts. The reaction of PhIP with dG resulted in a reddish precipitate that was likely the major adduct, N-(deoxyguanosin-8-yl)-PhIP (dG-C8-PhIP) adduct, with a more polar adduct fraction remaining in the supernatant. Reversed-phase HPLC analysis of the adducts in the supernatant revealed the existence of species of much shorter retention times than the dG-C8-PhIP adduct, confirming that these species are more polar than dG-C8-PhIP. At least four adducts were formed in the reaction of PhIP with DNA oligomer. HPLC analysis of the PhIP-DNA oligomer supernatant after butanol extractions revealed four unresolved peaks which spectra had maximum wavelengths between 340 and 360 nm. Though adduct peaks were not completely resolved, there was {approximately}3 minutes interval between the DNA oligomer peak and the adduct peaks. Furthermore, fluorescence emission data of the DNA oligomer-PhIP adduct solution show heterogeneous binding. The more polar PhIP adducts were fraction-collected and their structures will be solved by nuclear magnetic resonance or x-ray crystallography.

  13. Advances in Risk Classification and Treatment Strategies for Neuroblastoma

    PubMed Central

    Pinto, Navin R.; Applebaum, Mark A.; Volchenboum, Samuel L.; Matthay, Katherine K.; London, Wendy B.; Ambros, Peter F.; Nakagawara, Akira; Berthold, Frank; Schleiermacher, Gudrun; Park, Julie R.; Valteau-Couanet, Dominique; Pearson, Andrew D.J.

    2015-01-01

    Risk-based treatment approaches for neuroblastoma have been ongoing for decades. However, the criteria used to define risk in various institutional and cooperative groups were disparate, limiting the ability to compare clinical trial results. To mitigate this problem and enhance collaborative research, homogenous pretreatment patient cohorts have been defined by the International Neuroblastoma Risk Group classification system. During the past 30 years, increasingly intensive, multimodality approaches have been developed to treat patients who are classified as high risk, whereas patients with low- or intermediate-risk neuroblastoma have received reduced therapy. This treatment approach has resulted in improved outcome, although survival for high-risk patients remains poor, emphasizing the need for more effective treatments. Increased knowledge regarding the biology and genetic basis of neuroblastoma has led to the discovery of druggable targets and promising, new therapeutic approaches. Collaborative efforts of institutions and international cooperative groups have led to advances in our understanding of neuroblastoma biology, refinements in risk classification, and stratified treatment strategies, resulting in improved outcome. International collaboration will be even more critical when evaluating therapies designed to treat small cohorts of patients with rare actionable mutations. PMID:26304901

  14. A comprehensive characterization of rare mitochondrial DNA variants in neuroblastoma

    PubMed Central

    Pignataro, Piero; Lasorsa, Vito Alessandro; Hogarty, Michael D.; Castellano, Aurora; Conte, Massimo; Tonini, Gian Paolo; Iolascon, Achille; Gasparre, Giuseppe; Capasso, Mario

    2016-01-01

    Background Neuroblastoma, a tumor of the developing sympathetic nervous system, is a common childhood neoplasm that is often lethal. Mitochondrial DNA (mtDNA) mutations have been found in most tumors including neuroblastoma. We extracted mtDNA data from a cohort of neuroblastoma samples that had undergone Whole Exome Sequencing (WES) and also used snap-frozen samples in which mtDNA was entirely sequenced by Sanger technology. We next undertook the challenge of determining those mutations that are relevant to, or arisen during tumor development. The bioinformatics pipeline used to extract mitochondrial variants from matched tumor/blood samples was enriched by a set of filters inclusive of heteroplasmic fraction, nucleotide variability, and in silico prediction of pathogenicity. Results Our in silico multistep workflow applied both on WES and Sanger-sequenced neuroblastoma samples, allowed us to identify a limited burden of somatic and germline mitochondrial mutations with a potential pathogenic impact. Conclusions The few singleton germline and somatic mitochondrial mutations emerged, according to our in silico analysis, do not appear to impact on the development of neuroblastoma. Our findings are consistent with the hypothesis that most mitochondrial somatic mutations can be considered as ‘passengers’ and consequently have no discernible effect in this type of cancer. PMID:27351283

  15. Advances in Risk Classification and Treatment Strategies for Neuroblastoma.

    PubMed

    Pinto, Navin R; Applebaum, Mark A; Volchenboum, Samuel L; Matthay, Katherine K; London, Wendy B; Ambros, Peter F; Nakagawara, Akira; Berthold, Frank; Schleiermacher, Gudrun; Park, Julie R; Valteau-Couanet, Dominique; Pearson, Andrew D J; Cohn, Susan L

    2015-09-20

    Risk-based treatment approaches for neuroblastoma have been ongoing for decades. However, the criteria used to define risk in various institutional and cooperative groups were disparate, limiting the ability to compare clinical trial results. To mitigate this problem and enhance collaborative research, homogenous pretreatment patient cohorts have been defined by the International Neuroblastoma Risk Group classification system. During the past 30 years, increasingly intensive, multimodality approaches have been developed to treat patients who are classified as high risk, whereas patients with low- or intermediate-risk neuroblastoma have received reduced therapy. This treatment approach has resulted in improved outcome, although survival for high-risk patients remains poor, emphasizing the need for more effective treatments. Increased knowledge regarding the biology and genetic basis of neuroblastoma has led to the discovery of druggable targets and promising, new therapeutic approaches. Collaborative efforts of institutions and international cooperative groups have led to advances in our understanding of neuroblastoma biology, refinements in risk classification, and stratified treatment strategies, resulting in improved outcome. International collaboration will be even more critical when evaluating therapies designed to treat small cohorts of patients with rare actionable mutations.

  16. Neuroblastoma, a Paradigm for Big Data Science in Pediatric Oncology.

    PubMed

    Salazar, Brittany M; Balczewski, Emily A; Ung, Choong Yong; Zhu, Shizhen

    2016-12-27

    Pediatric cancers rarely exhibit recurrent mutational events when compared to most adult cancers. This poses a challenge in understanding how cancers initiate, progress, and metastasize in early childhood. Also, due to limited detected driver mutations, it is difficult to benchmark key genes for drug development. In this review, we use neuroblastoma, a pediatric solid tumor of neural crest origin, as a paradigm for exploring "big data" applications in pediatric oncology. Computational strategies derived from big data science-network- and machine learning-based modeling and drug repositioning-hold the promise of shedding new light on the molecular mechanisms driving neuroblastoma pathogenesis and identifying potential therapeutics to combat this devastating disease. These strategies integrate robust data input, from genomic and transcriptomic studies, clinical data, and in vivo and in vitro experimental models specific to neuroblastoma and other types of cancers that closely mimic its biological characteristics. We discuss contexts in which "big data" and computational approaches, especially network-based modeling, may advance neuroblastoma research, describe currently available data and resources, and propose future models of strategic data collection and analyses for neuroblastoma and other related diseases.

  17. Stromal heparan sulfate differentiates neuroblasts to suppress neuroblastoma growth.

    PubMed

    Knelson, Erik H; Gaviglio, Angela L; Nee, Jasmine C; Starr, Mark D; Nixon, Andrew B; Marcus, Stephen G; Blobe, Gerard C

    2014-07-01

    Neuroblastoma prognosis is dependent on both the differentiation state and stromal content of the tumor. Neuroblastoma tumor stroma is thought to suppress neuroblast growth via release of soluble differentiating factors. Here, we identified critical growth-limiting components of the differentiating stroma secretome and designed a potential therapeutic strategy based on their central mechanism of action. We demonstrated that expression of heparan sulfate proteoglycans (HSPGs), including TβRIII, GPC1, GPC3, SDC3, and SDC4, is low in neuroblasts and high in the Schwannian stroma. Evaluation of neuroblastoma patient microarray data revealed an association between TGFBR3, GPC1, and SDC3 expression and improved prognosis. Treatment of neuroblastoma cell lines with soluble HSPGs promoted neuroblast differentiation via FGFR1 and ERK phosphorylation, leading to upregulation of the transcription factor inhibitor of DNA binding 1 (ID1). HSPGs also enhanced FGF2-dependent differentiation, and the anticoagulant heparin had a similar effect, leading to decreased neuroblast proliferation. Dissection of individual sulfation sites identified 2-O, 3-O-desulfated heparin (ODSH) as a differentiating agent, and treatment of orthotopic xenograft models with ODSH suppressed tumor growth and metastasis without anticoagulation. These studies support heparan sulfate signaling intermediates as prognostic and therapeutic neuroblastoma biomarkers and demonstrate that tumor stroma biology can inform the design of targeted molecular therapeutics.

  18. Day care, childhood infections, and risk of neuroblastoma

    PubMed Central

    Menegaux, Florence; Olshan, Andrew F.; Neglia, Joseph P.; Pollock, Brad H.; Bondy, Melissa L.

    2004-01-01

    Neuroblastoma is the most common cancer in infants worldwide but little is known about its etiology. Infectious etiologies involving the immune system have been hypothesized for some childhood cancers, especially leukemia, but the role of infectious agents in neuroblastoma has not been fully investigated. We used data from a large case-control study conducted by the Children’s Oncology Group over the period 1992–1994 in United States or Canada to investigate if there was any relation between day care attendance, childhood infections, allergies and neuroblastoma. We interviewed mothers of 538 case and 504 age-matched control children by telephone about several factors including pregnancy, medical history, lifestyle, and childhood medical conditions and exposures. Our results suggested decreased risks associated with day care attendance (odds ratio (OR) = 0.81; 95% confidence interval ([CI]: 0.56–1.17), childhood infectious diseases (chickenpox, mumps, red and German measles) (OR = 0.60;CI: 0.39–0.93) and allergies (OR = 0.68; CI: 0.44–1.07). We found reduced neuroblastoma risk associated with markers of potential childhood infections, which suggests a possible role of infectious agents in neuroblastoma etiology. Future epidemiologic studies should incorporate more direct infection data. PMID:15105177

  19. Neuroblastoma, a Paradigm for Big Data Science in Pediatric Oncology

    PubMed Central

    Salazar, Brittany M.; Balczewski, Emily A.; Ung, Choong Yong; Zhu, Shizhen

    2016-01-01

    Pediatric cancers rarely exhibit recurrent mutational events when compared to most adult cancers. This poses a challenge in understanding how cancers initiate, progress, and metastasize in early childhood. Also, due to limited detected driver mutations, it is difficult to benchmark key genes for drug development. In this review, we use neuroblastoma, a pediatric solid tumor of neural crest origin, as a paradigm for exploring “big data” applications in pediatric oncology. Computational strategies derived from big data science–network- and machine learning-based modeling and drug repositioning—hold the promise of shedding new light on the molecular mechanisms driving neuroblastoma pathogenesis and identifying potential therapeutics to combat this devastating disease. These strategies integrate robust data input, from genomic and transcriptomic studies, clinical data, and in vivo and in vitro experimental models specific to neuroblastoma and other types of cancers that closely mimic its biological characteristics. We discuss contexts in which “big data” and computational approaches, especially network-based modeling, may advance neuroblastoma research, describe currently available data and resources, and propose future models of strategic data collection and analyses for neuroblastoma and other related diseases. PMID:28035989

  20. A Metastatic Mouse Model Identifies Genes That Regulate Neuroblastoma Metastasis.

    PubMed

    Seong, Bo Kyung A; Fathers, Kelly E; Hallett, Robin; Yung, Christina K; Stein, Lincoln D; Mouaaz, Samar; Kee, Lynn; Hawkins, Cynthia E; Irwin, Meredith S; Kaplan, David R

    2017-02-01

    Metastatic relapse is the major cause of death in pediatric neuroblastoma, where there remains a lack of therapies to target this stage of disease. To understand the molecular mechanisms mediating neuroblastoma metastasis, we developed a mouse model using intracardiac injection and in vivo selection to isolate malignant cell subpopulations with a higher propensity for metastasis to bone and the central nervous system. Gene expression profiling revealed primary and metastatic cells as two distinct cell populations defined by differential expression of 412 genes and of multiple pathways, including CADM1, SPHK1, and YAP/TAZ, whose expression independently predicted survival. In the metastatic subpopulations, a gene signature was defined (MET-75) that predicted survival of neuroblastoma patients with metastatic disease. Mechanistic investigations demonstrated causal roles for CADM1, SPHK1, and YAP/TAZ in mediating metastatic phenotypes in vitro and in vivo Notably, pharmacologic targeting of SPHK1 or YAP/TAZ was sufficient to inhibit neuroblastoma metastasis in vivo Overall, we identify gene expression signatures and candidate therapeutics that could improve the treatment of metastatic neuroblastoma. Cancer Res; 77(3); 696-706. ©2017 AACR.

  1. Implantable chemotherapy-loaded silk protein materials for neuroblastoma treatment.

    PubMed

    Coburn, Jeannine; Harris, Jamie; Zakharov, Alexander D; Poirier, Jennifer; Ikegaki, Naohiko; Kajdacsy-Balla, Andre; Pilichowska, Monika; Lyubimov, Alexander V; Shimada, Hiroyuki; Kaplan, David L; Chiu, Bill

    2017-02-01

    Neuroblastoma is the most common extracranial childhood solid tumor. Treatment of high risk tumors require intense multicycle chemotherapies, resulting in short- and long-term toxicities. Here, we present treatment of an orthotopic neuroblastoma mouse model, with silk fibroin materials loaded with vincristine, doxorubicin or the combination as a intratumoral, sustained release system. The materials, loaded with vincristine with or without doxorubicin, significantly decreased neuroblastoma tumor growth compared to materials loaded without drug or doxorubicin only as well as intravenous (IV) drug treatment. The intratumoral drug concentration was significantly higher with intratumoral delivery versus IV. Furthermore, intratumor delivery decreased the maximum plasma concentration compared to IV delivery, reducing systemic exposure and possibly reduing long-term side effects of chemotherapy exposure. Histopathologically, tumors with remission periods >25 days before recurrence transformed from a "small-round-blue cell" (SBRC) to predominantly "large cell" neuroblastoma (LCN) histopathology, a more aggressive tumor subtype with unfavorable clinical outcomes. These results show that intratumoral chemotherapy delivery may be a treatment strategy for pediatric neuroblastoma, potentially translatable to other focal tumors types. Furthermore, this treatment modality allows for a clinically relevant mouse model of tumor transformation that may be used for studying the phenotypical tumor recurrence and developing more effective treatment strategies for recurrent tumors.

  2. Imide Oligomers Endcapped with Phenylethynl Phthalic Anhydrides and Polymers Therefrom

    NASA Technical Reports Server (NTRS)

    Hergenrother, Paul M. (Inventor); Smith, Joseph G., Jr. (Inventor)

    1998-01-01

    Controlled molecular weight phenylethynyl terminated imide oligomers (PETIs) have been prepared by the cyclodehydration of precursor phenylethynyl terminated amic acid oligomers. Amino terminated amic acid oligomers are prepared from the reaction of dianhydride(s) with an excess of diamine(s) and subsequently endcapped with phenylethynyl phthalic anhydride(s) (PEPA). The polymerizations are carried out in polar aprotic solvents such as N-methyl-2-pyrrolidinone or N.N-dimethylacetamide under nitrogen at room temperature. The amic acid oligomers are subsequently cyclodehydrated either thermally or cheznicauy to the corresponding imide oligomers. Direct preparation of PETIs from the reaction of dianhydxide(s) with an excess of diamine(s) and endcapped with phenylethynyl phthalic anhydride(s) has been performed in m-cresol. Phenylethynyl phthalic anhydrides are synthesized by the palladium catalyzed reaction of phenylacetylene with bromo substituted phthalic anhydrides in triethylamine. These new materials exhibit excellent properties and are potentially useful as adhesives, coatings, films, moldings and composite matrices.

  3. Imide oligomers endcapped with phenylethynyl phthalic anhydrides and polymers therefrom

    NASA Technical Reports Server (NTRS)

    Hergenrother, Paul M. (Inventor); Smith, Jr., Joseph G. (Inventor)

    1996-01-01

    Controlled molecular weight phenylethynyl terminated imide oligomers (PETIs) have been prepared by the cyclodehydration of precursor phenylethynyl terminated amic acid oligomers. Amino terminated amic acid oligomers are prepared from the reaction of dianhydride(s) with an excess of diamine(s) and subsequently endcapped with phenylethynyl phthalic anhydride(s) (PEPA). The polymerizations are carried out in polar aprotic solvents such as N-methyl-2-pyrrolidinone or N,N-dimethylacetamide under nitrogen at room temperature. The amic acid oligomers are subsequently cyclodehydrated either thermally or chemically to the corresponding imide oligomers. Direct preparation of PETIs from the reaction of dianhydride(s) with an excess of diamine(s) and endcapped with phenylethynyl phthalic anhydride(s) has been performed in m-cresol. Phenylethynyl phthalic anhydrides are synthesized by the palladium catalyzed reaction of phenylacetylene with bromo substituted phthalic anhydrides in triethylamine. These new materials exhibit excellent properties and are potentially useful as adhesives, coatings, films, moldings and composite matrices.

  4. ortho-Phenylene oligomers with terminal push-pull substitution.

    PubMed

    He, Jian; Mathew, Sanyo M; Cornett, Sarah D; Grundy, Stephan C; Hartley, C Scott

    2012-05-07

    ortho-Phenylenes are an emerging class of helical oligomers and polymers. We have synthesized a series of push-pull-substituted o-phenylene oligomers (dimethylamino/nitro) up to the octamer. Conformational analysis of the hexamer using a combination of low-temperature NMR spectroscopy and ab initio predictions of (1)H NMR chemical shifts indicates that, like other o-phenylenes, they exist as compact helices in solution. However, the substituents are found to have a significant effect on their conformational behavior: the nitro-functionalized terminus is 3-fold more likely to twist out of the helix. Protonation of the dimethylamino group favors the helical conformer. UV/vis spectroscopy indicates that the direct charge-transfer interaction between the push-pull substituents attenuates quickly compared to other conjugated systems, with no significant charge-transfer band for oligomers longer than the trimer. On protonation of the dimethylamino group, significant bathochromic shifts with increasing oligomer length are observed: the effective conjugation length is 9 repeat units, more than twice that of the parent oligomer. This behavior may be rationalized through examination of the frontier molecular orbitals of these compounds, which exhibit greater delocalization after protonation, as shown by DFT calculations.

  5. Olfactory Neuroblastomas: An Experience of 24 Years

    PubMed Central

    Tural, Deniz; Yildiz, Ozcan; Selcukbiricik, Fatih; Ozturk, Mehmet Akif; Keles, Yildiz; Oz, Buge; Uzel, Omer; Demir, Gokhan; Mandel, Nil Molinas

    2011-01-01

    Objective. The aim of this study was to evaluate clinicopathological findings and the efficacy of the treatment modalities used in patients with olfactory neuroblastomas. Study Design. Retrospective record review. Setting. Istanbul University, Cerrahpasa Medical Faculty, medical oncology outpatient clinic. Subjects and Methods. There were 3 stage A tumors, 5 stage B and 11 stage C according to the Kadish staging system. There were 5 grade I/II and 12 grade III/IV according to the Hyams' histopathologic system. Involvement to orbita was detected in eight patients at the time of diagnosis. Results. The median follow-up period was 23.7 months. The 5-year survival rate for the whole group was 26%. The stage A/B groups exhibited a better survival rate than the C group with 2-year survival rates being 25 versus 71% respectively (P = .008). The grade I/II groups exhibited a better survival rate than the grade III/IV groups with 2-year survival rates being 50 versus 16% respectively (P = .001). The group who had orbital involvement exhibited a poor survival rate than the group of patients who had no involvement of the orbital. Conclusion. In our study, tumor stage, histopathologic grading, involvement of the orbita, brain and bone marow metastases were the statistically significant prognostic factors. PMID:22084732

  6. Refractory diarrhea: A paraneoplastic syndrome of neuroblastoma.

    PubMed

    Han, Wei; Wang, Huan-Min

    2015-07-07

    Neuroblastoma (NB) is the most common extracranial solid tumor in children. Diarrheal NB is quite rare and is not easy to diagnose in the early stage. Six cases of diarrheal NB in our hospital treated from 1996 to 2006 were retrospectively analyzed, including characteristics such as electrolyte imbalance, pathologic features, vasoactive intestinal peptide (VIP) immunohistochemical staining results, treatment, and prognosis. All patients were boys with 3-8 loose or watery stools each day and routine fecal tests were normal. Abdominal tumors were identified by B-ultrasound. Drugs were ineffective. Three patients underwent surgery, and the remaining three patients received surgery and chemotherapy. Diarrhea stopped after treatment in five patients. Two patients died due to intractable hypokalemia. The tumor was located in the adrenal gland in four patients, in the upper retroperitoneum in one patient, and in the presacral area in one patient. Pathologic findings were NB and ganglioneuroblastoma. Five patients were at clinical stage I-II, and one was at stage III. Four patients survived (followed-up for 6 mo to 4 years). Immunohistochemical staining for VIP was positive. Refractory diarrhea is a paraneoplastic syndrome of NB and is rare. Patients aged 1-3 years who present with chronic intractable diarrhea should be followed closely. Intractable diarrhea, hypokalemia, and dysplasia are the initial clinical manifestations. Increased VIP is characteristic of this disease. Potassium supplementation plays a vital role in the treatment procedure, especially preoperatively. The prognosis of diarrheal NB is good following appropriate treatment.

  7. Preparation and applications of a variety of fluoroalkyl end-capped oligomer/hydroxyapatite composites.

    PubMed

    Takashima, Hiroki; Iwaki, Ken-Ichi; Furukuwa, Rika; Takishita, Katsuhisa; Sawada, Hideo

    2008-04-15

    A variety of fluoroalkyl end-capped oligomers were applied to the preparation of fluorinated oligomer/hydroxyapatite (HAp) composites (particle size: 38-356 nm), which exhibit a good dispersibility in water and traditional organic solvents. These fluoroalkyl end-capped oligomer/HAp composites were easily prepared by the reactions of disodium hydrogen phosphate and calcium chloride in the presence of self-assembled molecular aggregates formed by fluoroalkyl end-capped oligomers in aqueous solutions. In these fluorinated HAp composites thus obtained, fluoroalkyl end-capped acrylic acid oligomers and 2-methacryloyloxyethanesulfonic acid oligomer/HAp nanocomposites afforded transparent colorless solutions toward water; however, fluoroalkyl end-capped N,N-dimethylacrylamide oligomer and acryloylmorpholine oligomer were found to afford transparent colorless solutions with trace amounts of white-colored HAp precipitants under similar conditions. HAp could be encapsulated more effectively into fluorinated 2-methacryloyloxyethanesulfonic acid oligomeric aggregate cores to afford colloidal stable fluorinated oligomer/HAp composites, compared to that of fluorinated acrylic acid oligomers. These fluorinated oligomer/HAp composites were applied to the surface modification of glass and PVA to exhibit a good oleophobicity imparted by fluorine. HAp formation was newly observed on the modified polyethylene terephthalate film surface treated with fluorinated 2-methacryloyloxyethanesulfonic acid oligomers and acrylic acid oligomer/HAp composites by soaking these films into the simulated body fluid.

  8. A Hybrid Robotic Control System Using Neuroblastoma Cultures

    NASA Astrophysics Data System (ADS)

    Ferrández, J. M.; Lorente, V.; Cuadra, J. M.; Delapaz, F.; Álvarez-Sánchez, José Ramón; Fernández, E.

    The main objective of this work is to analyze the computing capabilities of human neuroblastoma cultured cells and to define connection schemes for controlling a robot behavior. Multielectrode Array (MEA) setups have been designed for direct culturing neural cells over silicon or glass substrates, providing the capability to stimulate and record simultaneously populations of neural cells. This paper describes the process of growing human neuroblastoma cells over MEA substrates and tries to modulate the natural physiologic responses of these cells by tetanic stimulation of the culture. We show that the large neuroblastoma networks developed in cultured MEAs are capable of learning: establishing numerous and dynamic connections, with modifiability induced by external stimuli and we propose an hybrid system for controlling a robot to avoid obstacles.

  9. I-131 metaiodobenzylguanidine: diagnostic use in neuroblastoma patients in relapse

    SciTech Connect

    Heyman, S.; Evans, A.E.; D'Angio, G.J.

    1988-01-01

    Metaiodobenzylguanidine (MIBG) has been used for the detection and treatment of neuroectodermal tumors, including neuroblastoma. We report our experience with /sup 131/I-MIBG used diagnostically in neuroblastoma patients with relapse. Thirty-eight studies were performed in 26 patients. There were 24 children (range 3 months-14 years) and two adults. While the study was found to be both sensitive and specific for the presence of disease, there are instances of discordance. False-negative studies were found with a markedly anaplastic tumor and with two mature ganglioneuromas. A bone lesion was negative with /sup 131/I-MIBG, but positive on bone scan. A biopsy confirmed the presence of neuroblastoma. Caution should be exercised when scanning pretreated patients, and perhaps with newly diagnosed patients as well.

  10. Establishment of functional clonal lines of neurons from mouse neuroblastoma.

    PubMed

    Augusti-Tocco, G; Sato, G

    1969-09-01

    Clonal lines of neurons were obtained in culture from a mouse neuroblastoma. The neuroblastoma cells were adapted to culture growth by the animal-culture alternate passage technique and cloned after single-cell plating. The clonal lines retained the ability to form tumors when injected back into mice. A striking morphological change was observed in the cells adapted to culture growth; they appeared as mature neurons, while the cells of the tumor appeared as immature neuroblasts. Acetylcholinesterase and the enzymes for the synthesis of neurotransmitters, cholineacetylase and tyrosine hydroxylase were assayed in the tumor and compared with brain levels; tyrosine hydroxylase was found to be particularly high, as described previously in human neuroblastomas. The three enzymes were found in the clonal cultures at levels comparable to those found in the tumors. Similarly, there were no remarkable differences between the three clones examined.

  11. Single Particle Characterization of Aβ Oligomers in Solution

    PubMed Central

    Yusko, Erik C.; Prangkio, Panchika; Sept, David; Rollings, Ryan C.; Li, Jiali; Mayer, Michael

    2012-01-01

    Determining the pathological role of amyloids in amyloid-associated diseases will require a method for determining the dynamic distributions in size and shape of amyloid oligomers with high resolution. Here, we explored the potential of resistive-pulse sensing through lipid bilayer-coated nanopores to measure the size of individual amyloid-β oligomers directly in solution and without chemical modification. This method classified individual amyloid-β aggregates as spherical oligomers, protofibrils, or mature fibers and made it possible to account for the large heterogeneity of amyloid-β aggregate sizes. The approach revealed the distribution of protofibrillar lengths as well as the average cross-sectional area of protofibrils and fibers. PMID:22686709

  12. Proportion effect in diblock co-oligomer molecular diodes

    NASA Astrophysics Data System (ADS)

    Hu, G. C.; Zhang, G. P.; Li, Y.; Ren, J. F.; Wang, C. K.

    2014-10-01

    Based on ab-initio theory and nonequilibrium Green's function method, the effect of proportion on the rectification in pyrimidinyl-phenyl diblock co-oligomer diodes is investigated in two regimes. For a short co-oligomer diode, it is found that the 1:1 proportion of the two moieties favors the largest rectification ratio. For a long co-oligomer diode, an interesting proportion-dependent variation of the rectifying direction is observed. Furthermore, the optimal proportion for the largest rectification ratio is not 1:1 any longer. A deep understanding can be achieved by analyzing the bias-dependent transmission spectra combined with the evolution of the molecular orbitals.

  13. Aggregation of inorganic nanoparticles mediated by biomimetic oligomers.

    PubMed

    Tigger-Zaborov, Hagar; Maayan, Galia

    2015-09-14

    Assemblies of nanoparticles (NPs) have been broadly used for the construction of materials with unique spectroscopic and chiral properties for applications in various scientific disciplines such as sensing, bio-nanotechnology and medicine. Mediating the aggregation of NPs by synthetic biomimetic oligomers, namely, DNA, PNA, peptides and peptide mimics, rather than by small organic molecules has been shown to produce interesting supramolecular structures and enable the combination of the biocompatibility of the mediators and the spectroscopic properties of the NPs. Yet, the key to using this powerful approach for designing new functional materials is to understand the NPs aggregation patterns induced by biopolymers and biomimetic oligomers. Herein we describe the important developments in this field, from early studies to recent work with an emphasis on synthetic methods and tools for controlled assembly of metal NPs by biomimetic polymers and oligomers.

  14. Acetaminophen Induces Human Neuroblastoma Cell Death through NFKB Activation

    PubMed Central

    Posadas, Inmaculada; Santos, Pablo; Ceña, Valentín

    2012-01-01

    Neuroblastoma resistance to apoptosis may contribute to the aggressive behavior of this tumor. Therefore, it would be relevant to activate endogenous cellular death mechanisms as a way to improve neuroblastoma therapy. We used the neuroblastoma SH-SY5Y cell line as a model to study the mechanisms involved in acetaminophen (AAP)-mediated toxicity by measuring CYP2E1 enzymatic activity, NFkB p65 subunit activation and translocation to the nucleus, Bax accumulation into the mitochondria, cytochrome c release and caspase activation. AAP activates the intrinsic death pathway in the SH-SY5Y human neuroblastoma cell line. AAP metabolism is partially responsible for this activation, because blockade of the cytochrome CYP2E1 significantly reduced but did not totally prevent, AAP-induced SH-SY5Y cell death. AAP also induced NFkB p65 activation by phosphorylation and its translocation to the nucleus, where NFkB p65 increased IL-1β production. This increase contributed to neuroblastoma cell death through a mechanism involving Bax accumulation into the mitochondria, cytochrome c release and caspase3 activation. Blockade of NFkB translocation to the nucleus by the peptide SN50 prevented AAP-mediated cell death and IL-1β production. Moreover, overexpression of the antiapoptotic protein Bcl-xL did not decrease AAP-mediated IL-1β production, but prevented both AAP and IL-1β-mediated cell death. We also confirmed the AAP toxic actions on SK-N-MC neuroepithelioma and U87MG glioblastoma cell lines. The results presented here suggest that AAP activates the intrinsic death pathway in neuroblastoma cells through a mechanism involving NFkB and IL-1β. PMID:23166834

  15. Direct detection of alpha synuclein oligomers in vivo

    PubMed Central

    2013-01-01

    Background Rat models of Parkinson’s disease are widely used to elucidate the mechanisms underlying disease etiology or to investigate therapeutic approaches. Models were developed using toxins such as MPTP or 6-OHDA to specifically target dopaminergic neurons resulting in acute neuronal loss in the substantia nigra or by using viral vectors to induce the specific and gradual expression of alpha synuclein in the substantia nigra. The detection of alpha- synuclein oligomers, the presumed toxic species, in these models and others has been possible using only indirect biochemical approaches to date. Here we coinjected AAVs encoding alpha-synuclein fused to the N- or C-terminal half of VenusYFP in rat substantia nigra pars compacta and describe for the first time a novel viral vector rodent model with the unique ability to directly detect and track alpha synuclein oligomers ex vivo and in vivo. Results Viral coinjection resulted in widespread VenusYFP signal within the nigrostriatal pathway, including cell bodies in the substantia nigra and synaptic accumulation in striatal terminals, suggestive of in vivo alpha-synuclein oligomers formation. Transduced rats showed alpha-synuclein induced dopaminergic neuron loss in the substantia nigra, the appearance of dystrophic neurites, and gliosis in the striatum. Moreover, we have applied in vivo imaging techniques in the living mouse to directly image alpha-synuclein oligomers in the cortex. Conclusion We have developed a unique animal model that provides a tool for the Parkinson’s disease research community with which to directly detect alpha- synuclein oligomers in vivo and screen therapeutic approaches targeting alpha-synuclein oligomers. PMID:24252244

  16. Different effects of Alzheimer's peptide Aβ(1-40) oligomers and fibrils on supported lipid membranes.

    PubMed

    Canale, Claudio; Seghezza, Silvia; Vilasi, Silvia; Carrotta, Rita; Bulone, Donatella; Diaspro, Alberto; San Biagio, Pier Luigi; Dante, Silvia

    2013-12-01

    Beta-amyloid (1-40) is one of the two most abundant species of amyloid-beta peptides present as fibrils in the extracellular senile plaques in the brain of Alzheimer's patients. Recently, the molecular aggregates constituting the early stage of fibril formation, i.e., oligomers and protofibrils, have been investigated as the main responsible for amyloid-beta cytotoxic effect. The molecular mechanism leading to neurodegeneration is still under debate, and it is common opinion that it may reside in the interaction between amyloid species and the neural membrane. In this investigation Atomic Force Microscopy and spectroscopy have been used to understand how structural (and mechanical) properties of POPC/POPS lipid bilayers, simulating the phospholipid composition and negative net charge of neuritic cell membranes, are influenced by the interaction with Aβ(1-40), in different stages of the peptide aggregation. Substantial differences in the damage caused to the lipid bilayers have been observed, confirming the toxic effect exerted especially by Aβ(1-40) prefibrillar oligomers.

  17. Probenecid Sensitizes Neuroblastoma Cancer Stem Cells to Cisplatin.

    PubMed

    Campos-Arroyo, Denise; Maldonado, Vilma; Bahena, Ivan; Quintanar, Valeria; Patiño, Nelly; Carlos Martinez-Lazcano, Juan; Melendez-Zajgla, Jorge

    2016-01-01

    We used both in vitro cultures of neuroblastoma cell lines and nude-mice xenotransplants to explore the effects of co-administration of cisplatin and probenecid. Probenecid sensitized neuroblastoma cells, including tumor cells with stem features, to the effects of cisplatin, both in vitro and in vivo. This effect was mediated by an increase in the apoptotic cell death and a concomitant decrease in cell proliferation. This effect is accompanied by modulation of the mRNA and protein of the drug efflux transporters MDR1, MRP2, and BCRP. The co-administration of probenecid with cisplatin should be explored as a possible therapeutic strategy.

  18. Melatonin attenuates methamphetamine-induced disturbances in mitochondrial dynamics and degeneration in neuroblastoma SH-SY5Y cells.

    PubMed

    Parameyong, Arisa; Charngkaew, Komgrid; Govitrapong, Piyarat; Chetsawang, Banthit

    2013-10-01

    Methamphetamine (METH) is a psychostimulant drug that can cause toxicity and degeneration in the brain. The toxicity due to METH involves multiple pathways, including the mitochondrial-dependent death pathway. Several pieces of evidence have emphasized that the fragmentation of mitochondria into smaller structures plays some role in the cell-death process. In this study, we investigated the role of mitochondrial dynamics in METH-induced toxicity in human dopaminergic neuroblastoma SH-SY5Y cultured cell lines. In addition, the protective effect of melatonin against METH-induced toxicity was investigated. Our results show that METH significantly decreased cell viability and increased the levels of the mitochondrial fission protein, Fis1 and the Drp1 oligomer. However, the levels of the mitochondrial fusion proteins OPA1 and Mfn1 did not change in METH-treated cells. Melatonin can reverse the toxic effects of the METH-induced reduction in cell viability and the production of the Fis1 protein and the Drp1 oligomer. Moreover, the morphological alteration of mitochondria was investigated in METH-treated cells in the presence of melatonin using transmission electron microscopy (TEM). At 24 hr after METH exposure, typical cell shrinkage was observed in SH-SY5Y cells. Mitochondria were fragmented into small globular structures in a large proportion of METH-treated cells, but tubular networks of mitochondria were present in large proportions of control-untreated cells and METH-treated cells in the presence of melatonin. The results of the present study demonstrate the potential of melatonin to reduce cell death and restore mitochondrial function in neurons affected by METH-induced toxicity.

  19. Simultaneous measurement of neural spike recordings and multi-photon calcium imaging in neuroblastoma cells.

    PubMed

    Kim, Suhwan; Jung, Unsang; Baek, Juyeong; Kang, Shinwon; Kim, Jeehyun

    2012-11-08

    This paper proposes the design and implementation of a micro-electrode array (MEA) for neuroblastoma cell culturing. It also explains the implementation of a multi-photon microscope (MPM) customized for neuroblastoma cell excitation and imaging under ambient light. Electrical signal and fluorescence images were simultaneously acquired from the neuroblastoma cells on the MEA. MPM calcium images of the cultured neuroblastoma cell on the MEA are presented and also the neural activity was acquired through the MEA recording. A calcium green-1 (CG-1) dextran conjugate of 10,000 D molecular weight was used in this experiment for calcium imaging. This study also evaluated the calcium oscillations and neural spike recording of neuroblastoma cells in an epileptic condition. Based on our observation of neural spikes in neuroblastoma cells with our proposed imaging modality, we report that neuroblastoma cells can be an important model for epileptic activity studies.

  20. Memantine rescues transient cognitive impairment caused by high-molecular-weight aβ oligomers but not the persistent impairment induced by low-molecular-weight oligomers.

    PubMed

    Figueiredo, Cláudia P; Clarke, Julia R; Ledo, José Henrique; Ribeiro, Felipe C; Costa, Carine V; Melo, Helen M; Mota-Sales, Axa P; Saraiva, Leonardo M; Klein, William L; Sebollela, Adriano; De Felice, Fernanda G; Ferreira, Sergio T

    2013-06-05

    Brain accumulation of soluble amyloid-β oligomers (AβOs) has been implicated in synapse failure and cognitive impairment in Alzheimer's disease (AD). However, whether and how oligomers of different sizes induce synapse dysfunction is a matter of controversy. Here, we report that low-molecular-weight (LMW) and high-molecular-weight (HMW) Aβ oligomers differentially impact synapses and memory. A single intracerebroventricular injection of LMW AβOs (10 pmol) induced rapid and persistent cognitive impairment in mice. On the other hand, memory deficit induced by HMW AβOs (10 pmol) was found to be reversible. While memory impairment in LMW oligomer-injected mice was associated with decreased hippocampal synaptophysin and GluN2B immunoreactivities, synaptic pathology was not detected in the hippocampi of HMW oligomer-injected mice. On the other hand, HMW oligomers, but not LMW oligomers, induced oxidative stress in hippocampal neurons. Memantine rescued both neuronal oxidative stress and the transient memory impairment caused by HMW oligomers, but did not prevent the persistent cognitive deficit induced by LMW oligomers. Results establish that different Aβ oligomer assemblies act in an orchestrated manner, inducing different pathologies and leading to synapse dysfunction. Furthermore, results suggest a mechanistic explanation for the limited efficacy of memantine in preventing memory loss in AD.

  1. Oligomer Molecules for Efficient Organic Photovoltaics.

    PubMed

    Lin, Yuze; Zhan, Xiaowei

    2016-02-16

    Solar cells, a renewable, clean energy technology that efficiently converts sunlight into electricity, are a promising long-term solution for energy and environmental problems caused by a mass of production and the use of fossil fuels. Solution-processed organic solar cells (OSCs) have attracted much attention in the past few years because of several advantages, including easy fabrication, low cost, lightweight, and flexibility. Now, OSCs exhibit power conversion efficiencies (PCEs) of over 10%. In the early stage of OSCs, vapor-deposited organic dye materials were first used in bilayer heterojunction devices in the 1980s, and then, solution-processed polymers were introduced in bulk heterojunction (BHJ) devices. Relative to polymers, vapor-deposited small molecules offer potential advantages, such as a defined molecular structure, definite molecular weight, easy purification, mass-scale production, and good batch-to-batch reproducibility. However, the limited solubility and high crystallinity of vapor-deposited small molecules are unfavorable for use in solution-processed BHJ OSCs. Conversely, polymers have good solution-processing and film-forming properties and are easily processed into flexible devices, whereas their polydispersity of molecular weights and difficulty in purification results in batch to batch variation, which may hamper performance reproducibility and commercialization. Oligomer molecules (OMs) are monodisperse big molecules with intermediate molecular weights (generally in the thousands), and their sizes are between those of small molecules (generally with molecular weights <1000) and polymers (generally with molecular weights >10000). OMs not only overcome shortcomings of both vapor-deposited small molecules and solution-processed polymers, but also combine their advantages, such as defined molecular structure, definite molecular weight, easy purification, mass-scale production, good batch-to-batch reproducibility, good solution processability

  2. Electronic coherence dynamics in trans-polyacetylene oligomers.

    PubMed

    Franco, Ignacio; Brumer, Paul

    2012-04-14

    Electronic coherence dynamics in trans-polyacetylene oligomers are considered by explicitly computing the time dependent molecular polarization from the coupled dynamics of electronic and vibrational degrees of freedom in a mean-field mixed quantum-classical approximation. The oligomers are described by the Su-Schrieffer-Heeger Hamiltonian and the effect of decoherence is incorporated by propagating an ensemble of quantum-classical trajectories with initial conditions obtained by sampling the Wigner distribution of the nuclear degrees of freedom. The electronic coherence of superpositions between the ground and excited and between pairs of excited states is examined for chains of different length, and the dynamics is discussed in terms of the nuclear overlap function that appears in the off-diagonal elements of the electronic reduced density matrix. For long oligomers the loss of coherence occurs in tens of femtoseconds. This time scale is determined by the decay of population into other electronic states through vibronic interactions, and is relatively insensitive to the type and class of superposition considered. By contrast, for smaller oligomers the decoherence time scale depends strongly on the initially selected superposition, with superpositions that can decay as fast as 50 fs and as slow as 250 fs. The long-lived superpositions are such that little population is transferred to other electronic states and for which the vibronic dynamics is relatively harmonic.

  3. Synergistic effects of atmospheric pressure plasma-emitted components on DNA oligomers: a Raman spectroscopic study.

    PubMed

    Edengeiser, Eugen; Lackmann, Jan-Wilm; Bründermann, Erik; Schneider, Simon; Benedikt, Jan; Bandow, Julia E; Havenith, Martina

    2015-11-01

    Cold atmospheric-pressure plasmas have become of increasing importance in sterilization processes especially with the growing prevalence of multi-resistant bacteria. Albeit the potential for technological application is obvious, much less is known about the molecular mechanisms underlying bacterial inactivation. X-jet technology separates plasma-generated reactive particles and photons, thus allowing the investigation of their individual and joint effects on DNA. Raman spectroscopy shows that particles and photons cause different modifications in DNA single and double strands. The treatment with the combination of particles and photons does not only result in cumulative, but in synergistic effects. Profilometry confirms that etching is a minor contributor to the observed DNA damage in vitro. Schematics of DNA oligomer treatment with cold atmospheric-pressure plasma.

  4. CLU blocks HDACI-mediated killing of neuroblastoma.

    PubMed

    Subramanian, Chitra; Jarzembowski, Jason A; Halsey, Sonja M; Kuick, Rork; Opipari, Anthony W; Castle, Valerie P; Kwok, Roland P S

    2011-04-01

    Clusterin is a ubiquitously expressed glycoprotein with multiple binding partners including IL-6, Ku70, and Bax. Clusterin blocks apoptosis by binding to activated Bax and sequestering it in the cytoplasm, thereby preventing Bax from entering mitochondria, releasing cytochrome c, and triggering apoptosis. Because increased clusterin expression correlates with aggressive behavior in tumors, clusterin inhibition might be beneficial in cancer treatment. Our recent findings indicated that, in neuroblastoma cells, cytoplasmic Bax also binds to Ku70; when Ku70 is acetylated, Bax is released and can initiate cell death. Therefore, increasing Ku70 acetylation, such as by using histone deacetylase inhibitors, may be therapeutically useful in promoting cell death in neuroblastoma tumors. Since clusterin, Bax, and Ku70 form a complex, it seemed likely that clusterin would mediate its anti-apoptotic effects by inhibiting Ku70 acetylation and blocking Bax release. Our results, however, demonstrate that while clusterin level does indeed determine the sensitivity of neuroblastoma cells to histone deacetylase inhibitor-induced cell death, it does so without affecting histone deacetylase-inhibitor-induced Ku70 acetylation. Our results suggest that in neuroblastoma, clusterin exerts its anti-apoptotic effects downstream of Ku70 acetylation, likely by directly blocking Bax activation.

  5. Bilateral Cystic Adrenal Neuroblastoma with Cystic Liver metastasis

    PubMed Central

    Aslan, Mine; Kalyoncu, Ayse Ucar; Habibi, Hatice Arioz; Ozdemir, Gul Nihal; Koc, Basak; Adaletli, Ibrahim

    2017-01-01

    Bilateral congenital cystic adrenal neuroblastoma (NB) with cystic liver metastasis is a very rare condition and only few cases have been reported in the literature. Herein we report a case of a congenital bilateral cystic adrenal NB with cystic liver metastasis and briefly discuss characteristic imaging features of cystic NB. PMID:28163998

  6. Transcriptomic profiling of 39 commonly-used neuroblastoma cell lines.

    PubMed

    Harenza, Jo Lynne; Diamond, Maura A; Adams, Rebecca N; Song, Michael M; Davidson, Heather L; Hart, Lori S; Dent, Maiah H; Fortina, Paolo; Reynolds, C Patrick; Maris, John M

    2017-03-28

    Neuroblastoma cell lines are an important and cost-effective model used to study oncogenic drivers of the disease. While many of these cell lines have been previously characterized with SNP, methylation, and/or mRNA expression microarrays, there has not been an effort to comprehensively sequence these cell lines. Here, we present raw whole transcriptome data generated by RNA sequencing of 39 commonly-used neuroblastoma cell lines. These data can be used to perform differential expression analysis based on a genetic aberration or phenotype in neuroblastoma (e.g., MYCN amplification status, ALK mutation status, chromosome arm 1p, 11q and/or 17q status, sensitivity to pharmacologic perturbation). Additionally, we designed this experiment to enable structural variant and/or long-noncoding RNA analysis across these cell lines. Finally, as more DNase/ATAC and histone/transcription factor ChIP sequencing is performed in these cell lines, our RNA-Seq data will be an important complement to inform transcriptional targets as well as regulatory (enhancer or repressor) elements in neuroblastoma.

  7. N-linked glycan profiling in neuroblastoma cell lines.

    PubMed

    Hu, Yunli; Mayampurath, Anoop; Khan, Saira; Cohen, Joanna K; Mechref, Yehia; Volchenboum, Samuel L

    2015-05-01

    Although MYCN amplification has been associated with aggressive neuroblastoma, the molecular mechanisms that differentiate low-risk, MYCN-nonamplified neuroblastoma from high-risk, MYCN-amplified disease are largely unknown. Genomic and proteomic studies have been limited in discerning differences in signaling pathways that account for this heterogeneity. N-Linked glycosylation is a common protein modification resulting from the attachment of sugars to protein residues and is important in cell signaling and immune response. Aberrant N-linked glycosylation has been routinely linked to various cancers. In particular, glycomic markers have often proven to be useful in distinguishing cancers from precancerous conditions. Here, we perform a systematic comparison of N-linked glycomic variation between MYCN-nonamplified SY5Y and MYCN-amplified NLF cell lines with the aim of identifying changes in sugar abundance linked to high-risk neuroblastoma. Through a combination of liquid chromatography-mass spectrometry and bioinformatics analysis, we identified 16 glycans that show a statistically significant change in abundance between NLF and SY5Y samples. Closer examination revealed the preference for larger (in terms of total monosaccharide count) and more sialylated glycan structures in the MYCN-amplified samples in comparison to smaller, nonsialylated glycans that are more dominant in the MYCN-nonamplified samples. These results offer clues for deriving marker candidates for accurate neuroblastoma risk diagnosis.

  8. Immunolocalization of neuroblastoma using radiolabeled monoclonal antibody UJ13A

    SciTech Connect

    Goldman, A.; Vivian, G.; Gordon, I.; Pritchard, J.; Kemshead, J.

    1984-08-01

    The monoclonal antibody UJ13A, raised after immunization of mice with human fetal brain, recognized an antigen expressed on human neuroblastoma cell lines and fresh tumors. Antibody was purified and radiolabeled with iodine isotopes using chloramine-T. In preclinical studies, 125I-labeled UJ13A was injected intravenously into nude mice bearing xenografts of human neuroblastoma. Radiolabeled UJ13A uptake by the tumors was four to 23 times greater than that by blood. In control animals, injected with a similar quantity of a monoclonal antibody known not to bind to neuroblastoma cells in vitro (FD44), there was no selective tumor uptake. Nine patients with histologically confirmed neuroblastoma each received 100 to 300 micrograms UJ13A radiolabeled with 1 to 2.8 mCi 123I or 131I. Sixteen positive sites were visible on gamma scans 1 to 7 days after injection: 15 were primary or secondary tumor sites, and one was a false positive; there were two false negatives. In two of the 15 positive sites, tumor had not been demonstrated by other imaging techniques; these were later confirmed as areas of malignant infiltration. No toxicity was encountered.

  9. The role of the MEIS homeobox genes in neuroblastoma.

    PubMed

    Geerts, Dirk; Schilderink, Nathalie; Jorritsma, Gerda; Versteeg, Rogier

    2003-07-18

    We recently found amplification of the TALE homeobox gene MEIS1 in the IMR32 neuroblastoma cell line. We now demonstrate high-level expression of the MEIS1 and MEIS2 genes, as well as efficient expression of most other TALE family member genes in a panel of neuroblastoma cell lines. Stable transfection of MEIS1-expressing cell lines with cDNA encoding a naturally occurring dominant-negative splice variant of MEIS1 (MEIS1E) yielded clones with impaired cell proliferation, gain of differentiated phenotype, and increased contact inhibition and cell death. This indicated a relevance of MEIS expression for neuroblastoma cell growth and proliferation. We therefore determined the gene expression profiles of several MEIS1E transfectants using serial analysis of gene expression (SAGE). A large number of genes showed differential expression as a result of MEIS1E expression. These include genes involved in developmental signalling pathways, chromatin binding, cell cycle control, proliferation, and apoptosis. The results presented provide important clues for the oncogenic function of MEIS1 in neuroblastoma.

  10. Discovery – Ch14.18 Immunotherapy to Treat Neuroblastoma

    Cancer.gov

    Neuroblastoma is rare yet it's the most common cancer affecting infants. Prior to a discovery 20 years in the making, there was little hope for survival in children with advanced stages of the disease. Today, research is leading to a brighter outlook.

  11. Transcriptomic profiling of 39 commonly-used neuroblastoma cell lines

    PubMed Central

    Harenza, Jo Lynne; Diamond, Maura A.; Adams, Rebecca N.; Song, Michael M.; Davidson, Heather L.; Hart, Lori S.; Dent, Maiah H.; Fortina, Paolo; Reynolds, C. Patrick; Maris, John M.

    2017-01-01

    Neuroblastoma cell lines are an important and cost-effective model used to study oncogenic drivers of the disease. While many of these cell lines have been previously characterized with SNP, methylation, and/or mRNA expression microarrays, there has not been an effort to comprehensively sequence these cell lines. Here, we present raw whole transcriptome data generated by RNA sequencing of 39 commonly-used neuroblastoma cell lines. These data can be used to perform differential expression analysis based on a genetic aberration or phenotype in neuroblastoma (e.g., MYCN amplification status, ALK mutation status, chromosome arm 1p, 11q and/or 17q status, sensitivity to pharmacologic perturbation). Additionally, we designed this experiment to enable structural variant and/or long-noncoding RNA analysis across these cell lines. Finally, as more DNase/ATAC and histone/transcription factor ChIP sequencing is performed in these cell lines, our RNA-Seq data will be an important complement to inform transcriptional targets as well as regulatory (enhancer or repressor) elements in neuroblastoma. PMID:28350380

  12. Bilateral Synchronous Ectopic Ethmoid Sinus Olfactory Neuroblastoma: A Case Report

    PubMed Central

    Leon-Soriano, Elena; Alfonso, Carolina; Yebenes, Laura; Garcia-Polo, Julio; Lassaletta, Luis; Gavilan, Javier

    2016-01-01

    Patient: Male, 41 Final Diagnosis: Olfactory neuroblastoma Symptoms: Left nasal obstruction • occasional left epistaxis • headache Medication: None Clinical Procedure: Nasal endoscopic examination • neck palpation • CT • bilateral endoscopic resection • MRI • PET-CT • postoperative radiotherapy Specialty: Otolaryngology Objective: Unusual clinical course Background: Olfactory neuroblastoma (ONB), also known as esthesioneuroblastoma, is a rare malignant head and neck cancer thought to originate from the olfactory epithelium. It typically invades contiguous structures at presentation. We report a very rare case of multifocal and ectopic ONB. Case Report: A 41-year-old man presented with left nasal obstruction and occasional left epistaxis associated with headache. Endoscopic examination of the nasal cavities and computed tomography suggested bilateral polypoid masses. Histopathological diagnosis after endoscopic resection established bilateral olfactory neuroblastoma of the ethmoid sinuses. The patient received postoperative radiotherapy. He remains free of disease 4 years after treatment. Conclusions: To the best of our knowledge this is the second documented case of multifocal ectopic olfactory neuroblastoma. Clinicians should consider ONB in the differential diagnosis of bilateral synchronous nasal and paranasal masses to avoid delayed diagnosis. Endoscopic resection of ONB could be an option in selected cases. PMID:27097989

  13. ARID1A gene knockdown promotes neuroblastoma migration and invasion.

    PubMed

    Li, C; Xu, Z; Zhao, Z; An, Q; Wang, L; Yu, Y; Piao, D

    2017-03-03

    Neuroblastoma is the most common extracranial solid tumor in childhood which often acquires drug resistance and becomes aggressive phenotypes. The high-risk patients suffer from high mortality due to the limitation of the treatment strategies. ARID1A (AT-rich interactive domain-containing protein 1A), a subunit of SWI/SNF complexes, is considered as a tumor suppressor in many cancers. The aim of the present study was to investigate the effect of ARID1A on migration and invasion in neuroblastoma cells. The shRNA targeting ARID1A was designed and delivered into SK-N-SH cells to knock down ARID1A expression. Knockdown of ARID1A by shRNA significantly increased the viability and invasion ability, and caused G1 arrest inhibition and DNA synthesis increase in SK-N-SH cells. Moreover, Knockdown of ARID1A increased the activity and expression of matrix metalloproteinase (MMP)-2 and -9 in SK-N-SH cells. Furthermore, ARID1A knockdown caused diminished expression of E-cadherin, enhanced expression of N-cadherin and β-catenin nuclear translocation in SK-N-SH cells. These results suggest that loss of ARID1A may associate with the promotion of invasion and metastasis of neuroblastoma. Our findings indicate ARID1A is a tumor suppressor in neuroblastoma.

  14. Translational development of difluoromethylornithine (DFMO) for the treatment of neuroblastoma.

    PubMed

    Bassiri, Hamid; Benavides, Adriana; Haber, Michelle; Gilmour, Susan K; Norris, Murray D; Hogarty, Michael D

    2015-07-01

    Neuroblastoma is a childhood tumor in which MYC oncogenes are commonly activated to drive tumor progression. Survival for children with high-risk neuroblastoma remains poor despite treatment that incorporates high-dose chemotherapy, stem cell support, surgery, radiation therapy and immunotherapy. More effective and less toxic treatments are sought and one approach under clinical development involves re-purposing the anti-protozoan drug difluoromethylornithine (DFMO; Eflornithine) as a neuroblastoma therapeutic. DFMO is an irreversible inhibitor of ornithine decarboxylase (Odc), a MYC target gene, bona fide oncogene, and the rate-limiting enzyme in polyamine synthesis. DFMO is approved for the treatment of Trypanosoma brucei gambiense encephalitis ("African sleeping sickness") since polyamines are essential for the proliferation of these protozoa. However, polyamines are also critical for mammalian cell proliferation and the finding that MYC coordinately regulates all aspects of polyamine metabolism suggests polyamines may be required to support cancer promotion by MYC. Pre-emptive blockade of polyamine synthesis is sufficient to block tumor initiation in an otherwise fully penetrant transgenic mouse model of neuroblastoma driven by MYCN, underscoring the necessity of polyamines in this process. Moreover, polyamine depletion regimens exert potent anti-tumor activity in pre-clinical models of established neuroblastoma as well, in combination with numerous chemotherapeutic agents and even in tumors with unfavorable genetic features such as MYCN, ALK or TP53 mutation. This has led to the testing of DFMO in clinical trials for children with neuroblastoma. Current trial designs include testing lower dose DFMO alone (2,000 mg/m(2)/day) starting at the completion of standard therapy, or higher doses combined with chemotherapy (up to 9,000 mg/m(2)/day) for patients with relapsed disease that has progressed. In this review we will discuss important considerations for the

  15. Unique Properties of the Rabbit Prion Protein Oligomer

    PubMed Central

    Yu, Ziyao; Huang, Pei; Yu, Yuanhui; Zheng, Zhen; Huang, Zicheng; Guo, Chenyun; Lin, Donghai

    2016-01-01

    Prion diseases, also known as transmissible spongiform encephalopathies (TSEs), are a group of fatal neurodegenerative disorders infecting both humans and animals. Recent works have demonstrated that the soluble prion protein oligomer (PrPO), the intermediate of the conformational transformation from the host-derived cellular form (PrPC) to the disease-associated Scrapie form (PrPSc), exerts the major neurotoxicity in vitro and in vivo. Rabbits show strong resistance to TSEs, the underlying mechanism is unclear to date. It is expected that the relative TSEs-resistance of rabbits is closely associated with the unique properties of rabbit prion protein oligomer which remain to be addressed in detail. In the present work, we prepared rabbit prion protein oligomer (recRaPrPO) and human prion protein oligomer (recHuPrPO) under varied conditions, analyzed the effects of pH, NaCl concentration and incubation temperature on the oligomerization, and compared the properties of recRaPrPO and recHuPrPO. We found that several factors facilitated the formation of prion protein oligomers, including low pH, high NaCl concentration, high incubation temperature and low conformational stability of monomeric prion protein. RecRaPrPO was formed more slowly than recHuPrPO at physiological-like conditions (< 57°C, < 150 mM NaCl). Furthermore, recRaPrPO possessed higher susceptibility to proteinase K and lower cytotoxicity in vitro than recHuPrPO. These unique properties of recRaPrPO might substantially contribute to the TSEs-resistance of rabbits. Our work sheds light on the oligomerization of prion proteins and is of benefit to mechanistic understanding of TSEs-resistance of rabbits. PMID:27529173

  16. Graphene Oxide Nanoribbons Induce Autophagic Vacuoles in Neuroblastoma Cell Lines

    PubMed Central

    Mari, Emanuela; Mardente, Stefania; Morgante, Emanuela; Tafani, Marco; Lococo, Emanuela; Fico, Flavia; Valentini, Federica; Zicari, Alessandra

    2016-01-01

    Since graphene nanoparticles are attracting increasing interest in relation to medical applications, it is important to understand their potential effects on humans. In the present study, we prepared graphene oxide (GO) nanoribbons by oxidative unzipping of single-wall carbon nanotubes (SWCNTs) and analyzed their toxicity in two human neuroblastoma cell lines. Neuroblastoma is the most common solid neoplasia in children. The hallmark of these tumors is the high number of different clinical variables, ranging from highly metastatic, rapid progression and resistance to therapy to spontaneous regression or change into benign ganglioneuromas. Patients with neuroblastoma are grouped into different risk groups that are characterized by different prognosis and different clinical behavior. Relapse and mortality in high risk patients is very high in spite of new advances in chemotherapy. Cell lines, obtained from neuroblastomas have different genotypic and phenotypic features. The cell lines SK-N-BE(2) and SH-SY5Y have different genetic mutations and tumorigenicity. Cells were exposed to low doses of GO for different times in order to investigate whether GO was a good vehicle for biological molecules delivering individualized therapy. Cytotoxicity in both cell lines was studied by measuring cellular oxidative stress (ROS), mitochondria membrane potential, expression of lysosomial proteins and cell growth. GO uptake and cytoplasmic distribution of particles were studied by Transmission Electron Microscopy (TEM) for up to 72 h. The results show that GO at low concentrations increased ROS production and induced autophagy in both neuroblastoma cell lines within a few hours of exposure, events that, however, are not followed by growth arrest or death. For this reason, we suggest that the GO nanoparticle can be used for therapeutic delivery to the brain tissue with minimal effects on healthy cells. PMID:27916824

  17. Array comparative genomic hybridization analysis of olfactory neuroblastoma.

    PubMed

    Guled, Mohamed; Myllykangas, Samuel; Frierson, Henry F; Mills, Stacey E; Knuutila, Sakari; Stelow, Edward B

    2008-06-01

    Olfactory neuroblastoma is an unusual neuroectodermal malignancy, which is thought to arise at the olfactory membrane of the sinonasal tract. Due to its rarity, little is understood regarding its molecular and cytogenetic abnormalities. The aim of the current study is to identify specific DNA copy number changes in olfactory neuroblastoma. Thirteen dissected tissue samples were analyzed using array comparative genomic hybridization. Our results show that gene copy number profiles of olfactory neuroblastoma samples are complex. The most frequent changes included gains at 7q11.22-q21.11, 9p13.3, 13q, 20p/q, and Xp/q, and losses at 2q31.1, 2q33.3, 2q37.1, 6q16.3, 6q21.33, 6q22.1, 22q11.23, 22q12.1, and Xp/q. Gains were more frequent than losses, and high-stage tumors showed more alterations than low-stage olfactory neuroblastoma. Frequent changes in high-stage tumors were gains at 13q14.2-q14.3, 13q31.1, and 20q11.21-q11.23, and loss of Xp21.1 (in 66% of cases). Gains at 5q35, 13q, and 20q, and losses at 2q31.1, 2q33.3, and 6q16-q22, were present in 50% of cases. The identified regions of gene copy number change have been implicated in a variety of tumors, especially carcinomas. In addition, our results indicate that gains in 20q and 13q may be important in the progression of this cancer, and that these regions possibly harbor genes with functional relevance in olfactory neuroblastoma.

  18. Graphene Oxide Nanoribbons Induce Autophagic Vacuoles in Neuroblastoma Cell Lines.

    PubMed

    Mari, Emanuela; Mardente, Stefania; Morgante, Emanuela; Tafani, Marco; Lococo, Emanuela; Fico, Flavia; Valentini, Federica; Zicari, Alessandra

    2016-11-29

    Since graphene nanoparticles are attracting increasing interest in relation to medical applications, it is important to understand their potential effects on humans. In the present study, we prepared graphene oxide (GO) nanoribbons by oxidative unzipping of single-wall carbon nanotubes (SWCNTs) and analyzed their toxicity in two human neuroblastoma cell lines. Neuroblastoma is the most common solid neoplasia in children. The hallmark of these tumors is the high number of different clinical variables, ranging from highly metastatic, rapid progression and resistance to therapy to spontaneous regression or change into benign ganglioneuromas. Patients with neuroblastoma are grouped into different risk groups that are characterized by different prognosis and different clinical behavior. Relapse and mortality in high risk patients is very high in spite of new advances in chemotherapy. Cell lines, obtained from neuroblastomas have different genotypic and phenotypic features. The cell lines SK-N-BE(2) and SH-SY5Y have different genetic mutations and tumorigenicity. Cells were exposed to low doses of GO for different times in order to investigate whether GO was a good vehicle for biological molecules delivering individualized therapy. Cytotoxicity in both cell lines was studied by measuring cellular oxidative stress (ROS), mitochondria membrane potential, expression of lysosomial proteins and cell growth. GO uptake and cytoplasmic distribution of particles were studied by Transmission Electron Microscopy (TEM) for up to 72 h. The results show that GO at low concentrations increased ROS production and induced autophagy in both neuroblastoma cell lines within a few hours of exposure, events that, however, are not followed by growth arrest or death. For this reason, we suggest that the GO nanoparticle can be used for therapeutic delivery to the brain tissue with minimal effects on healthy cells.

  19. MicroRNA-181a suppresses parkin-mediated mitophagy and sensitizes neuroblastoma cells to mitochondrial uncoupler-induced apoptosis

    PubMed Central

    Lao, Yuanzhi; Liao, Weijie; Liao, Meijian; Luo, Xuan; Wu, Jiangbin; Xie, Weidong; Zhang, Yaou; Xu, Naihan

    2016-01-01

    Damage to mitochondria often results in the activation of both mitophagy and mitochondrial apoptosis. The elimination of dysfunctional mitochondria is necessary for mitochondrial quality maintenance and efficient energy supply. Here we report that miR-181a is a novel inhibitor of mitophagy. miR-181a is downregulated by mitochondrial uncouplers in human neuroblastoma SH-SY5Y cells. Overexpression of miR-181a inhibits mitochondrial uncoupling agents-induced mitophagy by inhibiting the degradation of mitochondrial proteins without affecting global autophagy. Knock down of endogenous miR-181a accelerates the autophagic degradation of damaged mitochondria. miR-181a directly targets Parkin E3 ubiquitin ligase and partially blocks the colocalization of mitochondria and autophagosomes/lysosomes. Re-expression of exogenous Parkin restores the inhibitory effect of miR-181a on mitophagy. Furthermore, miR-181a increases the sensitivity of neuroblastoma cells to mitochondrial uncoupler-induced apoptosis, whereas miR-181a antagomir prevents cell death. Because mitophagy defects are associated with a variety of human disorders, these findings indicate an important link between microRNA and Parkin-mediated mitophagy and highlights a potential therapeutic strategy for human diseases. PMID:27281615

  20. [Effect of estrogen on nucleotide excision repair of N2a neuroblastoma cells].

    PubMed

    Yoshioka, Akira; Yamamoto, Aya; Mori, Toshio; Nakamura, Yu; Morikawa, Masayuki; Yoshino, Hiroki; Kiuchi, Kuniaki; Makinodan, Manabu; Kishimoto, Toshifumi

    2007-04-01

    Until now reduced estrogen level has been considered to affect some psychiatric symptoms, because there are sex differences in onset of Schizophrenia and Alzheimer's disease. Estrogen is associated with cognitive functions, and it has been reported to protect oxidative damage of DNA related to base excision repair (BER). Some patients with Xeroderma Pigmentosum, who have normal BER and impaired nucleotide excision repair (NER), are known to be suffering from mental retardation. Therefore we hypothesized that impaired NER was partly associated with pathology of mental disorder and investigated the effects of estrogen on NER for ultraviolet-induced DNA damage. The N2a neuroblastoma cell line was used as a representative of neuronal cells and 17p-estradiol was selected as one of the most active estrogen derivatives. There were no significant effects of 17p-estradiol on prevention of DNA damage, promotion of DNA repair, or cell survival at the concentration of 0-0.1 microM 17p-estradiol (below cytotoxicity level). These results described that estrogen might not directly affect NER except through another DNA repair system.

  1. Capping of aβ42 oligomers by small molecule inhibitors.

    PubMed

    Fu, Ziao; Aucoin, Darryl; Ahmed, Mahiuddin; Ziliox, Martine; Van Nostrand, William E; Smith, Steven O

    2014-12-23

    Aβ42 peptides associate into soluble oligomers and protofibrils in the process of forming the amyloid fibrils associated with Alzheimer's disease. The oligomers have been reported to be more toxic to neurons than fibrils, and have been targeted by a wide range of small molecule and peptide inhibitors. With single touch atomic force microscopy (AFM), we show that monomeric Aβ42 forms two distinct types of oligomers, low molecular weight (MW) oligomers with heights of 1-2 nm and high MW oligomers with heights of 3-5 nm. In both cases, the oligomers are disc-shaped with diameters of ~10-15 nm. The similar diameters suggest that the low MW species stack to form the high MW oligomers. The ability of Aβ42 inhibitors to interact with these oligomers is probed using atomic force microscopy and NMR spectroscopy. We show that curcumin and resveratrol bind to the N-terminus (residues 5-20) of Aβ42 monomers and cap the height of the oligomers that are formed at 1-2 nm. A second class of inhibitors, which includes sulindac sulfide and indomethacin, exhibit very weak interactions across the Aβ42 sequence and do not block the formation of the high MW oligomers. The correlation between N-terminal interactions and capping of the height of the Aβ oligomers provides insights into the mechanism of inhibition and the pathway of Aβ aggregation.

  2. Alzheimer's therapeutics targeting amyloid beta 1-42 oligomers II: Sigma-2/PGRMC1 receptors mediate Abeta 42 oligomer binding and synaptotoxicity.

    PubMed

    Izzo, Nicholas J; Xu, Jinbin; Zeng, Chenbo; Kirk, Molly J; Mozzoni, Kelsie; Silky, Colleen; Rehak, Courtney; Yurko, Raymond; Look, Gary; Rishton, Gilbert; Safferstein, Hank; Cruchaga, Carlos; Goate, Alison; Cahill, Michael A; Arancio, Ottavio; Mach, Robert H; Craven, Rolf; Head, Elizabeth; LeVine, Harry; Spires-Jones, Tara L; Catalano, Susan M

    2014-01-01

    Amyloid beta (Abeta) 1-42 oligomers accumulate in brains of patients with Mild Cognitive Impairment (MCI) and disrupt synaptic plasticity processes that underlie memory formation. Synaptic binding of Abeta oligomers to several putative receptor proteins is reported to inhibit long-term potentiation, affect membrane trafficking and induce reversible spine loss in neurons, leading to impaired cognitive performance and ultimately to anterograde amnesia in the early stages of Alzheimer's disease (AD). We have identified a receptor not previously associated with AD that mediates the binding of Abeta oligomers to neurons, and describe novel therapeutic antagonists of this receptor capable of blocking Abeta toxic effects on synapses in vitro and cognitive deficits in vivo. Knockdown of sigma-2/PGRMC1 (progesterone receptor membrane component 1) protein expression in vitro using siRNA results in a highly correlated reduction in binding of exogenous Abeta oligomers to neurons of more than 90%. Expression of sigma-2/PGRMC1 is upregulated in vitro by treatment with Abeta oligomers, and is dysregulated in Alzheimer's disease patients' brain compared to age-matched, normal individuals. Specific, high affinity small molecule receptor antagonists and antibodies raised against specific regions on this receptor can displace synthetic Abeta oligomer binding to synaptic puncta in vitro and displace endogenous human AD patient oligomers from brain tissue sections in a dose-dependent manner. These receptor antagonists prevent and reverse the effects of Abeta oligomers on membrane trafficking and synapse loss in vitro and cognitive deficits in AD mouse models. These findings suggest sigma-2/PGRMC1 receptors mediate saturable oligomer binding to synaptic puncta on neurons and that brain penetrant, small molecules can displace endogenous and synthetic oligomers and improve cognitive deficits in AD models. We propose that sigma-2/PGRMC1 is a key mediator of the pathological effects of

  3. Sesquiterpene lactones derived from Saussurea lappa induce apoptosis and inhibit invasion and migration in neuroblastoma cells.

    PubMed

    Tabata, Keiichi; Nishimura, Yuki; Takeda, Taiji; Kurita, Masahiro; Uchiyama, Taketo; Suzuki, Takashi

    2015-04-01

    Neuroblastoma is among the most fatal of solid tumors in the pediatric age group, even when treated aggressively. Therefore, a new effective therapeutic drug(s) for neuroblastoma is urgently needed. To clarify the anticancer effects of the sesquiterpene lactones dehydrocostus lactone and costunolide, derived from Saussurea lappa, we examined the cytotoxic and migration/invasion-inhibitory effects of these compounds against neuroblastoma cell lines. Both the compounds exerted significant cytotoxicity against the neuroblastoma cell lines IMR-32, NB-39, SK-N-SH, and LA-N-1. Evidence of cellular apoptosis, such as nuclear condensation and membrane inversion, were observed after treatment with these compounds. Both compounds induced caspase-7 activation and PARP cleavage as confirmed by Western blotting. Furthermore, the sesquiterpene lactones also suppressed invasion and migration of the neuroblastoma cells. These results suggest that dehydrocostus lactone and costunolide are promising candidates for being developed into novel anticancer drugs effective against neuroblastoma.

  4. Multiple mechanisms disrupt the let-7 microRNA family in neuroblastoma.

    PubMed

    Powers, John T; Tsanov, Kaloyan M; Pearson, Daniel S; Roels, Frederik; Spina, Catherine S; Ebright, Richard; Seligson, Marc; de Soysa, Yvanka; Cahan, Patrick; Theißen, Jessica; Tu, Ho-Chou; Han, Areum; Kurek, Kyle C; LaPier, Grace S; Osborne, Jihan K; Ross, Samantha J; Cesana, Marcella; Collins, James J; Berthold, Frank; Daley, George Q

    2016-07-14

    Poor prognosis in neuroblastoma is associated with genetic amplification of MYCN. MYCN is itself a target of let-7, a tumour suppressor family of microRNAs implicated in numerous cancers. LIN28B, an inhibitor of let-7 biogenesis, is overexpressed in neuroblastoma and has been reported to regulate MYCN. Here we show, however, that LIN28B is dispensable in MYCN-amplified neuroblastoma cell lines, despite de-repression of let-7. We further demonstrate that MYCN messenger RNA levels in amplified disease are exceptionally high and sufficient to sponge let-7, which reconciles the dispensability of LIN28B. We found that genetic loss of let-7 is common in neuroblastoma, inversely associated with MYCN amplification, and independently associated with poor outcomes, providing a rationale for chromosomal loss patterns in neuroblastoma. We propose that let-7 disruption by LIN28B, MYCN sponging, or genetic loss is a unifying mechanism of neuroblastoma development with broad implications for cancer pathogenesis.

  5. A Genetically Engineered Mouse Model of Neuroblastoma Driven by Mutated ALK and MYCN

    DTIC Science & Technology

    2014-09-01

    AWARD NUMBER: W81XWH-13-1-0220 TITLE: A Genetically Engineered Mouse Model of Neuroblastoma ...CONTRACT NUMBER A Genetically Engineered Mouse Model of Neuroblastoma Driven by Mutated ALK and MYCN 5b. GRANT NUMBER W81XWH-13-1-0220 5c...common ALK mutations in neuroblastoma , F1174L and R1275Q. We have determined that in tumors cells expressing mutated ALK, different downstream

  6. The Development of a Primary Neural Crest Assay for Neuroblastoma Oncogenesis

    DTIC Science & Technology

    2015-09-01

    AWARD NUMBER: W81XWH-14-1-0090 TITLE: The Development of a Primary Neural Crest Assay for Neuroblastoma Oncogenesis PRINCIPAL INVESTIGATOR...TITLE AND SUBTITLE The Development of a Primary Neural Crest Assay for Neuroblastoma Oncogenesis 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-14-1...identification of novel oncogenic drivers of neuroblastoma as a starting point for the development of new therapies. Furthermore to use this technology to

  7. Aggressive cervical neuroblastoma with a rare paraneoplastic syndrome: A therapeutic dilemma

    PubMed Central

    Qureshi, Sajid S.; Bhagat, Monica; Anam, Jay; Vora, Tushar

    2016-01-01

    Neuroblastoma is infrequently associated with paraneoplastic syndromes. Amongst the few, opsomyoclonus (Kinsbourne syndrome) is the most common neurological paraneoplastic syndrome and diarrhea secondary to increased secretion of vasoactive intestinal peptide (Kerner-Morrison syndrome), hormonal paraneoplastic syndrome. Hypothalamic dysfunction (HD) is a rare disorder and its manifestation as a paraneoplastic syndrome of neuroblastoma is uncommonly reported. We present an interesting case of an unrelenting cervical neuroblastoma associated with HD, which posed a therapeutic challenge. PMID:27695211

  8. Treatment of neuroblastoma with /sup 131/I-metaiodobenzylguanidine: experience of the Muenster/Kassel Group

    SciTech Connect

    Fischer, M.; Wehinger, H.; Kraus, C.; Ritter, J.; Schroeter, W.

    1987-01-01

    I-131-metaiodobenzylguanidine was used for treatment of neuroblastoma stage IV in three children after surgery and or chemotherapy had failed to be effective. In two of the children with multilocular lesions, after an impressive improvement of clinical symptoms tumor progression was observed. Because in about 25% of children with relapsing neuroblastoma complete remission may be achieved by combining surgery, chemotherapy, and I-131-MIBG treatment, this therapeutic modality should be included in the therapeutic strategy of stage III and IV neuroblastoma.

  9. PI3K/AKT and ERK regulate retinoic acid-induced neuroblastoma cellular differentiation

    SciTech Connect

    Qiao, Jingbo; Paul, Pritha; Lee, Sora; Qiao, Lan; Josifi, Erlena; Tiao, Joshua R.; Chung, Dai H.

    2012-08-03

    Highlights: Black-Right-Pointing-Pointer Retinoic acid (RA) induces neuroblastoma cells differentiation, which is accompanied by G0/G1 cell cycle arrest. Black-Right-Pointing-Pointer RA resulted in neuroblastoma cell survival and inhibition of DNA fragmentation; this is regulated by PI3K pathway. Black-Right-Pointing-Pointer RA activates PI3K and ERK1/2 pathway; PI3K pathway mediates RA-induced neuroblastoma cell differentiation. Black-Right-Pointing-Pointer Upregulation of p21 is necessary for RA-induced neuroblastoma cell differentiation. -- Abstract: Neuroblastoma, the most common extra-cranial solid tumor in infants and children, is characterized by a high rate of spontaneous remissions in infancy. Retinoic acid (RA) has been known to induce neuroblastoma differentiation; however, the molecular mechanisms and signaling pathways that are responsible for RA-mediated neuroblastoma cell differentiation remain unclear. Here, we sought to determine the cell signaling processes involved in RA-induced cellular differentiation. Upon RA administration, human neuroblastoma cell lines, SK-N-SH and BE(2)-C, demonstrated neurite extensions, which is an indicator of neuronal cell differentiation. Moreover, cell cycle arrest occurred in G1/G0 phase. The protein levels of cyclin-dependent kinase inhibitors, p21 and p27{sup Kip}, which inhibit cell proliferation by blocking cell cycle progression at G1/S phase, increased after RA treatment. Interestingly, RA promoted cell survival during the differentiation process, hence suggesting a potential mechanism for neuroblastoma resistance to RA therapy. Importantly, we found that the PI3K/AKT pathway is required for RA-induced neuroblastoma cell differentiation. Our results elucidated the molecular mechanism of RA-induced neuroblastoma cellular differentiation, which may be important for developing novel therapeutic strategy against poorly differentiated neuroblastoma.

  10. Percutaneous transhepatic biliary drainage in an infant with obstructive jaundice caused by neuroblastoma.

    PubMed

    Saettini, Francesco; Agazzi, Roberto; Giraldi, Eugenia; Foglia, Carlo; Cavalleri, Laura; Morali, Laura; Fasolini, Giorgio; Spotti, Angelica; Provenzi, Massimo

    2015-04-01

    Neuroblastoma presenting with obstructive jaundice is a rare event. Management of this condition includes surgery, chemotherapy, radiotherapy, temporary cholecystostomy tube, endoscopic retrograde cholangiopancreatography (ERCP), and internal biliary drainage (IBD). We herein describe our experience with one infant affected by neuroblastoma presenting with jaundice, who successfully underwent percutaneous transhepatic biliary drainage (PTBD). This report introduces PTBD as a viable treatment option for neuroblastoma and obstructive jaundice and provides a review of the pertinent literature.

  11. Aggressive cervical neuroblastoma with a rare paraneoplastic syndrome: A therapeutic dilemma.

    PubMed

    Qureshi, Sajid S; Bhagat, Monica; Anam, Jay; Vora, Tushar

    2016-01-01

    Neuroblastoma is infrequently associated with paraneoplastic syndromes. Amongst the few, opsomyoclonus (Kinsbourne syndrome) is the most common neurological paraneoplastic syndrome and diarrhea secondary to increased secretion of vasoactive intestinal peptide (Kerner-Morrison syndrome), hormonal paraneoplastic syndrome. Hypothalamic dysfunction (HD) is a rare disorder and its manifestation as a paraneoplastic syndrome of neuroblastoma is uncommonly reported. We present an interesting case of an unrelenting cervical neuroblastoma associated with HD, which posed a therapeutic challenge.

  12. A Genetically Engineered Mouse Model of Neuroblastoma Driven by Mutated ALK and MYCN

    DTIC Science & Technology

    2015-09-01

    AWARD NUMBER: W81XWH-13-1-0220 TITLE: A Genetically Engineered Mouse Model of Neuroblastoma Driven by Mutated ALK and MYCN PRINCIPAL...4. TITLE AND SUBTITLE A Genetically Engineered Mouse Model of Neuroblastoma Driven by Mutated ALK and MYCN 5a. CONTRACT NUMBER 5b. GRANT NUMBER... genetic and epigenetic changes that occur during tumorigenesis. 15. SUBJECT TERMS Anaplastic lymphoma kinase, neuroblastoma, ALK, ALKF1174L, MYCN, CDK7

  13. Anticoagulant flavonoid oligomers from the rhizomes of Alpinia platychilus.

    PubMed

    Shen, Chuan-Pu; Luo, Jian-Guang; Yang, Ming-Hua; Kong, Ling-Yi

    2015-10-01

    Two pairs of enantiomers of flavonoid oligomers (1a and 1b, 2a and 2b) along with one known chalcone (3) were isolated from the rhizomes of Alpinia platychilus. Their structures were elucidated on the basis of spectroscopic data (MS and 1D/2D NMR). The absolute configurations of the flavonoid oligomers were established by their ECD spectra. Separation of the enantiomeric mixtures (1a and 1b, 2a and 2b) was achieved on a chiral column using hexane:isopropyl alcohol:ethanol (7:2:1) as eluents. The anticoagulant assay showed that 2a, 2b and 3 exhibited potent activities to prolong the prothrombin times (PT) and the thrombin times (TT).

  14. Phase transition in conjugated oligomers suspended in chloroform

    NASA Astrophysics Data System (ADS)

    Dwivedi, Shikha; Kumar, Anupam; Yadav, S. N. S.; Mishra, Pankaj

    2015-08-01

    Density functional theory (DFT) has been used to investigate the isotropic-nematic (I-N) phase transition in a system of high aspect ratio conjugated oligomers suspended in chloroform. The interaction between the oligomers is modeled using Gay-Berne potential in which effect of solvent is implicit. Percus-Yevick integral equation theory has been used to evaluate the pair correlation functions of the fluid phase at several temperatures and densities. These pair correlation function has been used in the DFT to evaluate the I-N freezing parameters. Highly oriented nematic is found to stabilize at low density. The results obtained are in qualitative agreement with the simulation and are verifiable.

  15. Synthesis of long prebiotic oligomers on mineral surfaces.

    PubMed

    Ferris, J P; Hill, A R; Liu, R; Orgel, L E

    1996-05-02

    Most theories of the origin of biological organization assume that polymers with lengths in the range of 30-60 monomers are needed to make a genetic system viable. But it has not proved possible to synthesize plausibly prebiotic polymers this long by condensation in aqueous solution, because hydrolysis competes with polymerization. The potential of mineral surfaces to facilitate prebiotic polymerization was pointed out long ago. Here we describe a system that models prebiotic polymerization by the oligomerization of activated monomers--both nucleotides and amino acids. We find that whereas the reactions in solution produce only short oligomers (the longest typically being a 10-mer), the presence of mineral surfaces (montmorillonite for nucleotides, illite and hydroxylapatite for amino acids) induces the formation of oligomers up to 55 monomers long. These are formed by successive 'feedings' with the monomers; polymerization takes place on the mineral surfaces in a manner akin to solid-phase synthesis of biopolymers.

  16. Synthesis of long Prebiotic Oligomers on Mineral Surfaces

    NASA Technical Reports Server (NTRS)

    Ferris, James P.; Hill, Aubrey R., Jr.; Liu, Rihe; Orgel, Leslie E.

    1996-01-01

    Most theories of the origin of biological organization assume that polymers with lengths in the range of 30-60 monomers are needed to make a genetic system viable. But it has not proved possible to synthesize plausibly prebiotic polymers this long by condensation in aqueous solution, because hydrolysis competes with polymerization. The potential of mineral surfaces to facilitate prebiotic polymerization was pointed out long ago. Here we describe a system that models prebiotic polymerization by the oligomerization of activated monomers -both nucleotides and amino acids. We find that whereas the reactions in solution produce only short oligomers (the longest typically being a 10-mer), the presence of mineral surfaces (montmorillonite for nucleotides, illite and hydroxylapatite for amino adds) induces the formation of oligomers up to 55 monomers long. These are formed by successive "feedings" with the monomers; polymerization takes place on the mineral surfaces in a manner akin to solid-phase synthesis of biopolymers.

  17. Phase behavior of a lattice hydrophobic oligomer in explicit water.

    PubMed

    Romero-Vargas Castrillón, Santiago; Matysiak, Silvina; Stillinger, Frank H; Rossky, Peter J; Debenedetti, Pablo G

    2012-08-09

    We investigate the thermodynamics of hydrophobic oligomer collapse using a water-explicit, three-dimensional lattice model. The model captures several aspects of protein thermodynamics, including the emergence of cold- and thermal-unfolding, as well as unfolding at high solvent density (a phenomenon akin to pressure-induced denaturation). We show that over a range of conditions spanning a ≈14% increase in solvent density, the oligomer transforms into a compact, strongly water-penetrated conformation at low temperature. This contrasts with thermal unfolding at high temperature, where the system "denatures" into an extended random coil conformation. We report a phase diagram for hydrophobic collapse that correctly captures qualitative aspects of cold and thermal unfolding at low to intermediate solvent densities.

  18. Production of random DNA oligomers for scalable DNA computing.

    PubMed

    Wang, Sixue S L; Johnson, John J X; Hughes, Bradley S T; Karabay, Dundar A O; Bader, Karson D W; Austin, Allen; Austin, Alan; Habib, Aisha; Hatef, Husnia; Joshi, Megha; Nguyen, Lawrence; Mills, Allen P

    2009-01-01

    While remarkably complex networks of connected DNA molecules can form from a relatively small number of distinct oligomer strands, a large computational space created by DNA reactions would ultimately require the use of many distinct DNA strands. The automatic synthesis of this many distinct strands is economically prohibitive. We present here a new approach to producing distinct DNA oligomers based on the polymerase chain reaction (PCR) amplification of a few random template sequences. As an example, we designed a DNA template sequence consisting of a 50-mer random DNA segment flanked by two 20-mer invariant primer sequences. Amplification of a dilute sample containing about 30 different template molecules allows us to obtain around 10(11) copies of these molecules and their complements. We demonstrate the use of these amplicons to implement some of the vector operations that will be required in a DNA implementation of an analog neural network.

  19. Changes of adiponectin oligomer composition by moderate weight reduction.

    PubMed

    Bobbert, Thomas; Rochlitz, Helmut; Wegewitz, Uta; Akpulat, Suzan; Mai, Knut; Weickert, Martin O; Möhlig, Matthias; Pfeiffer, Andreas F H; Spranger, Joachim

    2005-09-01

    Adiponectin affects lipid metabolism and insulin sensitivity. However, adiponectin circulates in three different oligomers that may also have distinct biological functions. We aimed to analyze the role of these oligomers in obesity and lipid metabolism after weight reduction. A total of 17 obese volunteers (15 women and 2 men) participated in a weight reduction program. Individuals were characterized before and after 6 months of a balanced diet. Adiponectin was determined by enzyme-linked immunosorbent assay, and oligomers were detected by nondenaturating Western blot. BMI decreased (35.1 +/- 1.2 to 32.8 +/- 1.1 kg/m(2), P < 0.001), which was associated with an improved metabolite profile. Total adiponectin increased from 5.3 +/- 0.5 to 6.1 +/- 0.6 microg/ml (P = 0.076). High (HMW) and medium molecular weight (MMW) adiponectin oligomers significantly increased during weight reduction (HMW: 0.37 +/- 0.07 to 0.4 +/- 0.08 microg/ml, P = 0.042; MMW: 2.3 +/- 0.2 to 2.9 +/- 0.3 microg/ml, P = 0.007), while low molecular weight (LMW) did not significantly change. Body weight inversely correlated with HMW (r = -0.695, P = 0.002) and positively with LMW (r = 0.579, P = 0.015). Interestingly, HDL cholesterol and HMW were strongly correlated (r = 0.665, P = 0.007). Indeed, HMW and free fatty acids before weight reduction predicted approximately 60% of HDL changes during intervention. In conclusion, weight reduction results in a relative increase of HMW/MMW adiponectin and a reduction of LMW adiponectin. Total adiponectin and especially HMW adiponectin are related to circulating HDL cholesterol.

  20. Ethynyl-terminated ester oligomers and polymers therefrom

    NASA Technical Reports Server (NTRS)

    Hergenrother, Paul M. (Inventor); Havens, Stephen J. (Inventor)

    1986-01-01

    A class of ethynyl terminated oligomers and the process for preparing the same are disclosed. Upon the application of heat, with or without a catalyst, the ethynyl groups react to provide crosslinking and chain extension to increase the polymer use temperature and improve the polymer solvent resistance. These polyesters are potentially useful in packaging, magnetic tapes, capacitors, industrial belting, protective coatings, structural adhesives and composite matrices.

  1. Using hyperbranched oligomer functionalized glass fillers to reduce shrinkage stress

    PubMed Central

    Ye, Sheng; Azarnoush, Setareh; Smith, Ian R.; Cramer, Neil B.; Stansbury, Jeffrey W.; Bowman, Christopher N

    2012-01-01

    Objective Fillers are widely utilized to enhance the mechanical properties of polymer resins. However, polymerization stress has the potential to increase due to the higher elastic modulus achieved upon filler addition. Here, we demonstrate a hyperbranched oligomer functionalized glass filler UV curable resin composite which is able to reduce the shrinkage stress without sacrificing mechanical properties. Methods A 16-functional alkene-terminated hyperbranched oligomer is synthesized by thiol-acrylate and thiol-yne reactions and the product structure is analyzed by 1H-NMR, mass spectroscopy, and gel permeation chromatography. Surface functionalization of the glass filler is measured by thermogravimetric analysis. Reaction kinetics, mechanical properties and shrinkage stress are studied via Fourier transform infrared spectroscopy, dynamic mechanical analysis and a tensometer, respectively. Results Silica nanoparticles are functionalized with a flexible 16-functional alkene-terminated hyperbranched oligomer which is synthesized by multistage thiol-ene/yne reactions. 93% of the particle surface was covered by this oligomer and an interfacial layer ranging from 0.7 – 4.5 nm thickness is generated. A composite system with these functionalized silica nanoparticles incorporated into the thiol-yne-methacrylate resin demonstrates 30% reduction of shrinkage stress (from 0.9 MPa to 0.6 MPa) without sacrificing the modulus (3100 ± 300 MPa) or glass transition temperature (62 ± 3 °C). Moreover, the shrinkage stress of the composite system builds up at much later stages of the polymerization as compared to the control system. Significance Due to the capability of reducing shrinkage stress without sacrificing mechanical properties, this composite system will be a great candidate for dental composite applications. PMID:22717296

  2. Characterization of reducible peptide oligomers as carriers for gene delivery.

    PubMed

    Kiselev, Anton; Egorova, Anna; Laukkanen, Antti; Baranov, Vladislav; Urtti, Arto

    2013-01-30

    The stability of DNA-polyplexes and intracellular DNA release are important features of gene delivery systems. To study these features, we have evaluated reducible cysteine-flanked linear lysine and arginine-rich peptides, modified with histidine residues. The reducible disulfide bonds in cysteine flanked peptides and histidine residues should augment DNA release from the peptide-DNA complexes upon disintegration of the reducible bonds. Template polymerization and oxidative polycondensation were applied to obtain peptide oligomers used for DNA-polyplex preparation. The peptides and DNA-peptide complexes were investigated with physical, chemical and transfection measurements. Physicochemical and transfection properties of DNA-polyplexes depended on the amino acid sequence of the peptidic polymers and type of the polymerization. MALDI-TOF analysis of oxidatively polycondensed products revealed several forms of peptide oligomers corresponding to 5-8 amino acid monomers. DNA-peptide particles based on template-polymerized complexes were more resistant to relaxation by negatively charged heparan sulfate than polyplexes formed with oxidatively condensed peptides. Complexes of DNA with the polycations prepared by oxidative polycondensation exhibited a 100-1000-fold higher level of gene expression compared to DNA/template-polymerized peptide complexes. The most efficient transgene expression was shown with arginine-rich polyplexes. Transfection efficacy of the arginine-rich polyplexes was even 10-fold better than that of DNA/PEI complexes. On average, polyplexes based on cysteine-flanked peptide oligomers showed lower cytotoxicity than non-reducible high molecular weight polylysine/DNA particles. We conclude that reducible peptide oligomers provide efficient DNA transfection and have the potential as vehicles for gene delivery.

  3. Selective elimination of neuroblastoma cells by synergistic effect of Akt kinase inhibitor and tetrathiomolybdate.

    PubMed

    Navrátilová, Jarmila; Karasová, Martina; Kohutková Lánová, Martina; Jiráková, Ludmila; Budková, Zuzana; Pacherník, Jiří; Šmarda, Jan; Beneš, Petr

    2017-02-28

    Neuroblastoma is the most common extracranial solid tumour of infancy. Pathological activation of glucose consumption, glycolysis and glycolysis-activating Akt kinase occur frequently in neuroblastoma cells, and these changes correlate with poor prognosis of patients. Therefore, several inhibitors of glucose utilization and the Akt kinase activity are in preclinical trials as potential anti-cancer drugs. However, metabolic plasticity of cancer cells might undermine efficacy of this approach. In this work, we identified oxidative phosphorylation as compensatory mechanism preserving viability of neuroblastoma cells with inhibited glucose uptake/Akt kinase. It was oxidative phosphorylation that maintained intracellular level of ATP and proliferative capacity of these cells. The oxidative phosphorylation inhibitors (rotenone, tetrathiomolybdate) synergized with inhibitor of the Akt kinase/glucose uptake in down-regulation of both viability of neuroblastoma cells and clonogenic potential of cells forming neuroblastoma spheroids. Interestingly, tetrathiomolybdate acted as highly specific inhibitor of oxygen consumption and activator of lactate production in neuroblastoma cells, but not in normal fibroblasts and neuronal cells. Moreover, the reducing effect of tetrathiomolybdate on cell viability and the level of ATP in the cells with inhibited Akt kinase/glucose uptake was also selective for neuroblastoma cells. Therefore, efficient elimination of neuroblastoma cells requires inhibition of both glucose uptake/Akt kinase and oxidative phosphorylation activities. The use of tetrathiomolybdate as a mitochondrial inhibitor contributes to selectivity of this combined treatment, preferentially targeting neuroblastoma cells.

  4. Computed tomography as a supplement to urography in the evaluation of suspected neuroblastoma

    SciTech Connect

    Siegel, M. J.; Sagel, S.S.

    1982-02-01

    Eleven children in whom a retropertioneal neuroblastoma was suspected on the basis of plain radiographic or urographic findings underwent computed tomography (CT). CT identified and localized a neurogenic tumor in eight patients. Calcifications were demonstrated by CT in six lesions, but by urography in only four. One neuroblastoma detected by CT was not seen on the urogram; in five patients greater extent of the tumor was defined by CT than by conventional radiologic procedures. In three patients CT excluded a neuroblastoma, but diagnosed other disorders (hepatic tumor, pancreatitis, and retrocaval ureter). Our results confirm that CT is a simple and accurate method for diagnosis, delineation of extent, or exclusion of neuroblastoma.

  5. Inhibition of FAK and VEGFR-3 Binding Decreases Tumorigenicity in Neuroblastoma

    PubMed Central

    Stewart, Jerry E.; Ma, Xiaojie; Megison, Michael; Nabers, Hugh; Cance, William G.; Kurenova, Elena V.; Beierle, Elizabeth A.

    2015-01-01

    Neuroblastoma is the most common extracranial solid tumor of childhood and is responsible for over 15% of pediatric cancer deaths. Focal adhesion kinase (FAK) is a nonreceptor tyrosine kinase that is important in many facets of tumor development and progression. Vascular endothelial growth factor receptor-3 (VEGFR-3), another tyrosine kinase, has also been found to be important in the development of many human tumors including neuroblastoma. Recent reports have found that FAK and VEGFR-3 interact, and we have previously shown that both of these kinases interact in neuroblastoma. We have hypothesized that interruption of the FAK–VEGFR-3 interaction would lead to decreased neuroblastoma cell survival. In the current study, we examined the effects of a small molecule, chloropyramine hydrochloride (C4), designed to disrupt the FAK–VEGFR-3 interaction, upon cellular attachment, migration, and survival in two human neuroblastoma cell lines. We also utilized a murine xenograft model to study the impact of C4 upon tumor growth. In these studies, we showed that disruption of the FAK–VEGFR-3 interaction led to decreased cellular attachment, migration, and survival in vitro. In addition, treatment of murine xenografts with chloropyramine hydrochloride decreased neuroblastoma xenograft growth. Further, this molecule acted synergistically with standard chemotherapy to further decrease neuroblastoma xenograft growth. The findings from this current study help to further our understanding of the regulation of neuroblastoma tumorigenesis, and may provide novel therapeutic strategies and targets for neuroblastoma and other solid tumors of childhood. PMID:23868727

  6. TRPM7 maintains progenitor-like features of neuroblastoma cells: implications for metastasis formation.

    PubMed

    Middelbeek, Jeroen; Visser, Daan; Henneman, Linda; Kamermans, Alwin; Kuipers, Arthur J; Hoogerbrugge, Peter M; Jalink, Kees; van Leeuwen, Frank N

    2015-04-20

    Neuroblastoma is an embryonal tumor derived from poorly differentiated neural crest cells. Current research is aimed at identifying the molecular mechanisms that maintain the progenitor state of neuroblastoma cells and to develop novel therapeutic strategies that induce neuroblastoma cell differentiation. Mechanisms controlling neural crest development are typically dysregulated during neuroblastoma progression, and provide an appealing starting point for drug target discovery. Transcriptional programs involved in neural crest development act as a context dependent gene regulatory network. In addition to BMP, Wnt and Notch signaling, activation of developmental gene expression programs depends on the physical characteristics of the tissue microenvironment. TRPM7, a mechanically regulated TRP channel with kinase activity, was previously found essential for embryogenesis and the maintenance of undifferentiated neural crest progenitors. Hence, we hypothesized that TRPM7 may preserve progenitor-like, metastatic features of neuroblastoma cells. Using multiple neuroblastoma cell models, we demonstrate that TRPM7 expression closely associates with the migratory and metastatic properties of neuroblastoma cells in vitro and in vivo. Moreover, microarray-based expression profiling on control and TRPM7 shRNA transduced neuroblastoma cells indicates that TRPM7 controls a developmental transcriptional program involving the transcription factor SNAI2. Overall, our data indicate that TRPM7 contributes to neuroblastoma progression by maintaining progenitor-like features.

  7. TRPM7 maintains progenitor-like features of neuroblastoma cells: implications for metastasis formation

    PubMed Central

    Middelbeek, Jeroen; Kamermans, Alwin; Kuipers, Arthur J.; Hoogerbrugge, Peter M.; Jalink, Kees; van Leeuwen, Frank N.

    2015-01-01

    Neuroblastoma is an embryonal tumor derived from poorly differentiated neural crest cells. Current research is aimed at identifying the molecular mechanisms that maintain the progenitor state of neuroblastoma cells and to develop novel therapeutic strategies that induce neuroblastoma cell differentiation. Mechanisms controlling neural crest development are typically dysregulated during neuroblastoma progression, and provide an appealing starting point for drug target discovery. Transcriptional programs involved in neural crest development act as a context dependent gene regulatory network. In addition to BMP, Wnt and Notch signaling, activation of developmental gene expression programs depends on the physical characteristics of the tissue microenvironment. TRPM7, a mechanically regulated TRP channel with kinase activity, was previously found essential for embryogenesis and the maintenance of undifferentiated neural crest progenitors. Hence, we hypothesized that TRPM7 may preserve progenitor-like, metastatic features of neuroblastoma cells. Using multiple neuroblastoma cell models, we demonstrate that TRPM7 expression closely associates with the migratory and metastatic properties of neuroblastoma cells in vitro and in vivo. Moreover, microarray-based expression profiling on control and TRPM7 shRNA transduced neuroblastoma cells indicates that TRPM7 controls a developmental transcriptional program involving the transcription factor SNAI2. Overall, our data indicate that TRPM7 contributes to neuroblastoma progression by maintaining progenitor-like features. PMID:25797249

  8. Synthesis of soybean oil-based thiol oligomers.

    PubMed

    Wu, Jennifer F; Fernando, Shashi; Weerasinghe, Dimuthu; Chen, Zhigang; Webster, Dean C

    2011-08-22

    Industrial grade soybean oil (SBO) and thiols were reacted to generate thiol-functionalized oligomers via a thermal, free radical initiated thiol-ene reaction between the SBO double bond moieties and the thiol functional groups. The effect of the reaction conditions, including thiol concentration, catalyst loading level, reaction time, and atmosphere, on the molecular weight and the conversion to the resultant soy-thiols were examined in a combinatorial high-throughput fashion using parallel synthesis, combinatorial FTIR, and rapid gel permeation chromatography (GPC). High thiol functionality and concentration, high thermal free radical catalyst concentration, long reaction time, and the use of a nitrogen reaction atmosphere were found to favor fast consumption of the SBO, and produced high molecular weight products. The thiol conversion during the reaction was inversely affected by a high thiol concentration, but was favored by a long reaction time and an air reaction atmosphere. These experimental observations were explained by the initial low affinity of the SBO and thiol, and the improved affinity between the generated soy-thiol oligomers and unreacted SBO during the reaction. The synthesized soy-thiol oligomers can be used for renewable thiol-ene UV curable materials and high molecular solids and thiourethane thermal cure materials.

  9. Molecular modeling of crystalline alkylthiophene oligomers and polymers.

    PubMed

    Moreno, Margherita; Casalegno, Mosè; Raos, Guido; Meille, Stefano V; Po, Riccardo

    2010-02-04

    We present the results of a thorough molecular modeling study of several alkylthiophene-based oligomers and polymers. In particular, we consider two polymers whose limit-ordered crystal structures have been recently reported by our group, on the basis of powder X-ray data analysis: poly(3-(S)-2-methylbutylthiophene) (P3MBT) and form I' of poly(3-butylthiophene) (P3BT). We first describe the development of a series general purpose force fields for the simulation of these and related systems. The force fields incorporate the results of ab initio calculations of the bond torsion energies of selected oligomers and differ in the set of atomic charges used to represent the electrostatic interactions. We then present the results of an extensive validation of these force fields, by means of molecular mechanics (MM) energy minimizations and molecular dynamics (MD) simulations of the crystal structures of these oligomers and polymers. While our "best" force field does not outperform the others on each of the investigated systems, it provides a balanced description of their overall structure and energetics. Finally, our MM minimizations and MD simulations confirm that the reported crystal structures of P3MBT and P3BT are stable and correspond to well-defined energetic minima. The room-temperature MD simulations reveal a certain degree of side-chain disorder, even in our virtually defect-free polymer crystal models.

  10. Deuteration-induced scission of C{sub 58} oligomers

    SciTech Connect

    Loeffler, Daniel; Jester, Stefan-S.; Weis, Patrick; Boettcher, Artur; Kappes, Manfred M.

    2006-12-14

    The reaction of solid C{sub 58} films with atomic deuterium to yield deuterofullerenes, C{sub 58}D{sub x}, has been investigated by thermal desorption spectroscopy coupled with mass spectrometric detection, ultraviolet photoionization spectroscopy (21.2 eV), and atomic force microscopy (AFM). The average composition of the deuterofullerenes created depends on deuterium dose, beam flux, and surface temperature. Low deuterium exposures at room temperature yield predominantly C{sub 58}D{sub 6-8} cages. Saturation exposures at room temperature yield mass spectra peaked at C{sub 58}D{sub 26}. After saturation exposures at elevated surface temperatures ({approx}500 K), the (subsequently) desorbed material reveals a comparatively narrow mass spectral distribution centered at C{sub 58}D{sub 30}. Deuteration is associated with cleavage of covalent cage-cage bonds in the starting C{sub 58} oligomer material, as evidenced by a considerable lowering of the sublimation energies of C{sub 58}D{sub x} compared to desorption of C{sub 58} desorbed from pure oligomer films. Correspondingly, AFM images reveal a D-induced, thermally activated transition from dendritic C{sub 58} oligomer islands into smooth-rimmed islands composed of deuterated cages. Deuterated films exhibit a significantly lower work function than bare C{sub 58} films. Progressing deuteration also gradually raises the surface ionization potential.

  11. α-Synuclein oligomers and clinical implications for Parkinson disease.

    PubMed

    Kalia, Lorraine V; Kalia, Suneil K; McLean, Pamela J; Lozano, Andres M; Lang, Anthony E

    2013-02-01

    Protein aggregation within the central nervous system has been recognized as a defining feature of neurodegenerative diseases since the early 20th century. Since that time, there has been a growing list of neurodegenerative disorders, including Parkinson disease, which are characterized by inclusions of specific pathogenic proteins. This has led to the long-held dogma that these characteristic protein inclusions, which are composed of large insoluble fibrillar protein aggregates and visible by light microscopy, are responsible for cell death in these diseases. However, the correlation between protein inclusion formation and cytotoxicity is inconsistent, suggesting that another form of the pathogenic proteins may be contributing to neurodegeneration. There is emerging evidence implicating soluble oligomers, smaller protein aggregates not detectable by conventional microscopy, as potential culprits in the pathogenesis of neurodegenerative diseases. The protein α-synuclein is well recognized to contribute to the pathogenesis of Parkinson disease and is the major component of Lewy bodies and Lewy neurites. However, α-synuclein also forms oligomeric species, with certain conformations being toxic to cells. The mechanisms by which these α-synuclein oligomers cause cell death are being actively investigated, as they may provide new strategies for diagnosis and treatment of Parkinson disease and related disorders. Here we review the possible role of α-synuclein oligomers in cell death in Parkinson disease and discuss the potential clinical implications.

  12. Oligomers, organosulfates, and nitroxy organosulfates identified in rainwater

    NASA Astrophysics Data System (ADS)

    Altieri, K. E.; Turpin, B. J.; Seitzinger, S. P.

    2008-12-01

    Wet deposition is an important removal mechanism for atmospheric organic matter, and a potentially important input for receiving ecosystems, yet less than 50 percent of rainwater organic matter is considered chemically characterized. Precipitation samples collected in New Jersey, USA, were analyzed by negative ion ultra-high resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). We document the presence of 552 unique compounds in the rainwater over a mass range of 50-500 Da, in four compound classes (i.e., CHO, CHOS, CHON, and CHONS). The presence of oligomers, organosulfates, nitroxy organosulfates, organic acids, and linear alkylbenzene sulfonates is reported. Some compounds detected have distinct primary sources; however, the composition of the bulk of this material suggests it is formed in the atmosphere and composed of known contributors to secondary organic aerosol. For example, eight oligomer series known to form through aqueous photooxidation of methylglyoxal and organosulfate compounds known to form from 4 precursors in smog chamber experiments were identified in the rainwater samples. The oligomers, organosulfates, and nitroxy organosulfates detected in the rainwater could all contribute to the HULIS fraction of atmospheric organic matter.

  13. Size-dependent neurotoxicity of β-amyloid oligomers

    PubMed Central

    Cizas, Paulius; Budvytyte, Rima; Morkuniene, Ramune; Moldovan, Radu; Broccio, Matteo; Lösche, Mathias; Niaura, Gediminas; Valincius, Gintaras; Borutaite, Vilmante

    2010-01-01

    The link between the size of soluble amyloid β (Aβ) oligomers and their toxicity to rat cerebellar granule cells (CGC) was investigated. Variation in conditions during in vitro oligomerization of Aβ1-42 resulted in peptide assemblies with different particle size as measured by atomic force microscopy and confirmed by the dynamic light scattering and fluorescence correlation spectroscopy. Small oligomers of Aβ1-42 with a mean particle z-height of 1-2 nm exhibited propensity to bind to the phospholipid vesicles and they were the most toxic species that induced rapid neuronal necrosis at submicromolar concentrations whereas the bigger aggregates (z-height above 4-5 nm) did not bind vesicles and did not cause detectable neuronal death. Similar neurotoxic pattern was also observed in primary cultures of cortex neurons whereas Aβ1–42 oligomers, monomers and fibrils were non-toxic to glial cells in CGC cultures or macrophage J774 cells. However, both oligomeric forms of Aβ1-42 induced reduction of neuronal cell densities in the CGC cultures. PMID:20153288

  14. Size-dependent neurotoxicity of beta-amyloid oligomers.

    PubMed

    Cizas, Paulius; Budvytyte, Rima; Morkuniene, Ramune; Moldovan, Radu; Broccio, Matteo; Lösche, Mathias; Niaura, Gediminas; Valincius, Gintaras; Borutaite, Vilmante

    2010-04-15

    The link between the size of soluble amyloid beta (Abeta) oligomers and their toxicity to rat cerebellar granule cells (CGC) was investigated. Variation in conditions during in vitro oligomerization of Abeta(1-42) resulted in peptide assemblies with different particle size as measured by atomic force microscopy and confirmed by dynamic light scattering and fluorescence correlation spectroscopy. Small oligomers of Abeta(1-42) with a mean particle z-height of 1-2 nm exhibited propensity to bind to phospholipid vesicles and they were the most toxic species that induced rapid neuronal necrosis at submicromolar concentrations whereas the bigger aggregates (z-height above 4-5 nm) did not bind vesicles and did not cause detectable neuronal death. A similar neurotoxic pattern was also observed in primary cultures of cortex neurons whereas Abeta(1-42) oligomers, monomers and fibrils were non-toxic to glial cells in CGC cultures or macrophage J774 cells. However, both oligomeric forms of Abeta(1-42) induced reduction of neuronal cell densities in the CGC cultures.

  15. The Viscoelastic Behavior of Polymer/Oligomer Blends

    NASA Astrophysics Data System (ADS)

    Zheng, Wei; McKenna, Gregory; Simon, Sindee

    2009-03-01

    The dynamics in athermal blends of poly(α-methyl styrene) (PaMS) and its short chain oligomer are investigated using rheometry and differential scanning calorimetry (DSC). Master curves for the dynamic shear responses, G' and G", are successfully constructed for both the pure materials and the blends, indicating the validity of the time-temperature superposition principle. The temperature dependence of the shift factor follows the WLF (Williams-Landel-Ferry) behavior over the temperature range studied, and for the blends, the dependence is dominated by the high mobility oligomer. The discrete relaxation spectra of the materials are calculated and are found to be broader for the blends than for the pure materials. A similar domination of the dynamics by the oligomer is observed in DSC enthalpy recovery studies and in the broadened glass transition from DSC. The ability to predict the dynamic responses of the blends from the responses of the neat materials is examined, and whether this prediction needs to incorporate the self-concentration idea as described in Colmenero's model will be discussed.

  16. Optimized Ultrasonic Irradiation Finds Out Ultrastable Aβ1-40 Oligomers.

    PubMed

    Nakajima, Kichitaro; So, Masatomo; Takahashi, Kazuma; Tagawa, Yoh-Ichi; Hirao, Masahiko; Goto, Yuji; Ogi, Hirotsugu

    2017-03-16

    Oligomer species of amyloid β (Aβ) peptides are intensively investigated because of their relevance to Alzheimer's disease (AD), and a stable oligomer will be a cause of AD. In this article, we investigate the structural stability of two representative Aβ1-40 oligomers, which are with and without the β-sheet structure, denoted by β and non-β oligomers, respectively, using optimized ultrasonic irradiation (OUI). Recent studies reveal that OUI significantly accelerates the fibril formation in Aβ1-40 monomers; it is capable of transforming any unstable oligomers into fibrils (the dead-end products) in a short time. First, we find that β oligomers can be produced under high-speed stirring agitation; their β-sheet structures are evaluated by the circular-dichroism spectrum measurement, by the immunoassay using the fibril-specific OC antibody, and by the seeding experiment, showing identical characteristics to those formed in previous reports. Second, we form non-β oligomers in a high-concentration NaCl solution and confirm that they include no β-sheet structure, and they are recognized by the oligomer-specific A11 antibody. Furthermore, we confirm the neurotoxicity of the two types of oligomers using the neural tissue derived from mouse embryonic stem cells. We apply the OUI agitation to the β and non-β oligomers. The non-β oligomers are transformed into the fibrils, indicating that they are intermediate species in the fibrillation pathway. However, the β oligomers are surprisingly unaffected by OUI, indicating their high thermodynamic stability. We conclude that the β oligomers should be the independent dead-end products of another pathway, different from the fibrillation pathway.

  17. Amyloid β oligomers in Alzheimer’s disease pathogenesis, treatment, and diagnosis

    PubMed Central

    Viola, Kirsten L.; Klein, William L.

    2015-01-01

    Protein aggregation is common to dozens of diseases including prionoses, diabetes, Parkinson’s and Alzheimer’s. Over the past 15 years, there has been a paradigm shift in understanding the structural basis for these proteinopathies. Precedent for this shift has come from investigation of soluble Aβ oligomers (AβOs), toxins now widely regarded as instigating neuron damage leading to Alzheimer’s dementia. Toxic AβOs accumulate in AD brain and constitute long-lived alternatives to the disease-defining Aβ fibrils deposited in amyloid plaques. Key experiments using fibril-free AβO solutions demonstrated that while Aβ is essential for memory loss, the fibrillar Aβ in amyloid deposits is not the agent. The AD-like cellular pathologies induced by AβOs suggest their impact provides a unifying mechanism for AD pathogenesis, explaining why early stage disease is specific for memory and accounting for major facets of AD neuropathology. Alternative ideas for triggering mechanisms are being actively investigated. Some research favors insertion of AβOs into membrane, while other evidence supports ligand-like accumulation at particular synapses. Over a dozen candidate toxin receptors have been proposed. AβO binding triggers a redistribution of critical synaptic proteins and induces hyperactivity in metabotropic and ionotropic glutamate receptors. This leads to Ca2+ overload and instigates major facets of AD neuropathology, including tau hyperphosphorylation, insulin resistance, oxidative stress, and synapse loss. Because different species of AβOs have been identified, a remaining question is which oligomer is the major pathogenic culprit. The possibility has been raised that more than one species plays a role. Despite some key unknowns, the clinical relevance of AβOs has been established, and new studies are beginning to point to co-morbidities such as diabetes and hypercholesterolemia as etiological factors. Because pathogenic AβOs appear early in the disease

  18. Nano-Bio-Mechanics of Neuroblastoma Cells Using AFM

    NASA Astrophysics Data System (ADS)

    Bastatas, Lyndon; Matthews, James; Kang, Min; Park, Soyeun

    2011-10-01

    We have conducted an in vitro study to determine the elastic moduli of neurobalstoma cell lines using atomic force microscopy. Using a panel of cell lines established from neuroblastoma patients at different stages of disease progress and treatment, we have investigated the differences in elastic moduli during a course of cancer progression and chemotherapy. The cells were grown on the hard substrates that are chemically functionalized to enhance adhesion. We have performed the AFM indentation experiments with different applied forces from the AFM probe. For the purpose of the comparison between cell lines, the indentations were performed only on cell centers. The obtained force-distance curves were analyzed using the Hertz model in order to extract the elastic moduli. We have found that the elastic moduli of human neuroblastoma cells significantly varied during the disease progression. We postulate that the observed difference might be affected by the treatment and chemotherapy.

  19. Occult neuroblastoma presenting with opsomyoclonus: utility of computed tomography

    SciTech Connect

    Farrelly, C.; Daneman, A.; Chan, H.L.S.; Martin, D.J.

    1984-04-01

    The clinical and radiographic findings in 10 children with neuroblastoma presenting with opsomyoclonus are described and the literature is reviewed. Children with opsomyoclonus are often a diagnostic dilemma, as they may not have a palpable tumor or increased urinary catecholamines. Computed tomography (CT) is the most sensitive imaging method in locating tumors (100%) compared with plain radiography of the chest and abdomen (sensitivity 40%), excretory urography (50%), and /sup 99m/Tc radionuclide bone scans (50%). Since most neuroblastomas are solitary lesions that may arise in the adrenal glands or along the sympathetic chain from the neck down into the pelvis, the policy is to use plain radiography, sonography, and /sup 99m/Tc methylene diphosphonate (MDP) bone scans for the preliminary investigations of patients with opsomyoclonus. Body CT can then be tailored to suit the needs of the individual patients.

  20. Immunoproteomic studies on paediatric opsoclonus-myoclonus associated with neuroblastoma.

    PubMed

    Torres-Vega, Estefanía; Durán-Moreno, María; Sánchez Del Pino, Manuel; Yáñez, Yania; Cañete, Adela; Castel, Victoria; López-Cuevas, Rogelio; Vílchez, Juan Jesús; Dalmau, Josep; Graus, Francesc; García Verdugo, José Manuel; Bataller, Luis

    2016-08-15

    We aimed to identify new cell-membrane antigens implicated in opsoclonus-myoclonus with neuroblastoma. The sera of 3 out of 14 patients showed IgG electron-microscopy immunogold reactivity on SH-SY5Y neuroblastoma cells. Immunoprecipitation experiments using rat brain synaptosomes and SH-SY5Y cells led to the identification of: (1) thirty-one nuclear/cytoplasmic proteins (including antigens HuB, HuC); (2) seven neuronal membrane proteins, including the Shaw-potassium channel Kv3.3 (KCNC3), whose genetic disruption in mice causes ataxia and generalized muscle twitching. Although cell-based assays did not demonstrate direct antigenicity, our findings point to Shaw-related subfamily of the potassium voltage-gated channels complexed proteins as hypothetical antigenic targets.

  1. Clusterin Binds to Aβ1–42 Oligomers with High Affinity and Interferes with Peptide Aggregation by Inhibiting Primary and Secondary Nucleation*

    PubMed Central

    Beeg, Marten; Stravalaci, Matteo; Romeo, Margherita; Carrá, Arianna Dorotea; Cagnotto, Alfredo; Rossi, Alessandro; Diomede, Luisa; Salmona, Mario

    2016-01-01

    The aggregation of amyloid β protein (Aβ) is a fundamental pathogenic mechanism leading to the neuronal damage present in Alzheimer disease, and soluble Aβ oligomers are thought to be a major toxic culprit. Thus, better knowledge and specific targeting of the pathways that lead to these noxious species may result in valuable therapeutic strategies. We characterized some effects of the molecular chaperone clusterin, providing new and more detailed evidence of its potential neuroprotective effects. Using a classical thioflavin T assay, we observed a dose-dependent inhibition of the aggregation process. The global analysis of time courses under different conditions demonstrated that clusterin has no effect on the elongation rate but mainly interferes with the nucleation processes (both primary and secondary), reducing the number of nuclei available for further fibril growth. Then, using a recently developed immunoassay based on surface plasmon resonance, we obtained direct evidence of a high-affinity (KD = 1 nm) interaction of clusterin with biologically relevant Aβ1–42 oligomers, selectively captured on the sensor chip. Moreover, with the same technology, we observed that substoichiometric concentrations of clusterin prevent oligomer interaction with the antibody 4G8, suggesting that the chaperone shields hydrophobic residues exposed on the oligomeric assemblies. Finally, we found that preincubation with clusterin antagonizes the toxic effects of Aβ1–42 oligomers, as evaluated in a recently developed in vivo model in Caenorhabditis elegans. These data substantiate the interaction of clusterin with biologically active regions exposed on nuclei/oligomers of Aβ1–42, providing a molecular basis for the neuroprotective effects of the chaperone. PMID:26884339

  2. Enrichment of Targetable Mutations in the Relapsed Neuroblastoma Genome

    PubMed Central

    Ostrovnaya, Irina; Rubnitz, Kaitlyn R.; Ali, Siraj M.; Miller, Vincent A.; Mossé, Yael P.; Maris, John M.

    2016-01-01

    Neuroblastoma is characterized by a relative paucity of recurrent somatic mutations at diagnosis. However, recent studies have shown that the mutational burden increases at relapse, likely as a result of clonal evolution of mutation-carrying cells during primary treatment. To inform the development of personalized therapies, we sought to further define the frequency of potentially actionable mutations in neuroblastoma, both at diagnosis and after chemotherapy. We performed a retrospective study to determine mutation frequency, the only inclusion criterion being availability of cancer gene panel sequencing data from Foundation Medicine. We analyzed 151 neuroblastoma tumor samples: 44 obtained at diagnosis, 42 at second look surgery or biopsy for stable disease after chemotherapy, and 59 at relapse (6 were obtained at unknown time points). Nine patients had multiple tumor biopsies. ALK was the most commonly mutated gene in this cohort, and we observed a higher frequency of suspected oncogenic ALK mutations in relapsed disease than at diagnosis. Patients with relapsed disease had, on average, a greater number of mutations reported to be recurrent in cancer, and a greater number of mutations in genes that are potentially targetable with available therapeutics. We also observed an enrichment of reported recurrent RAS/MAPK pathway mutations in tumors obtained after chemotherapy. Our data support recent evidence suggesting that neuroblastomas undergo substantial mutational evolution during therapy, and that relapsed disease is more likely to be driven by a targetable oncogenic pathway, highlighting that it is critical to base treatment decisions on the molecular profile of the tumor at the time of treatment. However, it will be necessary to conduct prospective clinical trials that match sequencing results to targeted therapeutic intervention to determine if cancer genomic profiling improves patient outcomes. PMID:27997549

  3. Tumor Growth Model with PK Input for Neuroblastoma Drug Development

    DTIC Science & Technology

    2015-09-01

    toward this goal by developing a whole-body PBPK model with an individualized tumor compartment for topotecan in mice bearing NB5 neuroblastoma tumors...utilized contrast-enhanced ultrasound (CEUS) derived individual tumor blood flow and blood volume measurements from NB5 tumor bearing mice. We were... bearing mice for each of the four TPT dosages. The second priority time points have been completed for three of the four dosages in tumor bearing

  4. Protein kinase Cepsilon is important for migration of neuroblastoma cells

    PubMed Central

    Stensman, Helena; Larsson, Christer

    2008-01-01

    Background Migration is important for the metastatic capacity and thus for the malignancy of cancer cells. There is limited knowledge on regulatory factors that promote the migration of neuroblastoma cells. This study investigates the hypothesis that protein kinase C (PKC) isoforms regulate neuroblastoma cell motility. Methods PKC isoforms were downregulated with siRNA or modulated with activators and inhibitors. Migration was analyzed with scratch and transwell assays. Protein phosphorylation and expression levels were measured with Western blot. Results Stimulation with 12-O-tetradecanoylphorbol-13-acetate (TPA) induced migration of SK-N-BE(2)C neuroblastoma cells. Treatment with the general protein kinase C (PKC) inhibitor GF109203X and the inhibitor of classical isoforms Gö6976 inhibited migration while an inhibitor of PKCβ isoforms did not have an effect. Downregulation of PKCε, but not of PKCα or PKCδ, with siRNA led to a suppression of both basal and TPA-stimulated migration. Experiments using PD98059 and LY294002, inhibitors of the Erk and phosphatidylinositol 3-kinase (PI3K) pathways, respectively, showed that PI3K is not necessary for TPA-induced migration. The Erk pathway might be involved in TPA-induced migration but not in migration driven by PKCε. TPA induced phosphorylation of the PKC substrate myristoylated alanine-rich C kinase substrate (MARCKS) which was suppressed by the PKC inhibitors. Treatment with siRNA oligonucleotides against different PKC isoforms before stimulation with TPA did not influence the phosphorylation of MARCKS. Conclusion PKCε is important for migration of SK-N-BE(2)C neuroblastoma cells. Neither the Erk pathway nor MARCKS are critical downstream targets of PKCε but they may be involved in TPA-mediated migration. PMID:19077250

  5. Long-Term Survival in Adult Neuroblastoma with Multiple Recurrences

    PubMed Central

    Vénat-Bouvet, L.; Le Brun-Ly, V.; Martin, J.; Gasnier, O.; Falkowsky, S.; Tubiana-Mathieu, N.

    2010-01-01

    Neuroblastoma (NB) rarely occurs in adults, and less than 10% of the cases occur in patients older than 10 years. Currently, there are no standard treatment guidelines for adult NB patients. We report the case of a young man suffering from NB in adulthood with multiple recurrences. Treatment included multiple resections, chemotherapy, and radiotherapy. This patient remains free of clinical disease more than 7 years after diagnosis. PMID:20740158

  6. Expression of the amplified domain in human neuroblastoma cells.

    PubMed Central

    Michitsch, R W; Montgomery, K T; Melera, P W

    1984-01-01

    Screening of a partial cDNA library prepared from the human neuroblastoma cell line BE(2)-C with genomic DNA probes containing sequences representative of the amplified domain of that cell line allowed us to identify cloned transcripts from an active gene within the domain. The gene BE(2)-C-59 is amplified ca. 150-fold and encodes a 3.0- and a 1.5-kilobase RNA transcript, both of which are overproduced in BE(2)-C cells. A survey of a large variety of human tumor cell types indicated that this gene is amplified to varying degrees in all neuroblastoma cell lines and a retinoblastoma cell line that exhibit obvious cytological manifestations of DNA sequence amplification, i.e., homogeneously staining regions and double-minute chromosomes. The BE(2)-C-59 gene is not amplified, however, in other nonrelated tumor types, even those containing amplified DNA. Although the functional significance of this specific gene amplification in neuroblastoma cells remains unknown, an indication that it may relate to the malignant phenotype of these cells follows from the remainder of our data which show that the amplified BE(2)-C-59 gene shares partial homology with both the second and third exons, but not the first exon, of the human c-myc oncogene. Images PMID:6549047

  7. Diagnosis of neonatal neuroblastoma with postmortem magnetic resonance imaging.

    PubMed

    Davis, James; Novotny, Nathan; Macknis, Jacqueline; Alpay-Savasan, Zeynep; Goncalves, Luis F

    2017-03-01

    Postmortem magnetic resonance imaging (MRI) is emerging as a valuable tool to accompany traditional autopsy and has potential for use in cases when traditional autopsy is not possible. This case report will review the use of postmortem MRI with limited tissue sampling to differentiate between metastatic neuroblastoma and hepatoblastoma which could not be clearly differentiated with prenatal ultrasound, prenatal MRI, or emergent postnatal ultrasound. The mother presented to our institution at 27 weeks gestation after an obstetric ultrasound at her obstetrician's office identified a large abdominal mass. Fetal ultrasonography and MRI confirmed the mass but were unable to differentiate between neuroblastoma and multifocal hepatoblastoma. The baby was delivered by cesarean section after nonreassuring heart tones led to an emergent cesarean section. The baby underwent decompressive laparotomy to relieve an abdominal compartment syndrome; however, the family eventually decided to withdraw life support. At this time, we performed a whole body postmortem MRI which further characterized the mass as an adrenal neuroblastoma which was confirmed with limited tissue sampling. Postmortem MRI was especially helpful in this case, as the patient's family declined traditional autopsy.

  8. Regulation of neuroblastoma differentiation by forkhead transcription factors FOXO1/3/4 through the receptor tyrosine kinase PDGFRA.

    PubMed

    Mei, Yang; Wang, Zhanxiang; Zhang, Lei; Zhang, Yiru; Li, Xiaoyu; Liu, Huihui; Ye, Jing; You, Han

    2012-03-27

    Neuroblastoma is a common childhood malignant tumor originated from the neural crest-derived sympathetic nervous system. A crucial early event in neuroblastoma pathogenesis is arrested differentiation of neuroblasts at various stages. Treatment of neuroblastoma with TPA and PDGF-BB leads to terminal differentiation of neuroblastoma cells. However, the signaling pathways that are involved in this process remain largely unknown. Here, we report that inhibition of endogenous FOXO proteins attenuated TPA/PDGF-BB mediated differentiation of neuroblastoma cells. Activated FOXO transcription factors acted on PDGFRA promoter to direct its basal mRNA expression as well as its induction upon serum deprivation. Depletion of endogenous PDGFRA in neuroblastoma cells significantly diminished neurite formation and extension under TPA/PDGF-BB treatment. Furthermore, ectopic expression of PDGFRA abolished the blockage of neuroblastoma differentiation by FOXOs inhibition. These findings define the FOXO-PDGFRA axis as crucial mechanistic components that govern TPA-induced neuroblastoma differentiation.

  9. Synthesis and Optoelectronic Characterization of Some Star-Shaped Oligomers with Benzene and Triphenylamine Cores

    PubMed Central

    Ivan, Teofilia; Vacareanu, Loredana; Grigoras, Mircea

    2012-01-01

    Six star-shaped oligomers containing triphenylamine (D1–D3) and benzene unit (D4–D6) as cores have been synthesized by Wittig condensation or Heck coupling reaction using aromatic aldehydes and triphenylphosphonium salts or aromatic halogenated compounds with vinyl triphenylamine. All oligomers have well-defined molecular structure and high purity. Characterization of the oligomers was made by FT-IR, 1H-NMR spectroscopy, UV-Vis, and fluorescence spectroscopy. The electrochemical behavior was studied by cyclic voltammetry (CV). The cyclic voltammograms have revealed that oligomers undergo quasireversible or irreversible redox processes. The irreversible process is associated with electrochemical polymerization of oligomers by dimerization of unsubstituted triphenylamine groups. Thermal characterization was accomplished by TGA and DSC methods and evidenced that all oligomers were stable materials until 250°C and have formed stable molecular glasses after first heating scan. PMID:24052859

  10. Radiative decay of excitons in model aggregates of {pi}-conjugated oligomers

    SciTech Connect

    Manas, E.S.; Spano, F.C.

    1998-07-01

    Spontaneous emission from exciton states in an aggregate of {pi}-conjugated oligomers is studied theoretically. Each oligomer is taken as a ring of N carbon atoms and is treated using a PPP Hamiltonian. Coulombic interactions between rings are treated to first order. The radiative decay rate {gamma} from an exciton state in an aggregate of M aligned oligomers is superradiant, being M times faster than the decay rate of an isolated oligomer exciton. Inter-oligomer interactions have little effect on the exciton size and energy when the oligomer size N is large compared to the interoligomer spacing. However, when N is small, both the exciton size and energy are strongly affected by these interactions, leading to a markedly different N dependence for {gamma}.

  11. Metaiodobenzylguanidine (mIBG) in treatment of 47 patients with neuroblastoma: Results of the German Neuroblastoma Trial

    SciTech Connect

    Klingebiel, T.; Berthold, F.; Treuner, J.; Schwabe, D.; Fischer, M.; Feine, U.; Maul, F.D.; Waters, W.; Wehinger, H.; Niethammer, D. F.R.)

    1991-01-01

    From 1984 to 1989, 47 children with relapsed, refractory, and/or metastasized neuroblastoma were treated with {sup 131}I-metaiodobenzylguanidine (mIBG) in several different treatment combinations. At initial diagnosis, 36 children had Evans stage IV and 11 stage III disease. In 16 of the 47 children, tumor recurred after complete remission prior to mIBG treatment, 26 of 47 progressed from residual or nonresponding tumor, and in 5 of 47 tumor progression during chemotherapy was observed. Altogether the children were treated with a total of 112 courses (range 1-6) with a mean dosage of 8.9 +/- 6.7 mCi/kg body weight/treatment course. Total dose was 283.2 +/- 203.7 mCi for stage III and 388.9 +/- 218.6 mCi for stage IV. Nine of 47 children reached a complete or a very good partial remission (CR and VGPR) from mIBG treatment alone, 13 of 47 achieved partial remission (PR). In an early analysis, 10 patients treated with mIBG in the neuroblastoma trial NB 85 of the German Society of Pediatric Oncology showed no significant difference in survival time compared with 30 conventionally treated children. However, the recent therapy series has been done with higher doses of mIBG, and during improved therapeutic scanning many more bone lesions could be detected than during earlier diagnostic scanning. We conclude that mIBG treatment has not yet fulfilled the expectations for it but still seems for certain indications to be a promising tool to treat neuroblastoma in the future. Moreover, the frontier of neuroblastoma detection is still advancing.

  12. PGC-1α or FNDC5 Is Involved in Modulating the Effects of Aβ1−42 Oligomers on Suppressing the Expression of BDNF, a Beneficial Factor for Inhibiting Neuronal Apoptosis, Aβ Deposition and Cognitive Decline of APP/PS1 Tg Mice

    PubMed Central

    Xia, De-Yu; Huang, Xin; Bi, Chong-Feng; Mao, Lin-Ling; Peng, Li-Jun; Qian, Hai-Rong

    2017-01-01

    Alzheimer's disease (AD) is generally defined as the aberrant production of β-amyloid protein (Aβ) and hyperphosphorylated tau protein, which are deposited in β-amyloid plaques (APs) and neurofibrillary tangles (NFTs), respectively. Decreased levels of brain-derived neurotrophic factor (BDNF) have been detected in patients with AD compared to control subjects. However, the underlying molecular mechanisms driving the downregulation of the BDNF remain unknown. Therefore, we explored the mechanisms underlying the regulation of BDNF in the neurons of APP/PS1 transgenic (Tg) mice, an AD experimental model. Using the APP/PS1 Tg mice, we found that BDNF expression was markedly downregualted at the age of 3- and 9-month-old. After cerebroventricular injection (i.c.v) of Aβ1−42 oligomers into the mice, BDNF was also found to be decreased, which demonstrated the critical roles of the Aβ1−42 oligomers in regulating the expression of BDNF. In neuronal culture, peroxisome proliferators-activated receptor γ coactivator 1α (PGC-1α) and fibronectin type III domain-containing 5 (FNDC5) were found to be downregulated by treatment with the Aβ1−42 oligomers. In addition, overexpression of either PGC-1α or FNDC5 reversed the suppressive effects of the Aβ1−42 oligomers on the expression of BDNF in neuroblastoma 2a (n2a) cells. More importantly, elevating the levels of PGC-1α, FNDC5 or BDNF in the n2a cells counteracted the effects of the Aβ1−42 oligomers on neuronal apoptosis. Additionally, intranasal administration BDNF in the APP/PS1 Tg mice decreased the Aβ deposition and reduced the cognitive decline of the mice. PMID:28377712

  13. Morus alba Accumulates Reactive Oxygen Species to Initiate Apoptosis via FOXO-Caspase 3-Dependent Pathway in Neuroblastoma Cells

    PubMed Central

    Kwon, Young Hwi; Bishayee, Kausik; Rahman, Ataur; Hong, Jae Seung; Lim, Soon-Sung; Huh, Sung-Oh

    2015-01-01

    Morus alba root extract (MARE) has been used to treat hyperglycaemic conditions in oriental medicine. Here, we studied whether MARE possesses a cytotoxic effect on neuroblastoma. To check the cytotoxicity generated by MARE was whether relatively higher against the cancer cells rather than normal cells, we chose a neuroblastoma cell line (B103) and a normal cell line (Rat-2). A CCK assay revealed that MARE (10 μg/ml) reduced cell viability to approximately 60% compared to an untreated control in B103 cells. But in Rat-2 cells, MARE induced relatively lower cytotoxicity. To investigate the mechanisms underlying the cytotoxic effect of MARE, we used flow cytometry combined with immunoblot analyses. We found that MARE-treatment could accumulate ROS and depolarize mitochondria membrane potential of B103 cells. Further treatment with MARE in B103 cells also could damage DNA and induce apoptosis. An expression study of p-Akt also suggested that there was a reduction in cellular proliferation and transcription along with the process of apoptosis, which was further evidenced by an increase in Bax and cleaved-caspase 3 activity. Together, our findings suggest that MARE produces more cytotoxicity in cancer cells while having a relatively attenuated effect on normal cells. As such, MARE may be a safer option in cancer therapeutics, and it also shows potential for the patients with symptoms of hyperglycemia and cancer. PMID:25921607

  14. Direct Correlation Between Ligand-Induced α-Synuclein Oligomers and Amyloid-like Fibril Growth

    PubMed Central

    Nors Perdersen, Martin; Foderà, Vito; Horvath, Istvan; van Maarschalkerweerd, Andreas; Nørgaard Toft, Katrine; Weise, Christoph; Almqvist, Fredrik; Wolf-Watz, Magnus; Wittung-Stafshede, Pernilla; Vestergaard, Bente

    2015-01-01

    Aggregation of proteins into amyloid deposits is the hallmark of several neurodegenerative diseases such as Alzheimer’s and Parkinson’s disease. The suggestion that intermediate oligomeric species may be cytotoxic has led to intensified investigations of pre-fibrillar oligomers, which are complicated by their transient nature and low population. Here we investigate alpha-synuclein oligomers, enriched by a 2-pyridone molecule (FN075), and the conversion of oligomers into fibrils. As probed by leakage assays, the FN075 induced oligomers potently disrupt vesicles in vitro, suggesting a potential link to disease related degenerative activity. Fibrils formed in the presence and absence of FN075 are indistinguishable on microscopic and macroscopic levels. Using small angle X-ray scattering, we reveal that FN075 induced oligomers are similar, but not identical, to oligomers previously observed during alpha-synuclein fibrillation. Since the levels of FN075 induced oligomers correlate with the amounts of fibrils among different FN075:protein ratios, the oligomers appear to be on-pathway and modeling supports an ‘oligomer stacking model’ for alpha-synuclein fibril elongation. PMID:26020724

  15. Low-resolution structure of a vesicle disrupting α-synuclein oligomer that accumulates during fibrillation

    PubMed Central

    Giehm, Lise; Svergun, Dmitri I.; Otzen, Daniel E.; Vestergaard, Bente

    2011-01-01

    One of the major hallmarks of Parkinson disease is aggregation of the protein α-synuclein (αSN). Aggregate cytotoxicity has been linked to an oligomeric species formed at early stages in the aggregation process. Here we follow the fibrillation process of αSN in solution over time using small angle X-ray scattering and resolve four major coexisting species in the fibrillation process, namely monomer, dimer, fibril and an oligomer. By ab initio modeling to fit the data, we obtain a low-resolution structure of a symmetrical and slender αSN fibril in solution, consisting of a repeating unit with a maximal distance of 900 Å and a diameter of ∼180 Å. The same approach shows the oligomer to be shaped like a wreath, with a central channel and with dimensions corresponding to the width of the fibril. The structure, accumulation and decay of this oligomer is consistent with an on-pathway role for the oligomer in the fibrillation process. We propose an oligomer-driven αSN fibril formation mechanism, where the fibril is built from the oligomers. The wreath-shaped structure of the oligomer highlights its potential cytotoxicity by simple membrane permeabilization. This is confirmed by the ability of the purified oligomer to disrupt liposomes. Our results provide the first structural description in solution of a potentially cytotoxic oligomer, which accumulates during the fibrillation of αSN. PMID:21300904

  16. Achaete-Scute Homolog 1 Expression Controls Cellular Differentiation of Neuroblastoma

    PubMed Central

    Kasim, Mumtaz; Heß, Vicky; Scholz, Holger; Persson, Pontus B.; Fähling, Michael

    2016-01-01

    Neuroblastoma, the major cause of infant cancer deaths, results from fast proliferation of undifferentiated neuroblasts. Treatment of high-risk neuroblastoma includes differentiation with retinoic acid (RA); however, the resistance of many of these tumors to RA-induced differentiation poses a considerable challenge. Human achaete-scute homolog 1 (hASH1) is a proneural basic helix-loop-helix transcription factor essential for neurogenesis and is often upregulated in neuroblastoma. Here, we identified a novel function for hASH1 in regulating the differentiation phenotype of neuroblastoma cells. Global analysis of 986 human neuroblastoma datasets revealed a negative correlation between hASH1 and neuron differentiation that was independent of the N-myc (MYCN) oncogene. Using RA to induce neuron differentiation in two neuroblastoma cell lines displaying high and low levels of hASH1 expression, we confirmed the link between hASH1 expression and the differentiation defective phenotype, which was reversed by silencing hASH1 or by hypoxic preconditioning. We further show that hASH1 suppresses neuronal differentiation by inhibiting transcription at the RA receptor element. Collectively, our data indicate hASH1 to be key for understanding neuroblastoma resistance to differentiation therapy and pave the way for hASH1-targeted therapies for augmenting the response of neuroblastoma to differentiation therapy. PMID:28066180

  17. TLR3 triggering regulates PD-L1 (CD274) expression in human neuroblastoma cells.

    PubMed

    Boes, Marianne; Meyer-Wentrup, Friederike

    2015-05-28

    Neuroblastoma is the most common extracranial solid tumor in children, causing 12% of all pediatric cancer mortality. Neuroblastoma specific T-cells have been detected in patients, but usually fail to attack and eradicate the tumors. Tumor immune evasion may thus play an important role in neuroblastoma pathogenicity. Recent research in adult cancer patients shows that targeting T-cell check-point molecules PD-1/PD-L1 (or CD279/CD274) may bolster immune reactivity against solid tumors. Also, infections can be associated with spontaneous neuroblastoma regression. In our current study, we therefore investigated if antibody targeting of PD-L1 and triggering of selective pathogen-receptor Toll-like receptors (TLRs) potentiates immunogenicity of neuroblastoma cells. We find this to be the case. TLR3 triggering induced strong upregulation of both MHC class I and PD-L1 on neuroblastoma cells. At the same time TGF-β levels decreased and IL-8 secretion was induced. The combined neuroblastoma cell treatment using PD-L1 blockade and TLR3 triggering using virus analog poly(I:C) moreover induced CD4(+) and CD8(+) T-cell activation. Thus, we propose combined treatment using PD-L1 blockade with synthetic TLR ligands as an avenue toward new immunotherapy against human neuroblastoma.

  18. Focal adhesion kinase and p53 synergistically decrease neuroblastoma cell survival.

    PubMed

    Gillory, Lauren A; Stewart, Jerry E; Megison, Michael L; Waters, Alicia M; Beierle, Elizabeth A

    2015-06-15

    Neuroblastoma is the most common extracranial solid tumor of childhood and is responsible for over 15% of pediatric cancer deaths. Focal adhesion kinase (FAK) is a nonreceptor tyrosine kinase that is important in many facets of neuroblastoma tumor development and progression. The p53 oncogene, although wild type in most neuroblastomas, lacks significant function as a tumor suppressor in these tumors. Recent reports have found that FAK and p53 interact in some tumor types. We have hypothesized FAK and p53 coordinately control each other's expression and also interact in neuroblastoma. In the present study, we showed that not only do FAK and p53 interact but each one controls the expression of the other. In addition, we also examined the effects of FAK inhibition combined with p53 activation in neuroblastoma and showed that these two, in combination, had a synergistic effect on neuroblastoma cell survival. The findings from this present study help to further our understanding of the regulation of neuroblastoma tumorigenesis and may provide novel therapeutic strategies and targets for neuroblastoma and other pediatric solid tumors.

  19. PGK1 as Predictor of CXCR4 Expression, Bone Marrow Metastases and Survival in Neuroblastoma

    PubMed Central

    von Loga, Katharina; Escherich, Gabriele; Wenke, Katharina; Izbicki, Jakob R.; Reinshagen, Konrad; Gros, Stephanie J.

    2013-01-01

    Background and Aim A close relationship between phosphoglycerate kinase 1 (PGK1) and the CXCR4/SDF1 axis (chemokine receptor 4/stromal cell derived factor 1) has been shown for several cancers. However, the role of PGK1 has not been investigated for neuroblastoma, and PGK1 might be a therapeutic target for this tumor entity. The aim of the current study was to evaluate the role of PGK1 expression in neuroblastoma patients, to determine the impact of PGK1 expression levels on survival, and to correlate PGK1 expression with CXCR4 expression and bone marrow dissemination. Materials and Methods Samples from 22 patients with neuroblastoma that were surgically treated at the University Medical Center Hamburg-Eppendorf were evaluated for expression of PGK1 and CXCR4 using immunohistochemistry. Results were correlated with clinical parameters, metastases and outcome of patients. Immunocytochemistry, proliferation and expression analysis of CXCR4 and PGK1 were performed in neuroblastoma cell lines. Results PGK1 is expressed in neuroblastoma cells. PGK1 expression is significantly positively correlated with CXCR4 expression and tumor dissemination to the bone marrow. Moreover the expression of PGK1 is significantly associated with a negative impact on survival in patients with neuroblastoma. PGK1 is downregulated by inhibition of CXCR4 in neuroblastoma cells. Conclusion PGK1 appears to play an important role for neuroblastoma, predicting survival and tumor dissemination. Further in vivo studies outstanding, it is a candidate target for novel therapeutic strategies. PMID:24376734

  20. Association of maternal education with the neuroblastoma susceptibility in children: a meta-analysis.

    PubMed

    Wang, Peng; Liao, Ning; Liao, Xin-Hong; Liang, Bing; Huang, Chun-Xia; Li, Wei

    2013-02-01

    Maternal education might be an important factor for the neuroblastoma risk in children, but it was conflicting. This meta-analysis was performed to evaluate the relationship between maternal education and neuroblastoma susceptibility and to explore whether maternal education was an important indicator to be associated with the neuroblastoma risk in children. The association studies were identified from the databases of PubMed, and Cochrane Library as of June 1, 2012, and eligible investigations were synthesized using meta-analysis method. Results were expressed with odds ratios (OR) for dichotomous data, and 95% confidence intervals (CI) were also calculated. Six literatures were identified for the analysis of association between maternal education and neuroblastoma susceptibility in children, consisting of 2063 patients with cancer and 13,925 controls. There was no a marked association between maternal education and neuroblastoma susceptibility when the maternal education was less than high school (OR = 0.66, 95% CI: 0.43-1.01, P = .06). We also found that maternal education was not associated with the neuroblastoma susceptibility when the maternal education was high school (OR = 0.74, 95% CI: 0.31-1.75, P = .49) and more than high school (OR = 0.78, 95% CI: 0.33-1.85, P = .58). In conclusion, maternal education is not associated with the neuroblastoma susceptibility in children. However, more investigations are required to further clarify the association of maternal education with the neuroblastoma susceptibility in children.

  1. Heparin-binding epidermal growth factor-like growth factor promotes neuroblastoma differentiation.

    PubMed

    Gaviglio, Angela L; Knelson, Erik H; Blobe, Gerard C

    2017-02-07

    High-risk neuroblastoma is characterized by undifferentiated neuroblasts and low Schwannian stroma content. The tumor stroma contributes to the suppression of tumor growth by releasing soluble factors that promote neuroblast differentiation. Here we identify heparin-binding epidermal growth factor-like growth factor (HBEGF) as a potent prodifferentiating factor in neuroblastoma. HBEGF mRNA expression is decreased in human neuroblastoma tumors compared with benign tumors, with loss correlating with decreased survival. HBEGF protein is expressed only in stromal compartments of human neuroblastoma specimens, with tissue from high-stage disease containing very little stroma or HBEGF expression. In 3 human neuroblastoma cell lines (SK-N-AS, SK-N-BE2, and SH-SY5Y), soluble HBEGF is sufficient to promote neuroblast differentiation and decrease proliferation. Heparan sulfate proteoglycans and heparin derivatives further enhance HBEGF-induced differentiation by forming a complex with the epidermal growth factor receptor, leading to activation of the ERK1/2 and STAT3 pathways and up-regulation of the inhibitor of DNA binding transcription factor. These data support a role for loss of HBEGF in the neuroblastoma tumor microenvironment in neuroblastoma pathogenesis.-Gaviglio, A. L., Knelson, E. H., Blobe, G. C. Heparin-binding epidermal growth factor-like growth factor promotes neuroblastoma differentiation.

  2. Common variations within HACE1 gene and neuroblastoma susceptibility in a Southern Chinese population.

    PubMed

    Zhang, Zhuorong; Zhang, Ruizhong; Zhu, Jinhong; Wang, Fenghua; Yang, Tianyou; Zou, Yan; He, Jing; Xia, Huimin

    2017-01-01

    Neuroblastoma is a common fatal pediatric cancer of the developing sympathetic nervous system, which accounts for ~10% of all pediatric cancer deaths. To investigate genetic risk factors related to neuroblastoma, many genome-wide association studies have been performed, and single nucleotide polymorphisms (SNPs) within HACE1 gene have been identified to associate with neuroblastoma risk. However, the association of the HACE1 SNPs with neuroblastoma needs to be validated in Southern Chinese children. We genotyped five SNPs located in the HACE1 gene (rs4336470 C>T, rs9404576 T>G, rs4079063 A>G, rs2499663 T>C, and rs2499667 A>G) in 256 Southern Chinese patients in comparison with 531 ethnically matched healthy controls. Single locus analysis showed no significant association between any of HACE1 SNPs and neuroblastoma risk in Southern Chinese children. However, when all the risk genotypes were combined, we found a borderline significant trend toward an increased neuroblastoma risk with 4-5 risk genotypes (adjusted odds ratio =1.36, 95% confidence interval =0.98-1.89, P=0.065). Moreover, stratified analysis found that carriers of 4-5 risk genotypes tended to develop neuroblastoma in the retroperitoneal region and have more aggressive tumors, progressing to advanced clinical stages III/IV, when compared with those of 0-3 risk genotypes. In conclusion, HACE1 gene may have weak effect on neuroblastoma risk in Southern Chinese children. Large well-designed studies are needed to strengthen our findings.

  3. Prominent Pulmonary Metastases Without Concurrent Osseous Involvement in Patients With High-Risk Neuroblastoma.

    PubMed

    Bai, Xia; Zhuang, Hongming

    2017-02-13

    Metastases from high-risk neuroblastomas generally are to the bone or bone marrow. Multiple lung metastases are rare, especially when there was no concurrent osseous metastasis. We report 2 cases of high-risk neuroblastomas having prominent lung metastases without concurrent osseous lesion observed.

  4. The colorimetric determination of selectively cleaved adenosines and guanosines in DNA oligomers using bicinchoninic acid and copper.

    PubMed

    Thomas, Elizabeth M; Testa, Stephen M

    2017-01-01

    Colorimetric methods combined with color-changing chemical probes are widely used as simple yet effective tools for identifying and quantifying a wide variety of molecules in solution. For nucleic acids (DNA and RNA), perhaps the most commonly used colorimetric probe is potassium permanganate, which can be used to identify single-stranded pyrimidines (thymine and cytosine) in polymers. Unfortunately, permanganate is not an effective probe for identifying purines (adenine and guanine), especially in the presence of the more reactive pyrimidines. Therefore, robust methods for discriminating between the purines remain elusive, thereby creating a barrier toward developing more complex colorimetric applications. In this proof-of-principle study, we demonstrate that bicinchoninic acid (BCA) and copper, when combined with purine-specific chemical cleavage reactions, can be a colorimetric probe for the identification and quantification of adenosines and/or guanosines in single-stranded DNA oligomers, even in the presence of pyrimidines. Furthermore, the reactions are stoichiometric, which allows for the quantification of the number of adenosines and/or guanosines in these oligomers. Because the BCA/copper reagent detects the reducing sugar, 2-deoxyribose, that results from the chemical cleavage of a given nucleotide's N-glycosidic bond, these colorimetric assays are effectively detecting apurinic sites in DNA oligomers, which are known to occur via DNA damage in biological systems. We demonstrate that simple digital analysis of the color-changing chromophore (BCA/copper) is all that is necessary to obtain quantifiable and reproducible data, which indicates that these assays should be broadly accessible.

  5. The Role of Intracellular Calcium for the Development and Treatment of Neuroblastoma

    PubMed Central

    Satheesh, Noothan Jyothi; Büsselberg, Dietrich

    2015-01-01

    Neuroblastoma is the second most common paediatric cancer. It develops from undifferentiated simpatico-adrenal lineage cells and is mostly sporadic; however, the aetiology behind the development of neuroblastoma is still not fully understood. Intracellular calcium ([Ca2+]i) is a secondary messenger which regulates numerous cellular processes and, therefore, its concentration is tightly regulated. This review focuses on the role of [Ca2+]i in differentiation, apoptosis and proliferation in neuroblastoma. It describes the mechanisms by which [Ca2+]i is regulated and how it modulates intracellular pathways. Furthermore, the importance of [Ca2+]i for the function of anti-cancer drugs is illuminated in this review as [Ca2+]i could be a target to improve the outcome of anti-cancer treatment in neuroblastoma. Overall, modulations of [Ca2+]i could be a key target to induce apoptosis in cancer cells leading to a more efficient and effective treatment of neuroblastoma. PMID:26010602

  6. NF1 is a tumor suppressor in neuroblastoma that determines retinoic acid response and disease outcome

    PubMed Central

    Hölzel, Michael; Huang, Sidong; Koster, Jan; Øra, Ingrid; Lakeman, Arjan; Caron, Huib; Nijkamp, Wouter; Xie, Jing; Callens, Tom; Asgharzadeh, Shahab; Seeger, Robert C.; Messiaen, Ludwine; Versteeg, Rogier; Bernards, René

    2010-01-01

    Summary Retinoic acid (RA) induces differentiation of neuroblastoma cells in vitro and is used with variable success to treat aggressive forms of this disease. This variability in clinical response to RA is enigmatic, as no mutations in components of the RA signaling cascade have been found. Using a large-scale RNAi genetic screen, we identify crosstalk between the tumor suppressor NF1 and retinoic acid induced differentiation in neuroblastoma. Loss of NF1 activates RAS-MEK signaling, which in turn represses ZNF423, a critical transcriptional co-activator of the retinoic acid receptors. Neuroblastomas with low levels of both NF1 and ZNF423 have extremely poor outcome. We find NF1 mutations in neuroblastoma cell lines and in primary tumors. Inhibition of MEK signaling downstream of NF1 restores responsiveness to RA, suggesting a therapeutic strategy to overcome RA resistance in NF1 deficient neuroblastomas. PMID:20655465

  7. Electrorheology of aniline-oligomer suspensions under oscillatory shear

    NASA Astrophysics Data System (ADS)

    Mrlik, M.; Pavlinek, V.; Almajdalawi, S.; Saha, P.; Bober, P.; Stejskal, J.

    2013-02-01

    Preparation of the aniline oligomers by the oxidation of aniline with p-benzoquinone in the solutions of methanesulfonic acid (MSA) and the rheology of their suspensions in silicone oil are presented in this study. This synthesis provides particles of flake-like morphology and various conductivities depending on the molar concentration of MSA. Further, the electrorheological (ER) performance of the particles suspended in the silicone oil was measured as well as dielectric properties of suspensions. Finally, the effect of the temperature on the ER activity was investigated.

  8. Aromatic small molecules remodel toxic soluble oligomers of amyloid beta through three independent pathways.

    PubMed

    Ladiwala, Ali Reza A; Dordick, Jonathan S; Tessier, Peter M

    2011-02-04

    In protein conformational disorders ranging from Alzheimer to Parkinson disease, proteins of unrelated sequence misfold into a similar array of aggregated conformers ranging from small oligomers to large amyloid fibrils. Substantial evidence suggests that small, prefibrillar oligomers are the most toxic species, yet to what extent they can be selectively targeted and remodeled into non-toxic conformers using small molecules is poorly understood. We have evaluated the conformational specificity and remodeling pathways of a diverse panel of aromatic small molecules against mature soluble oligomers of the Aβ42 peptide associated with Alzheimer disease. We find that small molecule antagonists can be grouped into three classes, which we herein define as Class I, II, and III molecules, based on the distinct pathways they utilize to remodel soluble oligomers into multiple conformers with reduced toxicity. Class I molecules remodel soluble oligomers into large, off-pathway aggregates that are non-toxic. Moreover, Class IA molecules also remodel amyloid fibrils into the same off-pathway structures, whereas Class IB molecules fail to remodel fibrils but accelerate aggregation of freshly disaggregated Aβ. In contrast, a Class II molecule converts soluble Aβ oligomers into fibrils, but is inactive against disaggregated and fibrillar Aβ. Class III molecules disassemble soluble oligomers (as well as fibrils) into low molecular weight species that are non-toxic. Strikingly, Aβ non-toxic oligomers (which are morphologically indistinguishable from toxic soluble oligomers) are significantly more resistant to being remodeled than Aβ soluble oligomers or amyloid fibrils. Our findings reveal that relatively subtle differences in small molecule structure encipher surprisingly large differences in the pathways they employ to remodel Aβ soluble oligomers and related aggregated conformers.

  9. Acute effects of vanadate oligomers on heart, kidney, and liver histology in the Lusitanian toadfish (Halobatrachus didactylus).

    PubMed

    Borges, G; Mendonça, P; Joaquim, N; Coucelo, J; Aureliano, M

    2003-10-01

    The contribution of vanadate oligomers to the acute histological effects of vanadium was analyzed in the heart, kidney, and liver of Halobatrachus didactylus (Schneider, 1801). A sublethal vanadium dose (5 mM, 1 mL/kg) in the form of metavanadate (containing ortho and metameric species) or in the form of decavanadate (containing only decameric species) was intraperitoneally administered by injection, and specimens of H. didactylus were sacrificed at one and seven days postinjection. Sections of heart ventricle and renal and hepatic tissue were stained with hematoxylin-eosin and examined by light microscopy to identify vanadium-induced tissue injury. In addition, PicroSirius-stained ventricular sections were analyzed by bipolarized light microscopy to determine the fraction of myocardium occupied by the ventricular wall structural elements (collagen I, collagen III, and cardiac muscle). Both vanadate solutions produced similar effects in the renal tissue. Morphological alterations included damaged renal tubules showing disorganized epithelial cells in different states of necrosis. Reabsorbed renal tubules and hyperchromatic interstitial tissue were also observed. The hepatic tissue presented hyperchromatic and hypertrophied nuclei, along with necrotic and hypertrophied hepatocytes, and more severe changes were observed in the liver with exposure to decavanadate. Vanadate oligomers promoted evident tissue lesions in the kidney and liver, but not in the cardiac tissue. However, cardiac tissue structural changes were produced. For example, decavanadate induced a hypertrophy of the ventricle due to a decrease in the percentage of myocardium occupied by collagen fibers. In general, decavanadate was shown to be more toxic than metavanadate.

  10. Novel multi-targeted ErbB family inhibitor afatinib blocks EGF-induced signaling and induces apoptosis in neuroblastoma

    PubMed Central

    Mao, Xinfang; Chen, Zhenghu; Zhao, Yanling; Yu, Yang; Guan, Shan; Woodfield, Sarah E.; Vasudevan, Sanjeev A.; Tao, Ling; Pang, Jonathan C.; Lu, Jiaxiong; Zhang, Huiyuan; Zhang, Fuchun; Yang, Jianhua

    2017-01-01

    Neuroblastoma is the most common extracranial solid tumor in children. The ErbB family of proteins is a group of receptor tyrosine kinases that promote the progression of various malignant cancers including neuroblastoma. Thus, targeting them with small molecule inhibitors is a promising strategy for neuroblastoma therapy. In this study, we investigated the anti-tumor effect of afatinib, an irreversible inhibitor of members of the ErbB family, on neuroblastoma. We found that afatinib suppressed the proliferation and colony formation ability of neuroblastoma cell lines in a dose-dependent manner. Afatinib also induced apoptosis and blocked EGF-induced activation of PI3K/AKT/mTOR signaling in all neuroblastoma cell lines tested. In addition, afatinib enhanced doxorubicin-induced cytotoxicity in neuroblastoma cells, including the chemoresistant LA-N-6 cell line. Finally, afatinib exhibited antitumor efficacy in vivo by inducing apoptosis in an orthotopic xenograft neuroblastoma mouse model. Taken together, these results show that afatinib inhibits neuroblastoma growth both in vitro and in vivo by suppressing EGFR-mediated PI3K/AKT/mTOR signaling. Our study supports the idea that EGFR is a potential therapeutic target in neuroblastoma. And targeting ErbB family protein kinases with small molecule inhibitors like afatinib alone or in combination with doxorubicin is a viable option for treating neuroblastoma. PMID:27902463

  11. Amyloid-β-induced Synapse Damage Is Mediated via Cross-linkage of Cellular Prion Proteins

    PubMed Central

    Bate, Clive; Williams, Alun

    2011-01-01

    The cellular prion protein (PrPC), which is highly expressed at synapses, was identified as a receptor for the amyloid-β (Aβ) oligomers that are associated with dementia in Alzheimer disease. Here, we report that Aβ oligomers secreted by 7PA2 cells caused synapse damage in cultured neurons via a PrPC-dependent process. Exogenous PrPC added to Prnp knock-out(0/0) neurons was targeted to synapses and significantly increased Aβ-induced synapse damage. In contrast, the synapse damage induced by a phospholipase A2-activating peptide was independent of PrPC. In Prnp wild-type(+/+) neurons Aβ oligomers activated synaptic cytoplasmic phospholipase A2 (cPLA2). In these cells, the addition of Aβ oligomers triggered the translocation of cPLA2 in synapses to cholesterol dense membranes (lipid rafts) where it formed a complex also containing Aβ and PrPC. In contrast, the addition of Aβ to Prnp(0/0) neurons did not activate synaptic cPLA2, which remained in the cytoplasm and was not associated with Aβ. Filtration assays and non-denaturing gels demonstrated that Aβ oligomers cross-link PrPC. We propose that it is the cross-linkage of PrPC by Aβ oligomers that triggers abnormal activation of cPLA2 and synapse damage. This hypothesis was supported by our observation that monoclonal antibody mediated cross-linkage of PrPC also activated synaptic cPLA2 and caused synapse damage. PMID:21900234

  12. A case of opsoclonus-myoclonus-ataxia with neuroblastoma.

    PubMed

    Mukherjee, Asha; Mukherjee, Arabinda; Chakrabarty, Suparna

    2004-11-01

    A 2 year old boy presented with features of opsoclonus, myoclonus and ataxia. Routine investigations of blood, urine, x-ray chest, bone scan, EEG and MRI of brain, were normal. Urine for VMA was negative. A right suprarenal mass was detected at MRI of abdomen. The mass was resected completely and was found histologically to be of differentiating type of neuroblastoma. The child was treated initially with prednisolone for 6 weeks along with sodium valproate. He is still on sodium valproate for his neurological symptoms. His symptoms still persist though they have decreased in intensity.

  13. Amyloid oligomer structure characterization from simulations: A general method

    SciTech Connect

    Nguyen, Phuong H.; Li, Mai Suan

    2014-03-07

    Amyloid oligomers and plaques are composed of multiple chemically identical proteins. Therefore, one of the first fundamental problems in the characterization of structures from simulations is the treatment of the degeneracy, i.e., the permutation of the molecules. Second, the intramolecular and intermolecular degrees of freedom of the various molecules must be taken into account. Currently, the well-known dihedral principal component analysis method only considers the intramolecular degrees of freedom, and other methods employing collective variables can only describe intermolecular degrees of freedom at the global level. With this in mind, we propose a general method that identifies all the structures accurately. The basis idea is that the intramolecular and intermolecular states are described in terms of combinations of single-molecule and double-molecule states, respectively, and the overall structures of oligomers are the product basis of the intramolecular and intermolecular states. This way, the degeneracy is automatically avoided. The method is illustrated on the conformational ensemble of the tetramer of the Alzheimer's peptide Aβ{sub 9−40}, resulting from two atomistic molecular dynamics simulations in explicit solvent, each of 200 ns, starting from two distinct structures.

  14. Broadband terahertz dynamics of propylene glycol monomer and oligomers

    NASA Astrophysics Data System (ADS)

    Koda, Shota; Mori, Tatsuya; Kojima, Seiji

    2016-12-01

    We investigated the broadband terahertz spectra (0.1-5.0 THz) of glass-forming liquids, propylene glycol (PG), its oligomers poly (propylene glycol)s (PPGs), and poly (propylene glycol) diglycidyl ether (PPG-de) using broadband terahertz time-domain spectroscopy and low-frequency Raman scattering. The numerical value of the dielectric loss at around 1.5 THz, which is the peak position of broad peaks in all samples, decreased as the molecular weight increased. Furthermore, the peak at around 1.5 THz is insensitive to the molecular weight. For PPGs, the side chain effect of the oligomer was observed in the terahertz region. Based on the experimental and calculation results for the PPGs and PPG-de, whose end groups are epoxy groups, the beginnings of the increases in the observed dielectric loss above 3.5 THz of the PPGs are assigned to the OH bending vibration. The higher value of the dielectric loss in the terahertz region for the PPG-de can be the tail of a broad peak located in the MHz region. The difference between the Raman susceptibility and dielectric loss reflects the difference in the observable molecular dynamics between the infrared and Raman spectroscopies.

  15. Amyloid oligomer structure characterization from simulations: A general method

    NASA Astrophysics Data System (ADS)

    Nguyen, Phuong H.; Li, Mai Suan; Derreumaux, Philippe

    2014-03-01

    Amyloid oligomers and plaques are composed of multiple chemically identical proteins. Therefore, one of the first fundamental problems in the characterization of structures from simulations is the treatment of the degeneracy, i.e., the permutation of the molecules. Second, the intramolecular and intermolecular degrees of freedom of the various molecules must be taken into account. Currently, the well-known dihedral principal component analysis method only considers the intramolecular degrees of freedom, and other methods employing collective variables can only describe intermolecular degrees of freedom at the global level. With this in mind, we propose a general method that identifies all the structures accurately. The basis idea is that the intramolecular and intermolecular states are described in terms of combinations of single-molecule and double-molecule states, respectively, and the overall structures of oligomers are the product basis of the intramolecular and intermolecular states. This way, the degeneracy is automatically avoided. The method is illustrated on the conformational ensemble of the tetramer of the Alzheimer's peptide Aβ9-40, resulting from two atomistic molecular dynamics simulations in explicit solvent, each of 200 ns, starting from two distinct structures.

  16. Charge transfer interactions in oligomer coated gold nanoclusters

    NASA Astrophysics Data System (ADS)

    Newmai, M. Boazbou; Kumar, Pandian Senthil

    2016-05-01

    Gold nanoclusters were synthesized by a bottom-up synergistic approach of in-situ oligomerization of the monomer, N-vinyl pyrrolidone (NVP) and simultaneous weak reduction of Au-NVP complexes in the absence of any other external energy sources, thereby making these tiny gold clusters as the most elemental building blocks to construct further novel nano/microstructures with application potentials. It is well-known that metal clusters with less than 2 nm size do not show the usual surface plasmon band, because of the presence of a band-gap at the fermi level. Nevertheless, our present oligomer coated gold clusters show a discrete intense band at around 630 nm, which could very well be attributed to the charge transfer between the oligomer chain and the surface Au atoms. Such kind of sacrificial plasmon induced charge transfer interaction, observed for the very first time to the best of our knowledge, were also strongly corroborated through the enhancement / shifting of specific vibrational / rotational peaks as observed from the FTIR and Raman measurements as a function of the metal oxidation states, thus representing a new prototype for an efficient solar energy conversion probe.

  17. Amyloid oligomer structure characterization from simulations: a general method.

    PubMed

    Nguyen, Phuong H; Li, Mai Suan; Derreumaux, Philippe

    2014-03-07

    Amyloid oligomers and plaques are composed of multiple chemically identical proteins. Therefore, one of the first fundamental problems in the characterization of structures from simulations is the treatment of the degeneracy, i.e., the permutation of the molecules. Second, the intramolecular and intermolecular degrees of freedom of the various molecules must be taken into account. Currently, the well-known dihedral principal component analysis method only considers the intramolecular degrees of freedom, and other methods employing collective variables can only describe intermolecular degrees of freedom at the global level. With this in mind, we propose a general method that identifies all the structures accurately. The basis idea is that the intramolecular and intermolecular states are described in terms of combinations of single-molecule and double-molecule states, respectively, and the overall structures of oligomers are the product basis of the intramolecular and intermolecular states. This way, the degeneracy is automatically avoided. The method is illustrated on the conformational ensemble of the tetramer of the Alzheimer's peptide Aβ9-40, resulting from two atomistic molecular dynamics simulations in explicit solvent, each of 200 ns, starting from two distinct structures.

  18. Lithium and memantine improve spatial memory impairment and neuroinflammation induced by β-amyloid 1-42 oligomers in rats.

    PubMed

    Budni, J; Feijó, D P; Batista-Silva, H; Garcez, M L; Mina, F; Belletini-Santos, T; Krasilchik, L R; Luz, A P; Schiavo, G L; Quevedo, J

    2017-03-27

    Alzheimer's disease (AD) is the most common cause of dementia in the elderly. The main hallmarks of this disease include progressive cognitive dysfunction and an accumulation of soluble oligomers of β-amyloid (Aβ) 1-42 peptide. In this research, we show the effects of lithium and memantine on spatial memory and neuroinflammation in an Aβ1-42 oligomers-induced animal model of dementia in rats. Aβ 1-42 oligomers were administered intrahippocampally to male wistar rats to induce dementia. Oral treatments with memantine (5mg/kg), lithium (5mg/kg), or both drugs in combination were performed over a period of 17days. 14days after the administration of the Aβ1-42 oligomers, the radial arm-maze task was performed. At the end of the test period, the animals were euthanized, and the frontal cortex and hippocampus were removed for use in our analysis. Our results showed that alone treatments with lithium or memantine ameliorate the spatial memory damage caused by Aβ1-42. The animals that received combined doses of lithium and memantine showed better cognitive performance in their latency time and total errors to find food when compared to the results from alone treatments. Moreover, in our study, lithium and/or memantine were able to reverse the decreases observed in the levels of interleukin (IL)-4 that were induced by Aβ1-42 in the frontal cortex. In the hippocampus, only memantine and the association of memantine and lithium were able to reverse this effect. Alone doses of lithium and memantine or the association of lithium and memantine caused reductions in the levels of IL-1β in the frontal cortex and hippocampus, and decreased the levels of TNF-α in the hippocampus. Taken together, these data suggest that lithium and memantine might be a potential therapy against cognitive impairment and neuroinflammation induced by Aβ1-42, and their association may be a promising alternative to be investigated in the treatment of AD-like dementia.

  19. Sedimentation studies on human amylin fail to detect low-molecular-weight oligomers.

    PubMed

    Vaiana, Sara M; Ghirlando, Rodolfo; Yau, Wai-Ming; Eaton, William A; Hofrichter, James

    2008-04-01

    Sedimentation velocity experiments show that only monomers coexist with amyloid fibrils of human islet amyloid-polypeptide. No oligomers containing <100 monomers could be detected, suggesting that the putative toxic oligomers are much larger than those found for the Alzheimer's peptide, Abeta(1-42).

  20. Heat Resistant Characteristics of Major Royal Jelly Protein 1 (MRJP1) Oligomer.

    PubMed

    Moriyama, Takanori; Ito, Aimi; Omote, Sumire; Miura, Yuri; Tsumoto, Hiroki

    2015-01-01

    Soluble royal jelly protein is a candidate factor responsible for mammiferous cell proliferation. Major royal jelly protein 1 (MRJP1), which consists of oligomeric and monomeric forms, is an abundant proliferative protein in royal jelly. We previously reported that MRJP1 oligomer has biochemical heat resistance. Therefore, in the present study, we investigated the effects of several heat treatments (56, 65 and 96°C) on the proliferative activity of MRJP1 oligomer. Heat resistance studies showed that the oligomer molecular forms were slightly maintained until 56℃, but the molecular forms were converted to macromolecular heat-aggregated MRJP1 oligomer at 65℃ and 96℃. But, the growth activity of MRJP1 oligomer treated with 96°C was slightly attenuated when compared to unheated MRJP1 oligomer. On the other hand, the cell proliferation activity was preserved until 96℃ by the cell culture analysis of Jurkat cells. In contrast, those of IEC-6 cells were not preserved even at 56°C. The present observations suggest that the bioactive heat-resistance properties were different by the origin of the cells. The cell proliferation analysis showed that MRJP1 oligomer, but not MRJP2 and MRJP3, significantly increased cell numbers, suggesting that MRJP1 oligomer is the predominant proliferation factor for mammiferous cells.

  1. Seeding induced by alpha-synuclein oligomers provides evidence for spreading of alpha-synuclein pathology.

    PubMed

    Danzer, Karin M; Krebs, Simon K; Wolff, Michael; Birk, Gerald; Hengerer, Bastian

    2009-10-01

    Lewy bodies, alpha-synuclein (alpha-syn) immunopositive intracellular deposits, are the pathological hallmark of Parkinson's disease (PD). Interestingly, Lewybody-like structures have been identified in fetal tissue grafts about one decade after transplantation into the striatum of PD patients. One possible explanation for the accelerated deposition of alpha-syn in the graft is that the aggregation of alpha-syn from the host tissue to the graft is spread by a prion disease-like mechanism. We discuss here an in vitro model which might recapitulate some aspects of disease propagation in PD. We found here that in vitro-generated alpha-syn oligomers induce transmembrane seeding of alpha-syn aggregation in a dose- and time-dependent manner. This effect was observed in primary neuronal cultures as well as in neuronal cell lines. The seeding oligomers were characterized by a distinctive lithium dodecyl sulfate-stable oligomer pattern and could be generated in a dynamic process out of pore-forming oligomers. We propose that alpha-syn oligomers form as a dynamic mixture of oligomer types with different properties and that alpha-syn oligomers can be converted into different types depending on the brain milieu conditions. Our data indicate that extracellular alpha-syn oligomers can induce intracellular alpha-syn aggregation, therefore we hypothesize that a similar mechanism might lead to alpha-syn pathology propagation.

  2. Amyloid-beta oligomers increase the localization of prion protein at the cell surface.

    PubMed

    Caetano, Fabiana A; Beraldo, Flavio H; Hajj, Glaucia N M; Guimaraes, Andre L; Jürgensen, Sofia; Wasilewska-Sampaio, Ana Paula; Hirata, Pedro H F; Souza, Ivana; Machado, Cleiton F; Wong, Daisy Y-L; De Felice, Fernanda G; Ferreira, Sergio T; Prado, Vania F; Rylett, R Jane; Martins, Vilma R; Prado, Marco A M

    2011-05-01

    In Alzheimer's disease, the amyloid-β peptide (Aβ) interacts with distinct proteins at the cell surface to interfere with synaptic communication. Recent data have implicated the prion protein (PrP(C)) as a putative receptor for Aβ. We show here that Aβ oligomers signal in cells in a PrP(C)-dependent manner, as might be expected if Aβ oligomers use PrP(C) as a receptor. Immunofluorescence, flow cytometry and cell surface protein biotinylation experiments indicated that treatment with Aβ oligomers, but not monomers, increased the localization of PrP(C) at the cell surface in cell lines. These results were reproduced in hippocampal neuronal cultures by labeling cell surface PrP(C). In order to understand possible mechanisms involved with this effect of Aβ oligomers, we used live cell confocal and total internal reflection microscopy in cell lines. Aβ oligomers inhibited the constitutive endocytosis of PrP(C), but we also found that after Aβ oligomer-treatment PrP(C) formed more clusters at the cell surface, suggesting the possibility of multiple effects of Aβ oligomers. Our experiments show for the first time that Aβ oligomers signal in a PrP(C)-dependent way and that they can affect PrP(C) trafficking, increasing its localization at the cell surface.

  3. Theory of microphase separation in homopolymer oligomer mixtures

    NASA Astrophysics Data System (ADS)

    Olemskoi, Alexander; Savelyev, Alexey

    2005-11-01

    This work starts with the review of theoretical methods proposed, during past decades, for description of phase behavior in different polymer systems, involving variety of linear polymers (regular and polydisperse block (co)polymers, random polymers) and the polymer systems with non-covalent bonds of different strength. Microphase separation (MS) into different ordered mesophases is known to be the principal property of such systems. It is shown that most of the theoretical approaches proposed for description of the MS are based on the simple random phase approximation (RPA). It turns out, however, that mean field RPA method applied to description of the systems with non-covalent bonds does not provide the whole picture of MS. We show that the problem here arises when one treats both Flory-Huggins non-associated interactions and non-covalent bonds (hydrogen, ionic) within the unified RPA scheme, which is obviously rough for description of the latter type of interactions. Such a theory was developed in a few recent papers for the systems involving weak hydrogen bonds between homopolymer chains and the low molecular weight oligomers (surfactants). However, it leaves some experimental data unaccounted. The purpose of this review is to consider more detailed theory which is able to explain not only all the experimental data for the above systems but also to take into account the strength variation of non-bonding interactions. In particular, we consider the strong ionic interactions, weak hydrogen bonding, and the interactions of intermediate strength between polymer chain and short oligomers within our unifying theory. To develop such a description in a self-consistent way we propose to use a general field theory of stochastic systems. The mesoscopic (lamellar) structure of the periodically alternating layers of stretched homopolymer chains surrounded by perpendicularly oriented oligomeric tails is studied for the systems with both strong (ionic) and weak (hydrogen

  4. Alzheimer's Therapeutics Targeting Amyloid Beta 1–42 Oligomers I: Abeta 42 Oligomer Binding to Specific Neuronal Receptors Is Displaced by Drug Candidates That Improve Cognitive Deficits

    PubMed Central

    Izzo, Nicholas J.; Staniszewski, Agnes; To, Lillian; Fa, Mauro; Teich, Andrew F.; Saeed, Faisal; Wostein, Harrison; Walko, Thomas; Vaswani, Anisha; Wardius, Meghan; Syed, Zanobia; Ravenscroft, Jessica; Mozzoni, Kelsie; Silky, Colleen; Rehak, Courtney; Yurko, Raymond; Finn, Patricia; Look, Gary; Rishton, Gilbert; Safferstein, Hank; Miller, Miles; Johanson, Conrad; Stopa, Edward; Windisch, Manfred; Hutter-Paier, Birgit; Shamloo, Mehrdad; Arancio, Ottavio; LeVine, Harry; Catalano, Susan M.

    2014-01-01

    Synaptic dysfunction and loss caused by age-dependent accumulation of synaptotoxic beta amyloid (Abeta) 1–42 oligomers is proposed to underlie cognitive decline in Alzheimer's disease (AD). Alterations in membrane trafficking induced by Abeta oligomers mediates reduction in neuronal surface receptor expression that is the basis for inhibition of electrophysiological measures of synaptic plasticity and thus learning and memory. We have utilized phenotypic screens in mature, in vitro cultures of rat brain cells to identify small molecules which block or prevent the binding and effects of Abeta oligomers. Synthetic Abeta oligomers bind saturably to a single site on neuronal synapses and induce deficits in membrane trafficking in neuronal cultures with an EC50 that corresponds to its binding affinity. The therapeutic lead compounds we have found are pharmacological antagonists of Abeta oligomers, reducing the binding of Abeta oligomers to neurons in vitro, preventing spine loss in neurons and preventing and treating oligomer-induced deficits in membrane trafficking. These molecules are highly brain penetrant and prevent and restore cognitive deficits in mouse models of Alzheimer's disease. Counter-screening these compounds against a broad panel of potential CNS targets revealed they are highly potent and specific ligands of the sigma-2/PGRMC1 receptor. Brain concentrations of the compounds corresponding to greater than 80% receptor occupancy at the sigma-2/PGRMC1 receptor restore cognitive function in transgenic hAPP Swe/Ldn mice. These studies demonstrate that synthetic and human-derived Abeta oligomers act as pharmacologically-behaved ligands at neuronal receptors - i.e. they exhibit saturable binding to a target, they exert a functional effect related to their binding and their displacement by small molecule antagonists blocks their functional effect. The first-in-class small molecule receptor antagonists described here restore memory to normal in multiple AD

  5. Alzheimer's therapeutics targeting amyloid beta 1-42 oligomers I: Abeta 42 oligomer binding to specific neuronal receptors is displaced by drug candidates that improve cognitive deficits.

    PubMed

    Izzo, Nicholas J; Staniszewski, Agnes; To, Lillian; Fa, Mauro; Teich, Andrew F; Saeed, Faisal; Wostein, Harrison; Walko, Thomas; Vaswani, Anisha; Wardius, Meghan; Syed, Zanobia; Ravenscroft, Jessica; Mozzoni, Kelsie; Silky, Colleen; Rehak, Courtney; Yurko, Raymond; Finn, Patricia; Look, Gary; Rishton, Gilbert; Safferstein, Hank; Miller, Miles; Johanson, Conrad; Stopa, Edward; Windisch, Manfred; Hutter-Paier, Birgit; Shamloo, Mehrdad; Arancio, Ottavio; LeVine, Harry; Catalano, Susan M

    2014-01-01

    Synaptic dysfunction and loss caused by age-dependent accumulation of synaptotoxic beta amyloid (Abeta) 1-42 oligomers is proposed to underlie cognitive decline in Alzheimer's disease (AD). Alterations in membrane trafficking induced by Abeta oligomers mediates reduction in neuronal surface receptor expression that is the basis for inhibition of electrophysiological measures of synaptic plasticity and thus learning and memory. We have utilized phenotypic screens in mature, in vitro cultures of rat brain cells to identify small molecules which block or prevent the binding and effects of Abeta oligomers. Synthetic Abeta oligomers bind saturably to a single site on neuronal synapses and induce deficits in membrane trafficking in neuronal cultures with an EC50 that corresponds to its binding affinity. The therapeutic lead compounds we have found are pharmacological antagonists of Abeta oligomers, reducing the binding of Abeta oligomers to neurons in vitro, preventing spine loss in neurons and preventing and treating oligomer-induced deficits in membrane trafficking. These molecules are highly brain penetrant and prevent and restore cognitive deficits in mouse models of Alzheimer's disease. Counter-screening these compounds against a broad panel of potential CNS targets revealed they are highly potent and specific ligands of the sigma-2/PGRMC1 receptor. Brain concentrations of the compounds corresponding to greater than 80% receptor occupancy at the sigma-2/PGRMC1 receptor restore cognitive function in transgenic hAPP Swe/Ldn mice. These studies demonstrate that synthetic and human-derived Abeta oligomers act as pharmacologically-behaved ligands at neuronal receptors--i.e. they exhibit saturable binding to a target, they exert a functional effect related to their binding and their displacement by small molecule antagonists blocks their functional effect. The first-in-class small molecule receptor antagonists described here restore memory to normal in multiple AD models

  6. X-ray Crystallographic Structure of Oligomers Formed by a Toxic β-Hairpin Derived from α-Synuclein: Trimers and Higher-Order Oligomers.

    PubMed

    Salveson, Patrick J; Spencer, Ryan K; Nowick, James S

    2016-04-06

    Oligomeric assemblies of the protein α-synuclein are thought to cause neurodegeneration in Parkinson's disease and related synucleinopathies. Characterization of α-synuclein oligomers at high resolution is an outstanding challenge in the field of structural biology. The absence of high-resolution structures of oligomers formed by α-synuclein impedes understanding the synucleinopathies at the molecular level. This paper reports the X-ray crystallographic structure of oligomers formed by a peptide derived from residues 36-55 of α-synuclein. The peptide 1a adopts a β-hairpin structure, which assembles in a hierarchical fashion. Three β-hairpins assemble to form a triangular trimer. Three copies of the triangular trimer assemble to form a basket-shaped nonamer. Two nonamers pack to form an octadecamer. Molecular modeling suggests that full-length α-synuclein may also be able to assemble in this fashion. Circular dichroism spectroscopy demonstrates that peptide 1a interacts with anionic lipid bilayer membranes, like oligomers of full-length α-synuclein. LDH and MTT assays demonstrate that peptide 1a is toxic toward SH-SY5Y cells. Comparison of peptide 1a to homologues suggests that this toxicity results from nonspecific interactions with the cell membrane. The oligomers formed by peptide 1a are fundamentally different than the proposed models of the fibrils formed by α-synuclein and suggest that α-Syn36-55, rather than the NAC, may nucleate oligomer formation.

  7. An investigation into the effect of amphiphilic siloxane oligomers on dermal fibroblasts.

    PubMed

    Farrugia, Brooke L; Keddie, Daniel J; George, Graeme A; Lynam, Emily C; Brook, Michael A; Upton, Zee; Dargaville, Tim R

    2012-07-01

    This study investigates the effect of well-defined poly(dimethylsiloxane)-poly(ethylene glycol) (PDMS-PEG) ABA linear block co-oligomers on the proliferation of human dermal fibroblasts. The co-oligomers assessed ranged in molecular weight (MW) from 1335 to 5208 Da and hydrophilic-lipophilic balance (HLB) from 5.9 to 16.6 by varying the number of both PDMS and PEG units. In general, it was found that co-oligomers of low MW or intermediate hydrophilicity significantly reduced fibroblast proliferation. A linear relationship between down-regulation of fibroblast proliferation, and the ratio HLB/MW was observed at concentrations of 0.1 and 1.0 wt % of the oligomers. This enabled the structures with highest efficiency to be determined. These results suggest the possible use of the PEG-PDMS-PEG block co-oligomers as an alternative to silicone gels for hypertrophic scar remediation.

  8. Direct PIP2 binding mediates stable oligomer formation of the serotonin transporter

    PubMed Central

    Anderluh, Andreas; Hofmaier, Tina; Klotzsch, Enrico; Kudlacek, Oliver; Stockner, Thomas; Sitte, Harald H.; Schütz, Gerhard J.

    2017-01-01

    The human serotonin transporter (hSERT) mediates uptake of serotonin from the synaptic cleft and thereby terminates serotonergic signalling. We have previously found by single-molecule microscopy that SERT forms stable higher-order oligomers of differing stoichiometry at the plasma membrane of living cells. Here, we report that SERT oligomer assembly at the endoplasmic reticulum (ER) membrane follows a dynamic equilibration process, characterized by rapid exchange of subunits between different oligomers, and by a concentration dependence of the degree of oligomerization. After trafficking to the plasma membrane, however, the SERT stoichiometry is fixed. Stabilization of the oligomeric SERT complexes is mediated by the direct binding to phosphoinositide phosphatidylinositol-4,5-biphosphate (PIP2). The observed spatial decoupling of oligomer formation from the site of oligomer operation provides cells with the ability to define protein quaternary structures independent of protein density at the cell surface. PMID:28102201

  9. Star-shaped tetrathiafulvalene oligomers towards the construction of conducting supramolecular assembly

    PubMed Central

    Hasegawa, Masashi

    2015-01-01

    Summary The construction of redox-active supramolecular assemblies based on star-shaped and radially expanded tetrathiafulvalene (TTF) oligomers with divergent and extended conjugation is summarized. Star-shaped TTF oligomers easily self-aggregate with a nanophase separation to produce supramolecular structures, and their TTF units stack face-to-face to form columnar structures using the fastener effect. Based on redox-active self-organizing supramolecular structures, conducting nanoobjects are constructed by doping of TTF oligomers with oxidants after the formation of such nanostructures. Although radical cations derived from TTF oligomers strongly interact in solution to produce a mixed-valence dimer and π-dimer, it seems to be difficult to produce nanoobjects of radical cations different from those of neutral TTF oligomers. In some cases, however, radical cations form nanostructured fibers and rods by controlling the supramolecular assembly, oxidation states, and counter anions employed. PMID:26664579

  10. Alginate gels with a combination of calcium and chitosan oligomer mixtures as crosslinkers.

    PubMed

    Feng, Yiming; Kopplin, Georg; Sato, Kimihiko; Draget, Kurt I; Vårum, Kjell M

    2017-01-20

    Alginates are polysaccharides that are widely used in relation to their ability to form gels. Recently we reported that alginates may also form gels with chitosan oligomers as crosslinkers (Khong, Aarstad, Skjåk-Bræk, Draget, & Vårum, 2013). The purpose of the present study was to characterize alginate gels crosslinked with calcium and chitosan oligomers. Using two different alginates of similar molecular weights but different chemical composition, i.e. guluronic acid content of 46 and 68%, we found that both alginates could form homogeneous gels with calcium and chitosan oligomers separately and without syneresis. Systematic combinations of calcium and chitosan oligomers as crosslinkers were tested, showing that up to 50% of the calcium could be substituted with chitosan oligomers without reduction in gel strength or increased syneresis for the alginate with the lowest guluronic acid content. Furthermore, the kinetics of the combined gels were different from pure calcium alginate gels.

  11. Preparation of Chito-Oligomers by Hydrolysis of Chitosan in the Presence of Zeolite as Adsorbent.

    PubMed

    Ibrahim, Khalid A; El-Eswed, Bassam I; Abu-Sbeih, Khaleel A; Arafat, Tawfeeq A; Al Omari, Mahmoud M H; Darras, Fouad H; Badwan, Adnan A

    2016-07-23

    An increasing interest has recently been shown to use chitin/chitosan oligomers (chito-oligomers) in medicine and food fields because they are not only water-soluble, nontoxic, and biocompatible materials, but they also exhibit numerous biological properties, including antibacterial, antifungal, and antitumor activities, as well as immuno-enhancing effects on animals. Conventional depolymerization methods of chitosan to chito-oligomers are either chemical by acid-hydrolysis under harsh conditions or by enzymatic degradation. In this work, hydrolysis of chitosan to chito-oligomers has been achieved by applying adsorption-separation technique using diluted HCl in the presence of different types of zeolite as adsorbents. The chito-oligomers were retrieved from adsorbents and characterized by differential scanning calorimetry (DSC), liquid chromatography/mass spectroscopy (LC/MS), and ninhydrin test.

  12. The Role of Amyloid-β Oligomers in Toxicity, Propagation, and Immunotherapy

    PubMed Central

    Sengupta, Urmi; Nilson, Ashley N.; Kayed, Rakez

    2016-01-01

    The incidence of Alzheimer's disease (AD) is growing every day and finding an effective treatment is becoming more vital. Amyloid-β (Aβ) has been the focus of research for several decades. The recent shift in the Aβ cascade hypothesis from all Aβ to small soluble oligomeric intermediates is directing the search for therapeutics towards the toxic mediators of the disease. Targeting the most toxic oligomers may prove to be an effective treatment by preventing their spread. Specific targeting of oligomers has been shown to protect cognition in rodent models. Additionally, the heterogeneity of research on Aβ oligomers may seem contradictory until size and conformation are taken into account. In this review, we will discuss Aβ oligomers and their toxicity in relation to size and conformation as well as their influence on inflammation and the potential of Aβ oligomer immunotherapy. PMID:27211547

  13. Preparation of Chito-Oligomers by Hydrolysis of Chitosan in the Presence of Zeolite as Adsorbent

    PubMed Central

    Ibrahim, Khalid A.; El-Eswed, Bassam I.; Abu-Sbeih, Khaleel A.; Arafat, Tawfeeq A.; Al Omari, Mahmoud M. H.; Darras, Fouad H.; Badwan, Adnan A.

    2016-01-01

    An increasing interest has recently been shown to use chitin/chitosan oligomers (chito-oligomers) in medicine and food fields because they are not only water-soluble, nontoxic, and biocompatible materials, but they also exhibit numerous biological properties, including antibacterial, antifungal, and antitumor activities, as well as immuno-enhancing effects on animals. Conventional depolymerization methods of chitosan to chito-oligomers are either chemical by acid-hydrolysis under harsh conditions or by enzymatic degradation. In this work, hydrolysis of chitosan to chito-oligomers has been achieved by applying adsorption-separation technique using diluted HCl in the presence of different types of zeolite as adsorbents. The chito-oligomers were retrieved from adsorbents and characterized by differential scanning calorimetry (DSC), liquid chromatography/mass spectroscopy (LC/MS), and ninhydrin test. PMID:27455287

  14. Scanning electron microscopic study of human neuroblastoma cells affected with Naegleria fowleri Thai strains.

    PubMed

    Tiewcharoen, Supathra; Rabablert, Jundee; Chetanachan, Pruksawan; Junnu, Virach; Worawirounwong, Dusit; Malainual, Nat

    2008-10-01

    In order to understand the pathogenesis of Naegleria fowleri in primary amoebic meningoencephalitis, the human neuroblastoma (SK-N-MC) and African green monkey kidney (Vero) cells were studied in vitro. Amoeba suspension in cell-culture medium was added to the confluent monolayer of SK-N-MC and Vero cells. The cytopathic activity of N. fowleri trophozoites in co-culture system was elucidated by scanning electron microscope at 3, 6, 9, 12, and 24 h. Two strains of N. fowleri displayed well-organized vigorous pseudopods in Nelson's medium at 37 degrees C. In co-culture, the target monolayer cells were damaged by two mechanisms, phagocytosis by vigorous pseudopods and engulfment by sucker-like apparatus. N. fowleri trophozoites produced amoebostomes only in co-culture with SK-N-MC cells. In contrast, we could not find such apparatus in the co-culture with Vero cells. The complete destruction time (100%) at 1:1 amoeba/cells ratio of SK-N-MC cells (1 day) was shorter than the Vero cells (12 days). In conclusion, SK-N-MC cells were confirmed to be a target model for studying neuropathogenesis of primary amoebic meningoencephalitis.

  15. Androgen Receptor Regulates the Growth of Neuroblastoma Cells in vitro and in vivo

    PubMed Central

    Sun, Junyan; Wang, Dongmei; Guo, Lianying; Fang, Shengyun; Wang, Yang; Xing, Rong

    2017-01-01

    Background: Neuroblastoma is the most common extracranial tumors in children. At present about the true etiology of neuroblastoma is unclear and many studies have tried to find effective treatments for these primary malignant tumors. Although it has been illustrated that androgen receptor (AR) was expressed in neuroblastoma cells in some former reports, the biological role of androgen receptor in the development of neuroblastoma is not fully understood. Methods: Androgen (R1881) and the antagonists of androgen receptor (MDV3100 and ARN509) were used to study the role of the androgen receptor signaling pathway in vitro and in vivo on SH-SY5Y and Neuro-2a (N2a) cell lines. Results: We found that AR expression showed an R1881 dose-dependent manner in neuroblastoma cells in vitro and R1881was able to increase, while both antagonists of androgen receptor (MDV3100 and ARN509) significantly decrease, the proliferation, migration, invasion and sphere formation of SH-SY5Y and N2a cells. Moreover, androgen promoted the growth of N2a tumor in vivo. However, when androgen receptor (AR) was effectively knocked down in the two cell lines by siRNA, either promoting or inhibiting effect of the androgen or androgen receptor antagonists, respectively, was attenuated. Conclusion: Our results suggested that androgen receptor may involve in the progression of neuroblastoma as well as provided insight into a new target for the diagnosis and treatment of neuroblastoma patients. PMID:28326012

  16. Neuroblastoma patient-derived orthotopic xenografts reflect the microenvironmental hallmarks of aggressive patient tumours.

    PubMed

    Braekeveldt, Noémie; Wigerup, Caroline; Tadeo, Irene; Beckman, Siv; Sandén, Caroline; Jönsson, Jimmie; Erjefält, Jonas S; Berbegall, Ana P; Börjesson, Anna; Backman, Torbjörn; Øra, Ingrid; Navarro, Samuel; Noguera, Rosa; Gisselsson, David; Påhlman, Sven; Bexell, Daniel

    2016-06-01

    Treatment of high-risk childhood neuroblastoma is a clinical challenge which has been hampered by a lack of reliable neuroblastoma mouse models for preclinical drug testing. We have previously established invasive and metastasising patient-derived orthotopic xenografts (PDXs) from high-risk neuroblastomas that retained the genotypes and phenotypes of patient tumours. Given the important role of the tumour microenvironment in tumour progression, metastasis, and treatment responses, here we analysed the tumour microenvironment of five neuroblastoma PDXs in detail. The PDXs resembled their parent tumours and retained important stromal hallmarks of aggressive lesions including rich blood and lymphatic vascularisation, pericyte coverage, high numbers of cancer-associated fibroblasts, tumour-associated macrophages, and extracellular matrix components. Patient-derived tumour endothelial cells occasionally formed blood vessels in PDXs; however, tumour stroma was, overall, of murine origin. Lymphoid cells and lymphatic endothelial cells were found in athymic nude mice but not in NSG mice; thus, the choice of mouse strain dictates tumour microenvironmental components. The murine tumour microenvironment of orthotopic neuroblastoma PDXs reflects important hallmarks of aggressive and metastatic clinical neuroblastomas. Neuroblastoma PDXs are clinically relevant models for preclinical drug testing.

  17. Survival of high-risk pediatric neuroblastoma patients in a developing country.

    PubMed

    Easton, Joseph C; Gomez, Sergio; Asdahl, Peter H; Conner, J Michael; Fynn, Alcira B; Ruiz, Claudia; Ojha, Rohit P

    2016-09-01

    Little information is available about survival of high-risk pediatric neuroblastoma patients in developing countries. We aimed to assess survival among high-risk pediatric neuroblastoma patients in La Plata, Argentina. Individuals eligible for our cohort were aged <20 yr when diagnosed with high-risk neuroblastoma and received cancer-directed therapy including stem cell transplantation at Hospital de Niños Sor Maria Ludovica between February 1999 and February 2015. We estimated overall survival probabilities using an extended Kaplan-Meier approach. Our study population comprised 39 high-risk neuroblastoma patients, of whom 39% were aged >4 yr at diagnosis, 54% were male, and 62% had adrenal neuroblastoma. We observed 18 deaths, and the median survival time of our study population was 1.7 yr. The five-yr overall survival probability was 24% (95% CL: 10%, 41%). In contrast, five-yr survival of high-risk neuroblastoma patients ranges between 23% and 76% in developed countries. Survival among high-risk neuroblastoma patients is generally poor regardless of geographic location, but our results illustrate dramatically worse survival for patients in a developing country. We speculate that the observed survival differences could be attenuated or eliminated with improvements in treatment and supportive care, but addressing these issues will require creative solutions because of resource limitations.

  18. Gene expression profiling in response to the histone deacetylase inhibitor BL1521 in neuroblastoma

    SciTech Connect

    Ruijter, Annemieke J.M. de; Kemp, Stephan . E-mail: a.b.vankuilenburg@amc.uva.nl

    2005-10-01

    Neuroblastoma is a childhood tumor with a poor survival in advanced stage disease despite intensive chemotherapeutic regimes. The new histone deacetylase (HDAC) inhibitor BL1521 has shown promising results in neuroblastoma. Inhibition of HDAC resulted in a decrease in proliferation and metabolic activity, induction of apoptosis and differentiation of neuroblastoma cells. In order to elucidate the mechanism mediating the effects of BL1521 on neuroblastoma cells, we investigated the gene expression profile of an MYCN single copy (SKNAS) and an MYCN amplified (IMR32) neuroblastoma cell line after treatment with BL1521 using the Affymetrix oligonucleotide array U133A. An altered expression of 255 genes was observed in both neuroblastoma cell lines. The majority of these genes were involved in gene expression, cellular metabolism, and cell signaling. We observed changes in the expression of vital genes belonging to the cell cycle (cyclin D1 and CDK4) and apoptosis (BNIP3, BID, and BCL2) pathway in response to BL1521. The expression of 37 genes was altered by both BL1521 and Trichostatin A, which could indicate a common gene set regulated by different HDAC inhibitors. BL1521 treatment changed the expression of a number of MYCN-associated genes. Several genes in the Wnt and the Delta/Notch pathways were changed in response to BL1521 treatment, suggesting that BL1521 is able to induce the differentiation of neuroblastoma cells into a more mature phenotype.

  19. Androgen Receptor Regulates the Growth of Neuroblastoma Cells in vitro and in vivo.

    PubMed

    Sun, Junyan; Wang, Dongmei; Guo, Lianying; Fang, Shengyun; Wang, Yang; Xing, Rong

    2017-01-01

    Background: Neuroblastoma is the most common extracranial tumors in children. At present about the true etiology of neuroblastoma is unclear and many studies have tried to find effective treatments for these primary malignant tumors. Although it has been illustrated that androgen receptor (AR) was expressed in neuroblastoma cells in some former reports, the biological role of androgen receptor in the development of neuroblastoma is not fully understood. Methods: Androgen (R1881) and the antagonists of androgen receptor (MDV3100 and ARN509) were used to study the role of the androgen receptor signaling pathway in vitro and in vivo on SH-SY5Y and Neuro-2a (N2a) cell lines. Results: We found that AR expression showed an R1881 dose-dependent manner in neuroblastoma cells in vitro and R1881was able to increase, while both antagonists of androgen receptor (MDV3100 and ARN509) significantly decrease, the proliferation, migration, invasion and sphere formation of SH-SY5Y and N2a cells. Moreover, androgen promoted the growth of N2a tumor in vivo. However, when androgen receptor (AR) was effectively knocked down in the two cell lines by siRNA, either promoting or inhibiting effect of the androgen or androgen receptor antagonists, respectively, was attenuated. Conclusion: Our results suggested that androgen receptor may involve in the progression of neuroblastoma as well as provided insight into a new target for the diagnosis and treatment of neuroblastoma patients.

  20. Tumor-infiltrating T lymphocytes improve clinical outcome of therapy-resistant neuroblastoma

    PubMed Central

    Mina, Marco; Boldrini, Renata; Citti, Arianna; Romania, Paolo; D'Alicandro, Valerio; De Ioris, Maretta; Castellano, Aurora; Furlanello, Cesare; Locatelli, Franco; Fruci, Doriana

    2015-01-01

    Neuroblastoma grows within an intricate network of different cell types including epithelial, stromal and immune cells. The presence of tumor-infiltrating T cells is considered an important prognostic indicator in many cancers, but the role of these cells in neuroblastoma remains to be elucidated. Herein, we examined the relationship between the type, density and organization of infiltrating T cells and clinical outcome within a large collection of neuroblastoma samples by quantitative analysis of immunohistochemical staining. We found that infiltrating T cells have a prognostic value greater than, and independent of, the criteria currently used to stage neuroblastoma. A variable in situ structural organization and different concurrent infiltration of T-cell subsets were detected in tumors with various outcomes. Low-risk neuroblastomas were characterized by a higher number of proliferating T cells and a more structured T-cell organization, which was gradually lost in tumors with poor prognosis. We defined an immunoscore based on the presence of CD3+, CD4+ and CD8+ infiltrating T cells that associates with favorable clinical outcome in MYCN-amplified tumors, improving patient survival when combined with the v-myc avian myelocytomatosis viral oncogene neuroblastoma derived homolog (MYCN) status. These findings support the hypothesis that infiltrating T cells influence the behavior of neuroblastoma and might be of clinical importance for the treatment of patients. PMID:26405592

  1. RUNX3 interacts with MYCN and facilitates protein degradation in neuroblastoma.

    PubMed

    Yu, F; Gao, W; Yokochi, T; Suenaga, Y; Ando, K; Ohira, M; Nakamura, Y; Nakagawara, A

    2014-05-15

    RUNX3, a runt-related transcription factor, has a crucial role in dorsal root ganglion neurogenesis. Recent studies have suggested that RUNX3 acts as a tumor suppressor in stomach, colon and breast cancer. However, the biological role of RUNX3 in neuroblastoma remains elusive. Here we report that high levels of RUNX3 expression contribute to the favorable outcome in patients with neuroblastoma, whereas low levels of RUNX3 expression result in poor outcome. Array-based analysis suggested that the allelic loss at chromosome 1p36 is one of the reasons why expression of RUNX3 is downregulated in advanced neuroblastomas. Interestingly, the several patients survived from neuroblastoma with both high mRNA expressions of MYCN and RUNX3, suggesting that RUNX3 high expression might overcome the aggressive behavior of MYCN. Exogenous expression of RUNX3 strongly inhibits cell proliferation and migration in neuroblastoma cell lines. Furthermore, RUNX3 reduces the stability of MYCN protein in MYCN-amplified neuroblastoma cell lines, and this RUNX3-mediated MYCN degradation may depend on the physical interaction between RUNX3 and MYCN. Thus, our findings provide a tumor-suppressing mechanism by which RUNX3 inhibits the MYCN activity in neuroblastoma.

  2. Targeting Notch pathway induces growth inhibition and differentiation of neuroblastoma cells.

    PubMed

    Ferrari-Toninelli, Giulia; Bonini, Sara Anna; Uberti, Daniela; Buizza, Laura; Bettinsoli, Paola; Poliani, Pietro Luigi; Facchetti, Fabio; Memo, Maurizio

    2010-12-01

    High-risk neuroblastoma is a severe pediatric tumor characterized by poor prognosis. Understanding the molecular mechanisms involved in tumor development and progression is strategic for the improvement of pharmacological therapies. Notch was recently proposed as a pharmacological target for the therapy of several cancers and is emerging as a new neuroblastoma-related molecular pathway. However, the precise role played by Notch in this cancer remains to be studied extensively. Here, we show that Notch activation by the Jagged1 ligand enhances the proliferation of neuroblastoma cells, and we propose the possible use of Notch-blocking γ-secretase inhibitors (GSIs) in neuroblastoma therapy. Two different GSIs, Compound E and DAPT, were tested alone or in combination with 13-cis retinoic acid (RA) on neuroblastoma cell lines. SH-SY5Y and IMR-32 cells were chosen as paradigms of lower and higher malignancy, respectively. Used alone, GSIs induced complete cell growth arrest, promoted neuronal differentiation, and significantly reduced cell motility. The combination of GSIs and 13-cis RA resulted in the enhanced growth inhibition, differentiation, and migration of neuroblastoma cells. In summary, our data suggest that a combination of GSIs with 13-cis RA offers a therapeutic advantage over a single agent, indicating a potential novel therapy for neuroblastoma.

  3. Clinical experiences in the treatment of neuroblastoma with sup 131 I-metaiodobenzylguanidine

    SciTech Connect

    Treuner, J.; Klingebiel, T.; Feine, U.; Buck, J.; Bruchelt, G.; Dopfer, R.; Girgert, R.; Mueller-Schauenburg, W.M.; Meinke, J.; Kaiser, W. )

    1986-01-01

    Treatment of neuroblastoma is an unsolved problem of pediatric oncology. In spite of highly intensified chemotherapy, the long-term survival rate of children with a metastatic neuroblastoma is below 10%. We therefore used {sup 131}I-metaiodobenzylguanidine (MIBG) for the first time to treat children with a neuroblastoma in relapse or primary unresponsiveness to chemotherapy. We had previously demonstrated that MIBG is useful for the scintigraphic imaging of neuroblastoma lesions and had investigated the cytotoxicity and uptake of MIBG in various neuroblastoma cell lines. We treated 6 children with neuroblastoma in a total of 19 courses. Three of the children suffered from a relapse of neuroblastoma; 3 had never gained a remission. Four of the 6 children lost their bone pain and fever during the first 3 days. In 5 of the 6 children the solid tumor as well as the bone marrow infiltration responded to MIBG treatment, with responses ranging from transitory decrease of the tumor mass to complete disappearance of abdominal tumors. We also witnessed a stabilization of osteolytic lesions, a decrease in elevated serum catecholamines, and a decrease in bone marrow infiltration. Five of the 6 children died of tumor progression 55-249 days after the first MIBG treatment.

  4. Neuroblastoma Arginase Activity Creates an Immunosuppressive Microenvironment That Impairs Autologous and Engineered Immunity.

    PubMed

    Mussai, Francis; Egan, Sharon; Hunter, Stuart; Webber, Hannah; Fisher, Jonathan; Wheat, Rachel; McConville, Carmel; Sbirkov, Yordan; Wheeler, Kate; Bendle, Gavin; Petrie, Kevin; Anderson, John; Chesler, Louis; De Santo, Carmela

    2015-08-01

    Neuroblastoma is the most common extracranial solid tumor of childhood, and survival remains poor for patients with advanced disease. Novel immune therapies are currently in development, but clinical outcomes have not matched preclinical results. Here, we describe key mechanisms in which neuroblastoma inhibits the immune response. We show that murine and human neuroblastoma tumor cells suppress T-cell proliferation through increased arginase activity. Arginase II is the predominant isoform expressed and creates an arginine-deplete local and systemic microenvironment. Neuroblastoma arginase activity results in inhibition of myeloid cell activation and suppression of bone marrow CD34(+) progenitor proliferation. Finally, we demonstrate that the arginase activity of neuroblastoma impairs NY-ESO-1-specific T-cell receptor and GD2-specific chimeric antigen receptor-engineered T-cell proliferation and cytotoxicity. High arginase II expression correlates with poor survival for patients with neuroblastoma. The results support the hypothesis that neuroblastoma creates an arginase-dependent immunosuppressive microenvironment in both the tumor and blood that leads to impaired immunosurveillance and suboptimal efficacy of immunotherapeutic approaches.

  5. Structural Characteristics of the Alpha-Synuclein Oligomers Stabilized By the Flavonoid Baicalein

    SciTech Connect

    Hong, D.-P.; Fink, A.L.; Uversky, V.N.

    2009-05-18

    The flavonoid baicalein inhibits fibrillation of alpha-synuclein, which is a major component of Lewy bodies in Parkinson's disease. It has been known that baicalein induces the formation of alpha-synuclein oligomers and consequently prevents their fibrillation. In order to evaluate the structural properties of baicalein-stabilized oligomers, we purified oligomer species by HPLC and examined their stability and structure by CD, Fourier transform infrared spectroscopy, size exclusion chromatography HPLC, small-angle X-ray scattering, and atomic force microscopy. Baicalein-stabilized oligomers are beta-sheet-enriched according to CD and Fourier transform infrared spectroscopy analyses. They did not form fibrils even after very prolonged incubation. From small-angle X-ray scattering data and atomic force microscopy images, the oligomers were characterized as quite compact globular species. Oligomers were extremely stable, with a GdmCl C(m)=3.3 M. This high stability explains the previously observed inhibition properties of baicalein against alpha-synuclein fibrillation. These baicalein-stabilized oligomers, added to the solution of aggregating alpha-synuclein, were able to noticeably inhibit its fibrillation. After prolonged coincubation, short fibrils were formed, suggesting an effective interaction of oligomers with monomeric alpha-synuclein. Membrane permeability tests suggested that the baicalein-stabilized oligomers had a mild effect on the integrity of the membrane surface. This effect was rather similar to that of the monomeric protein, suggesting that targeted stabilization of certain alpha-synuclein oligomers might offer a potential strategy for the development of novel Parkinson's disease therapies.

  6. One-Step Synthesis of Precursor Oligomers for Organic Photovoltaics: A Comparative Study between Polymers and Small Molecules.

    PubMed

    Li, Wei; Wang, Daojuan; Wang, Suhao; Ma, Wei; Hedström, Svante; James, David Ian; Xu, Xiaofeng; Persson, Petter; Fabiano, Simone; Berggren, Magnus; Inganäs, Olle; Huang, Fei; Wang, Ergang

    2015-12-16

    Two series of oligomers TQ and rhodanine end-capped TQ-DR were synthesized using a facile one-step method. Their optical, electrical, and thermal properties and photovoltaic performances were systematically investigated and compared. The TQ series of oligomers were found to be amorphous, whereas the TQ-DR series are semicrystalline. For the TQ oligomers, the results obtained in solar cells show that as the chain length of the oligomers increases, an increase in power conversion efficiency (PCE) is obtained. However, when introducing 3-ethylrhodanine into the TQ oligomers as end groups, the PCE of the TQ-DR series of oligomers decreases as the chain length increases. Moreover, the TQ-DR series of oligomers give much higher performances compared to the original amorphous TQ series of oligomers owing to the improved extinction coefficient (ε) and crystallinity afforded by the rhodanine. In particular, the highly crystalline oligomer TQ5-DR, which has the shortest conjugation length shows a high hole mobility of 0.034 cm(2) V(-1) s(-1) and a high PCE of 3.14%, which is the highest efficiency out of all of the six oligomers. The structure-property correlations for all of the oligomers and the TQ1 polymer demonstrate that structural control of enhanced intermolecular interactions and crystallinity is a key for small molecules/oligomers to achieve high mobilities, which is an essential requirement for use in OPVs.

  7. The mechanism of epithelial-mesenchymal transition induced by TGF-β1 in neuroblastoma cells.

    PubMed

    Shao, Jing-Bo; Gao, Zhi-Mei; Huang, Wen-Yan; Lu, Zhi-Bao

    2017-05-01

    Neuroblastoma is the second most common extracranial malignant solid tumor that occurs in childhood, and metastasis is one of the major causes of death in neuroblastoma patients. The epithelial-mesenchymal transition (EMT) is an important mechanism for both the initiation of tumor invasion and subsequent metastasis. Therefore, this study investigated the mechanism by which transforming growth factor (TGF)-β1 induces EMT in human neuroblastoma cells. Using quantitative RT-qPCR and western blot analyses, we found that the mRNA and protein expression levels of E-cadherin were significantly decreased, whereas that of α-SMA was significantly increased after neuroblastoma cells were treated with different concentrations of TGF-β1. A scratch test and Transwell migration assay revealed that cell migration significantly and directly correlated with the concentration of TGF-β1 indicating that TGF-β1 induced EMT in neuroblastoma cells and led to their migration. Inhibiting Smad2/3 expression did not affect the expression of the key molecules involved in EMT. Further investigation found that the expression of the glioblastoma transcription factor (Gli) significantly increased in TGF-β1-stimulated neuroblastoma cells undergoing EMT, accordingly, interfering with Gli1/2 expression inhibited TGF-β1-induced EMT in neuroblastoma cells. GANT61, which is a targeted inhibitor of Gli1 and Gli2, decreased cell viability and promoted cell apoptosis. Thus, TGF-β1 induced EMT in neuroblastoma cells to increase their migration. Specifically, EMT induced by TGF-β1 in neuroblastoma cells did not depend on the Smad signaling pathway, and the transcription factor Gli participated in TGF-β1-induced EMT independent of Smad signaling.

  8. Integrative genomics reveals hypoxia inducible genes that are associated with a poor prognosis in neuroblastoma patients

    PubMed Central

    Kao, Clara; Hernandez, Kyle M.; DeWane, Gillian; Salwen, Helen R.; Chlenski, Alexandre; Dobratic, Marija; Mariani, Christopher J.; Godley, Lucy A.; Prabhakar, Nanduri; White, Kevin; Stranger, Barbara E.; Cohn, Susan L.

    2016-01-01

    Neuroblastoma is notable for its broad spectrum of clinical behavior ranging from spontaneous regression to rapidly progressive disease. Hypoxia is well known to confer a more aggressive phenotype in neuroblastoma. We analyzed transcriptome data from diagnostic neuroblastoma tumors and hypoxic neuroblastoma cell lines to identify genes whose expression levels correlate with poor patient outcome and are involved in the hypoxia response. By integrating a diverse set of transcriptome datasets, including those from neuroblastoma patients and neuroblastoma derived cell lines, we identified nine genes (SLCO4A1, ENO1, HK2, PGK1, MTFP1, HILPDA, VKORC1, TPI1, and HIST1H1C) that are up-regulated in hypoxia and whose expression levels are correlated with poor patient outcome in three independent neuroblastoma cohorts. Analysis of 5-hydroxymethylcytosine and ENCODE data indicate that at least five of these nine genes have an increase in 5-hydroxymethylcytosine and a more open chromatin structure in hypoxia versus normoxia and are putative targets of hypoxia inducible factor (HIF) as they contain HIF binding sites in their regulatory regions. Four of these genes are key components of the glycolytic pathway and another three are directly involved in cellular metabolism. We experimentally validated our computational findings demonstrating that seven of the nine genes are significantly up-regulated in response to hypoxia in the four neuroblastoma cell lines tested. This compact and robustly validated group of genes, is associated with the hypoxia response in aggressive neuroblastoma and may represent a novel target for biomarker and therapeutic development. PMID:27765905

  9. Epidermal growth factor receptor is overexpressed in neuroblastoma tissues and cells.

    PubMed

    Zheng, Chao; Shen, Ruling; Li, Kai; Zheng, Na; Zong, Yuqing; Ye, Danrong; Wang, Qingcheng; Wang, Zuopeng; Chen, Lian; Ma, Yangyang

    2016-08-01

    Neuroblastoma is the most common abdominal malignant tumor in childhood. Immunotoxin (IT) that targets the tumor cell surface receptor is a new supplementary therapeutic treatment approach. The purpose of this study is to detect the expression of epidermal growth factor receptor (EGFR) in neuroblastoma cell lines and tissues, and to explore if IT therapy can be used to treat refractory neuroblastoma. The EGFR expression in human neuroblastoma tissue samples was detected by immunohistochemistry staining. The positive rate of EGFR expression was 81.0% in neuroblastoma tissue and 50.0% in gangliocytoma, respectively, but without statistical significance between them (P > 0.05). The positive rate of EGFR expression in favorable type and unfavorable type was 62.5% and 92.3%, respectively, but they were not statistically different (P > 0.05). Results from pre-chemotherapy and post-chemotherapy samples showed that there was no significant statistical difference (P > 0.05) between them in the EGFR expression. Furthermore, the EGFR expression levels in five neuroblastoma cell lines were measured using cell-based ELISA assay and western blot analysis. The results showed that the expression of EGFR was higher in KP-N-NS and BE(2)-C than those in other cell lines. Our results revealed that there are consistent and widespread expressions of EGFR in neuroblastoma tissues as well as in neuroblastoma cell lines, suggesting that it is possible to develop future treatment strategies of neuroblastoma by targeting at the EGFR.

  10. NeuroD1 promotes neuroblastoma cell growth by inducing the expression of ALK.

    PubMed

    Lu, Fangjin; Kishida, Satoshi; Mu, Ping; Huang, Peng; Cao, Dongliang; Tsubota, Shoma; Kadomatsu, Kenji

    2015-04-01

    Neuroblastoma is derived from the sympathetic neuronal lineage of neural crest cells, and is the most frequently observed of the extracranial pediatric solid tumors. The neuronal differentiation factor, NeuroD1, has previously been shown to promote cell motility in neuroblastoma by suppressing the expression of Slit2. Here we report that NeuroD1 is also involved in the proliferation of neuroblastoma cells, including human cell lines and primary tumorspheres cultured from the tumor tissues of model mice. Interestingly, the growth inhibition of neuroblastoma cells induced by knockdown of NeuroD1 was accompanied by a reduction of ALK expression. ALK is known to be one of the important predisposition genes for neuroblastoma. The phenotype resulting from knockdown of NeuroD1 was suppressed by forced expression of ALK and, therefore, NeuroD1 appears to act mainly through ALK to promote the proliferation of neuroblastoma cells. Furthermore, we showed that NeuroD1 directly bound to the promoter region of ALK gene. In addition, the particular E-box in the promoter was responsible for NeuroD1-mediated ALK expression. These results indicate that ALK should be a direct target gene of NeuroD1. Finally, the expressions of NeuroD1 and ALK in the early tumor lesions of neuroblastoma model mice coincided in vivo. We conclude that the novel mechanism would regulate the expression of ALK in neuroblastoma and that NeuroD1 should be significantly involved in neuroblastoma tumorigenesis.

  11. Common genetic variants in NEFL influence gene expression and neuroblastoma risk.

    PubMed

    Capasso, Mario; Diskin, Sharon; Cimmino, Flora; Acierno, Giovanni; Totaro, Francesca; Petrosino, Giuseppe; Pezone, Lucia; Diamond, Maura; McDaniel, Lee; Hakonarson, Hakon; Iolascon, Achille; Devoto, Marcella; Maris, John M

    2014-12-01

    The genetic etiology of sporadic neuroblastoma is still largely obscure. In a genome-wide association study, we identified single-nucleotide polymorphisms (SNP) associated with neuroblastoma at the CASC15, BARD1, LMO1, DUSP12, HSD17B12, HACE1, and LIN28B gene loci, but these explain only a small fraction of neuroblastoma heritability. Other neuroblastoma susceptibility genes are likely hidden among signals discarded by the multiple testing corrections. In this study, we evaluated eight additional genes selected as candidates for further study based on proven involvement in neuroblastoma differentiation. SNPs at these candidate genes were tested for association with disease susceptibility in 2,101 cases and 4,202 controls, with the associations found replicated in an independent cohort of 459 cases and 809 controls. Replicated associations were further studied for cis-effect using gene expression, transient overexpression, silencing, and cellular differentiation assays. The neurofilament gene NEFL harbored three SNPs associated with neuroblastoma (rs11994014: Pcombined = 0.0050; OR, 0.88; rs2979704: Pcombined = 0.0072; OR, 0.87; rs1059111: Pcombined = 0.0049; OR, 0.86). The protective allele of rs1059111 correlated with increased NEFL expression. Biologic investigations showed that ectopic overexpression of NEFL inhibited cell growth specifically in neuroblastoma cells carrying the protective allele. NEFL overexpression also enhanced differentiation and impaired the proliferation and anchorage-independent growth of cells with protective allele and basal NEFL expression, while impairing invasiveness and proliferation of cells homozygous for the risk genotype. Clinically, high levels of NEFL expression in primary neuroblastoma specimens were associated with better overall survival (P = 0.03; HR, 0.68). Our results show that common variants of NEFL influence neuroblastoma susceptibility and they establish that NEFL expression influences disease initiation and

  12. Adult Neuroblastoma-Case Report and Literature Review

    PubMed Central

    Basade, Maheboob M; Khan, Kamran; Thorat, Kiran

    2016-01-01

    Neuroblastoma is the most common solid malignant neoplasm in the paediatric age group; accounting for 7% of all childhood malignancies, but neuroblastoma in adult, is a rare occurrence, finding mention in aeons of medical literature with an overall incidence of 1 in 10 million adults/year. We report the case of a 24-year-old male patient presenting with the complaints of progressive abdominal distention of 2 months duration. Multiple Detector Computed Tomography (MD-CT) of abdomen revealed a huge enhancing mass in the retroperitoneum abutting the left kidney, and a subsequent CT-guided biopsy and immunohistochemistry confirmed the diagnosis of ganglioneuroblastoma. The patient was administered 3-cycles of neo-adjuvant chemotherapy with ifosphamide, carboplatin and etoposide (ICE-chemotherapy) and subsequently 3 more cycles of chemotherapy post surgery, followed by radiation. The rarity of this neoplasm in adults accounts for the lack of standardized staging and treatment protocols and the dismal prognosis even with aggressive multimodal treatment. We report this case because of its extreme rarity, and its tendency for capricious behavior. PMID:28208865

  13. Anti-Neuroblastoma Properties of a Recombinant Sunflower Lectin

    PubMed Central

    Pinedo, Marcela; Genoula, Melanie; Silveyra, María Ximena; De Oliveira Carvalho, André; Regente, Mariana; Del Río, Marianela; Ribeiro Soares, Júlia; Moreira Gomes, Valdirene; De La Canal, Laura

    2017-01-01

    According to their sugar recognition specificity, plant lectins are proposed as bioactive proteins with potential in cancer treatment and diagnosis. Helja is a mannose-specific jacalin-like lectin from sunflower which was shown to inhibit the growth of certain fungi. Here, we report its recombinant expression in a prokaryotic system and its activity in neurobalstoma cells. Helja coding sequence was fused to the pET-32 EK/LIC, the enterokinase/Ligation-independent cloning vector and a 35 kDa protein was obtained in Escherichia coli representing Helja coupled to thioredoxin (Trx). The identity of this protein was verified using anti-Helja antibodies. This chimera, named Trx-rHelja, was enriched in the soluble bacterial extracts and was purified using Ni+2-Sepharose and d-mannose-agarose chromatography. Trx-rHelja and the enterokinase-released recombinant Helja (rHelja) both displayed toxicity on human SH-SY5Y neuroblastomas. rHelja decreased the viability of these tumor cells by 75% according to the tetrazolium reduction assay, and microscopic analyses revealed that the cell morphology was disturbed. Thus, the stellate cells of the monolayer became spheroids and were isolated. Our results indicate that rHelja is a promising tool for the development of diagnostic or therapeutic methods for neuroblastoma cells, the most common solid tumors in childhood. PMID:28075401

  14. Identification of nuclear. tau. isoforms in human neuroblastoma cells

    SciTech Connect

    Loomis, P.A.; Howard, T.H.; Castleberry, R.P.; Binder, L.I. )

    1990-11-01

    The {tau} proteins have been reported only in association with microtubules and with ribosomes in situ, in the normal central nervous system. In addition, {tau} has been shown to be an integral component of paired helical filaments, the principal constituent of the neurofibrillary tangles found in brains of patients with Alzheimer's disease and of most aged individuals with Down syndrome (trisomy 21). The authors report here the localization of the well-characterized Tau-1 monoclonal antibody to the nucleolar organizer regions of the acrocentric chromosomes and to their interphase counterpart, the fibrillar component of the nucleolus, in human neuroblastoma cells. Similar localization to the nucleolar organizer regions was also observed in other human cell lines and in one monkey kidney cell line but was not seen in non-primate species. Immunochemically, they further demonstrated the existence of the entire {tau} molecule in the isolated nuclei of neuroblastoma cells. Nuclear {tau} proteins, like the {tau} proteins of the paired helical filaments, cannot be extracted in standard SDS-containing electrophoresis sample buffer but require pretreatment with formic acid prior to immunoblot analysis. This work indicates that {tau} may function in processes not directly associated with microtubules and that highly insoluble complexes of {tau} may also play a role in normal cellular physiology.

  15. Treatment of neuroblastoma with metaiodobenzylguanidine: results and side effects

    SciTech Connect

    Treuner, J.; Klingebiel, T.; Bruchelt, G.; Feine, U.; Niethammer, D.

    1987-01-01

    Between April 1984 and December 1985 we treated ten children suffering from neuroblastoma in a total of 25 metaiodobenzylguanidine (MIBG) courses. Five had had a relapse of neuroblastoma stage III or IV, three had never achieved a remission in spite of intensive chemotherapy, and two were treated with an unstable remission. The children were each administered from 1 to 5 courses with a dosage per course of between 1295 and 9065 MBq. The sum of the single doses during the whole course of therapy ranged between 3145 and 21,904 MBq per child. Five of five children suffering from bone pain and fever became free of complaints during the first three treatment days. Six of eight children with manifest tumor at onset of therapy responded well to the treatment: response extended from transitory decrease in elevated catecholamine levels in serum and urine to complete disappearance of large abdominal tumor masses. We also observed a decrease in bone marrow involvement and a stabilization of osteolytic lesions. Seven of these eight children died in spite of a good response from 55 to 350 days after the first MIBG treatment course. The only side effect we witnessed was a reversible bone marrow depression. In three children we combined the MIBG therapy with bone marrow transplantation.

  16. Treatment of advanced neuroblastoma with I-131 meta-iodobenzylguanidine

    SciTech Connect

    Garaventa, A.; Guerra, P.; Arrighini, A.; Bertolazzi, L.; Bestagno, M.; De Bernardi, B.; Lanino, E.; Villavecchia, G.P.; Claudiani, F. )

    1991-02-15

    From February 1986 to December 1988, 31 children with advanced pretreated neuroblastoma were treated with 131-I meta-Iodobenzylguanidine (131-MIBG). Thirteen children had been resistant to first-line therapy, three had suffered a local relapse, and fourteen had suffered a disseminated relapse without over bone marrow infiltration. One child was treated initially because of resistance to first-line therapy, and subsequently for a local relapse. A total of 72 courses of 131-MIBG was administered, with doses ranging from 2.8 to 6.0 GBq (median, 3.7 GBq). One child received five courses, two four courses, 13 three courses, four two courses, and 12 one course of 131-MIBG. The most common toxic effect was thrombocytopenia, with a platelet level of less than 50,000/cmm occurring after 19 of 60 evaluable courses. A leukocyte count less than 1000/cmm was seen only once. There were six major responses (two complete) lasting 4 to 9 months, and two minor responses lasting longer than 38 and 44 months. Responses were seen more commonly in children whose only lesion was a residual primary tumor and in children who had not been pretreated who experienced disseminated relapse. Further studies of the role of 131-I meta-Iodobenzylguanidine in treatment of neuroblastoma are needed.

  17. Preparation of chitosan oligomers COS and their effect on the retrogradation of intermediate amylose rice starch.

    PubMed

    Wu, Yue; Lin, Qin Lu; Chen, Zheng Xing; Wu, Wei; Xiao, Hua Xi

    2012-12-01

    Chitosan oligomers (COS) were obtained by enzymatic hydrolysis and H2O2 oxidative treatment, and then separated into different fractions using ultra-filtration membranes. Each COSM fraction prepared using enzymatic hydrolysis retained its structure, especially the reduced end residue (-NH2 group), and had a peak for molecular weight. On the other hand, each COSH fraction prepared by oxidative treatment had partly damaged -NH2 groups and two peaks for molecular weight. These results indicate that the same COS fractions prepared by the two methods differ in their amino groups and in their molecular weights, though they can both pass through the same size ultra-filtration membrane. The effect of COS on the retrogradation of intermediate amylose rice starch (IA-RS) was also investigated. The 5 k < COSM < 10 k fraction had the best anti-retrogradation ability; the retrogradation ratio of IA-RS with this fraction was reduced by 14.5%, compared to the control, and its relative crystallinity was only 59.69%. 10 k < COSM < 30 k fraction was second best, while the COSM < 5 k fraction had no effect. Therefore, the molecular size of COS determined its anti-retrogradation capability. All COSH fractions from oxidative treatment had no effect on the retrogradation.

  18. Rates of chemical cleavage of DNA and RNA oligomers containing guanine oxidation products.

    PubMed

    Fleming, Aaron M; Alshykhly, Omar; Zhu, Judy; Muller, James G; Burrows, Cynthia J

    2015-06-15

    The nucleobase guanine in DNA (dG) and RNA (rG) has the lowest standard reduction potential of the bases, rendering it a major site of oxidative damage in these polymers. Mapping the sites at which oxidation occurs in an oligomer via chemical reagents utilizes hot piperidine for cleaving oxidized DNA and aniline (pH 4.5) for cleaving oxidized RNA. In the present studies, a series of time-dependent cleavages of DNA and RNA strands containing various guanine lesions were examined to determine the strand scission rate constants. The guanine base lesions 8-oxo-7,8-dihydroguanine (OG), spiroiminodihydantoin (Sp), 5-guanidinohydantoin (Gh), 2,2,4-triamino-2H-oxazol-5-one (Z), and 5-carboxamido-5-formamido-2-iminohydantoin (2Ih) were evaluated in piperidine-treated DNA and aniline-treated RNA. These data identified wide variability in the chemical lability of the lesions studied in both DNA and RNA. Further, the rate constants for cleaving lesions in RNA were generally found to be significantly smaller than for lesions in DNA. The OG nucleotides were poorly cleaved in DNA and RNA; Sp nucleotides were slowly cleaved in DNA and did not cleave significantly in RNA; Gh and Z nucleotides cleaved in both DNA and RNA at intermediate rates; and 2Ih oligonucleotides cleaved relatively quickly in both DNA and RNA. The data are compared and contrasted with respect to future experimental design.

  19. Risk factors for scoliosis in children with neuroblastoma

    SciTech Connect

    Paulino, Arnold C. . E-mail: apaulino@tmh.tmc.edu; Fowler, B. Zach

    2005-03-01

    Purpose: To determine the risk factors for scoliosis in children treated for neuroblastoma. Methods and materials: From 1957 to 1997, 58 children with neuroblastoma were treated at one institution and have survived a minimum of 5 years. There were 35 boys and 23 girls with a median age of 6 months (range, 2 weeks to 15 years) at initial diagnosis. Primary site was located in the adrenal gland in 25 (43.1%), abdominal/nonadrenal in 16 (27.6%), thoracic in 12 (20.7%), cervical in 3 (5.3%), and pelvic region in 2 (3.5%). The International Neuroblastoma Staging System (INSS) stage was Stage 1 in 10 (17.2%), Stage 2A in 7 (12.1%), Stage 2B in 5 (8.6%), Stage 3 in 22 (37.9%), Stage 4 in 4 (6.9%), and Stage 4S in 10 (17.2%). Thirty-three (56.9%) received chemotherapy whereas 5 (8.6%) had a laminectomy as part of the surgical procedure. Twenty-seven (46.6%) received radiotherapy (RT). Beam energy was 1.25 MV in 11 (41%), 250 kV in 10 (37%), 4 MV in 4 (15%), and 6-MV photons in 1 patient. One patient received 300 cGy in 1 fraction total skin RT using 6-MeV electrons. For the remaining patients, fraction size was 100 cGy in 6 (22%), 150-180 cGy in 11 (41%), 200 cGy in 4 (15%), and 250-300 cGy in 3. Three patients had total body irradiation at 333 cGy for 3 fractions. For all children who received RT, median total dose was 2000 cGy (range, 300-3900 cGy). Patients who were treated with RT had plain films of the irradiated area every 1 to 2 years until at least the age of puberty. Median follow-up was 10 years (range, 5-46 years). Results: The overall 5-, 10-, and 15-year scoliosis-free rates were 87.6%, 79.0%, and 76.0% respectively. Twelve (21%) developed scoliosis at a median time of 51 months (range, 8-137 months). The degree of scoliosis was mild ({<=}20 deg ) in 8 (67%). Four had scoliosis ranging from 30 deg to 66 deg ; 3 of these patients required surgical intervention, whereas 1 had an underlying Duchenne muscular dystrophy which manifested itself 8 years after

  20. Brain amyloid-β oligomers in ageing and Alzheimer's disease.

    PubMed

    Lesné, Sylvain E; Sherman, Mathew A; Grant, Marianne; Kuskowski, Michael; Schneider, Julie A; Bennett, David A; Ashe, Karen H

    2013-05-01

    Alzheimer's disease begins about two decades before the onset of symptoms or neuron death, and is believed to be caused by pathogenic amyloid-β aggregates that initiate a cascade of molecular events culminating in widespread neurodegeneration. The microtubule binding protein tau may mediate the effects of amyloid-β in this cascade. Amyloid plaques comprised of insoluble, fibrillar amyloid-β aggregates are the most characteristic feature of Alzheimer's disease. However, the correspondence between the distribution of plaques and the pattern of neurodegeneration is tenuous. This discrepancy has stimulated the investigation of other amyloid-β aggregates, including soluble amyloid-β oligomers. Different soluble amyloid-β oligomers have been studied in several mouse models, but not systematically in humans. Here, we measured three amyloid-β oligomers previously described in mouse models-amyloid-β trimers, Aβ*56 and amyloid-β dimers-in brain tissue from 75 cognitively intact individuals, ranging from young children to the elderly, and 58 impaired subjects with mild cognitive impairment or probable Alzheimer's disease. As in mouse models, where amyloid-β trimers appear to be the fundamental amyloid-β assembly unit of Aβ*56 and are present in young mice prior to memory decline, amyloid-β trimers in humans were present in children and adolescents; their levels rose gradually with age and were significantly above baseline in subjects in their 70s. Aβ*56 levels were negligible in children and young adults, rose significantly above baseline in subjects in their 40s and increased steadily thereafter. Amyloid-β dimers were undetectable until subjects were in their 60s; their levels then increased sharply and correlated with plaque load. Remarkably, in cognitively intact individuals we found strong positive correlations between Aβ*56 and two pathological forms of soluble tau (tau-CP13 and tau-Alz50), and negative correlations between Aβ*56 and two postsynaptic

  1. Left atrial mass 16 years after radiation therapy for mediastinal neuroblastoma

    SciTech Connect

    Ensing, G.J.; Driscoll, D.J.; Smithson, W.A.

    1987-01-01

    Tumors involving the heart during childhood are rare. However, neuroblastoma, a common pediatric malignancy, has been described to involve the cardiovascular system in 3%-12% of patients dying with this tumor. Rarely is such involvement diagnosed ante mortem and never, to our knowledge, has a benign cardiac tumor been reported to present in childhood after successful eradication of neuroblastoma. We describe the identification and surgical resection of a nodular, hypertrophied, calcified, pedunculated left atrial mass in a 16-year-old boy who was complaining of exercise-associated presyncope and headaches 16 years after irradiation and chemotherapy for mediastinal neuroblastoma.

  2. Localization of m-lodo(/sup 131/I)benzylguanidine in neuroblastoma

    SciTech Connect

    Hattner, R.S.; Huberty, J.P.; Engelstad, B.L.; Gooding, C.A.; Ablin, A.R.

    1984-08-01

    Patient survival and the therapeutic strategy for treatment of neuroblastoma are highly dependent on the stage of the tumor at presentation. For routine staging, the Children's Cancer Study group currently recommends a chest radiograph, abdominal CT scan, radionuclide bone scan, bone marrow biopsy, catecholamine metabolite estimations, and surgical determination of tumor extent. A noninvasive method for detectiton of neuroblastoma that avoids surgery and bone marrow biopsy would be a most welcome addition to the armamentarium of the pediatric oncologist. A case of neuroblastoma demonstrated with m-iodo(/sup 131/I)benzylguanidine (MIBG) scintigraphy is reported.

  3. Translocation involving 1p and 17q is a recurrent genetic alteration of human neuroblastoma cells

    SciTech Connect

    Savelyeva, L.; Corvi, R.; Schwab, M. )

    1994-08-01

    Human neuroblastoma cells often are monosomic for the distal portion of 1p (1p36). The authors report that the deleted 1p material in cells of neuroblastoma lines is preferentially replaced by material from chromosome 17, resulting from an unbalanced 1;17 translocation. Chromosome 17 often acquires instability, followed by the integration of fragments into various marker chromosomes. As a consequence, 17q material can increase over 17p material. The nonrandom frequency of 1;17 translocations appears to indicate an as-yet-undefined contribution to neuroblastoma development. 35 refs., 4 figs., 1 tab.

  4. The use of an investigational radiopharmaceutical in neuroblastoma: A nursing perspective

    SciTech Connect

    Kelly, J.U.

    1989-10-01

    Children with advanced-stage neuroblastoma usually have a poor prognosis. While conventional treatment with surgery, chemotherapy, and radiation may provide some palliation, long-term survival is rare. A number of investigational therapies are being performed nationwide in an attempt to improve the prognosis for children with neuroblastoma. One such treatment is the use of {sup 131}I-metaiodobenzylguanidine. This article will review the pathophysiology of neuroblastoma, give an overview of this investigational treatment, and discuss the nursing care associated with radioactive treatment.

  5. Establishing a high-risk neuroblastoma cohort using the Pediatric Health Information System Database.

    PubMed

    Desai, Ami V; Kavcic, Marko; Huang, Yuan-Shung; Herbst, Nicole; Fisher, Brian T; Seif, Alix E; Li, Yimei; Hennessy, Sean; Aplenc, Richard; Bagatell, Rochelle

    2014-06-01

    International Classification of Diseases, 9th Revision (ICD-9) code(s) for neuroblastoma do not exist, preventing identification of these patients in administrative databases. To overcome this challenge, a three-step algorithm, using ICD-9 codes, exclusion criteria, and manual review of chemotherapy billing data, was utilized to assemble a high-risk neuroblastoma cohort (n = 952) from the Pediatric Health Information System (PHIS) Database and validated at a single institution [sensitivity 89.1%; positive predictive value (PPV) 96.1%]. This cohort provides a data source for future comparative effectiveness and clinical epidemiology studies in high-risk neuroblastoma patients.

  6. Opsoclonus-myoclonus and anti-Hu positive limbic encephalitis in a patient with neuroblastoma.

    PubMed

    Morales La Madrid, Andres; Rubin, Charles M; Kohrman, Michael; Pytel, Peter; Cohn, Susan L

    2012-03-01

    Opsoclonus-myoclonus syndrome (OMS) is seen in 2-3% of children with neuroblastoma and is believed to be caused by an autoimmune process elicited by the tumor. Although long-term neurologic sequelae are common in children with OMS, limbic encephalitis has not previously been reported. We report a child who developed limbic encephalitis associated with anti-Hu antibodies, 6 years after her initial diagnosis of neuroblastoma and OMS. This case demonstrates that patients with neuroblastoma and OMS are at risk for developing new paraneoplastic symptoms years after their original diagnosis and emphasizes the need for careful long-term follow-up.

  7. Bronchiectasis following treatment for high-risk neuroblastoma: A case series.

    PubMed

    Adams, Madeleine; Traunecker, Heidi; Doull, Iolo; Cox, Rachel

    2017-03-10

    High-risk (HR) neuroblastoma remains a very challenging disease to treat and long-term cure is only possible with intensive, multimodal treatment including chemotherapy, high-dose therapy, radiotherapy, surgery, and immunotherapy. As a result, treatment-related morbidity and late effects are common in survivors. This report outlines a case series of six patients who developed a chronic productive cough following treatment for HR neuroblastoma. High-resolution computed tomography scanning confirmed the diagnosis of bronchiectasis. Two of the patients who have undergone immunological testing demonstrate hypogammaglobulinaemia and impaired vaccine response. Persistent cough in patients treated for neuroblastoma warrants investigation and consideration of immunological referral.

  8. Treatment of localised resectable neuroblastoma. Results of the LNESG1 study by the SIOP Europe Neuroblastoma Group

    PubMed Central

    De Bernardi, B; Mosseri, V; Rubie, H; Castel, V; Foot, A; Ladenstein, R; Laureys, G; Beck-Popovic, M; de Lacerda, A F; Pearson, A D J; De Kraker, J; Ambros, P F; de Rycke, Y; Conte, M; Bruzzi, P; Michon, J

    2008-01-01

    Main objective of this study was to confirm that surgery alone is an effective and safe treatment for localised resectable neuroblastoma except stage 2 with amplified MYCN gene (MYCNA). Of 427 eligible stages 1–2 patients, 411 had normal MYCN and 16 had MYCNA. Of the 288 stage 1 patients with normal MYCN, 1 died of complications and 16 relapsed, 2 of whom died; 5-year relapse-free survival (RFS) and overall survival (OS) rates were 94.3% (95% confidence interval (CI): 91.6–97) and 98.9% (95% CI: 97.7–100), respectively. Of the 123 stage 2 patients with normal MYCN, 1 died of sepsis and 22 relapsed, 8 of whom died (RFS 82.8%, 95% CI: 76.2–89.5; OS 93.2%, 95% CI: 88.7–97.8). In stage 2, OS and RFS were worse for patients with elevated LDH and unfavourable histopathology. Of 16 children with MYCNA, 7 were stage 1 (5 relapses and 4 deaths) and 9 were stage 2 (3 relapses and 2 deaths) patients. In conclusion, surgery alone yielded excellent OS for both stage 1 and 2 neuroblastoma without MYCNA, although stage 2 patients with unfavourable histopathology and elevated LDH suffered a high number of relapses. Both stage 1 and 2 patients with MYCNA were at greater risk of relapse. PMID:18766186

  9. Formation of RNA oligomers on montmorillonite: site of catalysis

    NASA Technical Reports Server (NTRS)

    Ertem, G.; Ferris, J. P.

    1998-01-01

    Certain montmorillonites catalyze the self condensation of the 5'-phosphorimidazolide of nucleosides in pH 8 aqueous electrolyte solutions at ambient temperatures leading to formation of RNA oligomers. In order to establish the nature of the sites on montmorillonite responsible for this catalytic activity, oligomerization reactions were run with montmorillonites which had been selectively modified (I) at the edges by (a) fluoride treatment, (b) silylation, (c) metaphosphate treatment of the anion exchange sites (II) in the interlayer by (a) saturation with quaternary alkylammonium ions of increasing size, (b) aluminum polyoxo cations. High pressure liquid chromatography, HPLC, analysis of condensation products for their chain lengths and yields indicated that modification at the edges did not affect the catalytic activity to a significant extent, while blocking the interlayer strongly inhibited product formation.

  10. VCD Studies on Chiral Characters of Metal Complex Oligomers

    PubMed Central

    Sato, Hisako; Yamagishi, Akihiko

    2013-01-01

    The present article reviews the results on the application of vibrational circular dichroism (VCD) spectroscopy to the study of stereochemical properties of chiral metal complexes in solution. The chiral characters reflecting on the vibrational properties of metal complexes are revealed by measurements of a series of β-diketonato complexes with the help of theoretical calculation. Attention is paid to the effects of electronic properties of a central metal ion on vibrational energy levels or low-lying electronic states. The investigation is further extended to the oligomers of β-diketonato complex units. The induction of chiral structures is confirmed by the VCD spectra when chiral inert moieties are connected with labile metal ions. These results have demonstrated how VCD spectroscopy is efficient in revealing the static and dynamic properties of mononuclear and multinuclear chiral metal complexes, which are difficult to clarify by means of other spectroscopes. PMID:23296273

  11. VCD studies on chiral characters of metal complex oligomers.

    PubMed

    Sato, Hisako; Yamagishi, Akihiko

    2013-01-07

    The present article reviews the results on the application of vibrational circular dichroism (VCD) spectroscopy to the study of stereochemical properties of chiral metal complexes in solution. The chiral characters reflecting on the vibrational properties of metal complexes are revealed by measurements of a series of β-diketonato complexes with the help of theoretical calculation. Attention is paid to the effects of electronic properties of a central metal ion on vibrational energy levels or low-lying electronic states. The investigation is further extended to the oligomers of β-diketonato complex units. The induction of chiral structures is confirmed by the VCD spectra when chiral inert moieties are connected with labile metal ions. These results have demonstrated how VCD spectroscopy is efficient in revealing the static and dynamic properties of mononuclear and multinuclear chiral metal complexes, which are difficult to clarify by means of other spectroscopes.

  12. Neuroblastoma patient outcomes, tumor differentiation, and ERK activation are correlated with expression levels of the ubiquitin ligase UBE4B

    PubMed Central

    Woodfield, Sarah E.; Guo, Rong Jun; Liu, Yin; Major, Angela M.; Hollingsworth, Emporia Faith; Indiviglio, Sandra; Whittle, Sarah B.; Mo, Qianxing; Bean, Andrew J.; Ittmann, Michael; Lopez-Terrada, Dolores; Zage, Peter E.

    2016-01-01

    Background UBE4B is an E3/E4 ubiquitin ligase whose gene is located in chromosome 1p36.22. We analyzed the associations of UBE4B gene and protein expression with neuroblastoma patient outcomes and with tumor prognostic features and histology. Methods We evaluated the association of UBE4B gene expression with neuroblastoma patient outcomes using the R2 Platform. We screened neuroblastoma tumor samples for UBE4B protein expression using immunohistochemistry. FISH for UBE4B and 1p36 deletion was performed on tumor samples. We then evaluated UBE4B expression for associations with prognostic factors and with levels of phosphorylated ERK in neuroblastoma tumors and cell lines. Results Low UBE4B gene expression is associated with poor outcomes in patients with neuroblastoma and with worse outcomes in all patient subgroups. UBE4B protein expression was associated with neuroblastoma tumor differentiation, and decreased UBE4B protein levels were associated with high-risk features. UBE4B protein levels were also associated with levels of phosphorylated ERK. Conclusions We have demonstrated associations between UBE4B gene expression and neuroblastoma patient outcomes and prognostic features. Reduced UBE4B protein expression in neuroblastoma tumors was associated with high-risk features, a lack of differentiation, and with ERK activation. These results suggest UBE4B may contribute to the poor prognosis of neuroblastoma tumors with 1p36 deletions and that UBE4B expression may mediate neuroblastoma differentiation. PMID:27014418

  13. The herbal compound geniposide rescues formaldehyde-induced apoptosis in N2a neuroblastoma cells.

    PubMed

    Chen, JinYan; Sun, MengRu; Wang, XingHua; Lu, Jing; Wei, Yan; Tan, Yan; Liu, Ying; Götz, Jürgen; He, RongQiao; Hua, Qian

    2014-04-01

    The herbal medicine Tong Luo Jiu Nao (TLJN) contains geniposide (GP) and ginsenoside Rg1 at a molar ratio of 10:1. Rg1 is the major component of another herbal medicine, panax notoginseng saponin (PNS). TLJN has been shown to strengthen brain function in humans, and in animals it improves learning and memory. We have previously shown that TLJN reduces amyloidogenic processing in Alzheimer's disease (AD) mouse models. Together this suggests TLJN may be a potential treatment for patients with dementia. Because chronic damage of the central nervous system by formaldehyde (FA) has been presented as a risk factor for age-associated cognitive dysfunction, in the present study we investigated the protective effect of both TLJN and GP in neuron-like cells exposed to FA. FA-exposed murine N2a neuroblastoma cells were incubated with TLJN, its main ingredient GP, as well as PNS, to measure cell viability and morphology, the rate of apoptosis and expression of genes encoding Akt, FOXO3, Bcl2 and p53. The CCK-8 assay, cytoskeletal staining and flow cytometry were used to test cell viability, morphology and apoptosis, respectively. Fluorescent quantitative real-time PCR (qRT-PCR) was used to monitor changes in gene expression, and HPLC to determine the rate of FA clearance. Treatment of N2a cells with 0.09 mmol L(-1) FA for 24 h significantly reduced cell viability, changed cell morphology and promoted apoptosis. Both TLJN and GP conferred neuroprotection to FA-treated N2a cells, whereas PNS, which had to be used at lower concentrations because of its toxicity, did not. Our data demonstrate that TLJN can rescue neuronal damage caused by FA and that its main ingredient, GP, has a major role in this efficacy. This presents purified GP as a drug or lead compound for the treatment of AD.

  14. EGFP oligomers as natural fluorescence and hydrodynamic standards

    PubMed Central

    Vámosi, György; Mücke, Norbert; Müller, Gabriele; Krieger, Jan Wolfgang; Curth, Ute; Langowski, Jörg; Tóth, Katalin

    2016-01-01

    EGFP oligomers are convenient standards for experiments on fluorescent protein-tagged biomolecules. In this study, we characterized their hydrodynamic and fluorescence properties. Diffusion coefficients D of EGFP1–4 were determined by analytical ultracentrifugation with fluorescence detection and by fluorescence correlation spectroscopy (FCS), yielding 83.4…48.2 μm2/s and 97.3…54.8 μm2/s from monomer to tetramer. A “barrels standing in a row” model agreed best with the sedimentation data. Oligomerization red-shifted EGFP emission spectra without any shift in absorption. Fluorescence anisotropy decreased, indicating homoFRET between the subunits. Fluorescence lifetime decreased only slightly (4%) indicating insignificant quenching by FRET to subunits in non-emitting states. FCS-measured D, particle number and molecular brightness depended on dark states and light-induced processes in distinct subunits, resulting in a dependence on illumination power different for monomers and oligomers. Since subunits may be in “on” (bright) or “off” (dark) states, FCS-determined apparent brightness is not proportional to that of the monomer. From its dependence on the number of subunits, the probability of the “on” state for a subunit was determined to be 96% at pH 8 and 77% at pH 6.38, i.e., protonation increases the dark state. These fluorescence properties of EGFP oligomeric standards can assist interpreting results from oligomerized EGFP fusion proteins of biological interest. PMID:27622431

  15. Fluorene- and benzofluorene-cored oligomers as low threshold and high gain amplifying media

    SciTech Connect

    Kazlauskas, Karolis Kreiza, Gediminas; Bobrovas, Olegas; Adomėnienė, Ona; Adomėnas, Povilas; Juršėnas, Saulius; Jankauskas, Vygintas

    2015-07-27

    Deliberate control of intermolecular interactions in fluorene- and benzofluorene-cored oligomers was attempted via introduction of different-length alkyl moieties to attain high emission amplification and low amplified spontaneous emission (ASE) threshold at high oligomer concentrations. Containing fluorenyl peripheral groups decorated with different-length alkyl moieties, the oligomers were found to express weak concentration quenching of emission, yet excellent carrier drift mobilities (close to 10{sup −2} cm{sup 2}/V/s) in the amorphous films. Owing to the larger radiative decay rates (>1.0 × 10{sup 9 }s{sup −1}) and smaller concentration quenching, fluorene-cored oligomers exhibited down to one order of magnitude lower ASE thresholds at higher concentrations as compared to those of benzofluorene counterparts. The lowest threshold (300 W/cm{sup 2}) obtained for the fluorene-cored oligomers at the concentration of 50 wt % in polymer matrix is among the lowest reported for solution-processed amorphous films in ambient conditions, what makes the oligomers promising for lasing application. Great potential in emission amplification was confirmed by high maximum net gain (77 cm{sup −1}) revealed for these compounds. Although the photostability of the oligomers was affected by photo-oxidation, it was found to be comparable to that of various organic lasing materials including some commercial laser dyes evaluated under similar excitation conditions.

  16. High-resolution atomic force microscopy of soluble Abeta42 oligomers.

    PubMed

    Mastrangelo, Iris A; Ahmed, Mahiuddin; Sato, Takeshi; Liu, Wei; Wang, Chengpu; Hough, Paul; Smith, Steven O

    2006-04-21

    Soluble oligomers and protofibrils are widely thought to be the toxic forms of the Abeta42 peptide associated with Alzheimer's disease. We have investigated the structure and formation of these assemblies using a new approach in atomic force microscopy (AFM) that yields high-resolution images of hydrated proteins and allows the structure of the smallest molecular weight (MW) oligomers to be observed and characterized. AFM images of monomers, dimers and other low MW oligomers at early incubation times (< 1h) are consistent with a hairpin structure for the monomeric Abeta42 peptide. The low MW oligomers are relatively compact and have significant order. The most constant dimension of these oligomers is their height (approximately 1-3 nm) above the mica surface; their lateral dimensions (width and length) vary between 5 nm and 10nm. Flat nascent protofibrils with lengths of over 40 nm are observed at short incubation times (< or = 3h); their lateral dimensions of 6-8 nm are consistent with a mass-per-length of 9 kDa/nm previously predicted for the elementary fibril subunit. High MW oligomers with lateral dimensions of 15-25 nm and heights ranging from 2-8 nm are common at high concentrations of Abeta. We show that an inhibitor designed to block the sheet-to-sheet packing in Abeta fibrils is able to cap the heights of these oligomers at approximately 4 nm. The observation of fine structure in the high MW oligomers suggests that they are able to nucleate fibril formation. AFM images obtained as a function of incubation time reveal a sequence of assembly from monomers to soluble oligomers and protofibrils.

  17. Evaluation of phenylpiperazines as targeting agents for neuroblastoma.

    PubMed Central

    Babich, J. W.; Graham, W. A.; Fischman, A. J.

    1996-01-01

    The potential of radiolabelled phenylpiperazines as agents for the detection and therapy of tumours of neural crest origin was evaluated by in vitro pharmacological studies with human neuroblastoma cell lines [SK-N-SH and SK-N-BE(2C)], and in vivo by biodistribution measurements. The ability of phenylpiperazines: 4-phenyl-piperazine (PP), 1-carboxamidino-4-phenyl-piperazine (CAPP), [4-(3-chlorophenyl)-piperazine (mCPP), 4-(3-trifluoro methyl phenyl)-piperazine (TFMPP), and (1,1-dimethyl-4-phenyl)-piperazinium hydrochloride (DMPP) and chlorophenyl hydroxypiperidine [CP(OH)P], to inhibit MIBG uptake by neuroblastoma cells was determined by incubation with [125I]MIBG (0.1 microM) for 2 h in the presence of varying concentrations (10(-8)-10(-3) M) of ligand. For measuring uptake, cells were incubated with [125I]IPP (0.1 microM) and cell-associated radioactivity was measured at various times. Retention was studied by incubating cells in the presence of [125I]IPP (0.1 microM) for 2 h, followed by replacement with drug-free medium and determination of cell-bound radioactivity. Selectivity of [125I]IPP uptake was studied by inhibition studies with MIBG, DMI, 5HT and phenylpiperazines. The biodistribution of [125I]IPP was measured in normal rats at 0.083, 0.5, 1, 2 and 24 h (six animals per group). The IC50S (microM) for inhibition of [125I]MIBG uptake were: PP, 1.5; CPP, 2.5; CAPP, 2.5; DMPP, 5; CP(OH)P, 30 and TFMPP, 65. The rate of cellular uptake of [125I]IPP was greatest between 0 and 60 min and decreased after 60 min, similar to MIBG. After an initial rapid washout of approximately 50% of the radioactivity, retention remained constant for 3 h. The IC50S (microM) for inhibition of [125I]IPP uptake were: MIBG, 18-25; DMI, 0.6-1.5; 5HT, > 100; IPP, 1.8-2.5; CPP, 7.0-9.0 and TFMPP, > or = 20. The in vivo studies demonstrated a pattern of distribution similar to MIBG. The results demonstrate that phenylpiperazines display significant affinity for neuroblastoma with uptake

  18. Iodine-131 MIBG scintigraphy of the extremities in metastatic pheochromocytoma and neuroblastoma

    SciTech Connect

    Shulkin, B.L.; Shen, S.W.; Sisson, J.C.; Shapiro, B.

    1987-03-01

    Iodine-131 MIBG scintigraphy may be used to determine the presence or absence of metastases to the appendicular skeleton in malignant pheochromocytoma and neuroblastoma. Normal bones show no uptake of (/sup 131/I)MIBG and the joints are seen as photon-deficient areas surrounded by background muscle activity. Discrete concentrations of radioactivity in bone are often seen in patients with malignant pheochromocytoma and neuroblastoma. Bone marrow involvement in neuroblastoma may be indicated by diffuse uptake of (/sup 131/I)MIBG or focal accumulation at the metaphyses. Uncommonly, bone involvement may not be displayed by the (/sup 131/I)MIBG images. Since conventional bone scanning agents may also fail to detect these tumors, skeletal scintigraphy with both (/sup 131/I)MIBG and (/sup 99m/Tc)MDP is necessary to reliably stage malignant pheochromocytoma and neuroblastoma.

  19. Thymic neuroblastoma with the syndrome of inappropriate secretion of antidiuretic hormone.

    PubMed

    Ogawa, Fumihiro; Amano, Hideki; Iyoda, Akira; Satoh, Yukitoshi

    2009-11-01

    We describe a rare case of thymic neuroblastoma with the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). A 60-year-old male patient was admitted to our hospital for further examination and treatment of anterior mediastinal tumor found at a regular health check-up. On examination there was hyponatremia, decrease in plasma osmolarity and elevation of plasma antidiuretic hormone (ADH) level. Thus, he underwent total thymectomy under the diagnosis of thymoma with SIADH. The tumor was located in the right lobe of the thymus and the final diagnosis was thymic neuroblastoma. To our knowledge, this is the first reported case of thymic neuroblastoma in which production of ADH by tumor cells is demonstrated immunohistochemically. This case highlights the need to consider functional activity of thymic neuroblastoma and complete resection of the tumor is warranted for treatment.

  20. [Epidemiology of neuroblastoma in Brittany over a 10-year period (1980-1989)].

    PubMed

    Blanchot, I; Bergeron, C; Roussey, M; De Parscau, L; Le Gall, E

    1993-01-01

    We report the results of a retrospective epidemiologic study on neuroblastoma in Brittany, a region of France characterized by an homogeneous sedentary population living on a granitic ground. During a period of 10 years (1980-1989), 48 cases of neuroblastoma were observed, which gives an incidence of 7.92 cases per million of children under 15 years. There were 25 boys and 23 girls and 20 infants under 1 year (41%). The localisation was abdominal in 39 cases (81%). Among the 28 children older than 1 year, 25 (89%) had stage III and stage IV neuroblastomas, half of them with metastases. We conclude that the incidence and the clinical presentation of neuroblastoma in Brittany are similar to those reported in other countries.

  1. Is there a role for retinoids to treat minimal residual disease in neuroblastoma?

    PubMed Central

    Matthay, K K; Reynolds, C P

    2000-01-01

    A variety of pre-clinical and clinical data point toward high drug levels of retinoids being required to achieve optimal efficacy against neuroblastoma. The results of the Kohler trial reported in this issue demonstrate that low-dose 13-cis-RA does not have clinical efficacy against neuroblastoma in a setting of minimal residual disease. A comparison of the Kohler trial with the US CCG trial provides clinical evidence that high-dose levels of retinoids are optimal for treating minimal residual disease in neuroblastoma. The comparison of high-dose and low-dose 13-cis-RA studies in neuroblastoma suggests the intriguing possibility that high dose, pulse schedules of other retinoids could be effective as therapeutic and chemopreventive agents in diseases where low-dose, chronic retinoid administration was not effective. Pre-clinical and perhaps clinical studies of the latter concept should be considered. © 2000 Cancer Research Campaign PMID:11027422

  2. Thermal Reaction of Cinnamate Oligomers and Their Effect on the Orientational Stability of Liquid Crystals

    NASA Astrophysics Data System (ADS)

    Hah, Hyundae; Sung, Shi‑Joon; Park, Jung‑Ki

    2006-08-01

    Cinnamate groups are well-known for a dimerization reaction upon exposure to ultraviolet irradiation and a thermal reaction after being heated. In this study, to verify the thermal reaction of the cinnamate group in detail, we investigated the thermal crosslinking of cinnamate oligomers. The thermal reaction of cinnamate oligomers of low molecular weight is induced more readily by thermal energy compared with that of cinnamate polymers. This reaction is attributed to a radical reaction involving the carbon-carbon double bond in the cinnamate group. The orientation of the liquid crystal depended on the length of the spacers in the cinnamate oligomers.

  3. Studies on Oligomer Metal Complexes Derived from Bisamic Acid of Pyromellitic Dianhydride and 4-Bromoaniline

    PubMed Central

    Patel, Yogesh S.

    2014-01-01

    Novel oligomer metal complexes (2a–f) of the ligand 2,5-bis((4-bromophenyl)carbamoyl) terephthalic acid (1) were prepared using transition metal salts and characterized by various spectroscopic techniques. The geometry of oligomer metal complexes was carried out by electronic spectral analysis and magnetic measurement studies. Polymeric properties have also been carried out. Ligand was synthesized using pyromellitic dianhydride and 4-bromoaniline. It was duly characterized. All novel synthesized compounds 1 and 2a–f were evaluated for their antibacterial and antifungal activity. The results showed significantly higher antibacterial and antifungal activity of oligomer metal complexes compared to the ligand. PMID:27379295

  4. Studies on Oligomer Metal Complexes Derived from Bisamic Acid of Pyromellitic Dianhydride and 4-Bromoaniline.

    PubMed

    Patel, Yogesh S

    2014-01-01

    Novel oligomer metal complexes (2a-f) of the ligand 2,5-bis((4-bromophenyl)carbamoyl) terephthalic acid (1) were prepared using transition metal salts and characterized by various spectroscopic techniques. The geometry of oligomer metal complexes was carried out by electronic spectral analysis and magnetic measurement studies. Polymeric properties have also been carried out. Ligand was synthesized using pyromellitic dianhydride and 4-bromoaniline. It was duly characterized. All novel synthesized compounds 1 and 2a-f were evaluated for their antibacterial and antifungal activity. The results showed significantly higher antibacterial and antifungal activity of oligomer metal complexes compared to the ligand.

  5. Common structure and toxic function of amyloid oligomers implies a common mechanism of pathogenesis.

    PubMed

    Glabe, Charles G; Kayed, Rakez

    2006-01-24

    Recent findings indicate that soluble amyloid oligomers may represent the primary pathologic species in degenerative diseases. These amyloid oligomers share common structural features and the ability to permeabilize membranes, suggesting that they also share a common primary mechanism of pathogenesis. Membrane permeabilization by amyloid oligomers may initiate a common group of downstream pathologic processes, including intracellular calcium dyshomeostasis, production of reactive oxygen species, altered signaling pathways, and mitochondrial dysfunction that represent key effectors of cellular dysfunction and cell death in amyloid-associated degenerative disease, such as sporadic inclusion-body myositis.

  6. Red-emitting π-conjugated oligomers infused single-wall carbon nanotube sheets

    NASA Astrophysics Data System (ADS)

    Fujimori, Toshihiko; Urita, Koki

    2016-04-01

    We demonstrate the one-step thermal fusion and infusion of pyrene molecules inside single-wall carbon nanotubes (SWCNTs). Despite the presence of metallic-SWCNTs, which behave as a quencher due to gapless electronic states, the nanohybrids consisting of pyrene and/or azupyrene oligomers infused SWCNT sheets exhibit red fluorescence by the ultraviolet, blue, and green light excitations. The wavelength-independent light-emitting behavior is explained by (1) infused PAH oligomers inside semiconducting-SWCNTs and (2) the peculiar π-π interaction through mixed π-conjugated state between the π-conjugated oligomers and non-armchair metallic-SWCNTs.

  7. Phenylethynyl Terminated Arylene Ether Oxadiazole and Triazole Oligomers and Their Cured Polymers

    NASA Technical Reports Server (NTRS)

    Thompson, C. M.; Hergenrother, P. M.

    2001-01-01

    Several novel phenylethynyl terminated arylene ether oligomers containing oxadiazole and triazole rings were prepared as part of an effort to develop high performance polymers with an attractive combination of properties (e.g. processability and mechanical performance) for future NASA applications. The oligomers displayed low melt viscosities and good solubilities. Thin films cast from solutions of the oligomers and cured for one hour at 350 C in air gave good tensile properties. Titanium to titanium (6Al-4V) tensile shear specimens were readily fabricated and provided moderate strengths. The chemistry and properties of these new materials are discussed.

  8. Effect of molecular weight of oligomer on ionic diffusion in oligomer electrolytes and its implication for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Park, Jong Hyuk; Choi, Kyu Jin; Kim, Junkyung; Kang, Yong Soo; Lee, Sang-Soo

    This study measures the diffusion coefficients of I - and I 3 - in oligomer electrolytes as a function of the molecular weight of oligomers and investigates their effect on the performance of dye-sensitized solar cells (DSSCs). The high-diffusion coefficients of ions in an oligomer electrolyte with a lower molecular weight can help to promote the redox mechanism in DSSCs and thereby increase the short-circuit current density. They can also cause a decrease in the open-circuit voltage since a high-diffusion coefficient of I 3 - is capable of reducing the lifetime of electrons in TiO 2 electrodes. To offset these effects, N-methyl-benzimidazole is added to the oligomer electrolytes, thereby improving the open-circuit voltage and fill factor and, consequently, the overall energy-conversion efficiency, which increases to over 5%. A further test involving storage at a high temperature of 75 °C demonstrates that DSSCs employing the oligomer electrolytes show excellent thermal stability over 200 h.

  9. Large Soluble Oligomers of Amyloid β-Protein from Alzheimer Brain Are Far Less Neuroactive Than the Smaller Oligomers to Which They Dissociate.

    PubMed

    Yang, Ting; Li, Shaomin; Xu, Huixin; Walsh, Dominic M; Selkoe, Dennis J

    2017-01-04

    Soluble oligomers of amyloid β-protein (oAβ) isolated from the brains of Alzheimer's disease (AD) patients have been shown experimentally (in the absence of amyloid plaques) to impair hippocampal synaptic plasticity, decrease synapses, induce tau hyperphosphorylation and neuritic dystrophy, activate microglial inflammation, and impair memory in normal adult rodents. Nevertheless, there has been controversy about what types of oligomers actually confer these AD-like phenotypes. Here, we show that the vast majority of soluble Aβ species obtained from brains of humans who died with confirmed AD elute at high molecular weight (HMW) on nondenaturing size-exclusion chromatography. These species have little or no cytotoxic activity in several bioassays. However, incubation of HMW oAβ in mildly alkaline buffer led to their quantitative dissociation into low molecular weight oligomers (∼8-70 kDa), and these were now far more bioactive: they impaired hippocampal LTP, decreased neuronal levels of β2-adrenergic receptors, and activated microglia in wt mice in vivo Thus, most soluble Aβ assemblies in AD cortex are large and inactive but under certain circumstances can dissociate into smaller, highly bioactive species. Insoluble amyloid plaques likely sequester soluble HMW oligomers, limiting their potential to dissociate. We conclude that conditions that destabilize HMW oligomers or retard the sequestration of their smaller, more bioactive components are important drivers of Aβ toxicity. Selectively targeting these small, cytotoxic forms should be therapeutically beneficial.

  10. Coulombic free energy and salt ion association per phosphate of all-atom models of DNA oligomer: dependence on oligomer size.

    PubMed

    Shkel, Irina A; Record, M Thomas

    2012-08-23

    We investigate how the coulombic Gibbs free energy and salt ion association per phosphate charge of DNA oligomers vary with oligomer size (i.e. number of charged residues ∣ZD∣) at 0.15 M univalent salt by non-linear Poisson Boltzmann (NLPB) analysis of all-atom DNA models. Calculations of these quantities ([Formula: see text], [Formula: see text]) are performed for short and long double-stranded (ds) and single-stranded (ss) DNA oligomers, ranging from 4 to 118 phosphates (ds) and from 2 to 59 phosphates (ss). Behaviors of [Formula: see text] and [Formula: see text] as functions of ∣ZD∣ provide a measure of the range of the coulombic end effect and determine the size of an oligomer at which an interior region with the properties (per charge) of the infinite-length polyelectrolyte first appears. This size (10-11 phosphates at each end for ds DNA and 6-9 for ss DNA at 0.15 M salt) is in close agreement with values obtained previously by Monte Carlo and NLPB calculations for cylindrical models of polyions, and by analysis of binding of oligocations to DNA oligomers. Differences in [Formula: see text] and in [Formula: see text] between ss and ds DNA are used to predict effects of oligomeric size and salt concentration on duplex stability in the vicinity of 0.15 M salt. Results of all-atom calculations are compared with results of less structurally detailed models and with experimental data.

  11. High frequency of p53/MDM2/p14ARF pathway abnormalities in relapsed neuroblastoma

    PubMed Central

    Carr-Wilkinson, Jane; O' Toole, Kieran; Wood, Katrina M.; Challen, Christine C.; Baker, Angela G.; Board, Julian R.; Evans, Laura; Cole, Michael; Cheung, Nai-Kong V.; Boos, Joachim; Köhler, Gabriele; Leuschner, Ivo; Pearson, Andrew D.J.; Lunec, John; Tweddle, Deborah A.

    2010-01-01

    Purpose: Most neuroblastomas initially respond to therapy but many relapse with chemoresistant disease. p53 mutations are rare in diagnostic neuroblastomas, but we have previously reported inactivation of the p53/MDM2/p14ARF pathway in 9/17 (53%) neuroblastoma cell lines established at relapse. Hypothesis: Inactivation of the p53/MDM2/p14ARF pathway develops during treatment and contributes to neuroblastoma relapse. Methods: Eighty-four neuroblastomas were studied from 41 patients with relapsed neuroblastoma including 38 paired neuroblastomas at different stages of therapy. p53 mutations were detected by automated sequencing, p14ARF methylation and deletion by methylation-specific PCR and duplex PCR respectively, and MDM2 amplification by fluorescent in-situ hybridisation. Results: Abnormalities in the p53 pathway were identified in 20/41(49%) cases. Downstream defects due to inactivating missense p53 mutations were identified in 6/41 (15%) cases, 5 following chemotherapy and/or at relapse and 1 at diagnosis, post chemotherapy and relapse. The presence of a p53 mutation was independently prognostic for overall survival (hazard ratio 3.4, 95% confidence interval 1.2, 9.9; p = 0.02). Upstream defects were present in 35% cases: MDM2 amplification in 3 cases, all at diagnosis & relapse and p14ARF inactivation in 12/41 (29%) cases: 3 had p14ARF methylation, 2 after chemotherapy, and 9 had homozygous deletions, 8 at diagnosis and relapse. Conclusions: These results show that a high proportion of neuroblastomas which relapse have an abnormality in the p53 pathway. The majority have upstream defects suggesting that agents which reactivate wild-type p53 would be beneficial, in contrast to those with downstream defects where p53 independent therapies are indicated. PMID:20145180

  12. Relapsed neuroblastomas show frequent RAS-MAPK pathway mutations | Office of Cancer Genomics

    Cancer.gov

    The majority of patients with neuroblastoma have tumors that initially respond to chemotherapy, but a large proportion will experience therapy-resistant relapses. The molecular basis of this aggressive phenotype is unknown. Whole-genome sequencing of 23 paired diagnostic and relapse neuroblastomas showed clonal evolution from the diagnostic tumor, with a median of 29 somatic mutations unique to the relapse sample. Eighteen of the 23 relapse tumors (78%) showed mutations predicted to activate the RAS-MAPK pathway.

  13. Didymin Induces Apoptosis by Inhibiting N-Myc and up regulating RKIP in Neuroblastoma

    PubMed Central

    Singhal, Jyotsana; Nagaprashantha, Lokesh Dalasanur; Vatsyayan, Rit; Singhal, Ashutosh; Awasthi, Sanjay; Singhal, Sharad S

    2011-01-01

    Neuroblastomas arise from the neural crest cells and represent the most common solid tumors outside the nervous system in children. The amplification of N-Myc plays a primary role in the pathogenesis of neuroblastomas whereas acquired mutations of p53 lead to refractory and relapsed cases of neuroblastomas. In this regard, dietary compounds which can target N-Myc and exert anti-cancer effects independent of p53 status acquire significance in the management of neuroblastomas. Hence, we investigated the anti-cancer properties of the flavonoid didymin in neuroblastomas. Didymin effectively inhibited proliferation and induced apoptosis irrespective of p53 status in neuroblastomas. Didymin down regulated PI3K, pAkt, Akt, vimentin and up regulated RKIP levels. Didymin induced G2/M arrest along with decreasing the levels of cyclin D1, CDK4 and cyclin B1. Importantly, didymin inhibited NMyc as confirmed at protein, mRNA and transcriptional level by promoter-reporter assays. HPLC analysis of didymin (2 mg/kg b.w.) treated mice serum revealed effective oral absorption with free didymin concentration of 2.1 μM. Further in vivo mice xenograft studies revealed that didymin (2 mg/kg b.w.) treated animals had significant reductions in tumors size compared to controls. Didymin strongly inhibited the proliferation (Ki67) and angiogenesis (CD31) markers as well as N-Myc expression as revealed by the histopathological examination of paraffin embedded section of resected tumors. Collectively, our in vitro and in vivo studies elucidated the anti-cancer properties and mechanisms of action of a novel, orally active and palatable flavonoid didymin which makes it a potential new approach for neuroblastoma therapy (NANT) to target pediatric neuroblastomas. PMID:22174364

  14. Transcription factor activating protein 2 beta (TFAP2B) mediates noradrenergic neuronal differentiation in neuroblastoma.

    PubMed

    Ikram, Fakhera; Ackermann, Sandra; Kahlert, Yvonne; Volland, Ruth; Roels, Frederik; Engesser, Anne; Hertwig, Falk; Kocak, Hayriye; Hero, Barbara; Dreidax, Daniel; Henrich, Kai-Oliver; Berthold, Frank; Nürnberg, Peter; Westermann, Frank; Fischer, Matthias

    2016-02-01

    Neuroblastoma is an embryonal pediatric tumor that originates from the developing sympathetic nervous system and shows a broad range of clinical behavior, ranging from fatal progression to differentiation into benign ganglioneuroma. In experimental neuroblastoma systems, retinoic acid (RA) effectively induces neuronal differentiation, and RA treatment has been therefore integrated in current therapies. However, the molecular mechanisms underlying differentiation are still poorly understood. We here investigated the role of transcription factor activating protein 2 beta (TFAP2B), a key factor in sympathetic nervous system development, in neuroblastoma pathogenesis and differentiation. Microarray analyses of primary neuroblastomas (n = 649) demonstrated that low TFAP2B expression was significantly associated with unfavorable prognostic markers as well as adverse patient outcome. We also found that low TFAP2B expression was strongly associated with CpG methylation of the TFAP2B locus in primary neuroblastomas (n = 105) and demethylation with 5-aza-2'-deoxycytidine resulted in induction of TFAP2B expression in vitro, suggesting that TFAP2B is silenced by genomic methylation. Tetracycline inducible re-expression of TFAP2B in IMR-32 and SH-EP neuroblastoma cells significantly impaired proliferation and cell cycle progression. In IMR-32 cells, TFAP2B induced neuronal differentiation, which was accompanied by up-regulation of the catecholamine biosynthesizing enzyme genes DBH and TH, and down-regulation of MYCN and REST, a master repressor of neuronal genes. By contrast, knockdown of TFAP2B by lentiviral transduction of shRNAs abrogated RA-induced neuronal differentiation of SH-SY5Y and SK-N-BE(2)c neuroblastoma cells almost completely. Taken together, our results suggest that TFAP2B is playing a vital role in retaining RA responsiveness and mediating noradrenergic neuronal differentiation in neuroblastoma.

  15. MYCN gene expression is required for the onset of the differentiation programme in neuroblastoma cells

    PubMed Central

    Guglielmi, L; Cinnella, C; Nardella, M; Maresca, G; Valentini, A; Mercanti, D; Felsani, A; D'Agnano, I

    2014-01-01

    Neuroblastoma is an embryonic tumour of the sympathetic nervous system and is one of the most common cancers in childhood. A high differentiation stage has been associated with a favourable outcome; however, the mechanisms governing neuroblastoma cell differentiation are not completely understood. The MYCN gene is considered the hallmark of neuroblastoma. Even though it has been reported that MYCN has a role during embryonic development, it is needed its decrease so that differentiation can be completed. We aimed to better define the role of MYCN in the differentiation processes, particularly during the early stages. Considering the ability of MYCN to regulate non-coding RNAs, our hypothesis was that N-Myc protein might be necessary to activate differentiation (mimicking embryonic development events) by regulating miRNAs critical for this process. We show that MYCN expression increased in embryonic cortical neural precursor cells at an early stage after differentiation induction. To investigate our hypothesis, we used human neuroblastoma cell lines. In LAN-5 neuroblastoma cells, MYCN was upregulated after 2 days of differentiation induction before its expected downregulation. Positive modulation of various differentiation markers was associated with the increased MYCN expression. Similarly, MYCN silencing inhibited such differentiation, leading to negative modulation of various differentiation markers. Furthermore, MYCN gene overexpression in the poorly differentiating neuroblastoma cell line SK-N-AS restored the ability of such cells to differentiate. We identified three key miRNAs, which could regulate the onset of differentiation programme in the neuroblastoma cells in which we modulated MYCN. Interestingly, these effects were accompanied by changes in the apoptotic compartment evaluated both as expression of apoptosis-related genes and as fraction of apoptotic cells. Therefore, our idea is that MYCN is necessary during the activation of neuroblastoma

  16. Altered expression of miRNAs and methylation of their promoters are correlated in neuroblastoma.

    PubMed

    Maugeri, Marco; Barbagallo, Davide; Barbagallo, Cristina; Banelli, Barbara; Di Mauro, Stefania; Purrello, Francesco; Magro, Gaetano; Ragusa, Marco; Di Pietro, Cinzia; Romani, Massimo; Purrello, Michele

    2016-12-13

    Neuroblastoma is the most common human extracranial solid tumor during infancy. Involvement of several miRNAs in its pathogenesis has been ascertained. Interestingly, most of their encoding genes reside in hypermethylated genomic regions: thus, their tumor suppressor function is normally disallowed in these tumors. To date, the therapeutic role of the demethylating agent 5'-Aza-2 deoxycytidine (5'-AZA) and its effects on miRNAome modulation in neuroblastoma have not been satisfactorily explored. Starting from a high-throughput expression profiling of 754 miRNAs and based on a proper selection, we focused on miR-29a-3p, miR-34b-3p, miR-181c-5p and miR-517a-3p as candidate miRNAs for our analysis. They resulted downregulated in four neuroblastoma cell lines with respect to normal adrenal gland. MiRNAs 29a-3p and 34b-3p also resulted downregulated in vivo in a murine neuroblastoma progression model. Unlike the amount of methylation of their encoding gene promoters, all these miRNAs were significantly overexpressed following treatment with 5'-AZA. Transfection with candidate miRNAs mimics significantly decreased neuroblastoma cells proliferation rate. A lower expression of miR-181c was significantly associated to a worse overall survival in a public dataset of 498 neuroblastoma samples (http://r2.amc.nl). Our data strongly suggest that CDK6, DNMT3A, DNMT3B are targets of miR-29a-3p, while CCNE2 and E2F3 are targets of miR-34b-3p. Based on all these data, we propose that miR-29a-3p, miR-34b-3p, miR-181c-5p and miR-517a-3p are disallowed tumor suppressor genes in neuroblastoma and suggest them as new therapeutic targets in neuroblastoma.

  17. Intracellular fragment of NLRR3 (NLRR3-ICD) stimulates ATRA-dependent neuroblastoma differentiation

    SciTech Connect

    Akter, Jesmin; Takatori, Atsushi; Islam, Md. Sazzadul; Nakazawa, Atsuko; Ozaki, Toshinori; Nagase, Hiroki; Nakagawara, Akira

    2014-10-10

    Highlights: • NLRR3 is a membrane protein highly expressed in favorable neuroblastoma. • NLRR3-ICD was produced through proteolytic processing by secretases. • NLRR3-ICD was induced to be translocated into cell nucleus following ATRA exposure. • NLRR3-ICD plays a pivotal role in ATRA-mediated neuroblastoma differentiation. - Abstract: We have previously identified neuronal leucine-rich repeat protein-3 (NLRR3) gene which is preferentially expressed in favorable human neuroblastomas as compared with unfavorable ones. In this study, we have found for the first time that NLRR3 is proteolytically processed by secretases and its intracellular domain (NLRR3-ICD) is then released to translocate into cell nucleus during ATRA-mediated neuroblastoma differentiation. According to our present observations, NLRR3-ICD was induced to accumulate in cell nucleus of neuroblastoma SH-SY5Y cells following ATRA treatment. Since the proteolytic cleavage of NLRR3 was blocked by α- or γ-secretase inhibitor, it is likely that NLRR3-ICD is produced through the secretase-mediated processing of NLRR3. Intriguingly, forced expression of NLRR3-ICD in neuroblastoma SK-N-BE cells significantly suppressed their proliferation as examined by a live-cell imaging system and colony formation assay. Similar results were also obtained in neuroblastoma TGW cells. Furthermore, overexpression of NLRR3-ICD stimulated ATRA-dependent neurite elongation in SK-N-BE cells. Together, our present results strongly suggest that NLRR3-ICD produced by the secretase-mediated proteolytic processing of NLRR3 plays a crucial role in ATRA-mediated neuronal differentiation, and provide a clue to develop a novel therapeutic strategy against aggressive neuroblastomas.

  18. Prostaglandin E2 promotes MYCN non-amplified neuroblastoma cell survival via β-catenin stabilization

    PubMed Central

    Jansen, Sepp R; Holman, Rian; Hedemann, Ilja; Frankes, Ewoud; Elzinga, Carolina R S; Timens, Wim; Gosens, Reinoud; de Bont, Eveline S; Schmidt, Martina

    2015-01-01

    Amplification of MYCN is the most well-known prognostic marker of neuroblastoma risk classification, but still is only observed in 25% of cases. Recent evidence points to the cyclic adenosine monophosphate (cAMP) elevating ligand prostaglandin E2 (PGE2) and β-catenin as two novel players in neuroblastoma. Here, we aimed to define the potential role of PGE2 and cAMP and its potential interplay with β-catenin, both of which may converge on neuroblastoma cell behaviour. Gain and loss of β-catenin function, PGE2, the adenylyl cyclase activator forskolin and pharmacological inhibition of cyclooxygenase-2 (COX-2) were studied in two human neuroblastoma cell lines without MYCN amplification. Our findings show that PGE2 enhanced cell viability through the EP4 receptor and cAMP elevation, whereas COX-2 inhibitors attenuated cell viability. Interestingly, PGE2 and forskolin promoted glycogen synthase kinase 3β inhibition, β-catenin phosphorylation at the protein kinase A target residue ser675, β-catenin nuclear translocation and TCF-dependent gene transcription. Ectopic expression of a degradation-resistant β-catenin mutant enhances neuroblastoma cell viability and inhibition of β-catenin with XAV939 prevented PGE2-induced cell viability. Finally, we show increased β-catenin expression in human high-risk neuroblastoma tissue without MYCN amplification. Our data indicate that PGE2 enhances neuroblastoma cell viability, a process which may involve cAMP-mediated β-catenin stabilization, and suggest that this pathway is of relevance to high-risk neuroblastoma without MYCN amplification. PMID:25266063

  19. A high-content morphological screen identifies novel microRNAs that regulate neuroblastoma cell differentiation.

    PubMed

    Zhao, Zhenze; Ma, Xiuye; Hsiao, Tzu-Hung; Lin, Gregory; Kosti, Adam; Yu, Xiaojie; Suresh, Uthra; Chen, Yidong; Tomlinson, Gail E; Pertsemlidis, Alexander; Du, Liqin

    2014-05-15

    Neuroblastoma, the most common extracranial solid tumor of childhood, arises from neural crest cell precursors that fail to differentiate. Inducing cell differentiation is an important therapeutic strategy for neuroblastoma. We developed a direct functional high-content screen to identify differentiation-inducing microRNAs, in order to develop microRNA-based differentiation therapy for neuroblastoma. We discovered novel microRNAs, and more strikingly, three microRNA seed families that induce neuroblastoma cell differentiation. In addition, we showed that microRNA seed families were overrepresented in the identified group of fourteen differentiation-inducing microRNAs, suggesting that microRNA seed families are functionally more important in neuroblastoma differentiation than microRNAs with unique sequences. We further investigated the differentiation-inducing function of the microRNA-506-3p/microRNA-124-3p seed family, which was the most potent inducer of differentiation. We showed that the differentiation-inducing function of microRNA-506-3p/microRNA-124-3p is mediated, at least partially, by down-regulating expression of their targets CDK4 and STAT3. We further showed that expression of miR-506-3p, but not miR-124-3p, is dramatically upregulated in differentiated neuroblastoma cells, suggesting the important role of endogenous miR-506-3p in differentiation and tumorigenesis. Overall, our functional screen on microRNAs provided the first comprehensive analysis on the involvements of microRNA species in neuroblastoma cell differentiation and identified novel differentiation-inducing microRNAs. Further investigations are certainly warranted to fully characterize the function of the identified microRNAs in order to eventually benefit neuroblastoma therapy.

  20. The genetic landscape of high-risk neuroblastoma | Office of Cancer Genomics

    Cancer.gov

    Abstract: Neuroblastoma is a malignancy of the developing sympathetic nervous system that often presents with widespread metastatic disease, resulting in survival rates of less than 50%. To determine the spectrum of somatic mutation in high-risk neuroblastoma, we studied 240 affected individuals (cases) using a combination of whole-exome, genome and transcriptome sequencing as part of the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) initiative.

  1. Common variations within HACE1 gene and neuroblastoma susceptibility in a Southern Chinese population

    PubMed Central

    Zhang, Zhuorong; Zhang, Ruizhong; Zhu, Jinhong; Wang, Fenghua; Yang, Tianyou; Zou, Yan; He, Jing; Xia, Huimin

    2017-01-01

    Neuroblastoma is a common fatal pediatric cancer of the developing sympathetic nervous system, which accounts for ~10% of all pediatric cancer deaths. To investigate genetic risk factors related to neuroblastoma, many genome-wide association studies have been performed, and single nucleotide polymorphisms (SNPs) within HACE1 gene have been identified to associate with neuroblastoma risk. However, the association of the HACE1 SNPs with neuroblastoma needs to be validated in Southern Chinese children. We genotyped five SNPs located in the HACE1 gene (rs4336470 C>T, rs9404576 T>G, rs4079063 A>G, rs2499663 T>C, and rs2499667 A>G) in 256 Southern Chinese patients in comparison with 531 ethnically matched healthy controls. Single locus analysis showed no significant association between any of HACE1 SNPs and neuroblastoma risk in Southern Chinese children. However, when all the risk genotypes were combined, we found a borderline significant trend toward an increased neuroblastoma risk with 4–5 risk genotypes (adjusted odds ratio =1.36, 95% confidence interval =0.98–1.89, P=0.065). Moreover, stratified analysis found that carriers of 4–5 risk genotypes tended to develop neuroblastoma in the retroperitoneal region and have more aggressive tumors, progressing to advanced clinical stages III/IV, when compared with those of 0–3 risk genotypes. In conclusion, HACE1 gene may have weak effect on neuroblastoma risk in Southern Chinese children. Large well-designed studies are needed to strengthen our findings. PMID:28223827

  2. Acrometastasis of Neuroblastoma to the Great Toe Revealed by MIBG Scan.

    PubMed

    Zheng, Kun; Zhuang, Hongming

    2017-02-03

    A 3-year-old boy with history of neuroblastoma underwent I-MIBG scan. The whole-body images showed relatively normal tracer distribution except for mild activity in the right foot, which was located in the first metatarsal on SPECT/CT images. The subsequent MRI scan of the right foot showed infiltration of the metatarsal of the right first toe. The findings were consistent with solitary acrometastasis of neuroblastoma to the great toe.

  3. Neuroblastoma in a boy with MCA/MR syndrome, deletion 11q, and duplication 12q

    SciTech Connect

    Koiffmann, C.P.; Vianna-Morgante, A.M.; Wajntal, A.

    1995-07-31

    Deletion 11q23{r_arrow}qter and duplication 12q23{r_arrow}qter are described in a boy with neuroblastoma, multiple congenital anomalies, and mental retardation. The patient has clinical manifestations of 11q deletion and 12q duplication syndromes. The possible involvement of the segment 11q23{r_arrow}24 in the cause of the neuroblastoma is discussed. 18 refs., 2 figs., 1 tab.

  4. Synaptotoxic amyloid-β oligomers: a molecular basis for the cause, diagnosis, and treatment of Alzheimer's disease?

    PubMed

    Klein, William L

    2013-01-01

    The oligomer hypothesis for Alzheimer's disease (AD)was introduced in 1998. It was based on evidence that oligomers could exist free of amyloid fibrils, that fibril-free oligomer solutions rapidly inhibited long term potentiation, and that oligomers ultimately caused a highly selective nerve cell death. Fibrils no longer were the only toxins made by amyloid-β (Aβ), and likely not the most important ones. Oligomers provided a new basis for instigating AD. Since introduction of the hypothesis, more than 1,500 articles on oligomers have been published. Articles for this review were selected for contributions to oligomer theory at three different levels. The first set demonstrated new aspects of oligomer pathobiology in cell models, showing that exposure of neurons to oligomers is sufficient to cause key features of AD neuropathology. The second set confirmed the relationship between oligomers and salient AD neuropathology in animal models, consistent with other in vivo studies that overall have substantiated cell-based discoveries. The third set developed strategies for therapeutic targeting of oligomers, introducing both small molecule and antibody-based approaches. These and related findings from many groups have helped establish oligomers as central to the mechanism of AD pathogenesis. Comprising a ligand-based attack on specific synapses, the action of toxic oligomers gives a molecular basis to account for key features of AD neuropathology and to explain why early disease targets memory. Although there still is no effective treatment for AD, insights over the past five years raise hopes that new approaches targeting Aβ oligomers could finally bring disease-modifying therapeutics.

  5. Polysulfide promotes neuroblastoma cell differentiation by accelerating calcium influx.

    PubMed

    Koike, Shin; Shibuya, Norihiro; Kimura, Hideo; Ishii, Kazuyuki; Ogasawara, Yuki

    2015-04-10

    Polysulfides are a typical type of bound sulfur, which is physiologically stable form of sulfur species, derived from the hydrogen sulfide (H2S) that is generated endogenously in cells. We previously reported that bound sulfur protects neuronal cells from oxidative injury. In the present study, we demonstrated that polysulfides inhibited cell growth and promoted neurite outgrowth in mouse neuroblastoma Neuro2A (N2A) cells. However, Na2S showed no effect on neurite outgrowth in N2A cells. Furthermore, 2-APB and SKF96365, which are typical transient receptor potential (TRP) channel inhibitors, suppressed the neurite outgrowth induced by Na2S4. These new findings suggest that bound sulfur could induce neurite outgrowth and cell differentiation of N2A cells by accelerating calcium influx.

  6. Biochemical effects of chlorpromazine on mouse neuroblastoma cells.

    PubMed

    Andres, M I; Repetto, G; Sanz, P; Repetto, M

    1999-10-01

    Chlorpromazine and other phenothiazine derivatives are neuroleptic drugs of widespread use for clinical situations beyond the realm of psychiatry, such as to control nausea, vomiting and intractable hiccups. The present study investigated in vitro different cytotoxic effects of chlorpromazine in cultures of mouse neuroblastoma cell line Neuro-2a exposed to different concentrations of this compound. Indicators assessed were cell proliferation by quantification of total protein content of the cell culture, lysosomal function evaluated by the relative uptake of neutral red cytosolic phosphofructokinase (PFK) and enolase (ENL) activities in glycolysis, mitochondrial succinate dehydrogenase (SDH) activity in the citric acid cycle, lysosomal beta-galactosidase (GAL) activity, and neuronal acetylcholinesterase activity. Marked inhibitory effects were found for cell proliferation and relative neutral red uptake; PFK, ENL and GAL activities had no significant differences from control. Stimulation was specifically detected on SDH and the Krebs cycle at concentrations up to 30 microM. Chlorpromazine did not have high toxicity for cytotoxic effects on lysosomes.

  7. Cyclic, low-dose total body irradiation for metastatic neuroblastoma

    SciTech Connect

    D'Angio, G.J.; Evans, A.E.

    1983-12-01

    Total body irradiation (TBI) can be thought of as a systemic anticancer agent. It therefore might best be given like an adjuvant drug, i.e., in tolerable doses, cyclically. The therapeutic ratio between normal bone marrow stem cells and suitably sensitive cancer cells should be widened by these means. Fourteen children with advanced (Stage IV) neuroblastomas were given 100-150 rad TBI in 50 rad daily fractions along with each three-week cycle of standard triple-agent chemotherapy (vincristine, DTIC, cyclophosphamide). Two patients died of toxicity and one is still undergoing therapy. Four of the remaining 12 survive free of disease for 12+ to 31+ months. The regimen is well tolerated, but prolonged, pronounced bone marrow depression, especially thrombocytopenia, commonly occurs after doses of 300-450 rad.

  8. Pathological features of olfactory neuroblastoma in an axolotl (Ambystoma mexicanum).

    PubMed

    Shioda, Chieko; Uchida, Kazuyuki; Nakayama, Hiroyuki

    2011-08-01

    A one-year-old, female Mexican axolotl (Ambystoma mexicanum) had a rough-surfaced, polypoid, pink tumor mass of approximately 10 mm in diameter in the oral cavity. Histologically, the tumor extended from the ethmoturbinate region and into the oral cavity and had replaced some of the maxillary bone tissue. The tumor mass was composed of a lobular architecture of small round-shaped tumor cells with occasional Flexner-Wintersteiner-like rosette formation. There were no metastatic lesions in the other organs. Immunohistochemically, the tumor cells were partly positive for several neural markers (class III beta-tubulin, S-100 protein, and doublecortin) and intensely positive for an epithelial marker (cytokeratin AE1/AE3). These results suggest that the present tumor originated from neuroectodermal tissue. Considering the location and histological and immunohistochemical features of the tumor, a diagnosis of olfactory neuroblastoma was made.

  9. Toxicity study of cerium oxide nanoparticles in human neuroblastoma cells.

    PubMed

    Kumari, Monika; Singh, Shailendra Pratap; Chinde, Srinivas; Rahman, Mohammed Fazlur; Mahboob, Mohammed; Grover, Paramjit

    2014-01-01

    The present study consisted of cytotoxic, genotoxic, and oxidative stress responses of human neuroblastoma cell line (IMR32) following exposure to different doses of cerium oxide nanoparticles (CeO2 NPs; nanoceria) and its microparticles (MPs) for 24 hours. Cytotoxicity was evaluated by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide and lactate dehydrogenase assays whereas genotoxicity was assessed using the cytokinesis-block micronucleus and comet assays. A battery of assays including lipid peroxidation, reactive oxygen species (ROS), hydrogen peroxide, reduced glutathione, nitric oxide, glutathione reductase, glutathione peroxidase, superoxide dismutase, catalase, and glutathione S-transferase were performed to test the hypothesis that ROS was responsible for the toxicity of nanoceria. The results showed that nanosized CeO2 was more toxic than cerium oxide MPs. Hence, further study on safety evaluation of CeO2 NPs on other models is recommended.

  10. Disseminated fusariosis secondary to neuroblastoma with fatal outcome.

    PubMed

    Silva, Gleiciere Maia; Silveira, Alice Rangel Cristiane; Betânia, Claudia Abreu Rodrigues; Macêdo, Danielle Patrícia Cerqueira; Neves, Rejane Pereira

    2013-10-01

    Disseminated fusariosis is an uncommon clinical condition in immunocompromised patients. We report a fatal case of disseminated fusariosis secondary to neuroblastoma in a male patient, 15 years old, who underwent a bone marrow transplant. The patient was admitted to the pediatric intensive care unit (PICU) of a public hospital in Recife-PE, Brazil, presenting bone marrow aplasia, severe leukopenia, and thrombocytopenia. After 15 days, the patient developed right knee effusion. Synovial fluid and blood samples were analyzed at the Medical Mycology Laboratory of the Federal University of Pernambuco. Mycological diagnosis was based on the presence of hyaline septate hyphae on direct examination and the isolation of Fusarium oxysporum in culture, confirming the case of disseminated fusariosis. In vitro, the isolate showed fluconazole resistance and sensitivity to amphotericin B, anidulafungin, and voriconazole. Therapy with voriconazole in combination with liposomal amphotericin B led to an improved clinical response; however, due to underlying disease complications, the patient progressed to death.

  11. Future aspects of immunotherapy and gene therapy in neuroblastoma.

    PubMed

    Aktas, S

    2009-09-01

    Immunotherapy against cancer aims at stimulating the immune system or building an immune response against targeted tumor-associated antigens (TAAs). It was proposed theoretically as a potential therapy for cancer over a century ago but it became popular in the past two decades. Gene therapy represents a promising approach for reversing the neoplastic phenotype or driving tumor cells to self-destruction. Although survival rates of neuroblastoma (NB) with biologically favorable disease are greater than 90%, outcomes of patients with high risk disease are less than 40%. Stage 4 metastatic NB cases over 18 months of age are often incurable with multimodality chemotherapy regimens. In this article, translation of immuno-gene therapy strategies into clinical trials for NB are reviewed. Future aspects of immuno-gene therapy are discussed.

  12. Netrin-1 acts as a survival factor for aggressive neuroblastoma

    PubMed Central

    Delloye-Bourgeois, Céline; Fitamant, Julien; Paradisi, Andrea; Cappellen, David; Douc-Rasy, Setha; Raquin, Marie-Anne; Stupack, Dwayne; Nakagawara, Akira; Rousseau, Raphaël; Combaret, Valérie; Puisieux, Alain; Valteau-Couanet, Dominique; Bénard, Jean; Bernet, Agnès

    2009-01-01

    Neuroblastoma (NB), the most frequent solid tumor of early childhood, is diagnosed as a disseminated disease in >60% of cases, and several lines of evidence support the resistance to apoptosis as a prerequisite for NB progression. We show that autocrine production of netrin-1, a multifunctional laminin-related molecule, conveys a selective advantage in tumor growth and dissemination in aggressive NB, as it blocks the proapoptotic activity of the UNC5H netrin-1 dependence receptors. We show that such netrin-1 up-regulation is a potential marker for poor prognosis in stage 4S and, more generally, in NB stage 4 diagnosed infants. Moreover, we propose that interference with the netrin-1 autocrine loop in malignant neuroblasts could represent an alternative therapeutic strategy, as disruption of this loop triggers in vitro NB cell death and inhibits NB metastasis in avian and mouse models. PMID:19349462

  13. Transport of carnitine in neuroblastoma NB-2a cells.

    PubMed

    Nałecz, K A; Korzon, D; Wawrzeńczyk, A; Nałecz, M J

    1995-09-10

    Carnitine accumulation was measured in cultured neuroblastoma NB-2a cells. This process was found partially sodium dependent and its kinetics to be a sum of a saturable transport (Km = 123 +/- 13 microM) and diffusion (D = 63 +/- 7 pmol/mg protein/min/mM). On the contrary to previous reports on neural cells, the accumulation of carnitine was found insensitive to gamma-aminobutyric acid (GABA). Measurements of carnitine accumulation in the presence of different compounds resulted in the conclusion that carnitine transport does not occur through the known systems specific toward choline and/or amino acids. For instance, an observed inhibition of carnitine transport by serine and cysteine, without any effect of alanine, excluded a possible role of ASC amino acid transport system. An involvement of a new transporter is thus postulated, specific toward compounds with a polar group in the beta position with respect to the carboxylic group.

  14. Phosphoproteomics reveals ALK promote cell progress via RAS/JNK pathway in neuroblastoma

    PubMed Central

    Xu, Guofeng; Zhang, Min; Wu, Yeming; Wu, Zhixiang

    2016-01-01

    Emerging evidence suggests receptor tyrosine kinase ALK as a promising therapeutic target in neuroblastoma. However, clinical trials reveal that a limited proportion of ALK-positive neuroblastoma patients experience clinical benefits from Crizotinib, a clinically approved specific inhibitor of ALK. The precise molecular mechanisms of aberrant ALK activity in neuroblastoma remain elusive, limiting the clinical application of ALK as a therapeutic target in neuroblastoma. Here, we describe a deep quantitative phosphoproteomic approach in which Crizotinib-treated neuroblastoma cell lines bearing aberrant ALK are used to investigate downstream regulated phosphoproteins. We identified more than 19,500—and quantitatively analyzed approximately 10,000—phosphorylation sites from each cell line, ultimately detecting 450–790 significantly-regulated phosphorylation sites. Multiple layers of bioinformatic analysis of the significantly-regulated phosphoproteins identified RAS/JNK as a downstream signaling pathway of ALK, independent of the ALK variant present. Further experiments demonstrated that ALK/JNK signaling could be inactivated by either ALK- or JNK-specific inhibitors, resulting in cell growth inhibition by induction of cell cycle arrest and cell apoptosis. Our study broadly defines the phosphoproteome in response to ALK inhibition and provides a resource for further clinical investigation of ALK as therapeutic target for the treatment of neuroblastoma. PMID:27732954

  15. MYCN promotes neuroblastoma malignancy by establishing a regulatory circuit with transcription factor AP4

    PubMed Central

    Xue, Chengyuan; Yu, Denise M.T.; Gherardi, Samuele; Koach, Jessica; Milazzo, Giorgio; Gamble, Laura; Liu, Bing; Valli, Emanuele; Russell, Amanda J.; London, Wendy B.; Liu, Tao; Cheung, Belamy B.; Marshall, Glenn M.; Perini, Giovanni; Haber, Michelle; Norris, Murray D.

    2016-01-01

    Amplification of the MYCN oncogene, a member of the MYC family of transcriptional regulators, is one of the most powerful prognostic markers identified for poor outcome in neuroblastoma, the most common extracranial solid cancer in childhood. While MYCN has been established as a key driver of malignancy in neuroblastoma, the underlying molecular mechanisms are poorly understood. Transcription factor activating enhancer binding protein-4 (TFAP4) has been reported to be a direct transcriptional target of MYC. We show for the first time that high expression of TFAP4 in primary neuroblastoma patients is associated with poor clinical outcome. siRNA-mediated suppression of TFAP4 in MYCN-expressing neuroblastoma cells led to inhibition of cell proliferation and migration. Chromatin immunoprecipitation assay demonstrated that TFAP4 expression is positively regulated by MYCN. Microarray analysis identified genes regulated by both MYCN and TFAP4 in neuroblastoma cells, including Phosphoribosyl-pyrophosphate synthetase-2 (PRPS2) and Syndecan-1 (SDC1), which are involved in cancer cell proliferation and metastasis. Overall this study suggests a regulatory circuit in which MYCN by elevating TFAP4 expression, cooperates with it to control a specific set of genes involved in tumor progression. These findings highlight the existence of a MYCN-TFAP4 axis in MYCN-driven neuroblastoma as well as identifying potential therapeutic targets for aggressive forms of this disease. PMID:27448979

  16. Unveiling MYCN regulatory networks in neuroblastoma via integrative analysis of heterogeneous genomics data

    PubMed Central

    Hsu, Chia-Lang; Chang, Hsin-Yi; Chang, Jen-Yun; Hsu, Wen-Ming; Huang, Hsuan-Cheng; Juan, Hsueh-Fen

    2016-01-01

    MYCN, an oncogenic transcription factor of the Myc family, is a major driver of neuroblastoma tumorigenesis. Due to the difficulty in drugging MYCN directly, revealing the molecules in MYCN regulatory networks will help to identify effective therapeutic targets for neuroblastoma therapy. Here we perform ChIP-sequencing and small RNA-sequencing of neuroblastoma cells to determine the MYCN-binding sites and MYCN-associated microRNAs, and integrate various types of genomic data to construct MYCN regulatory networks. The overall analysis indicated that MYCN-regulated genes were involved in a wide range of biological processes and could be used as signatures to identify poor-prognosis MYCN-non-amplified patients. Analysis of the MYCN binding sites showed that MYCN principally served as an activator. Using a computational approach, we identified 32 MYCN co-regulators, and some of these findings are supported by previous studies. Moreover, we investigated the interplay between MYCN transcriptional and microRNA post-transcriptional regulations and identified several microRNAs, such as miR-124-3p and miR-93-5p, which may significantly contribute to neuroblastoma pathogenesis. We also found MYCN and its regulated microRNAs acted together to repress the tumor suppressor genes. This work provides a comprehensive view of MYCN regulations for exploring therapeutic targets in neuroblastoma, as well as insights into the mechanism of neuroblastoma tumorigenesis. PMID:27167114

  17. Multiple mechanisms disrupt the let-7 microRNA family in neuroblastoma

    PubMed Central

    Powers, John T; Tsanov, Kaloyan M; Pearson, Daniel S; Roels, Frederik; Spina, Catherine S; Ebright, Richard; Seligson, Marc; de Soysa, Yvanka; Cahan, Patrick; Theiβen, Jessica; Tu, Ho-Chou; Han, Areum; Kurek, Kyle C; LaPier, Grace S; Osborne, Jihan K; Ross, Samantha J; Cesana, Marcella; Collins, James J; Berthold, Frank; Daley, George Q

    2016-01-01

    Poor prognosis in neuroblastoma is associated with genetic amplification of MYCN. MYCN is itself a target of let-7, a tumor suppressor family of microRNAs implicated in numerous cancers. LIN28B, an inhibitor of let-7 biogenesis, is overexpressed in neuroblastoma and has been reported to regulate MYCN. However, here we show that LIN28B is dispensable in MYCN-amplified neuroblastoma cell lines, despite de-repression of let-7. We further demonstrate that MYCN mRNA levels in amplified disease are exceptionally high and sufficient to sponge let-7, which reconciles the dispensability of LIN28B. We found that genetic loss of let-7 is common in neuroblastoma, inversely associated with MYCN-amplification, and independently associated with poor outcomes, providing a rationale for chromosomal loss patterns in neuroblastoma. We propose that let-7 disruption by LIN28B, MYCN sponging, or genetic loss is a unifying mechanism of neuroblastoma pathogenesis with broad implications for cancer pathogenesis. PMID:27383785

  18. Glycolytic inhibitor 2-deoxyglucose simultaneously targets cancer and endothelial cells to suppress neuroblastoma growth in mice.

    PubMed

    Huang, Chao-Cheng; Wang, Shuo-Yu; Lin, Li-Ling; Wang, Pei-Wen; Chen, Ting-Ya; Hsu, Wen-Ming; Lin, Tsu-Kung; Liou, Chia-Wei; Chuang, Jiin-Haur

    2015-10-01

    Neuroblastoma is characterized by a wide range of clinical manifestations and associated with poor prognosis when there is amplification of MYCN oncogene or high expression of Myc oncoproteins. In a previous in vitro study, we found that the glycolytic inhibitor 2-deoxyglucose (2DG) could suppress the growth of neuroblastoma cells, particularly in those with MYCN amplification. In this study, we established a mouse model of neuroblastoma xenografts with SK-N-DZ and SK-N-AS cells treated with 2DG by intraperitoneal injection twice a week for 3 weeks at 100 or 500 mg/kg body weight. We found that 2DG was effective in suppressing the growth of both MYCN-amplified SK-N-DZ and MYCN-non-amplified SK-N-AS neuroblastoma xenografts, which was associated with downregulation of HIF-1α, PDK1 and c-Myc, and a reduction in the number of tumor blood vessels. In vitro study showed that 2DG can suppress proliferation, cause apoptosis and reduce migration of murine endothelial cells, with inhibition of the formation of lamellipodia and filopodia and disorganization of F-actin filaments. The results suggest that 2DG might simultaneously target cancer cells and endothelial cells in the neuroblastoma xenografts in mice regardless of the status of MYCN amplification, providing a potential therapeutic opportunity to use 2DG or other glycolytic inhibitors for the treatment of patients with refractory neuroblastoma.

  19. RD3 loss dictates high-risk aggressive neuroblastoma and poor clinical outcomes.

    PubMed

    Khan, Faizan H; Pandian, Vijayabaskar; Ramraj, Satish Kumar; Aravindan, Sheeja; Natarajan, Mohan; Azadi, Seifollah; Herman, Terence S; Aravindan, Natarajan

    2015-11-03

    Clinical outcomes for high-risk neuroblastoma patients remains poor, with only 40-50% 5-Year overall survival (OS) and <10% long-term survival. The ongoing acquisition of genetic/molecular rearrangements in undifferentiated neural crest cells may endorse neuroblastoma progression. This study recognized the loss of Retinal Degeneration protein 3, RD3 in aggressive neuroblastoma, and identified its influence in better clinical outcomes and defined its novel metastasis suppressor function. The results showed ubiquitous expression of RD3 in healthy tissues, complete-loss and significant TNM-stage association of RD3 in clinical samples. RD3-loss was intrinsically associated with reduced OS, abridged relapse-free survival, aggressive stage etc., in neuroblastoma patient cohorts. RD3 was transcriptionally and translationally regulated in metastatic site-derived aggressive (MSDAC) cells (regardless of CSC status) ex vivo and in tumor manifolds from metastatic sites in reproducible aggressive disease models in vivo. Re-expressing RD3 in MSDACs reverted their metastatic potential both in vitro and in vivo. Conversely muting RD3 in neuroblastoma cells not only heightened invasion/migration but also dictated aggressive disease with metastasis. These results demonstrate the loss of RD3 in high-risk neuroblastoma, its novel, thus-far unrecognized metastasis suppressor function and further imply that RD3-loss may directly relate to tumor aggressiveness and poor clinical outcomes.

  20. Targeting the mTOR Complex by Everolimus in NRAS Mutant Neuroblastoma.

    PubMed

    Kiessling, Michael K; Curioni-Fontecedro, Alessandra; Samaras, Panagiotis; Lang, Silvia; Scharl, Michael; Aguzzi, Adriano; Oldrige, Derek A; Maris, John M; Rogler, Gerhard

    2016-01-01

    High-risk neuroblastoma remains lethal in about 50% of patients despite multimodal treatment. Recent attempts to identify molecular targets for specific therapies have shown that Neuroblastoma RAS (NRAS) is significantly mutated in a small number of patients. However, few inhibitors for the potential treatment for NRAS mutant neuroblastoma have been investigated so far. In this in-vitro study, we show that MEK inhibitors AZD6244, MEK162 and PD0325901 block cell growth in NRAS mutant neuroblastoma cell lines but not in NRAS wild-type cell lines. Several studies show that mutant NRAS leads to PI3K pathway activation and combined inhibitors of PI3K/mTOR effectively block cell growth. However, we observed the combination of MEK inhibitors with PI3K or AKT inhibitors did not show synergestic effects on cell growth. Thus, we tested single mTOR inhibitors Everolimus and AZD8055. Interestingly, Everolimus and AZD8055 alone were sufficient to block cell growth in NRAS mutant cell lines but not in wild-type cell lines. We found that Everolimus alone induced apoptosis in NRAS mutant neuroblastoma. Furthermore, the combination of mTOR and MEK inhibitors resulted in synergistic growth inhibition. Taken together, our results show that NRAS mutant neuroblastoma can be targeted by clinically available Everolimus alone or in combination with MEK inhibitors which could impact future clinical studies.

  1. Computer-aided prognosis of neuroblastoma: classification of stromal development on whole-slide images

    NASA Astrophysics Data System (ADS)

    Sertel, Olcay; Kong, Jun; Shimada, Hiroyuki; Catalyurek, Umit; Saltz, Joel H.; Gurcan, Metin

    2008-03-01

    Neuroblastoma is a cancer of the nervous system and one of the most common tumors in children. In clinical practice, pathologists examine the haematoxylin and eosin (H&E) stained tissue slides under the microscope for the diagnosis. According to the International Neuroblastoma Classification System, neuroblastoma tumors are categorized into favorable and unfavorable histologies. The subsequent treatment planning is based on this classification. However, this qualitative evaluation is time consuming, prone to error and subject to inter- and intra-reader variations and sampling bias. To overcome these shortcomings, we are developing a computerized system for the quantitative analysis of neuroblastoma slides. In this study, we present a novel image analysis system to determine the degree of stromal development from digitized whole-slide neuroblastoma samples. The developed method uses a multi-resolution approach that works similar to how pathologists examine slides. Due to their very large resolutions, the whole-slide images are divided into non-overlapping image tiles and the proposed image analysis steps are applied to each image tile using a parallel computation infrastructure developed earlier by our group. The computerized system classifies image tiles as stroma-poor or stroma-rich subtypes using texture characteristics. The developed method has been independently tested on 20 whole-slide neuroblastoma slides and it has achieved 95% classification accuracy.

  2. MYCN-targeting miRNAs are predominantly downregulated during MYCN‑driven neuroblastoma tumor formation.

    PubMed

    Beckers, Anneleen; Van Peer, Gert; Carter, Daniel R; Mets, Evelien; Althoff, Kristina; Cheung, Belamy B; Schulte, Johannes H; Mestdagh, Pieter; Vandesompele, Jo; Marshall, Glenn M; De Preter, Katleen; Speleman, Frank

    2015-03-10

    MYCN is a transcription factor that plays key roles in both normal development and cancer. In neuroblastoma, MYCN acts as a major oncogenic driver through pleiotropic effects regulated by multiple protein encoding genes as well as microRNAs (miRNAs). MYCN activity is tightly controlled at the level of transcription and protein stability through various mechanisms. Like most genes, MYCN is further controlled by miRNAs, but the full complement of all miRNAs implicated in this process has not been determined through an unbiased approach. To elucidate the role of miRNAs in regulation of MYCN, we thus explored the MYCN-miRNA interactome to establish miRNAs controlling MYCN expression levels. We combined results from an unbiased and genome-wide high-throughput miRNA target reporter screen with miRNA and mRNA expression data from patients and a murine neuroblastoma progression model. We identified 29 miRNAs targeting MYCN, of which 12 miRNAs are inversely correlated with MYCN expression or activity in neuroblastoma tumor tissue. The majority of MYCN-targeting miRNAs in neuroblastoma showed a decrease in expression during murine MYCN-driven neuroblastoma tumor development. Therefore, we provide evidence that MYCN-targeting miRNAs are preferentially downregulated in MYCN-driven neuroblastoma, suggesting that MYCN negatively controls the expression of these miRNAs, to safeguard its expression.

  3. Dextran-Catechin: An anticancer chemically-modified natural compound targeting copper that attenuates neuroblastoma growth

    PubMed Central

    Vittorio, Orazio; Brandl, Miriam; Cirillo, Giuseppe; Kimpton, Kathleen; Hinde, Elizabeth; Gaus, Katharina; Yee, Eugene; Kumar, Naresh; Duong, Hien; Fleming, Claudia; Haber, Michelle; Norris, Murray; Boyer, Cyrille; Kavallaris, Maria

    2016-01-01

    Neuroblastoma is frequently diagnosed at advanced stage disease and treatment includes high dose chemotherapy and surgery. Despite the use of aggressive therapy survival rates are poor and children that survive their disease experience long term side effects from their treatment, highlighting the need for effective and less toxic therapies. Catechin is a natural polyphenol with anti-cancer properties and limited side effects, however its mechanism of action is unknown. Here we report that Dextran-Catechin, a conjugated form of catechin that increases serum stability, is preferentially and markedly active against neuroblastoma cells having high levels of intracellular copper, without affecting non-malignant cells. Copper transporter 1 (CTR1) is the main transporter of copper in mammalian cells and it is upregulated in neuroblastoma. Functional studies showed that depletion of CTR1 expression reduced intracellular copper levels and led to a decrease in neuroblastoma cell sensitivity to Dextran-Catechin, implicating copper in the activity of this compound. Mechanistically, Dextran-Catechin was found to react with copper, inducing oxidative stress and decreasing glutathione levels, an intracellular antioxidant and regulator of copper homeostasis. In vivo, Dextran-Catechin significantly attenuated tumour growth in human xenograft and syngeneic models of neuroblastoma. Thus, Dextran-Catechin targets copper, inhibits tumour growth, and may be valuable in the treatment of aggressive neuroblastoma and other cancers dependent on copper for their growth. PMID:27374085

  4. The GSK461364 PLK1 inhibitor exhibits strong antitumoral activity in preclinical neuroblastoma models.

    PubMed

    Pajtler, Kristian W; Sadowski, Natalie; Ackermann, Sandra; Althoff, Kristina; Schönbeck, Kerstin; Batzke, Katharina; Schäfers, Simon; Odersky, Andrea; Heukamp, Lukas; Astrahantseff, Kathy; Künkele, Annette; Deubzer, Hedwig E; Schramm, Alexander; Sprüssel, Annika; Thor, Theresa; Lindner, Sven; Eggert, Angelika; Fischer, Matthias; Schulte, Johannes H

    2017-01-24

    Polo-like kinase 1 (PLK1) is a serine/threonine kinase that promotes G2/M-phase transition, is expressed in elevated levels in high-risk neuroblastomas and correlates with unfavorable patient outcome. Recently, we and others have presented PLK1 as a potential drug target for neuroblastoma, and reported that the BI2536 PLK1 inhibitor showed antitumoral actvity in preclinical neuroblastoma models. Here we analyzed the effects of GSK461364, a competitive inhibitor for ATP binding to PLK1, on typical tumorigenic properties of preclinical in vitro and in vivo neuroblastoma models. GSK461364 treatment of neuroblastoma cell lines reduced cell viability and proliferative capacity, caused cell cycle arrest and massively induced apoptosis. These phenotypic consequences were induced by treatment in the low-dose nanomolar range, and were independent of MYCN copy number status. GSK461364 treatment strongly delayed established xenograft tumor growth in nude mice, and significantly increased survival time in the treatment group. These preclinical findings indicate PLK1 inhibitors may be effective for patients with high-risk or relapsed neuroblastomas with upregulated PLK1 and might be considered for entry into early phase clinical trials in pediatric patients.

  5. T cells targeting NY-ESO-1 demonstrate efficacy against disseminated neuroblastoma.

    PubMed

    Singh, Nathan; Kulikovskaya, Irina; Barrett, David M; Binder-Scholl, Gwendolyn; Jakobsen, Bent; Martinez, Daniel; Pawel, Bruce; June, Carl H; Kalos, Michael D; Grupp, Stephan A

    The cancer-testis antigen NY-ESO-1 is expressed by many solid tumors and has limited expression by mature somatic tissues, making it a highly attractive target for tumor immunotherapy. Targeting NY-ESO-1 using engineered T cells has demonstrated clinical efficacy in the treatment of some adult tumors. Neuroblastoma is a significant cause of cancer mortality in children, and is a tumor type shown to be responsive to immunotherapies. We evaluated a large panel of primarily resected neuroblastoma samples and demonstrated that 23% express NY-ESO-1. After confirming antigen-specific activity of T cells genetically engineered to express an NY-ESO-1 directed high-affinity transgenic T cell receptor in vitro, we performed xenograft mouse studies assessing the efficacy of NY-ESO-1-targeted T cells in both localized and disseminated models of neuroblastoma. Disease responses were monitored by tumor volume measurement and in vivo bioluminescence. After delivery of NY-ESO-1 transgenic TCR T cells, we observed significant delay of tumor progression in mice bearing localized and disseminated neuroblastoma, as well as enhanced animal survival. These data demonstrate that NY-ESO-1 is an antigen target in neuroblastoma and that targeted T cells represent a potential therapeutic option for patients with neuroblastoma.

  6. Iodine-131 Metaiodobenzylguanidine Therapy for Neuroblastoma: Reports So Far and Future Perspective

    PubMed Central

    Kayano, Daiki

    2015-01-01

    Neuroblastoma, which derives from neural crest, is the most common extracranial solid cancer in childhood. The tumors express the norepinephrine (NE) transporters on their cell membrane and take in metaiodobenzylguanidine (MIBG) via a NE transporter. Since iodine-131 (I-131) MIBG therapy was firstly reported, many trails of MIBG therapy in patients with neuroblastoma were performed. Though monotherapy with a low dose of I-131 MIBG could achieve high-probability pain reduction, the objective response was poor. In contrast, more than 12 mCi/kg I-131 MIBG administrations with or without hematopoietic cell transplantation (HCT) obtain relatively good responses in patients with refractory or relapsed neuroblastoma. The combination therapy with I-131 MIBG and other modalities such as nonmyeloablative chemotherapy and myeloablative chemotherapy with HCT improved the therapeutic response in patients with refractory or relapsed neuroblastoma. In addition, I-131 MIBG therapy incorporated in the induction therapy was proved to be feasible in patients with newly diagnosed neuroblastoma. To expand more the use of MIBG therapy for neuroblastoma, further studies will be needed especially in the use at an earlier stage from diagnosis, in the use with other radionuclide formations of MIBG, and in combined use with other therapeutic agents. PMID:25874239

  7. Gene therapy as a potential tool for treating neuroblastoma-a focused review.

    PubMed

    Kumar, M D; Dravid, A; Kumar, A; Sen, D

    2016-05-01

    Neuroblastoma, a solid tumor caused by rapid division of undifferentiated neuroblasts, is the most common childhood malignancy affecting children aged <5 years. Several approaches and strategies developed and tested to cure neuroblastoma have met with limited success due to different reasons. Many oncogenes are deregulated during the onset and development of neuroblastoma and thus offer an opportunity to circumvent this disease if the expression of these genes is restored to normalcy. Gene therapy is a powerful tool with the potential to inhibit the deleterious effects of oncogenes by inserting corrected/normal genes into the genome. Both viral and non-viral vector-based gene therapies have been developed and adopted to deliver the target genes into neuroblastoma cells. These attempts have given hope to bringing in a new regime of treatment against neuroblastoma. A few gene-therapy-based treatment strategies have been tested in limited clinical trials yielding some positive results. This mini review is an attempt to provide an overview of the available options of gene therapy to treat neuroblastoma.

  8. Primitive neuroectodermal tumor in an ovarian cystic teratoma: natural killer and neuroblastoma cell analysis.

    PubMed

    Tabellini, Giovanna; Benassi, Marzia; Marcenaro, Emanuela; Coltrini, Daniela; Patrizi, Ornella; Ricotta, Doris; Rampinelli, Fabio; Moretta, Alessandro; Parolini, Silvia

    2014-01-01

    In the present study, we report an extremely rare case of a 31-year-old woman with neuroblastoma arising in an ovarian cystic teratoma. We analyzed the expression of activating receptors on natural killer (NK) cells derived from the patient's peripheral blood and peritoneal fluid. In addition, we investigated the presence of specific ligands recognized by different NK cell receptors on tumor cells. We show that NK cells isolated from peritoneal fluid expressed certain triggering receptors including DNAM-1 (CD226) and CD16 with lower intensity as compared to peripheral blood NK cells. Remarkably, at variance with most cases of childhood neuroblastoma, the tumor cells from this patient expressed substantial amounts of HLA class-I molecules. These molecules are known to be protective against NK cell-mediated lysis. In addition, neuroblastoma cells expressed B7-H3 (CD276), another surface molecule that inhibits NK cell function. Finally, this tumor did not express the PVR (CD155) and nectin-2 (CD112) ligands for the DNAM-1 activating NK receptor, which plays a crucial role in NK/neuroblastoma interactions. Altogether, these findings indicate that the neuroblastoma cells of this patient express an NK-resistant surface phenotype, which is at least in part similar to that previously described in a fraction of childhood neuroblastoma.

  9. The GSK461364 PLK1 inhibitor exhibits strong antitumoral activity in preclinical neuroblastoma models

    PubMed Central

    Pajtler, Kristian W; Sadowski, Natalie; Ackermann, Sandra; Althoff, Kristina; Schönbeck, Kerstin; Batzke, Katharina; Sch, Simonäfers; Odersky, Andrea; Heukamp, Lukas; Astrahantseff, Kathy; Künkele, Annette; Deubzer, Hedwig E; Schramm, Alexander; Spr, Annikaüssel; Thor, Theresa; Lindner, Sven; Eggert, Angelika; Fischer, Matthias; Schulte, Johannes H

    2017-01-01

    Polo-like kinase 1 (PLK1) is a serine/threonine kinase that promotes G2/M-phase transition, is expressed in elevated levels in high-risk neuroblastomas and correlates with unfavorable patient outcome. Recently, we and others have presented PLK1 as a potential drug target for neuroblastoma, and reported that the BI2536 PLK1 inhibitor showed antitumoral actvity in preclinical neuroblastoma models. Here we analyzed the effects of GSK461364, a competitive inhibitor for ATP binding to PLK1, on typical tumorigenic properties of preclinical in vitro and in vivo neuroblastoma models. GSK461364 treatment of neuroblastoma cell lines reduced cell viability and proliferative capacity, caused cell cycle arrest and massively induced apoptosis. These phenotypic consequences were induced by treatment in the low-dose nanomolar range, and were independent of MYCN copy number status. GSK461364 treatment strongly delayed established xenograft tumor growth in nude mice, and significantly increased survival time in the treatment group. These preclinical findings indicate PLK1 inhibitors may be effective for patients with high-risk or relapsed neuroblastomas with upregulated PLK1 and might be considered for entry into early phase clinical trials in pediatric patients. PMID:28036269

  10. Main caregivers' experiences of managing pain for children with neuroblastoma in Taiwan.

    PubMed

    Lu, Ching-Hui; Huang, Chu-Yu; Park, Jeong-Hwan; Lin, Hung-Ru; Lee, Ya-Ling; Cheng, Su-Fen

    2011-01-01

    Neuroblastoma is a common malignant tumor among children. Seventy percent of children with neuroblastoma have metastatic disease when the diagnosis is established. The aim of this study was to understand the main caregivers' lived experiences in managing pain for children with neuroblastoma. A descriptive qualitative design was used. Twelve main caregivers of children with neuroblastoma were interviewed. Two themes evolved: experiences of pain and coping with pain. Three subthemes were found under the theme "experience of pain": pain assessment based on language expressions and behavioral observations, tendency of misdiagnosing tumor metastasis-related pain, and unique manifestations of pain at various phases. Four subthemes evolved under the theme "coping with pain": utilization of pharmacological and nonpharmacological modalities for pain management, learning to confront pain, seeking mental and emotional support, and adjustment of family lifestyle. The results provide a description regarding the expression of pain in children with neuroblastoma and the pain management modalities used by the main caregivers. The findings serve as a reference for health care providers in Taiwan as they manage pain for children with neuroblastoma and seek to understand the needs of the main caregivers.

  11. Novel risk stratification of patients with neuroblastoma by genomic signature, which is independent of molecular signature.

    PubMed

    Tomioka, N; Oba, S; Ohira, M; Misra, A; Fridlyand, J; Ishii, S; Nakamura, Y; Isogai, E; Hirata, T; Yoshida, Y; Todo, S; Kaneko, Y; Albertson, D G; Pinkel, D; Feuerstein, B G; Nakagawara, A

    2008-01-17

    Human neuroblastoma remains enigmatic because it often shows spontaneous regression and aggressive growth. The prognosis of advanced stage of sporadic neuroblastomas is still poor. Here, we investigated whether genomic and molecular signatures could categorize new therapeutic risk groups in primary neuroblastomas. We conducted microarray-based comparative genomic hybridization (array-CGH) with a DNA chip carrying 2464 BAC clones to examine genomic aberrations of 236 neuroblastomas and used in-house cDNA microarrays for gene-expression profiling. Array-CGH demonstrated three major genomic groups of chromosomal aberrations: silent (GGS), partial gains and/or losses (GGP) and whole gains and/or losses (GGW), which well corresponded with the patterns of chromosome 17 abnormalities. They were further classified into subgroups with different outcomes. In 112 sporadic neuroblastomas, MYCN amplification was frequent in GGS (22%) and GGP (53%) and caused serious outcomes in patients. Sporadic tumors with a single copy of MYCN showed the 5-year cumulative survival rates of 89% in GGS, 53% in GGP and 85% in GGW. Molecular signatures also segregated patients into the favorable and unfavorable prognosis groups (P=0.001). Both univariate and multivariate analyses revealed that genomic and molecular signatures were mutually independent, powerful prognostic indicators. Thus, combined genomic and molecular signatures may categorize novel risk groups and confer new clues for allowing tailored or even individualized medicine to patients with neuroblastoma.

  12. Paternal occupational exposure to electromagnetic fields and neuroblastoma in offspring

    SciTech Connect

    Wilkins, J.R. 3d.; Hundley, V.D. )

    1990-06-01

    Investigators in Texas have reported an association between paternal employment in jobs linked with exposure to electromagnetic fields and risk of neuroblastoma in offspring. In an attempt to replicate this finding, the authors conducted a case-control study in Ohio. A total of 101 incident cases of neuroblastoma were identified through the Columbus (Ohio) Children's Hospital Tumor Registry. All cases were born sometime during the period 1942-1967. From a statewide roster of birth certificates, four controls were selected for each case, with individual matching on the case's year of birth, race, and sex, and the mother's county of residence at the time of the (index) child's birth. Multiple definitions were employed to infer the potential for paternal occupational exposure to electromagnetic fields from the industry/occupation statements on the birth certificates. Case-control comparisons revealed adjusted odds ratios ranging in magnitude from 0.5 to 1.9. For two of the exposure definitions employed--both of which are similar to one used by the Texas investigators--the corresponding odds ratios were modestly elevated (odds ratios = 1.6 and 1.9). Notably, the magnitude of these odds ratios is not inconsistent with the Texas findings, where the exposure definition referred to yielded an odds ratio of 2.1. Because the point estimates in this study are imprecise, and because the biologic plausibility of the association is uncertain, the results reported here must be interpreted cautiously. However, the apparent consistency between two independent studies suggests that future evaluation of the association is warranted.

  13. Effects of dopamine on LC3-II activation as a marker of autophagy in a neuroblastoma cell model.

    PubMed

    Giménez-Xavier, Pol; Francisco, Roser; Santidrián, Antonio F; Gil, Joan; Ambrosio, Santiago

    2009-07-01

    Dopamine at 100-500 microM has toxic effects on human SH-SY5Y neuroblastoma cells, manifested as apoptotic cell loss and strong autophagy. The molecular mechanisms and types of dopamine-induced cell death are not yet well known. Their identification is important in the study of neurodegenerative diseases that specifically involve dopaminergic neurons. We looked for changes in expression and content of proteins involved in apoptosis and autophagy after dopamine treatment. All the changes found were prevented by avoiding dopamine oxidation with N-acetylcysteine, indicating a key role for the products of dopamine oxidation in dopamine toxicity. As early as 1-2h after treatment we found an increase in hypoxia-inducible factor-1alpha (HIF-1alpha) and an accumulation of ubiquitinated proteins. Proteins regulated by HIF-1alpha and involved in apoptosis and/or autophagy, such as p53, Puma and Bnip3, were subsequently increased. However, apoptotic parameters (caspase-3, caspase-7, PARP) were only activated after 12h of 500muM dopamine treatment. Autophagy, monitored by the LC3-II increase after LC3-I linkage to autophagic vacuoles, was evident after 6h of treatment with both 100 and 500 microM dopamine. The mTOR pathway was inhibited by dopamine, probably due to the intracellular redox changes and energy depletion leading to AMPK activation. However, this mechanism is not sufficient to explain the high LC3-II activation caused by dopamine: the LC3-II increase was not reversed by IGF-1, which prevented this effect when caused by the mTOR inhibitor rapamycin. Our results suggest that the aggregation of ubiquitinated non-degraded proteins may be the main cause of LC3-II activation and autophagy. As we have reported previously, cytosolic dopamine may cause damage by autophagy in neuroblastoma cells (and presumably in dopaminergic neurons), which develops to apoptosis and leads to cell degeneration.

  14. Selection of optimal therapy for neuroblastoma: a study of the immunomodulatory effects of surgery and irradiation in the murine C1300 neuroblastoma model

    SciTech Connect

    Topalian, S.L.; Ziegler, M.M.

    1987-02-01

    Human neuroblastoma is an immunogenic tumor for which therapy directed in an immunologic context may offer some advantage over conventional treatment. This study examines the immunomodulatory effects of surgery and irradiation in the murine C1300 neuroblastoma model. In vivo studies of primary tumor growth characteristics after treatment demonstrated no superiority of either therapeutic modality in control of local tumor or prolongation of host survival. However, irradiated hosts showed an increased ability to reject a secondary tumor challenge, compared to their surgical counterparts. That this phenomenon may be immune-related is suggested by in vitro studies of T lymphocyte function utilizing mixed lymphocyte-tumor cell cultures and PHA lymphoblastogenesis.

  15. Reactive Processing with Difunctional Oligomers to Increase Interfacial Adhesion in Polymer Blends

    NASA Astrophysics Data System (ADS)

    O'Brien, Charles; Rice+, Kevin; Dadmun, Mark

    2000-03-01

    The intoduction of blocky copolymers represents a possible method of compatibilizing two immiscible polymers in a blend. However, copolymers do not diffuse quickly to the interface of a polymer blend system. Therefore, reactive processing is being investigated as a means to form in-situ compatibilizers for polymer blends. A model system composed of poly(bisphenol A-co-epichlorohydrin) blended with poly(ethylene oxide) that is compatibilized with difunctional oligomers that are the same structure as the blend components is currently under investigation. It is expected that the oligomers can undergo an addition copolymerization during processing to create the blocky copolymers at the biphasic interface. Initial tensile measurements show that the addition of the reactive oligomers improves the properties of the blend. Additionally, preliminary results indicate that reactive oligomers may act as plasticizers and continue to polymerize at room temperature after the blend is removed from the melt mixer if insufficiently mixed.

  16. Enhanced Emission of Highly Labeled DNA Oligomers near Silver Metallic Surfaces

    PubMed Central

    Malicka, Joanna; Gryczynski, Ignacy; Lakowicz, Joseph R.

    2009-01-01

    Fluorescein is a widely used fluorescent probe in DNA analysis. One difficulty with fluorescein is its self-quenching due to resonance energy transfer between the residues, which results in decreased intensities with increasing labeling density. We examined the emission spectral properties of DNA oligomers labeled with one or five fluorescein residues. The emission intensity of the more highly labeled oligomer was decreased due to self-quenching. The self-quenching was mostly eliminated when this oligomer was held ~90 Å from the surface of metallic silver particles. The intensities increased 7- and 19-fold for the oligomers with one or five fluoresceins, respectively. The increased intensity did not result in increased photobleaching. These results suggest the use of substrates coated with silver particles for increased sensitivity on DNA arrays or for DNA analysis. PMID:14632044

  17. Microwave assisted synthesis of bithiophene based donor-acceptor-donor oligomers and their optoelectronic performances

    NASA Astrophysics Data System (ADS)

    Bathula, Chinna; Buruga, Kezia; Lee, Sang Kyu; Khazi, Imtiyaz Ahmed M.; Kang, Youngjong

    2017-07-01

    In this article we present the synthesis of two novel bithiophene based symmetrical π conjugated oligomers with donor-acceptor-donor (D-A-D) structures by microwave assisted PdCl2(dppf) catalyzed Suzuki coupling reaction. These molecules contain electron rich bithiophene as a donor, dithienothiadiazole[3,4-c]pyridine and phthalic anhydride units as acceptors. The shorter reaction time, excellent yields and easy product isolation are the advantages of this method. The photophysical prerequisites for electronic application such as strong and broad optical absorption, thermal stability, and compatible energy levels were determined for synthesized oligomers. Optical band gap for the oligomers is found to be 1.72-1.90 eV. The results demonstrated the novel oligomers to be promising candidates in organic optoelectronic applications.

  18. The Anti-Prion Antibody 15B3 Detects Toxic Amyloid-β Oligomers

    PubMed Central

    Stravalaci, Matteo; Tapella, Laura; Beeg, Marten; Rossi, Alessandro; Joshi, Pooja; Pizzi, Erika; Mazzanti, Michele; Balducci, Claudia; Forloni, Gianluigi; Biasini, Emiliano; Salmona, Mario; Diomede, Luisa; Chiesa, Roberto; Gobbi, Marco

    2016-01-01

    15B3 is a monoclonal IgM antibody that selectively detects pathological aggregates of the prion protein (PrP). We report the unexpected finding that 15B3 also recognizes oligomeric but not monomeric forms of amyloid-β (Aβ)42, an aggregating peptide implicated in the pathogenesis of Alzheimer’s disease (AD). The 15B3 antibody: i) inhibits the binding of synthetic Aβ42 oligomers to recombinant PrP and neuronal membranes; ii) prevents oligomer-induced membrane depolarization; iii) antagonizes the inhibitory effects of oligomers on the physiological pharyngeal contractions of the nematode Caenorhabditis elegans; and iv) counteracts the memory deficits induced by intracerebroventricular injection of Aβ42 oligomers in mice. Thus this antibody binds to pathologically relevant forms of Aβ, and offers a potential research, diagnostic, and therapeutic tool for AD. PMID:27392850

  19. Vesicle permeabilization by purified soluble oligomers of prion protein: a comparative study of the interaction of oligomers and monomers with lipid membranes.

    PubMed

    Chich, J-F; Chapuis, C; Henry, C; Vidic, J; Rezaei, H; Noinville, S

    2010-04-09

    The conversion of normal cellular prion protein (PrP) into its pathological isoform, scrapie PrP, may occur at the cell surface or, more probably, in late endosomes. The early events leading to the structural conversion of PrP appear to be related to the presence of more or less stable soluble oligomers, which might mediate neurotoxicity. In the current study, we investigate the interaction of alpha-rich PrP monomers and beta-rich size-exclusion-chromatography-purified PrP oligomers with lipid membranes. We compare their structural properties when associated with lipid bilayers and study their propensities to permeabilize the membrane at physiological pH. We also study the influence of the N-terminal flexible region (residues 24-103) by comparing full-length PrP(24-234) and N-terminally truncated PrP(104-234) oligomers. We showed that both 12-subunit oligomers cause an immediate and large increase in the permeability of the membrane, whereas equivalent amounts of monomeric forms cause no detectable leakage. Although the two monomeric PrP constructs undergo an alpha-to-beta conformational change when bound to the negatively charged membrane, only the full-length form of monomeric PrP has a weak fusogenic effect. Finally, the oligomers affect the integrity of the membrane differently from the monomers, independently of the presence of the N-terminal flexible domain. As for other forms of amyloidogenesis, a reasonable mechanism for the toxicity arising from PrP fibrillization must be associated with low-molecular-weight oligomeric intermediates, rather than with mature fibrils. Knowledge of the mechanism of action of these soluble oligomers would have a high impact on the development of novel therapeutic targets.

  20. Salt anions promote the conversion of HypF-N into amyloid-like oligomers and modulate the structure of the oligomers and the monomeric precursor state.

    PubMed

    Campioni, Silvia; Mannini, Benedetta; López-Alonso, Jorge P; Shalova, Irina N; Penco, Amanda; Mulvihill, Estefania; Laurents, Douglas V; Relini, Annalisa; Chiti, Fabrizio

    2012-12-07

    An understanding of the solution factors contributing to the rate of aggregation of a protein into amyloid oligomers, to the modulation of the conformational state populated prior to aggregation and to the structure/morphology of the resulting oligomers is one of the goals of present research in this field. We have studied the influence of six different salts on the conversion of the N-terminal domain of Escherichiacoli HypF (HypF-N) into amyloid-like oligomers under conditions of acidic pH. Our results show that salts having different anions (NaCl, NaClO(4), NaI, Na(2)SO(4)) accelerate oligomerization with an efficacy that follows the electroselectivity series of the anions (SO(4)(2-)≥ ClO(4)(-)>I(-)>Cl(-)). By contrast, salts with different cations (NaCl, LiCl, KCl) have similar effects. We also investigated the effect of salts on the structure of the final and initial states of HypF-N aggregation. The electroselectivity series does not apply to the effect of anions on the structure of the oligomers. By contrast, it applies to their effect on the content of secondary structure and on the exposure of hydrophobic clusters of the monomeric precursor state. The results therefore indicate that the binding of anions to the positively charged residues of HypF-N at low pH is the mechanism by which salts modulate the rate of oligomerization and the structure of the monomeric precursor state but not the structure of the resulting oligomers. Overall, the data contribute to rationalize the effect of salts on amyloid-like oligomer formation and to explain the role of charged biological macromolecules in protein aggregation processes.

  1. Advances in the translational genomics of neuroblastoma: From improving risk stratification and revealing novel biology to identifying actionable genomic alterations.

    PubMed

    Bosse, Kristopher R; Maris, John M

    2016-01-01

    Neuroblastoma is an embryonal malignancy that commonly affects young children and is remarkably heterogenous in its malignant potential. Recently, the genetic basis of neuroblastoma has come into focus and not only has catalyzed a more comprehensive understanding of neuroblastoma tumorigenesis but also has revealed novel oncogenic vulnerabilities that are being therapeutically leveraged. Neuroblastoma is a model pediatric solid tumor in its use of recurrent genomic alterations, such as high-level MYCN (v-myc avian myelocytomatosis viral oncogene neuroblastoma-derived homolog) amplification, for risk stratification. Given the relative paucity of recurrent, activating, somatic point mutations or gene fusions in primary neuroblastoma tumors studied at initial diagnosis, innovative treatment approaches beyond small molecules targeting mutated or dysregulated kinases will be required moving forward to achieve noticeable improvements in overall patient survival. However, the clonally acquired, oncogenic aberrations in relapsed neuroblastomas are currently being defined and may offer an opportunity to improve patient outcomes with molecularly targeted therapy directed toward aberrantly regulated pathways in relapsed disease. This review summarizes the current state of knowledge about neuroblastoma genetics and genomics, highlighting the improved prognostication and potential therapeutic opportunities that have arisen from recent advances in understanding germline predisposition, recurrent segmental chromosomal alterations, somatic point mutations and translocations, and clonal evolution in relapsed neuroblastoma.

  2. Bacterial Resistance to Antisense Peptide Phosphorodiamidate Morpholino Oligomers

    PubMed Central

    Puckett, Susan E.; Reese, Kaleb A.; Mitev, Georgi M.; Mullen, Valerie; Johnson, Rudd C.; Pomraning, Kyle R.; Mellbye, Brett L.; Tilley, Lucas D.; Iversen, Patrick L.; Freitag, Michael

    2012-01-01

    Peptide phosphorodiamidate morpholino oligomers (PPMOs) are synthetic DNA mimics that bind cRNA and inhibit bacterial gene expression. The PPMO (RFF)3RXB-AcpP (where R is arginine, F, phenylalanine, X is 6-aminohexanoic acid, B is β-alanine, and AcpP is acyl carrier protein) is complementary to 11 bases of the essential gene acpP (which encodes acyl carrier protein). The MIC of (RFF)3RXB-AcpP was 2.5 μM (14 μg/ml) in Escherichia coli W3110. The rate of spontaneous resistance of E. coli to (RFF)3RXB-AcpP was 4 × 10−7 mutations/cell division. A spontaneous (RFF)3RXB-AcpP-resistant mutant (PR200.1) was isolated. The MIC of (RFF)3RXB-AcpP was 40 μM (224 μg/ml) for PR200.1. The MICs of standard antibiotics for PR200.1 and W3110 were identical. The sequence of acpP was identical in PR200.1 and W3110. PR200.1 was also resistant to other PPMOs conjugated to (RFF)3RXB or peptides with a similar composition or pattern of cationic and nonpolar residues. Genomic sequencing of PR200.1 identified a mutation in sbmA, which encodes an active transport protein. In separate experiments, a (RFF)3RXB-AcpP-resistant isolate (RR3) was selected from a transposome library, and the insertion was mapped to sbmA. Genetic complementation of PR200.1 or RR3 with sbmA restored susceptibility to (RFF)3RXB-AcpP. Deletion of sbmA caused resistance to (RFF)3RXB-AcpP. We conclude that resistance to (RFF)3RXB-AcpP was linked to the peptide and not the phosphorodiamidate morpholino oligomer, dependent on the composition or repeating pattern of amino acids, and caused by mutations in sbmA. The data further suggest that (RFF)3R-XB PPMOs may be transported across the plasma membrane by SbmA. PMID:22985881

  3. Bacterial resistance to antisense peptide phosphorodiamidate morpholino oligomers.

    PubMed

    Puckett, Susan E; Reese, Kaleb A; Mitev, Georgi M; Mullen, Valerie; Johnson, Rudd C; Pomraning, Kyle R; Mellbye, Brett L; Tilley, Lucas D; Iversen, Patrick L; Freitag, Michael; Geller, Bruce L

    2012-12-01

    Peptide phosphorodiamidate morpholino oligomers (PPMOs) are synthetic DNA mimics that bind cRNA and inhibit bacterial gene expression. The PPMO (RFF)(3)RXB-AcpP (where R is arginine, F, phenylalanine, X is 6-aminohexanoic acid, B is β-alanine, and AcpP is acyl carrier protein) is complementary to 11 bases of the essential gene acpP (which encodes acyl carrier protein). The MIC of (RFF)(3)RXB-AcpP was 2.5 μM (14 μg/ml) in Escherichia coli W3110. The rate of spontaneous resistance of E. coli to (RFF)(3)RXB-AcpP was 4 × 10(-7) mutations/cell division. A spontaneous (RFF)(3)RXB-AcpP-resistant mutant (PR200.1) was isolated. The MIC of (RFF)(3)RXB-AcpP was 40 μM (224 μg/ml) for PR200.1. The MICs of standard antibiotics for PR200.1 and W3110 were identical. The sequence of acpP was identical in PR200.1 and W3110. PR200.1 was also resistant to other PPMOs conjugated to (RFF)(3)RXB or peptides with a similar composition or pattern of cationic and nonpolar residues. Genomic sequencing of PR200.1 identified a mutation in sbmA, which encodes an active transport protein. In separate experiments, a (RFF)(3)RXB-AcpP-resistant isolate (RR3) was selected from a transposome library, and the insertion was mapped to sbmA. Genetic complementation of PR200.1 or RR3 with sbmA restored susceptibility to (RFF)(3)RXB-AcpP. Deletion of sbmA caused resistance to (RFF)(3)RXB-AcpP. We conclude that resistance to (RFF)(3)RXB-AcpP was linked to the peptide and not the phosphorodiamidate morpholino oligomer, dependent on the composition or repeating pattern of amino acids, and caused by mutations in sbmA. The data further suggest that (RFF)(3)R-XB PPMOs may be transported across the plasma membrane by SbmA.

  4. Optically and redox-active ferroceneacetylene polymers and oligomers

    PubMed

    Plenio; Hermann; Sehring

    2000-05-15

    The palladium-catalyzed Sonogashira reaction can be used to build optically active, oligomeric 1,2,3-substituted ferrocenes up to the tetramer, as well as polymers, by sequential coupling of optically active (ee > 98 %), planar chiral iodoferroceneacetylenes and ferroceneacetylenes. (SFC)-1-Iodoferrocene-2-carbaldehyde (1) was reduced to the alcohol and methylated to give the corresponding methyl ether, which was Sonogashira-coupled with HC(triple bond)CSiEt3, resulting in (RFc)-1-(C(triple bond)CSiEt3)-2-methoxymethylferrocene (4) (79%, three steps). Orthometalation with tBuLi followed by quenching with 1,2-diodoethane gave (RFc)-1-(C(triple bond)CSiEt3)-2-methoxymethyl-3-iodoferrocene (5). Deprotection of the acetylene with nBu4NF resulted in (RFc)-1-ethynyl-2-methoxymethyl-3-iodoferrocene (6), which was Sonogashira-coupled with itself to produce an optically active polymer. Deprotection of 4 with nBu4NF and Sonogashira coupling of the product with 5 resulted in the dinuclear ferrocene 9. Deprotection of 9 and coupling with 5, followed by deprotection of the resulting acetylene 11, gave the trinuclear ferrocene 12. Another such sequence involving 11 and 5 produced a tetranuclear ferrocene 13. To study the electronic communication in such oligomers in more detail, two symmetrical, closely interrelated, trinuclear ferrocenes 18 and 19 were synthesized. The redox potentials of all the ferrocenes and the ferroceneacetylene polymer were determined by cyclic and square-wave voltammetry. All the metallocenes were investigated by UV/Vis spectroscopy. A linear relationship was found between lambdamax and l/n (n=number of ferrocene units in the oligomer). The polymer displayed two redox waves in the cyclic voltammogram, at 0.65 and 0.795 V. The corresponding mixed-valence oligoferrocene cations were synthesized from four ferroceneacetylenes, and their metal-metal charge transfer bands were examined by UV/Vis-NIR. The resonance exchange integrals Had, calculated on the

  5. Short duration, high dose, alternating chemotherapy in metastatic neuroblastoma. (ENSG 3C induction regimen). The European Neuroblastoma Study Group.

    PubMed Central

    Pinkerton, C. R.; Zucker, J. M.; Hartmann, O.; Pritchard, J.; Broadbent, V.; Morris-Jones, P.; Breatnach, F.; Craft, A. E.; Pearson, A. D.; Wallendszus, K. R.

    1990-01-01

    Fifty-one children, aged from 15 months to 13 years 5 months with metastatic neuroblastoma presenting sequentially at the participating institutions received four 3 to 4 weekly courses of high dose multiagent chemotherapy. High dose cisplatin (200 mg m-2) combined with etoposide (500 mg m-2), HIPE, was alternated with ifosfamide (9 g m-2), vincristine (1.5 mg m-2), and adriamycin (60 mg m-1), IVAd. Disease status was re-evaluated 3 to 4 weeks after the fourth course and the response classified according to the International Neuroblastoma Response Criteria (INRC). The overall response rate in evaluable patients was 55% and response rates by site were: bone marrow 67% (complete response 47%); bone scan 68%; primary tumour 61%, and urinary catecholamine metabolites (VMA/HVA) 95%. Serial 51Cr EDTA renal clearance studies showed a glomerular filtration rate (GFR) decline in 40% of patients but in only seven cases to below 50% of the pretreatment value. There was no instance of renal failure during induction, though two patients developed severe renal failure following 'megatherapy' given to consolidate remission. Serial audiometry showed a significant decline in hearing at frequencies above 2,000 Hz in 37% of children but at or below 2,000 Hz in only 17%. Neutropenia and thrombocytopenia were severe and intravenous antibiotics were required after 30% of courses. Each of two treatment-related deaths occurred during pancytopenia following courses of IVAd. Complete, or greater than 90%, removal of primary site tumour was possible in 70% of cases following this induction regimen and 75% of patients proceeded to elective megatherapy within a median time of 24 weeks after diagnosis. This short intensive induction programme is highly effective at achieving cytoreduction, enabling early surgery and early megatherapy procedures. It is, however, too early to draw firm conclusions about the impact of this approach to treatment on the cure rate. PMID:2386751

  6. Styrene-terminated polysulfone oligomers as matrix material for graphite reinforced composites: An initial study

    NASA Technical Reports Server (NTRS)

    Garcia, Dana; Bowles, Kenneth J.; Vannucci, Raymond D.

    1987-01-01

    Styrene terminated polysulfone oligomers are part of an oligomeric class of compounds with end groups capable of thermal polymerization. These materials can be used as matrices for graphite reinforced composites. The initial evaluation of styrene terminated polysulfone oligomer based composites are summarized in terms of fabrication methods, and mechanical and environmental properties. In addition, a description and evaluation is provided of the NASA/Industry Fellowship Program for Technology Transfer.

  7. Soluble Prion Protein Binds Isolated Low Molecular Weight Amyloid-β Oligomers Causing Cytotoxicity Inhibition.

    PubMed

    Williams, Thomas L; Choi, Jin-Kyu; Surewicz, Krystyna; Surewicz, Witold K

    2015-12-16

    A growing number of observations indicate that soluble amyloid-β (Aβ) oligomers play a major role in Alzheimer's disease. Recent studies strongly suggest that at least some of the neurotoxic effects of these oligomers are mediated by cellular, membrane-anchored prion protein and that Aβ neurotoxicity can be inhibited by soluble recombinant prion protein (rPrP) and its fragments. However, the mechanism by which rPrP interacts with Aβ oligomers and prevents their toxicity is largely unknown, and studies in this regard are hindered by the large structural heterogeneity of Aβ oligomers. To overcome this difficulty, here we used photoinduced cross-linking of unmodified proteins (PICUP) to isolate well-defined oligomers of Aβ42 and characterize these species with regard to their cytotoxicity and interaction with rPrP, as well the mechanism by which rPrP inhibits Aβ42 cytotoxicity. Our data shows that the addition of rPrP to the assembling Aβ42 results in a shift in oligomer size distribution, decreasing the population of toxic tetramers and higher order oligomers and increasing the population of nontoxic (and possibly neuroprotective) monomers. Isolated oligomeric species of Aβ42 are cytotoxic to primary neurons and cause permeation of model lipid bilayers. These toxic effects, which are oligomer size-dependent, can be inhibited by the addition of rPrP, and our data suggest potential mechanisms of this inhibitory action. This insight should help in current efforts to develop PrP-based therapeutics for Alzheimer's disease.

  8. Oligomer formation of the gB glycoprotein of herpes simplex virus type 1.

    PubMed Central

    Highlander, S L; Goins, W F; Person, S; Holland, T C; Levine, M; Glorioso, J C

    1991-01-01

    Oligomer formation of the gB glycoprotein of herpes simplex virus type 1 was studied by sedimentation analysis of radioactively labeled infected cell and virion lysates. Fractions from sucrose gradients were precipitated with a pool of gB-specific monoclonal antibodies and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Pulse-labeled gB from infected cell was synthesized as monomers and converted to oligomers posttranslationally. The oligomers from infected cells and from virions sedimented as dimers, and there was no evidence of higher-molecular-weight forms. To identify amino acid sequences of gB that contribute to oligomer formation, pairs of mutant plasmids were transfected into Vero cells and superinfected with a gB-null mutant virus to stimulate plasmid-specified gene expression. Radioactively labeled lysates were precipitated with antibodies and examined by SDS-PAGE. Polypeptides from cotransfections were precipitated with an antibody that recognized amino acid sequences present in only one of the two polypeptides. A coprecipitated polypeptide lacking the antibody target epitope was presumed to contain the sequences necessary for oligomer formation. Using this technique, two noncontiguous sites for oligomer formation were detected. An upstream site was localized between residues 93 and 282, and a downstream site was localized between residues 596 and 711. Oligomer formation resulted from molecular interactions between two upstream sites, between two downstream sites, and between an upstream and a downstream site. A schematic diagram of a gB oligomer is presented that is consistent with these data. Images PMID:1649330

  9. A HRMS study of oligomer formation through aqueous phase photooxidation of methylvinyl-ketone and methacrolein

    NASA Astrophysics Data System (ADS)

    Salque-moreton, G.; Liu, Y.; Voisin, D.; Siekmann, F.; Renard, P.; Monod, A.; Thissen, R.

    2012-04-01

    Global estimates of secondary organic aerosol (SOA) formation flux show that the current descriptions miss a large fraction of the sources. Aqueous phase photochemistry in cloud droplets and deliquescent aerosol may provide some of this missing flux. Organic reactions in those media, particularly leading to higher molecular weight products thus need better understanding. Here, we investigated the aqueous phase photooxidation of methacrolein (MACR) and methylvinyl-ketone (MVK), which are the two main oxidation products of isoprene, the volatile organic compound (VOC) that is mostly emitted on the global scale. In our experiments, photolysis of H2O2 provided OH radicals whose reaction with MACR or MVK produced oligomers. Firstly, oligomers were analyzed using electrospray ionization coupled with high-resolution linear ion trap Orbitrap™ (Thermo Corp.) mass spectrometer (HRMS). This technique enabled to propose the unambiguous elemental composition of the produced compounds as data were collected for a mass range of m/z 50-2000 amu. The mass of oligomers increased strongly in positive and negative ionization modes when initial concentrations of MACR and MVK were increased from 2 to 20 mM. Typical regular patterns of oligomer formation were observed for both precursors, and extended up to 1400 amu. These patterns were very different from each other for the two precursors although both showed regular mass differences of 70 amu. In addition, we used a Kendrick analysis and identified more than 20 distinct chemical oligomer series produced by photooxidation of both MACR and MVK, some of which reaching more than 1400 amu. The HRMS investigations allowed us to propose a mechanism of production of oligomers. Upon nebulization, both oligomer systems produce SOA with a mass yield of 2-12%. This mass yield increases with reaction time and precursor concentration. Moreover, time evolution of the oligomer systems observed with the Orbitrap will be compared to HR

  10. KCTD Hetero-oligomers Confer Unique Kinetic Properties on Hippocampal GABAB Receptor-Induced K+ Currents.

    PubMed

    Fritzius, Thorsten; Turecek, Rostislav; Seddik, Riad; Kobayashi, Hiroyuki; Tiao, Jim; Rem, Pascal D; Metz, Michaela; Kralikova, Michaela; Bouvier, Michel; Gassmann, Martin; Bettler, Bernhard

    2017-02-01

    GABAB receptors are the G-protein coupled receptors for the main inhibitory neurotransmitter in the brain, GABA. GABAB receptors were shown to associate with homo-oligomers of auxiliary KCTD8, KCTD12, KCTD12b, and KCTD16 subunits (named after their T1 K(+)-channel tetramerization domain) that regulate G-protein signaling of the receptor. Here we provide evidence that GABAB receptors also associate with hetero-oligomers of KCTD subunits. Coimmunoprecipitation experiments indicate that two-thirds of the KCTD16 proteins in the hippocampus of adult mice associate with KCTD12. We show that the KCTD proteins hetero-oligomerize through self-interacting T1 and H1 homology domains. Bioluminescence resonance energy transfer measurements in live cells reveal that KCTD12/KCTD16 hetero-oligomers associate with both the receptor and the G-protein. Electrophysiological experiments demonstrate that KCTD12/KCTD16 hetero-oligomers impart unique kinetic properties on G-protein-activated Kir3 currents. During prolonged receptor activation (one min) KCTD12/KCTD16 hetero-oligomers produce moderately desensitizing fast deactivating K(+) currents, whereas KCTD12 and KCTD16 homo-oligomers produce strongly desensitizing fast deactivating currents and nondesensitizing slowly deactivating currents, respectively. During short activation (2 s) KCTD12/KCTD16 hetero-oligomers produce nondesensitizing slowly deactivating currents. Electrophysiological recordings from hippocampal neurons of KCTD knock-out mice are consistent with these findings and indicate that KCTD12/KCTD16 hetero-oligomers increase the duration of slow IPSCs. In summary, our data demonstrate that simultaneous assembly of distinct KCTDs at the receptor increases the molecular and functional repertoire of native GABAB receptors and modulates physiologically induced K(+) current responses in the hippocampus.

  11. Oligomers of the amyloid-beta protein disrupt working memory: confirmation with two behavioral procedures.

    PubMed

    Poling, Alan; Morgan-Paisley, Kineta; Panos, John J; Kim, Eun-Mee; O'Hare, Eugene; Cleary, James P; Lesné, Sylvain; Ashe, Karen H; Porritt, Matthew; Baker, Lisa E

    2008-11-21

    Converging lines of evidence suggest that oligomers of amyloid-beta play a role in the cognitive impairment characteristic of Alzheimer's disease, but only three studies have provided experimental evidence of such impairment. To provide additional information about the effects of these oligomers on memory, the present study examined the memory of groups of rats exposed to ICV injections of the culture media (CM) of Chinese Hamster Ovary cells that were (7PA2) and were not (CHO-) transfected with a human mutation of amyloid precursor protein that appears to cause early-onset Alzheimer's disease. The 7PA2 CM, which contained concentrations of soluble amyloid-beta oligomers physiologically relevant to those found in human brain, significantly disrupted working memory in rats tested in a radial-arm maze. In contrast, CHO- CM, which did not contain such oligomers, had no effect on memory. The disruptive effects of 7PA2-derived amyloid-beta oligomers, evident 2h after exposure, disappeared within a day. These findings are compared to results from 7PA2 CM tested under a complex procedure thought to measure aspects of executive function. The results confirm the disruptive effects of low-n amyloid-beta oligomers and extend them to a well-established rat model of memory.

  12. Low Molecular Weight Oligomers with Aromatic Backbone as Efficient Nonviral Gene Vectors.

    PubMed

    Luan, Chao-Ran; Liu, Yan-Hong; Zhang, Ji; Yu, Qing-Ying; Huang, Zheng; Wang, Bing; Yu, Xiao-Qi

    2016-05-04

    A series of oligomers were synthesized via ring-opening polymerization. Although the molecular weights of these oligomers are only ∼2.5 kDa, they could efficiently bind and condense DNA into nanoparticles. These oligomers gave comparable transfection efficiency (TE) to PEI 25 kDa, while their TE could even increase with the presence of serum, and up to 65 times higher TE than PEI was obtained. The excellent serum tolerance was also confirmed by TEM, flow cytometry, and BSA adsorption assay. Moreover, structure-activity relationship studies revealed some interesting factors. First, oligomers containing aromatic rings in the backbone showed better DNA binding ability. These materials could bring more DNA cargo into the cells, leading to much better TE. Second, the isomerism of the disubstituted phenyl group on the oligomer backbone has large effect on the transfection. The ortho-disubstituted ones gave at least 1 order of magnitude higher TE than meta- or para-disubstituted oligomers. Gel electrophoresis involving DNase and heparin indicated that the difficulty to release DNA might contribute to the lower TE of the latter. Such clues may help us to design novel nonviral gene vectors with high efficiency and biocompatibility.

  13. Liquid crystalline thermosets from ester, ester-imide, and ester-amide oligomers

    NASA Technical Reports Server (NTRS)

    Dingemans, Theodorous J. (Inventor); Weiser, Erik S. (Inventor); St. Clair, Terry L. (Inventor)

    2005-01-01

    Main chain thermotropic liquid crystal esters, ester-imides, and ester-amides were prepared from AA, BB, and AB type monomeric materials and were end-capped with phenylacetylene, phenylmaleimide, or nadimide reactive end-groups. The resulting reactive end-capped liquid crystal oligomers exhibit a variety of improved and preferred physical properties. The end-capped liquid crystal oligomers are thermotropic and have, preferably, molecular weights in the range of approximately 1000-15,000 grams per mole. The end-capped liquid crystal oligomers have broad liquid crystalline melting ranges and exhibit high melt stability and very low melt viscosities at accessible temperatures. The end-capped liquid crystal oligomers are stable for up to an hour in the melt phase. These properties make the end-capped liquid crystal oligomers highly processable by a variety of melt process shape forming and blending techniques including film extrusion, fiber spinning, reactive injection molding (RIM), resin transfer molding (RTM), resin film injection (RFI), powder molding, pultrusion, injection molding, blow molding, plasma spraying and thermo-forming. Once processed and shaped, the end-capped liquid crystal oligomers were heated to further polymerize and form liquid crystalline thermosets (LCT). The fully cured products are rubbers above their glass transition temperatures. The resulting thermosets display many properties that are superior to their non-end-capped high molecular weight analogs.

  14. Liquid Crystalline Thermosets from Ester, Ester-Imide, and Ester-Amide Oligomers

    NASA Technical Reports Server (NTRS)

    Dingemans, Theodornus J. (Inventor); Weiser, Erik S. (Inventor); SaintClair, Terry L. (Inventor)

    2005-01-01

    Main chain thermotropic liquid crystal esters, ester-imides, and ester-amides were prepared from AA, BB, and AB type monomeric materials and were end-capped with phenylacetylene, phenylmaleimide, or nadimide reactive end-groups. The resulting reactive end-capped liquid crystal oligomers exhibit a variety of improved and preferred physical properties. The end-capped liquid crystal oligomers are thermotropic and have, preferably, molecular weights in the range of approximately 1000-15,OOO grams per mole. The end-capped liquid crystal oligomers have broad liquid crystalline melting ranges and exhibit high melt stability and very low melt viscosities at accessible temperatures. The end-capped liquid crystal oligomers are stable for up to an hour in the melt phase. These properties make the end-capped liquid crystal oligomers highly processable by a variety of melt process shape forming and blending techniques including film extrusion, fiber spinning, reactive injection molding (RIM), resin transfer molding (RTM), resin film injection (RFI), powder molding, pultrusion, injection molding, blow molding, plasma spraying and thermo-forming. Once processed and shaped, the end- capped liquid crystal oligomers were heated to further polymerize and form liquid crystalline thermosets (LCT). The fully cured products are rubbers above their glass transition temperatures. The resulting thermosets display many properties that are superior to their non-end-capped high molecular weight analogs.

  15. π-Conjugated Discrete Oligomers Containing Planar and Nonplanar Aromatic Motifs.

    PubMed

    Li, Ji; Terec, Anamaria; Wang, Yue; Joshi, Hrishikesh; Lu, Yunpeng; Sun, Handong; Stuparu, Mihaiela C

    2017-03-01

    A new family of π-conjugated oligomers featuring a nonplanar polycyclic aromatic hydrocarbon, corannulene, and a planar aromatic unit, thiophene, is synthesized through an iterative metal-catalyzed coupling protocol. The two structural motifs are connected through an acetylene linkage. In the shorter oligomers, a thiophene unit is attached to one or two corannulenes. In the higher analogues, two, three, and four thiophene units are placed in an alternating fashion with three, four, and five corannulene units, respectively. Photophysical studies reveal extended π-effects that initially increase and then attenuate as a function of the oligomer length. Notably, longer oligomers are found to be highly active for nonlinear absorption and emission properties. The oligomer with three corannulene and two thiophene units exhibits a two-photon absorption cross section of 600 GM and two-photon-excited intense green luminescence. This work, therefore, introduces the concept of combining planar and nonplanar aromatic motifs in the design of π-conjugated discrete oligomers, establishes synthetic feasibility of such hybrid materials, reports on their photophysical properties that is anticipated to have significant implications for future research targets, and features the discovery that corannulene derivatives can exhibit excellent nonlinear optical activity when extended through π-bridges.

  16. α-Synuclein Oligomers Induced by Docosahexaenoic Acid Affect Membrane Integrity

    PubMed Central

    Fecchio, Chiara; De Franceschi, Giorgia; Relini, Annalisa; Greggio, Elisa; Dalla Serra, Mauro; Bubacco, Luigi; Polverino de Laureto, Patrizia

    2013-01-01

    A key feature of Parkinson disease is the aggregation of α-synuclein and its intracellular deposition in fibrillar form. Increasing evidence suggests that the pathogenicity of α-synuclein is correlated with the activity of oligomers formed in the early stages of its aggregation process. Oligomers toxicity seems to be associated with both their ability to bind and affect the integrity of lipid membranes. Previously, we demonstrated that α-synuclein forms oligomeric species in the presence of docosahexaenoic acid and that these species are toxic to cells. Here we studied how interaction of these oligomers with membranes results in cell toxicity, using cellular membrane-mimetic and cell model systems. We found that α-synuclein oligomers are able to interact with large and small unilamellar negatively charged vesicles acquiring an increased amount of α-helical structure, which induces small molecules release. We explored the possibility that oligomers effects on membranes could be due to pore formation, to a detergent-like effect or to fibril growth on the membrane. Our biophysical and cellular findings are consistent with a model where α-synuclein oligomers are embedded into the lipid bilayer causing transient alteration of membrane permeability. PMID:24312431

  17. Effect of Zn(2+) ions on the assembly of amylin oligomers: insight into the molecular mechanisms.

    PubMed

    Wineman-Fisher, Vered; Miller, Yifat

    2016-08-03

    Amylin is an endocrine hormone and is a member of the family of amyloid peptides and proteins that emerge as potential scaffolds by self-assembly processes. Zn(2+) ions can bind to amylin peptides to form self-assembled Zn(2+)-amylin oligomers. In the current work the binding sites of Zn(2+) ions in the self-assembled amylin oligomers at various concentrations of zinc have been investigated. Our results yield two conclusions. First, in the absence of Zn(2+) ions polymorphic states (i.e. various classes of amylin oligomers) are obtained, but when Zn(2+) ions bind to amylin peptides to form Zn(2+)-amylin oligomers, the polymorphism is decreased, i.e. Zn(2+) ions bind only to specific classes of amylin. At low concentrations of Zn(2+) ions the polymorphism is smaller than at high concentrations. Second, the structural features of the self-assembled amylin oligomers are not affected by the presence of Zn(2+) ions. This study proposes new molecular mechanisms of the self-assembly of Zn(2+)-amylin oligomers.

  18. Cyclen-based lipidic oligomers as potential gene delivery vehicles.

    PubMed

    Yi, Wen-Jing; Zhang, Qin-Fang; Zhang, Ji; Liu, Qiang; Ren, Laifeng; Chen, Qian-Ming; Guo, Liandi; Yu, Xiao-Qi

    2014-03-01

    A series of cyclen-based linear oligomers bearing hydrophobic long chains (lipopolymers Cy-LC, where Cy and LC represent cyclen-based linear backbone and hydrophobic long chain substituents, respectively) were designed and synthesized. The effects of type and degree of substitution (DS) of hydrophobic long chains on the transfection efficiency were systematically studied. The nitrogen atoms with relatively strong basicity on the cyclen ensure their good DNA binding ability, which was confirmed by gel retardation and ethidium bromide exclusion assays. Lipopolyplexes could be formed as nanoparticles with suitable sizes and zeta potentials for gene transfection. In vitro gene delivery experiments revealed that the linoleic acid (LIN) substituted material Cy-LIN has better transfection efficiency than 25 kDa polyethylenimine in the absence or in the presence of serum. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and hemolysis assays showed low cytotoxicity and good biocompatibility of the lipopolyplexes. Fluorescent labeled DNA was used to study the cellular uptake and intracellular distribution of transfected DNA. Flow cytometry results suggested that a long chain is necessary for efficient cellular uptake, and images from confocal laser scanning microscopy showed that after 4h transfection, most of the fluorescent labeled DNA accumulated in the perinuclear region, which was required for efficient gene expression. Moreover, it was also found that the DS of the hydrophobic moiety can adjust the balance between DNA binding ability and dissociation of polyplexes, significantly affecting the transfection efficiency.

  19. Synthesis and Characterization of Poly (Arylene Ether Benzimidazole) Oligomers

    NASA Technical Reports Server (NTRS)

    Leonard, Michael J.

    1995-01-01

    Several poly(arylene ether benzimidazole) oligomers were prepared by the nucleophilic aromatic substitution reaction of a bisphenol benzimidazole and various alkyl-substituted aromatic bisphenols with an activated aromatic dihalide in N, N-dimethylacetarnide. Moderate to high molecular weight terpolymers were obtained in all cases, as shown by their inherent viscosities, which ranged from 0.50 to 0.87 dL g(sup -1). Glass transition temperatures (T(sub g)s) of polymer powders ranged from 267-280 C. Air-dried unoriented thin film T(sub g)s were markedly lower than those of the powders, whereas T(sub g)s of films dried in a nitrogen atmosphere were identical to those of the corresponding powders. In addition, air-dried films were dark amber and brittle, whereas nitrogen-dried films were yellow and creasable. Nitrogen-dried films showed slightly higher thin-film tensile properties than the air-dried films, as well.

  20. Amyloid beta oligomers induce impairment of neuronal insulin receptors.

    PubMed

    Zhao, Wei-Qin; De Felice, Fernanda G; Fernandez, Sara; Chen, Hui; Lambert, Mary P; Quon, Michael J; Krafft, Grant A; Klein, William L

    2008-01-01

    Recent studies have indicated an association between Alzheimer's disease (AD) and central nervous system (CNS) insulin resistance. However, the cellular mechanisms underlying the link between these two pathologies have not been elucidated. Here we show that signal transduction by neuronal insulin receptors (IR) is strikingly sensitive to disruption by soluble Abeta oligomers (also known as ADDLs). ADDLs are known to accumulate in AD brain and have recently been implicated as primary candidates for initiating deterioration of synapse function, composition, and structure. Using mature cultures of hippocampal neurons, a preferred model for studies of synaptic cell biology, we found that ADDLs caused a rapid and substantial loss of neuronal surface IRs specifically on dendrites bound by ADDLs. Removal of dendritic IRs was associated with increased receptor immunoreactivity in the cell body, indicating redistribution of the receptors. The neuronal response to insulin, measured by evoked IR tyrosine autophosphorylation, was greatly inhibited by ADDLs. Inhibition also was seen with added glutamate or potassium-induced depolarization. The effects on IR function were completely blocked by NMDA receptor antagonists, tetrodotoxin, and calcium chelator BAPTA-AM. Downstream from the IR, ADDLs induced a phosphorylation of Akt at serine473, a modification associated with neurodegenerative and insulin resistance diseases. These results identify novel factors that affect neuronal IR signaling and suggest that insulin resistance in AD brain is a response to ADDLs, which disrupt insulin signaling and may cause a brain-specific form of diabetes as part of an overall pathogenic impact on CNS synapses.

  1. Structure and stability of oligomer/α-cyclodextrin inclusion complexes.

    NASA Astrophysics Data System (ADS)

    Hunt, Marcus; Villar, Silvia; Gomez, Marian; Tonelli, Alan; Balik, Maury

    2007-03-01

    Cyclomaltohexaose (α-cyclodextrin, α-CD) can form inclusion complexes (ICs) with polymer molecules in the columnar crystal in which α-CD molecules stack to form a molecular tube. Complementary water vapor sorption and wide-angle X-ray diffractomery (WAXD) were performed on oligomer/α-CD ICs to probe their structures and stabilities. To discern the effect of guest molecule hydrophobicity on water adsorption isotherms, polyethylene glycol (PEG, MW = 600 g/mol) and hexatriacontane (HTC) guests were used. Sorption isotherms for PEG/α-CD IC are similar to those obtained for pure α-CD and PEG, suggesting the presence of dethreaded PEG in the sample. WAXD collected before and after water vapor sorption of PEG/α-CD IC indicated a partial conversion from columnar to cage crystal structure, the thermodynamically preferred structure for pure α-CD, due to dethreading of PEG. This behavior does not occur for HTC/α-CD IC. Sorption isotherms collected at 20, 30, 40 and 50 C allowed the calculation of differential heats of adsorption and integral entropies of adsorbed water, while solid-state ^13C NMR suggested a dramatic increase in HTC and α-CD mobilities upon complexation.

  2. Unique copper-induced oligomers mediate alpha-synuclein toxicity.

    PubMed

    Wright, Josephine A; Wang, Xiaoyan; Brown, David R

    2009-08-01

    Parkinson's disease and a number of other neurodegenerative diseases have been linked to either genetic mutations in the alpha-synuclein gene or show evidence of aggregates of the alpha-synuclein protein, sometimes in the form of Lewy bodies. There currently is no clear evidence of a distinct neurotoxic species of alpha-synuclein to explain the death of neurons in these diseases. We undertook to assess the toxicity of alpha-synuclein via exogenous application in cell culture. Initially, we showed that only aggregated alpha-synuclein is neurotoxic and requires the presence copper but not iron. Other members of the synuclein family showed no toxicity in any form and inherited point mutations did not alter the effective toxic concentration of alpha-synuclein. Through protein fractionation techniques, we were able to isolate an oligomeric species responsible for the toxicity of alpha-synuclein. This oligomeric species has a unique stellate appearance under EM and again, requires association with copper to induce cell death. The results allow us to suggest that the toxic species of alpha-synuclein in vivo could possibly be these stellate oligomers and not fibrils. Our data provide a link between the recently noted association of copper and alpha-synuclein and a potential role for the combination in causing neurodegeneration.

  3. GeneGenie: optimized oligomer design for directed evolution

    PubMed Central

    Swainston, Neil; Currin, Andrew; Day, Philip J.; Kell, Douglas B.

    2014-01-01

    GeneGenie, a new online tool available at http://www.gene-genie.org, is introduced to support the design and self-assembly of synthetic genes and constructs. GeneGenie allows for the design of oligonucleotide cohorts encoding the gene sequence optimized for expression in any suitable host through an intuitive, easy-to-use web interface. The tool ensures consistent oligomer overlapping melting temperatures, minimizes the likelihood of misannealing, optimizes codon usage for expression in a selected host, allows for specification of forward and reverse cloning sequences (for downstream ligation) and also provides support for mutagenesis or directed evolution studies. Directed evolution studies are enabled through the construction of variant libraries via the optional specification of ‘variant codons’, containing mixtures of bases, at any position. For example, specifying the variant codon TNT (where N is any nucleotide) will generate an equimolar mixture of the codons TAT, TCT, TGT and TTT at that position, encoding a mixture of the amino acids Tyr, Ser, Cys and Phe. This facility is demonstrated through the use of GeneGenie to develop and synthesize a library of enhanced green fluorescent protein variants. PMID:24782527

  4. Oligomer Formation of Tau Protein Hyperphosphorylated in Cells*

    PubMed Central

    Tepper, Katharina; Biernat, Jacek; Kumar, Satish; Wegmann, Susanne; Timm, Thomas; Hübschmann, Sabrina; Redecke, Lars; Mandelkow, Eva-Maria; Müller, Daniel J.; Mandelkow, Eckhard

    2014-01-01

    Abnormal phosphorylation (“hyperphosphorylation”) and aggregation of Tau protein are hallmarks of Alzheimer disease and other tauopathies, but their causative connection is still a matter of debate. Tau with Alzheimer-like phosphorylation is also present in hibernating animals, mitosis, or during embryonic development, without leading to pathophysiology or neurodegeneration. Thus, the role of phosphorylation and the distinction between physiological and pathological phosphorylation needs to be further refined. So far, the systematic investigation of highly phosphorylated Tau was difficult because a reliable method of preparing reproducible quantities was not available. Here, we generated full-length Tau (2N4R) in Sf9 cells in a well defined phosphorylation state containing up to ∼20 phosphates as judged by mass spectrometry and Western blotting with phospho-specific antibodies. Despite the high concentration in living Sf9 cells (estimated ∼230 μm) and high phosphorylation, the protein was not aggregated. However, after purification, the highly phosphorylated protein readily formed oligomers, whereas fibrils were observed only rarely. Exposure of mature primary neuronal cultures to oligomeric phospho-Tau caused reduction of spine density on dendrites but did not change the overall cell viability. PMID:25339173

  5. HAMLET forms annular oligomers when deposited with phospholipid monolayers.

    PubMed

    Baumann, Anne; Gjerde, Anja Underhaug; Ying, Ming; Svanborg, Catharina; Holmsen, Holm; Glomm, Wilhelm R; Martinez, Aurora; Halskau, Oyvind

    2012-04-20

    Recently, the anticancer activity of human α-lactalbumin made lethal to tumor cells (HAMLET) has been linked to its increased membrane affinity in vitro, at neutral pH, and ability to cause leakage relative to the inactive native bovine α-lactalbumin (BLA) protein. In this study, atomic force microscopy resolved membrane distortions and annular oligomers (AOs) produced by HAMLET when deposited at neutral pH on mica together with a negatively charged lipid monolayer. BLA, BAMLET (HAMLET's bovine counterpart) and membrane-binding Peptide C, corresponding to BLA residues 75-100, also form AO-like structures under these conditions but at higher subphase concentrations than HAMLET. The N-terminal Peptide A, which binds to membranes at acidic but not at neutral pH, did not form AOs. This suggests a correlation between the capacity of the proteins/peptides to integrate into the membrane at neutral pH-as observed by liposome content leakage and circular dichroism experiments-and the formation of AOs, albeit at higher concentrations. Formation of AOs, which might be important to HAMLET's tumor toxic action, appears related to the increased tendency of the protein to populate intermediately folded states compared to the native protein, the formation of which is promoted by, but not uniquely dependent on, the oleic acid molecules associated with HAMLET.

  6. Carboxybetaine methacrylate oligomer modified nylon for circulating tumor cells capture.

    PubMed

    Dong, Chaoqun; Wang, Huiyu; Zhang, Zhuo; Zhang, Tao; Liu, Baorui

    2014-10-15

    Circulating tumor cells (CTC) capture is one of the most effective approaches in diagnosis and treatment of cancers in the field of personalized cancer medicine. In our study, zwitterionic carboxybetaine methacrylate (CBMA) oligomers were grafted onto nylon via atomic transfer random polymerization (ATRP) which would serve as a novel material for the development of convenient CTC capture interventional medical devices. The chemical, physical and biological properties of pristine and modified nylon surfaces were assessed by Fourier transform infrared spectra, atomic force microscope, water contact angle measurements, X-ray photoelectron spectroscopy, protein adsorption, platelet adhesion, and plasma recalcification time (PRT) determinations, etc. The results, including the significant decrease of proteins adsorption and platelets adhesion, as well as prolonged PRTs demonstrated the extraordinary biocompatibility and blood compatibility of the modified surface. Furthermore, we showed that upon immobilization of anti-epithelial cell adhesion molecular (anti-EpCAM) antibody onto the CBMA moiety, the modified nylon surface can selectively capture EpCAM positive tumor cells from blood with high efficiency, indicating the potential of the modified nylon in the manufacture of convenient interventional CTC capture medical devices.

  7. Cloud forming potential of oligomers relevant to secondary organic aerosols

    NASA Astrophysics Data System (ADS)

    Xu, Wen; Guo, Song; Gomez-Hernandez, Mario; Zamora, Misti L.; Secrest, Jeremiah; Marrero-Ortiz, Wilmarie; Zhang, Annie L.; Collins, Don R.; Zhang, Renyi

    2014-09-01

    The hygroscopic growth factor (HGF) and cloud condensation nuclei (CCN) activity are measured for surrogates that mimic atmospherically relevant oligomers, including glyoxal trimer dihydrate, methyl glyoxal trimer dihydrate, sucrose, methyl glyoxal mixtures with sulfuric acid and glycolic acid, and 2,4-hexandienal mixtures with sulfuric acid and glycolic acid. For the single-component aerosols, the measured HGF ranges from 1.3 to 1.4 at a relative humidity of 90%, and the hygroscopicity parameter (κ) is in the range of 0.06 to 0.19 on the basis of the measured CCN activity and 0.13 to 0.22 on the basis of the measured HGF, compared to the calculated values of 0.08 to 0.16. Large differences exist in the κ values derived using the measured HGF and CCN data for the multi-component aerosols. Our results reveal that, in contrast to the oxidation process, oligomerization decreases particle hygroscopicity and CCN activity and provides guidance for analyzing the organic species in ambient aerosols.

  8. Nanoscale Synaptic Membrane Mimetic Allows Unbiased High Throughput Screen That Targets Binding Sites for Alzheimer’s-Associated Aβ Oligomers

    PubMed Central

    Wilcox, Kyle C.; Marunde, Matthew R.; Das, Aditi; Velasco, Pauline T.; Kuhns, Benjamin D.; Marty, Michael T.; Jiang, Haoming; Luan, Chi-Hao; Sligar, Stephen G.; Klein, William L.

    2015-01-01

    Despite their value as sources of therapeutic drug targets, membrane proteomes are largely inaccessible to high-throughput screening (HTS) tools designed for soluble proteins. An important example comprises the membrane proteins that bind amyloid β oligomers (AβOs). AβOs are neurotoxic ligands thought to instigate the synapse damage that leads to Alzheimer’s dementia. At present, the identities of initial AβO binding sites are highly uncertain, largely because of extensive protein-protein interactions that occur following attachment of AβOs to surface membranes. Here, we show that AβO binding sites can be obtained in a state suitable for unbiased HTS by encapsulating the solubilized synaptic membrane proteome into nanoscale lipid bilayers (Nanodiscs). This method gives a soluble membrane protein library (SMPL)—a collection of individualized synaptic proteins in a soluble state. Proteins within SMPL Nanodiscs showed enzymatic and ligand binding activity consistent with conformational integrity. AβOs were found to bind SMPL Nanodiscs with high affinity and specificity, with binding dependent on intact synaptic membrane proteins, and selective for the higher molecular weight oligomers known to accumulate at synapses. Combining SMPL Nanodiscs with a mix-incubate-read chemiluminescence assay provided a solution-based HTS platform to discover antagonists of AβO binding. Screening a library of 2700 drug-like compounds and natural products yielded one compound that potently reduced AβO binding to SMPL Nanodiscs, synaptosomes, and synapses in nerve cell cultures. Although not a therapeutic candidate, this small molecule inhibitor of synaptic AβO binding will provide a useful experimental antagonist for future mechanistic studies of AβOs in Alzheimer’s model systems. Overall, results provide proof of concept for using SMPLs in high throughput screening for AβO binding antagonists, and illustrate in general how a SMPL Nanodisc system can facilitate drug

  9. Neuroprotection from diazinon-induced toxicity in differentiating murine N2a neuroblastoma cells.

    PubMed

    Harris, Wayne; Sachana, Magda; Flaskos, John; Hargreaves, Alan J

    2009-11-01

    In previous work, the outgrowth of axon-like processes by differentiating mouse N2a neuroblastoma cells was shown to be inhibited by exposure to 10 microM diazinon. In the present work, N2a cells were induced to differentiate for 24 h in the presence and absence of 10 microM diazinon and 20% (v/v) conditioned medium derived from differentiating rat C6 glioma cells. Cells were then stained or lysed for morphological and biochemical analyses, respectively. The data showed that co-treatment with conditioned medium prevented the neurite inhibitory effect of diazinon. Furthermore, a significant recovery was also observed in the reduced levels of neurofilament heavy chain (NFH), heat shock protein-70 (HSP-70) and growth-associated protein-43 (GAP-43) observed as a result of diazinon treatment in the absence of conditioned medium, as seen by densitometric analysis of Western blots of cell lysates probed with monoclonal antibodies N52, BRM-22 and GAP-7B10. By contrast, no significant change was noted in the reactivity of cell lysates with antibodies against alpha- and beta-tubulin under any condition tested. After pre-incubation with a polyclonal anti-glial cell line-derived neurotrophic factor (GDNF) antibody, conditioned medium derived from rat C6 glioma cells lost its ability to protect N2a cells against the neurite inhibitory effects of diazinon. In conclusion, these data demonstrate that C6 conditioned medium protects N2a cells from the neurite inhibitory effects of diazinon by blocking molecular events leading to axon damage and that GDNF is implicated in these effects.

  10. Potential anticancer activity of carvone in N2a neuroblastoma cell line.

    PubMed

    Aydın, Elanur; Türkez, Hasan; Keleş, Mevlüt Sait

    2015-08-01

    Carvone (CVN) is a monocyclic monoterpene found in the essential oils of Mentha spicata var. crispa (Lamiaceae) and Carum carvi L. (Apiaceae) plants and has been reported to have antioxidant, antimicrobial, anticonvulsant, and antitumor activities. The beneficial health properties of CVN have encouraged us to look into its anticancer activity. To the best of our knowledge, reports are not available on the anticancer activity of CVN in cultured primary rat neuron and N2a neuroblastoma (NB) cells. Therefore, the present study is an attempt toward exploring the potential anticancer activity of CVN, if any, in cultured primary rat neuron and N2a NB cells. Our results indicated that CVN (only at 25 mg/L) treatment led to an increase in the total antioxidant capacity levels in cultured primary rat neuron cells compared with control cells. Also, CVN (at concentrations higher than 100 mg/L) treatment led to an increase in the total oxidative stress levels in both cell types. The mean values of the total scores of cells showing DNA damage (for comet assay) were not found to be significantly different from the control values in both cells (p > 0.05). On the other hand, after 24 h treatment with CVN, 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide assay showed that CVN application significantly reduced the cell viability rates in both cell types at concentrations higher than 100 mg/L. Summarizing, our data suggest that CVN represents little potential for promising anticancer agent to improve brain tumors therapy.

  11. Seladin-1/DHCR24 protects neuroblastoma cells against Aβ toxicity by increasing membrane cholesterol content

    PubMed Central

    Cecchi, C; Rosati, F; Pensalfini, A; Formigli, L; Nosi, D; Liguri, G; Dichiara, F; Morello, M; Danza, G; Pieraccini, G; Peri, A; Serio, M; Stefani, M

    2008-01-01

    The role of brain cholesterol in Alzheimer's disease (AD) is currently a matter of debate. Experimental evidence suggests that reducing circulating and brain cholesterol protects against AD, however recent data indicate that low membrane cholesterol results in neurode-generation and that the cholesterol synthesis catalyst seladin-1 is down-regulated in AD-affected brain regions. We previously reported a significant correlation between resistance to amyloid toxicity and content of membrane cholesterol in differing cultured cell types. Here we provide evidence that Aβ42 pre-fibrillar aggregates accumulate more slowly and in reduced amount at the plasma membrane of human SH-SY5Y neuroblastoma cells overexpressing seladin-1 or treated with PEG-cholesterol than at the membrane of control cells. The accumulation was significantly increased in cholesterol-depleted cells following treatment with the specific seladin-1 inhibitor 5,22E-cholestadien-3-ol or with methyl-β-cyclodextrin. The resistance to amyloid toxicity and the early cytosolic Ca2+ rise following exposure to Aβ42 aggregates were increased and prevented, respectively, by increasing membrane cholesterol whereas the opposite effects were found in cholesterol-depleted cells. These results suggest that seladin-1-dependent cholesterol synthesis reduces membrane-aggregate interaction and cell damage associated to amyloid-induced imbalance of cytosolic Ca2+. Our findings extend recently reported data indicating that seladin-1 overexpression directly enhances the resistance to Aβ toxicity featuring seladin-1/DHCR 24 as a possible new susceptibility gene for sporadic AD. PMID:18194465

  12. Nutrient deprivation in neuroblastoma cells alters 4-hydroxynonenal-induced stress response.

    PubMed

    Zimmermann, Lars; Moldzio, Rudolf; Vazdar, Katarina; Krewenka, Christopher; Pohl, Elena E

    2017-01-31

    4-hydroxy-2-nonenal (HNE), a toxic lipid peroxidation product, is associated with oxidative damage in cells and involved in various diseases including the initiation and progression of cancer. Cancer cells have a high, adaptable metabolism with a shift from oxidative phosphorylation to glycolysis and rely on high levels of glucose and glutamine as essential nutrients for cell growth. Here we investigated whether the toxic effects of HNE on the mitochondrial membrane potential (MMP) of cancer cells depends on their metabolic state by deprivation of glucose and/or glutamine. The addition of 16 μM HNE to N18TG2 neuroblastoma cells incubated in glucose medium led to a severe reduction of MMP, which was similar to the MMP of cells fed with both glucose and glutamine. In contrast, HNE addition to cells starved in glutamine medium increased their MMP slightly for a prolonged time period and this was accompanied by increased cellular survival. We found that ß-oxidation of HNE did not cause the increased MMP, since the aldehyde dehydrogenase was distinctly more active in cells with glucose medium. However, after blocking fatty acid ß-oxidation in cells starved in glutamine medium with etomoxir, which inhibits carnitine palmitoyltransferase 1, HNE addition induced a strong reduction of MMP similar to cells in glucose medium. Surprisingly, the effect of more toxic 4-oxo-2-nonenal was less pronounced. Our results suggest that in contrast to cells fed with glucose, glutamine-fed cancer cells are capable of ß-oxidizing fatty acids to maintain their MMP to combat the toxic effects of HNE.

  13. LMO1 gene polymorphisms contribute to decreased neuroblastoma susceptibility in a Southern Chinese population

    PubMed Central

    Zhu, Jinhong; Zhang, Ruizhong; Wang, Fenghua; Yang, Tianyou; Zou, Yan; Xia, Huimin

    2016-01-01

    Neuroblastoma is one of the most commonly diagnosed extracranial solid tumors in infancy; however, the etiology of neuroblastoma remains largely unknown. Previous genome-wide association study (GWAS) indicated that several common genetic variations (rs110419 A > G, rs4758051 G > A, rs10840002 A > G and rs204938 A > G) in the LIM domain only 1 (LMO1) gene were associated with neuroblastoma susceptibility. The aim of this study was to evaluate the correlation between the four GWAS-identified LMO1 gene polymorphisms and neuroblastoma risk in a Southern Chinese population. We genotyped the four polymorphisms in 256 neuroblastoma cases and 531 controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the strength of the associations. False-positive report probability was calculated for all significant findings. We found that the rs110419 A > G polymorphism was associated with a significantly decreased neuroblastoma risk (AG vs. AA: adjusted OR = 0.65, 95% CI = 0.47–0.91; GG vs. AA: adjusted OR = 0.58, 95% CI = 0.36–0.91; AG/GG vs. AA: adjusted OR = 0.63, 95% CI = 0.46–0.86), and the protective effect was more predominant in children of age > 18 months, males, subgroups with tumor in adrenal gland and mediastinum, and patients in clinical stages III/IV. These results suggested that LMO1 gene rs110419 A > G polymorphism may contribute to protection against neuroblastoma. Our findings call for further validation studies with larger sample size. PMID:27009839

  14. Confocal Raman microscopy for investigation of the level of differentiation in living neuroblastoma tumor cells

    NASA Astrophysics Data System (ADS)

    Scalfi-Happ, Claudia; Jauss, Andrea; Hollricher, Olaf; Fulda, Simone; Hauser, Carmen; Steiner, Rudolf; Rück, Angelika

    2007-07-01

    The investigation of living cells at physiological conditions requires very sensitive, sophisticated, non invasive methods. In this study, Raman spectral imaging is used to identify different biomolecules inside of cells. Raman spectroscopy, a chemically and structurally sensitive measuring technique, is combined with high resolution confocal microscopy. In Raman spectral imaging mode, a complete Raman spectrum is recorded at every confocal image point, giving insight into the chemical composition of each sample compartment. Neuroblastoma is the most common solid extra-cranial tumor in children. One of the unique features of neuroblastoma cells is their ability to differentiate spontaneously, eventually leading to complete remission. Since differentiation agents are currently used in the clinic for neuroblastoma therapy, there is a special need to develop non-invasive and sensitive new methods to monitor neuroblastoma cell differentiation. Neuroblastoma cells at different degrees of differentiation were analysed with the confocal Raman microscope alpha300 R (WITec GmbH, Germany), using a frequency doubled Nd:YAG laser at 532 nm and 10 mW for excitation. Integration time per spectrum was 80-100 ms. A lateral resolution in submicrometer range was achieved by using a 60x water immersion lens with a numerical aperture of 1,0. Raman images of cells were generated from these sets of data by either integrating over specific Raman bands, by basis analysis using reference spectra or by cluster analysis. The automated evaluation of all spectra results in spectral unmixed images providing insight into the chemical composition of the sample. With these procedures, different cell organelles, cytosol, membranes could be distinguished. Since neuroblastoma cells at high degree of differentiation overproduce noradrenaline, an attempt was made to trace the presence of this neurotransmitter as a marker for differentiation. The results of this work may have applications in the

  15. MYCN and HDAC5 transcriptionally repress CD9 to trigger invasion and metastasis in neuroblastoma

    PubMed Central

    Fabian, Johannes; Opitz, Desirée; Althoff, Kristina; Lodrini, Marco; Hero, Barbara; Volland, Ruth; Beckers, Anneleen; de Preter, Katleen; Decock, Anneleen; Patil, Nitin; Abba, Mohammed; Kopp-Schneider, Annette; Astrahantseff, Kathy; Wünschel, Jasmin; Pfeil, Sebastian; Ercu, Maria; Künkele, Annette; Hu, Jamie; Thole, Theresa; Schweizer, Leonille; Mechtersheimer, Gunhild; Carter, Daniel; Cheung, Belamy B.; Popanda, Odilia; von Deimling, Andreas; Koster, Jan; Versteeg, Rogier; Schwab, Manfred; Marshall, Glenn M.; Speleman, Frank; Erb, Ulrike; Zoeller, Margot; Allgayer, Heike; Simon, Thorsten; Fischer, Matthias; Kulozik, Andreas E.; Eggert, Angelika; Witt, Olaf; Schulte, Johannes H.; Deubzer, Hedwig E.

    2016-01-01

    The systemic and resistant nature of metastatic neuroblastoma renders it largely incurable with current multimodal treatment. Clinical progression stems mainly from the increasing burden of metastatic colonization. Therapeutically inhibiting the migration-invasion-metastasis cascade would be of great benefit, but the mechanisms driving this cycle are as yet poorly understood. In-depth transcriptome analyses and ChIP-qPCR identified the cell surface glycoprotein, CD9, as a major downstream player and direct target of the recently described GRHL1 tumor suppressor. CD9 is known to block or facilitate cancer cell motility and metastasis dependent upon entity. High-level CD9 expression in primary neuroblastomas correlated with patient survival and established markers for favorable disease. Low-level CD9 expression was an independent risk factor for adverse outcome. MYCN and HDAC5 colocalized to the CD9 promoter and repressed transcription. CD9 expression diminished with progressive tumor development in the TH-MYCN transgenic mouse model for neuroblastoma, and CD9 expression in neuroblastic tumors was far below that in ganglia from wildtype mice. Primary neuroblastomas lacking MYCN amplifications displayed differential CD9 promoter methylation in methyl-CpG-binding domain sequencing analyses, and high-level methylation was associated with advanced stage disease, supporting epigenetic regulation. Inducing CD9 expression in a SH-EP cell model inhibited migration and invasion in Boyden chamber assays. Enforced CD9 expression in neuroblastoma cells transplanted onto chicken chorioallantoic membranes strongly reduced metastasis to embryonic bone marrow. Combined treatment of neuroblastoma cells with HDAC/DNA methyltransferase inhibitors synergistically induced CD9 expression despite hypoxic, metabolic or cytotoxic stress. Our results show CD9 is a critical and indirectly druggable suppressor of the invasion-metastasis cycle in neuroblastoma. PMID:27572323

  16. MYCN and HDAC5 transcriptionally repress CD9 to trigger invasion and metastasis in neuroblastoma.

    PubMed

    Fabian, Johannes; Opitz, Desirée; Althoff, Kristina; Lodrini, Marco; Hero, Barbara; Volland, Ruth; Beckers, Anneleen; de Preter, Katleen; Decock, Anneleen; Patil, Nitin; Abba, Mohammed; Kopp-Schneider, Annette; Astrahantseff, Kathy; Wünschel, Jasmin; Pfeil, Sebastian; Ercu, Maria; Künkele, Annette; Hu, Jamie; Thole, Theresa; Schweizer, Leonille; Mechtersheimer, Gunhild; Carter, Daniel; Cheung, Belamy B; Popanda, Odilia; von Deimling, Andreas; Koster, Jan; Versteeg, Rogier; Schwab, Manfred; Marshall, Glenn M; Speleman, Frank; Erb, Ulrike; Zoeller, Margot; Allgayer, Heike; Simon, Thorsten; Fischer, Matthias; Kulozik, Andreas E; Eggert, Angelika; Witt, Olaf; Schulte, Johannes H; Deubzer, Hedwig E

    2016-10-11

    The systemic and resistant nature of metastatic neuroblastoma renders it largely incurable with current multimodal treatment. Clinical progression stems mainly from the increasing burden of metastatic colonization. Therapeutically inhibiting the migration-invasion-metastasis cascade would be of great benefit, but the mechanisms driving this cycle are as yet poorly understood. In-depth transcriptome analyses and ChIP-qPCR identified the cell surface glycoprotein, CD9, as a major downstream player and direct target of the recently described GRHL1 tumor suppressor. CD9 is known to block or facilitate cancer cell motility and metastasis dependent upon entity. High-level CD9 expression in primary neuroblastomas correlated with patient survival and established markers for favorable disease. Low-level CD9 expression was an independent risk factor for adverse outcome. MYCN and HDAC5 colocalized to the CD9 promoter and repressed transcription. CD9 expression diminished with progressive tumor development in the TH-MYCN transgenic mouse model for neuroblastoma, and CD9 expression in neuroblastic tumors was far below that in ganglia from wildtype mice. Primary neuroblastomas lacking MYCN amplifications displayed differential CD9 promoter methylation in methyl-CpG-binding domain sequencing analyses, and high-level methylation was associated with advanced stage disease, supporting epigenetic regulation. Inducing CD9 expression in a SH-EP cell model inhibited migration and invasion in Boyden chamber assays. Enforced CD9 expression in neuroblastoma cells transplanted onto chicken chorioallantoic membranes strongly reduced metastasis to embryonic bone marrow. Combined treatment of neuroblastoma cells with HDAC/DNA methyltransferase inhibitors synergistically induced CD9 expression despite hypoxic, metabolic or cytotoxic stress. Our results show CD9 is a critical and indirectly druggable suppressor of the invasion-metastasis cycle in neuroblastoma.

  17. Reduced folate carrier-1 G80a gene polymorphism is associated with neuroblastoma's development.

    PubMed

    de Miranda, Dyego O; Barros, Jemima E X S; Vieira, Maria Madalena S; Lima, Elker L S; Moraes, Vera L L; da Silva, Helker A; Garcia, Helder L B O; Lima, Cássia A; Gomes, Adriana V; Santos, Neide; Muniz, Maria T C

    2014-08-01

    Neuroblastoma is a malignant embryonal tumor of neural crest cells that give rise to the sympathetic nervous system, responsible for 10-70% of all cases of childhood cancer. Because of its early appearance, it has been suggested that risk factors active in the prenatal can be associated with the pathogenesis of neuroblastoma. The aim of this study was to investigate whether the genetic polymorphisms MTHFR C677T and A1298C, MTR A2756G, TYMS 2R/3R and SLC19A1 G80A, involved in folate metabolism, increase the risk of neuroblastoma in Brazilian children. This study comprised 31 Brazilian children (0-14 years old) diagnosed with neuroblastoma compared with 92 controls. Investigation of polymorphisms MTHFR C677T, MTR A2756G and SLC19A1 A80G was performed using PCR-RFLP, the TYMS 2R/3R using PCR and MTHFR A1298C using AS-PCR. The SLC19A1 A80A genotype was significantly associated with the development of neuroblastoma, compared with the control group (Williams G-Test = 0.0286; OR = 5.1667; 95% CI = 1.4481-18.4338; p = 0.0175). When analyzed together, the 80AG+AA genotypes showed a trend toward association (OR = 3.3033; 95% CI = 1.0586-10.3080; p = 0.0563). Our results suggest that individuals carriers of genotype AA for the SLC19A1 gene present risk for the development of neuroblastoma and possibly have difficulty in absorption of folic acid by the cells, and this may adversely affect the metabolism of folate causing genomic instability and promoting the development of cancer. This is the first retrospective/prospective study to examine the relationship between polymorphisms of folate pathway genes and risk of neuroblastoma.

  18. Improved therapy for neuroblastoma using a combination approach: superior efficacy with vismodegib and topotecan.

    PubMed

    Chaturvedi, Nagendra K; McGuire, Timothy R; Coulter, Don W; Shukla, Ashima; McIntyre, Erin M; Sharp, John Graham; Joshi, Shantaram S

    2016-03-22

    Aberrant activation/expression of pathways/molecules including NF-kB, mTOR, hedgehog and polo-like-kinase-1 (PLK1) are correlated with poor-prognosis neuroblastoma. Therefore, to identify a most efficacious treatment for neuroblastoma, we investigated the efficacy of NF-kB/mTOR dual-inhibitor 13-197, hedgehog inhibitor vismodegib and PLK1 inhibitor BI2536 alone or combined with topotecan against high-risk neuroblastoma. The in vitro efficacy of the inhibitors alone or combined with topotecan on cell growth/apoptosis and molecular mechanism(s) were investigated. Results showed that as single agents 13-197, BI2536 and vismodegib significantly decreased neuroblastoma cell growth and induced apoptosis by targeting associated pathways/molecules. In combination with topotecan, 13-197 did not show significant additive/synergistic effects against neuroblastoma. However, BI2536 or vismodegib further significantly decreased neuroblastoma cell growth/survival. These results clearly showed that vismodegib combination with topotecan was synergistic and more efficacious compared with BI2536 in combination. Together, in vitro data demonstrated that vismodegib was most efficacious in potentiating topotecan-induced antineuroblastoma effects. Therefore, we tested the combined efficacy of vismodegib and topotecan against neuroblastoma in vivo using NSG mice. This resulted in significantly (p<0.001) reduced tumor growth and increased survival of mice. Together, the combination of vismodegib and topotecan showed a significant enhanced antineuroblastoma efficacy by targeting associated pathways/molecules which warrants further preclinical evaluation for translation to the clinic.

  19. The metastatic microenvironment: lung-derived factors control the viability of neuroblastoma lung metastasis.

    PubMed

    Maman, Shelly; Edry-Botzer, Liat; Sagi-Assif, Orit; Meshel, Tsipi; Yuan, Weirong; Lu, Wuyuan; Witz, Isaac P

    2013-11-15

    Recent data suggest that the mechanisms determining whether a tumor cell reaching a secondary organ will enter a dormant state, progress toward metastasis, or go through apoptosis are regulated by the microenvironment of the distant organ. In neuroblastoma, 60-70% of children with high-risk disease will ultimately experience relapse due to the presence of micrometastases. The main goal of this study is to evaluate the role of the lung microenvironment in determining the fate of neuroblastoma lung metastases and micrometastases. Utilizing an orthotopic mouse model for human neuroblastoma metastasis, we were able to generate two neuroblastoma cell populations-lung micrometastatic (MicroNB) cells and lung macrometastatic (MacroNB) cells. These two types of cells share the same genetic background, invade the same distant organ, but differ in their ability to create metastasis in the lungs. We hypothesize that factors present in the lung microenvironment inhibit the propagation of MicroNB cells preventing them from forming overt lung metastasis. This study indeed shows that lung-derived factors significantly reduce the viability of MicroNB cells by up regulating the expression of pro-apoptotic genes, inducing cell cycle arrest and decreasing ERK and FAK phosphorylation. Lung-derived factors affected various additional progression-linked cellular characteristics of neuroblastoma cells, such as the expression of stem-cell markers, morphology, and migratory capacity. An insight into the microenvironmental effects governing neuroblastoma recurrence and progression would be of pivotal importance as they could have a therapeutic potential for the treatment of neuroblastoma residual disease.

  20. The Ews/Fli-1 fusion gene changes the status of p53 in neuroblastoma tumor cell lines.

    PubMed

    Rorie, Checo J; Weissman, Bernard E

    2004-10-15

    One hallmark of Ewing's sarcoma/peripheral neuroectodermal tumors is the presence of the Ews/Fli-1 chimeric oncogene. Interestingly, infection of neuroblastoma tumor cell lines with Ews/Fli-1 switches the differentiation program of neuroblastomas to Ewing's sarcoma/peripheral neuroectodermal tumors. Here we examined the status of cytoplasmically sequestered wt-p53 in neuroblastomas after stable expression of Ews/Fli-1. Immunofluorescence revealed that in the neuroblastoma-Ews/Fli-1 infectant cell lines, p53 went from a punctate-pattern of cytoplasmic sequestration to increased nuclear localization. Western blot analysis revealed that PARC was down-regulated in one neuroblastoma cell line but not expressed in the second. Therefore, decreased PARC expression could not fully account for relieving p53 sequestration in the neuroblastoma tumor cells. Neuroblastoma-Ews/Fli-1 infectant cell lines showed marked increases in p53 protein expression without transcriptional up-regulation. Interestingly, p53 was primarily phosphorylated, without activation of its downstream target p21(WAF1). Western blot analysis revealed that whereas MDM2 gene expression does not change, p14(ARF), a negative protein regulator of MDM2, increases. These observations suggest that the downstream p53 pathway may be inactivated as a result of abnormal p53. We also found that p53 has an extended half-life in the neuroblastoma-Ews/Fli-1 infectants despite the retention of a wild-type sequence in neuroblastoma-Ews/Fli-1 infectant cell lines. We then tested the p53 response pathway and observed that the neuroblastoma parent cells responded to genotoxic stress, whereas the neuroblastoma-Ews/Fli-1 infectants did not. These results suggest that Ews/Fli-1 can directly abrogate the p53 pathway to promote tumorigenesis. These studies also provide additional insight into the relationship among the p53 pathway proteins.

  1. Intracellular soluble α‐synuclein oligomers reduce pyramidal cell excitability

    PubMed Central

    Kaufmann, Timothy J.; Harrison, Paul M.; Richardson, Magnus J. E.; Pinheiro, Teresa J. T.

    2016-01-01

    Key points The presynaptic protein α‐synuclein forms aggregates during Parkinson's disease.Accumulating evidence suggests that the small soluble oligomers of α‐synuclein are more toxic than the larger aggregates appearing later in the disease.The link between oligomer toxicity and structure still remains unclear.In the present study, we have produced two structurally‐defined oligomers that have a similar morphology but differ in secondary structure.These oligomers were introduced into neocortical pyramidal cells during whole‐cell recording and, using a combination of experimentation and modelling, electrophysiological parameters were extracted.Both oligomeric species had similar effects on neuronal properties reducing input resistance, time constant and increasing capacitance. The net effect was a marked reduction in neuronal excitability that could impact on network activity. Abstract The presynaptic protein α‐synuclein (αSyn) aggregates during Parkinson's disease (PD) to form large proteinaceous amyloid plaques, the spread of which throughout the brain clinically defines the severity of the disease. During early stages of aggregation, αSyn forms soluble annular oligomers that show greater toxicity than much larger fibrils. These oligomers produce toxicity via a number of possible mechanisms, including the production of pore‐forming complexes that permeabilize membranes. In the present study, two well‐defined species of soluble αSyn oligomers were produced by different protocols: by polymerization of monomer and by sonication of fibrils. The two oligomeric species produced were morphologically similar, with both having an annular structure and consisting of approximately the same number of monomer subunits, although they differed in their secondary structure. Oligomeric and monomeric αSyn were injected directly into the soma of pyramidal neurons in mouse neocortical brain slices during whole‐cell patch clamp recording. Using a combined

  2. Cytotoxic effect of p-Coumaric acid on neuroblastoma, N2a cell via generation of reactive oxygen species leading to dysfunction of mitochondria inducing apoptosis and autophagy.

    PubMed

    Shailasree, S; Venkataramana, M; Niranjana, S R; Prakash, H S

    2015-02-01

    p-Coumaric acid (p-CA), an ubiquitous plant phenolic acid, has been proven to render protection against pathological conditions. In the present study, p-CA was evaluated for its capacity to induce cytotoxic effect to neuroblastoma N2a cells and we report here the possible mechanism of its action. p-CA at a concentration of 150 μmol/L, upon exposure for 72 h, stimulated 81.23 % of cells to apoptosis, as evidenced by flow cytometer studies mediated through elevated levels of ROS (7.5-fold over control). Excess ROS production activated structural injury to mitochondrial membrane, observed as dissipation of its membrane potential and followed by the release of cytochrome c (8.73-fold). Enhanced generation of intracellular ROS correlated well with the decreased levels (~60 %) of intracellular GSH. Sensitizing neuroblastoma cells for induction of apoptosis by p-CA identified p53-mediated upregulated accumulation of caspase-8 messenger RNA (2.8-fold). Our data report on autophagy, representing an additional mechanism of p-CA to induce growth arrest, detected by immunoblotting and fluorescence, correlated with accumulation of elevated levels (1.2-fold) of the LC3-II protein and acridine orange-stained autophagosomes, both autophagy markers. The present study indicates p-CA was effective in production of ROS-dependent mitochondrial damage-induced cytotoxicity in N2a cells.

  3. Solvent free low-melt viscosity imide oligomers and thermosetting polymide composites

    NASA Technical Reports Server (NTRS)

    Chuang, Chun-Hua (Inventor)

    2012-01-01

    .[.This invention relates to the composition and a solvent-free process for preparing novel imide oligomers and polymers specifically formulated with effective amounts of a dianhydride such as 2,3,3',4-biphenyltetra carboxylic dianydride (a-BPDA), at least one aromatic diamine and an endcapped of 4-phenylethynylphthalic anhydride (PEPA) or nadic anhydride to produce imide oligomers that possess a low-melt viscosity of 1-60 poise at 260-280.degree. C. When the imide oligomer melt is cured at about 371.degree. C. in a press or autoclave under 100-500 psi, the melt resulted in a thermoset polyimide having a glass transition temperature (T.sub.g) equal to and above 310.degree. C. A novel feature of this process is that the monomers; namely the dianhydrides, diamines and the endcaps, are melt processable to form imide oligomers at temperatures ranging between 232-280.degree. C. (450-535.degree. F.) without any solvent. These low-melt imide oligomers can be easily processed by resin transfer molding (RTM), vacuum-assisted resin transfer molding (VARTM) or the resin infusion process with fiber preforms e.g. carbon, glass or quartz preforms to produce polyimide matrix composites with 288-343.degree. C. (550-650.degree. F.) high temperature performance capability..]. .Iadd.This invention relates to compositions and a solvent-free reaction process for preparing imide oligomers and polymers specifically derived from effective amounts of dianhydrides such as 2,3,3',4'-biphenyltetracarboxylic dianhydride (a-BPDA), at least one aromatic polyamine and an end-cap such as 4-phenylethynyphthalic anhydride (PEPA) or nadic anhydride to produce imide oligomers that possess a low-melt viscosity of 1-60 poise at 260.degree. C.-280.degree. C..Iaddend.

  4. Novel demonstration of amyloid-β oligomers in sporadic inclusion-body myositis muscle fibers.

    PubMed

    Nogalska, Anna; D'Agostino, Carla; Engel, W King; Klein, William L; Askanas, Valerie

    2010-11-01

    Accumulation of amyloid-β (Aβ) within muscle fibers has been considered an upstream step in the development of the s-IBM pathologic phenotype. Aβ42, which is considered more cytotoxic than Aβ40 and has a higher propensity to oligomerize, is preferentially increased in s-IBM muscle fibers. In Alzheimer disease (AD), low-molecular weight Aβ oligomers and toxic oligomers, also referred to as "Aβ-Derived Diffusible Ligands" (ADDLs), are considered strongly cytotoxic and proposed to play an important pathogenic role. ADDLs have been shown to be increased in AD brain. We now report for the first time that in s-IBM muscle biopsies Aβ-dimer, -trimer, and -tetramer are identifiable by immunoblots. While all the s-IBM samples we studied had Aβ-oligomers, their molecular weights and intensity varied between the patient samples. None of the control muscle biopsies had Aβ oligomers. Dot-immunoblots using highly specific anti-ADDL monoclonal antibodies also showed highly increased ADDLs in all s-IBM biopsies studied, while controls were negative. By immunofluorescence, in some of the abnormal s-IBM muscle fibers ADDLs were accumulated in the form of plaque-like inclusions, and were often increased diffusely in very small fibers. Normal and disease-controls were negative. By gold-immuno-electron microscopy, ADDL-immunoreactivities were in close proximity to 6-10 nm amyloid-like fibrils, and also were immunodecorating amorphous and floccular material. In cultured human muscle fibers, we found that inhibition of autophagy led to the accumulation of Aβ oligomers. This novel demonstration of Aβ42 oligomers in s-IBM muscle biopsy provides additional evidence that intra-muscle fiber accumulation of Aβ42 oligomers in s-IBM may contribute importantly to s-IBM pathogenic cascade.

  5. Discrete Molecular Dynamics Study of Oligomer Formation by N-Terminally Truncated Amyloid β-Protein

    PubMed Central

    Meral, Derya; Urbanc, Brigita

    2013-01-01

    In Alzheimer’s disease (AD), amyloid β-protein (Aβ) self–assembles into toxic oligomers. Of the two predominant Aβ alloforms, Aβ1–40 and Aβ1–42, the latter is particularly strongly linked to AD. N-terminally truncated and pyroglutamated Aβ peptides were recently shown to seed Aβ aggregation and contribute significantly to Aβ–mediated toxicity, yet their folding and assembly were not explored computationally. Discrete molecular dynamics (DMD) approach previously captured in vitro–derived distinct Aβ1–40 and Aβ1–42 oligomer size distributions and predicted that the more toxic Aβ1–42 oligomers had more flexible and solvent exposed N-termini than Aβ1–40 oligomers. Here, we examined oligomer formation of Aβ3–40, Aβ3–42, Aβ11–40, and Aβ11–42 by the DMD approach. The four N-terminally truncated peptides showed increased oligomerization propensity relative to the full–length peptides, consistent with in vitro findings. Conformations formed by Aβ3–40/42 had significantly more flexible and solvent–exposed N-termini than Aβ1–40/42 conformations. In contrast, in Aβ11–40/42 conformations the N-termini formed more contacts and were less accessible to the solvent. The compactness of the Aβ11–40/42 conformations was in part facilitated by Val12. Two single amino acid substitutions that reduced and abolished hydrophobicity at position 12, respectively, resulted in a proportionally increased structural variability. Our results suggest that Aβ11–40 and Aβ11–42 oligomers might be less toxic than Aβ1–40 and Aβ1–42 oligomers and offer a plausible explanation for the experimentally–observed increased toxicity of Aβ3–40 and Aβ3–42 and their pyroglutamated forms. PMID:23500806

  6. Humanin Specifically Interacts with Amyloid-β Oligomers and Counteracts Their in vivo Toxicity.

    PubMed

    Romeo, Margherita; Stravalaci, Matteo; Beeg, Marten; Rossi, Alessandro; Fiordaliso, Fabio; Corbelli, Alessandro; Salmona, Mario; Gobbi, Marco; Cagnotto, Alfredo; Diomede, Luisa

    2017-03-06

    The 24-residue peptide humanin (HN) has been proposed as peptide-based inhibitors able to interact directly with amyloid-β (Aβ) oligomers and interfere with the formation and/or biological properties of toxic Aβ species. When administered exogenously HN, or its synthetic S14G-derivative (HNG), exerted multiple cytoprotective effects, counteracting the Aβ-induced toxicity. Whether these peptides interact directly with Aβ, particularly with the soluble oligomeric assemblies, remains largely unknown. We here investigated the ability of HN and HNG to interact directly with highly aggregating Aβ42, and interfere with the formation and toxicity of its oligomers. Experiments were run in cell-free conditions and in vivo in a transgenic C. elegans strain in which the Aβ toxicity was specifically due to oligomeric species. Thioflavin-T assay indicated that both HN and HNG delay the formation and reduce the final amount of Aβ42 fibrils. In vitro surface plasmon resonance studies indicated that they interact with Aβ42 oligomers favoring the formation of amorphous larger assemblies, observed with turbidity and electron microscopy. In vivo studies indicated that both HN and HNG decrease the relative abundance of A11-positive prefibrillar oligomers as well as OC-positive fibrillar oligomers and had similar protective effects. However, while HN possibly decreased the oligomers by promoting their assembly into larger aggregates, the reduction of oligomers caused by HNG can be ascribed to a marked decrease of the total Aβ levels, likely the consequence of the HNG-induced overexpression of the Aβ-degrading enzyme neprilysin. These findings provide information on the mechanisms underlying the anti-oligomeric effects of HN and HNG and illustrate the role of S14G substitution in regulating the in vivo mechanism of action.

  7. Self-assembly of conjugated oligomers and polymers at the interface: structure and properties.

    PubMed

    Xu, Lirong; Yang, Liu; Lei, Shengbin

    2012-08-07

    In this review, we give a brief account on the recent scanning tunneling microscopy investigation of interfacial structures and properties of π-conjugated semiconducting oligomers and polymers, either at the solid-air (including solid-vacuum) or at the solid-liquid interface. The structural aspects of the self-assembly of both oligomers and polymers are highlighted. Conjugated oligomers can form well ordered supramolecular assemblies either at the air-solid or liquid-solid interface, thanks to the relatively high mobility and structural uniformity in comparison with polymers. The backbone structure, substitution of side chains and functional groups can affect the assembling behavior significantly, which offers the opportunity to tune the supramolecular structure of these conjugated oligomers at the interface. For conjugated polymers, the large molecular weight limits the mobility on the surface and the distribution in size also prevents the formation of long range ordered supramolecular assembly. The submolecular resolution obtained on the assembling monolayers enables a detailed investigation of the chain folding at the interface, both the structural details and the effect on electronic properties. Besides the ability in studying the assembling structures at the interfaces, STM also provides a reasonable way to evaluate the distribution of the molecular weight of conjugated polymers by statistic of the contour length of the adsorbed polymer chains. Both conjugated oligomers and polymers can form composite assemblies with other materials. The ordered assembly of oligomers can act as a template to controllably disperse other molecules such as coronene or fullerene. These investigations open a new avenue to fine tune the assembling structure at the interface and in turn the properties of the composite materials. To summarize scanning tunneling microscopy has demonstrated its surprising ability in the investigation of the assembling structures and properties of

  8. Critical Role for GAB2 in Neuroblastoma Pathogenesis through the Promotion of SHP2/MYCN Cooperation.

    PubMed

    Zhang, Xiaoling; Dong, Zhiwei; Zhang, Cheng; Ung, Choong Yong; He, Shuning; Tao, Ting; Oliveira, Andre M; Meves, Alexander; Ji, Baoan; Look, A Thomas; Li, Hu; Neel, Benjamin G; Zhu, Shizhen

    2017-03-21

    Growing evidence suggests a major role for Src-homology-2-domain-containing phosphatase 2 (SHP2/PTPN11) in MYCN-driven high-risk neuroblastoma, although biologic confirmation and a plausible mechanism for this contribution are lacking. Using a zebrafish model of MYCN-overexpressing neuroblastoma, we demonstrate that mutant ptpn11 expression in the adrenal gland analog of MYCN transgenic fish promotes the proliferation of hyperplastic neuroblasts, accelerates neuroblastomagenesis, and increases tumor penetrance. We identify a similar mechanism in tumors with wild-type ptpn11 and dysregulated Gab2, which encodes a Shp2 activator that is overexpressed in human neuroblastomas. In MYCN transgenic fish, Gab2 overexpression activated the Shp2-Ras-Erk pathway, enhanced neuroblastoma induction, and increased tumor penetrance. We conclude that MYCN cooperates with either GAB2-activated or mutant SHP2 in human neuroblastomagenesis. Our findings further suggest that combined inhibition of MYCN and the SHP2-RAS-ERK pathway could provide effective targeted therapy for high-risk neuroblastoma patients with MYCN amplification and aberrant SHP2 activation.

  9. The value of anterior displacement of the abdominal aorta in diagnosing neuroblastoma in children*

    PubMed Central

    Schiavon, Jose Luiz de Oliveira; Caran, Eliana Maria Monteiro; Odone Filho, Vicente; Lederman, Henrique Manoel

    2016-01-01

    Objective To determine the value of anterior displacement of the abdominal aorta, when present at any level or only at the level of the adrenal gland, contralateral to the mass, in diagnosing neuroblastoma on computed tomography or magnetic resonance imaging in children up to 7 years of age. Materials and Methods Imaging examinations of 66 patients were classified by consensus as for the presence of anterior aorta displacement and were compared with the pathology report. Results We found anterior abdominal aorta displacement in 26 (39.39%) of the 66 patients evaluated. Among those 26 patients, we identified neuroblastoma in 22 (84.62%), nephroblastoma in 3 (11.54%), and Burkitt lymphoma in 1 (3.85%). The positive predictive value was 84.62%, and the specificity was 88.24%. The displacement of the aorta was at the adrenal level, contralateral to the mass, in 14 cases, all of which were attributed to neuroblastoma. Conclusion When the abdominal aorta is displaced at the level of the adrenal gland, contralateral to the mass, it can be said that the diagnosis is neuroblastoma, whereas abdominal aorta displacement occurring at other abdominal levels has a positive predictive value for neuroblastoma of approximately 85%. PMID:28100931

  10. Melatonin inhibits angiogenesis in SH-SY5Y human neuroblastoma cells by downregulation of VEGF.

    PubMed

    González, Alicia; González-González, Alicia; Alonso-González, Carolina; Menéndez-Menéndez, Javier; Martínez-Campa, Carlos; Cos, Samuel

    2017-04-01

    Vascular endothelial growth factor (VEGF) produced from tumor cells plays a crucial role in the pathogenesis and neovascularization of neuroblastoma. Inhibition of VEGF secretion by tumor cells, as well as VEGF-regulated signaling in endothelial cells, are important to reduce the angiogenesis and growth of neuroblastoma. Since melatonin has anti-angiogenic effects in tumor cell lines, the aim of the present study was to study melatonin modulation of the pro-angiogenic effects of VEGF in neuroblastoma cells (SH-SY5Y). We used co-cultures of SH-SY5Y and endothelial cells. VEGF expression and protein levels were analyzed by quantitative RT-PCR and ELISA, respectively. Endothelial cell migration was assessed by wound-healing assay and endothelial angiogenesis by a tube formation assay. Melatonin inhibited the pro-angiogenic effects of SH-SY5Y cells. The conditioned medium collected from the neuroblastoma cells was angiogenically active and stimulated proliferation, migration and tube formation in endothelial cells. This effect was significantly counteracted by the addition of either anti-VEGF or melatonin. Melatonin inhibited VEGF expression and secretion in SH-SY5Y cells, decreasing the levels of VEGF available for endothelial cells. Melatonin has anti-angiogenic effects at different steps of the angiogenic process in SH-SY5Y neuroblastoma cells, through the downregulation of VEGF.

  11. Carbonic anhydrase IX correlates with survival and is a potential therapeutic target for neuroblastoma.

    PubMed

    Ameis, Helen M; Drenckhan, Astrid; Freytag, Morton; Izbicki, Jakob R; Supuran, Claudiu T; Reinshagen, Konrad; Holland-Cunz, Stefan; Gros, Stephanie J

    2016-01-01

    Carbonic anhydrase IX (CAIX) is involved in pathological processes including tumorgenicity, metastases and poor survival in solid tumors. Twenty-two neuroblastoma samples of patients who were surgically treated at the University Medical Center Hamburg-Eppendorf were evaluated immunohistochemically for expression of CAIX. Results were correlated with clinical parameters and outcome. Neuroblastoma Kelly and SH-EP-Tet-21/N cells were examined for CAIX expression and inhibited with specific inhibitors, FC5-207A and FC8-325A. 32% of neuroblastoma tumors expressed CAIX. This was significantly associated with poorer survival. Kelly and SH-EP-Tet-21/N cells showed a major increase of CAIX RNA under hypoxic conditions. Proliferation of Kelly cells was significantly decreased by CAIX inhibitors, FC5-207A and FC8-325A, while proliferation of SH-EP-Tet-21/N cells was only significantly affected by FC8-325A. CAIX is a potent biomarker that predicts survival in neuroblastoma patients. CAIX-targeted therapy in neuroblastoma cell lines is highly effective and strengthens the potential of CAIX as a clinical therapeutic target in a selected patient collective.

  12. Meta-iodobenzylguanidine scintigraphy in neuroblastoma--a comparison with conventional X-ray and ultrasound

    SciTech Connect

    Mueller-Gaertner, H.W.Er.; Erttmann, R.; Helmke, K. )

    1986-01-01

    To evaluate the accuracy of meta-iodobenzylguanidine (MIBG) imaging in comparison with bone X-ray and ultrasound, 15 patients with histologically verified neuroblastoma were investigated using 123- or 131MIBG scintigraphy. 123MIBG and 131MIBG are used as the abbreviations for 123-iodine-labeled-MIBG and 131-iodine-labeled-MIBG, respectively. Either 7.4 MBq 131MIBG (n = 4) or 111-185 MBq 123MIBG (n = 11) was applied, and scans were performed 24 and 48 h PI. Anatomical orientation was provided in selected cases by single-photon emission CT or scintigraphy of other organs. X-ray procedures or ultrasound depicted 27 neuroblastoma manifestations (primary tumors and metastatic deposits); 24 of these (89%) were identified by MIBG scintigraphy. Of 42 primary neuroblastomas and metastatic deposits, 27 (64%) were detected by corresponding bone X-ray or ultrasound. The 15 neuroblastoma lesions depicted solely by MIBG scans were mainly (80%) situated in the skeletal system. Because of the pronounced physiological MIBG uptake by liver tissue, detection of intrahepatic or perihepatic tumor involvement is difficult. MIBG scintigraphy is a safe and noninvasive means of locating a wide range of neuroblastoma lesions. Its main diagnostic advantage in comparison with bone X-ray lies in the detection of bone marrow infiltration.

  13. Antibiotic drug tigecycline reduces neuroblastoma cells proliferation by inhibiting Akt activation in vitro and in vivo.

    PubMed

    Zhong, Xiaoxia; Zhao, Erhu; Tang, Chunling; Zhang, Weibo; Tan, Juan; Dong, Zhen; Ding, Han-Fei; Cui, Hongjuan

    2016-06-01

    As the first member of glycylcycline bacteriostatic agents, tigecycline is approved as a novel expanded-spectrum antibiotic, which is clinically available. However, accumulating evidence indicated that tigecycline was provided with the potential application in cancer therapy. In this paper, tigecycline was shown to exert an anti-proliferative effect on neuroblastoma cell lines. Furthermore, it was found that tigecycline induced G1-phase cell cycle arrest instead of apoptosis by means of Akt pathway inhibition. In neuroblastoma cell lines, the Akt activator insulin-like growth factor-1 (hereafter referred to as IGF-1) reversed tigecycline-induced cell cycle arrest. Besides, tigecycline inhibited colony formation and suppressed neuroblastoma cells xenograft formation and growth. After tigecycline treatment in vivo, the Akt pathway inhibition was confirmed as well. Collectively, our data provided strong evidences that tigecycline inhibited neuroblastoma cells growth and proliferation through the Akt pathway inhibition in vitro and in vivo. In addition, these results were supported by previous studies concerning the application of tigecycline in human tumors treatment, suggesting that tigecycline might act as a potential candidate agent for neuroblastoma treatment.

  14. Skeletal assessment in neuroblastoma--the pitfalls of iodine-123-MIBG scans

    SciTech Connect

    Gordon, I.; Peters, A.M.; Gutman, A.; Morony, S.; Dicks-Mireaux, C.; Pritchard, J. )

    1990-02-01

    This study was carried out to compare iodine-123 metaiodobenzylguanidine ((I123I)MIBG) and technetium-99m-methylene diphosphonate bone scans ({sup 99m}Tc-MDP) in the detection of skeletal involvement by neuroblastoma. Forty-four children with neuroblastoma underwent both ({sup 123}I) MIBG and {sup 99m}Tc-MDP scans within a 4-wk period; bone marrow examination also was performed; all these investigations were done both at diagnosis and at follow-up. At diagnosis, four children with Stage 4 disease had normal ({sup 123}I)MIBG scans but abnormal {sup 99m}Tc-MDP scans, while at follow-up there were four children with negative ({sup 123}I)MIBG studies who later died from disseminated neuroblastoma. All eight scans are considered false-negative. In 24 children, the ({sup 123}I)MIBG revealed more extensive disease with 161 positive sites while the {sup 99m}Tc-MDP scan showed only 100 positive sites; 34 of these sites were common to both studies. This study shows that underassessment of skeletal involvement by neuroblastoma occurred using ({sup 123}I)MIBG scans and that one cannot therefore substitute ({sup 123}I)MIBG for {sup 99m}Tc-MDP bone scans in the staging of neuroblastoma.

  15. Oncogene MYCN regulates localization of NKT cells to the site of disease in neuroblastoma.

    PubMed

    Song, Liping; Ara, Tasnim; Wu, Hong-Wei; Woo, Chan-Wook; Reynolds, C Patrick; Seeger, Robert C; DeClerck, Yves A; Thiele, Carol J; Sposto, Richard; Metelitsa, Leonid S

    2007-09-01

    Valpha24-invariant natural killer T (NKT) cells are potentially important for antitumor immunity. We and others have previously demonstrated positive associations between NKT cell presence in primary tumors and long-term survival in distinct human cancers. However, the mechanism by which aggressive tumors avoid infiltration with NKT and other T cells remains poorly understood. Here, we report that the v-myc myelocytomatosis viral related oncogene, neuroblastoma derived (MYCN), the hallmark of aggressive neuroblastoma, repressed expression of monocyte chemoattractant protein-1/CC chemokine ligand 2 (MCP-1/CCL2), a chemokine required for NKT cell chemoattraction. MYCN knockdown in MYCN-amplified neuroblastoma cell lines restored CCL2 production and NKT cell chemoattraction. Unlike other oncogenes, MYCN repressed chemokine expression in a STAT3-independent manner, requiring an E-box element in the CCL2 promoter to mediate transcriptional repression. MYCN overexpression in neuroblastoma xenografts in NOD/SCID mice severely inhibited their ability to attract human NKT cells, T cells, and monocytes. Patients with MYCN-amplified neuroblastoma metastatic to bone marrow had 4-fold fewer NKT cells in their bone marrow than did their nonamplified counterparts, indicating that the MYCN-mediated immune escape mechanism, which we believe to be novel, is operative in metastatic cancer and should be considered in tumor immunobiology and for the development of new therapeutic strategies.

  16. A multidisciplinary team care approach improves outcomes in high-risk pediatric neuroblastoma patients.

    PubMed

    Chang, Hsiu-Hao; Liu, Yen-Lin; Lu, Meng-Yao; Jou, Shiann-Tarng; Yang, Yung-Li; Lin, Dong-Tsamn; Lin, Kai-Hsin; Tzen, Kai-Yuan; Yen, Ruoh-Fang; Lu, Ching-Chu; Liu, Chia-Ju; Peng, Steven Shinn-Forng; Jeng, Yung-Ming; Huang, Shiu-Feng; Lee, Hsinyu; Juan, Hsueh-Fen; Huang, Min-Chuan; Liao, Yung-Feng; Lee, Ya-Ling; Hsu, Wen-Ming

    2017-01-17

    We assessed the impact of a multidisciplinary team care program on treatment outcomes in neuroblastoma patients. Newly diagnosed neuroblastoma patients received treatment under the Taiwan Pediatric Oncology Group (TPOG) N2002 protocol at the National Taiwan University Hospital beginning in 2002. A multidisciplinary team care approach that included nurse-led case management for patients treated under this protocol began in January 2010. Fifty-eight neuroblastoma patients, including 29 treated between 2002 and 2009 (Group 1) and 29 treated between 2010 and 2014 (Group 2), were enrolled in the study. The 5-year overall survival (OS) and event-free survival (EFS) rates for all 58 patients were 59% and 54.7%, respectively. Group 2 patients, who were treated after implementation of the multidisciplinary team care program, had better 3-year EFS (P = 0.046), but not OS (P = 0.16), rates than Group 1 patients. In a multivariate analysis, implementation of the multidisciplinary team approach was the only significant independent prognostic factor for neuroblastoma patients. In further subgroup analyses, the multidisciplinary team approach improved EFS, but not OS, in patients with stage 4 disease, those in the high-risk group, and those with non-MYCN amplified tumors. These data indicate a multidisciplinary team care approach improved survival outcomes in high-risk neuroblastoma patients. However, further investigation will be required to evaluate the long-term effects of this approach over longer follow-up periods.

  17. Induction of thrombospondin 1 by retinoic acid is important during differentiation of neuroblastoma cells.

    PubMed Central

    Castle, V P; Ou, X; O'Shea, S; Dixit, V M

    1992-01-01

    Neuroblastoma, a malignant neoplasm that arises in the adrenal medulla or sympathetic ganglion, is one of the most common solid tumors of childhood. Reports that neuroblastomas spontaneously mature to form benign ganglioneuromas have prompted investigations into the efficacy of using agents that induce neuronal differentiation in the treatment of this malignancy. Retinoic acid is one agent in particular that has been shown to induce growth inhibition and terminal differentiation of neuroblastoma cell lines in vitro. Using the human neuroblastoma cell line SMH-KCNR, we have investigated the role of the extracellular matrix protein thrombospondin in retinoic acid induced neuroblastoma differentiation. Treatment with retinoic acid results in a rapid induction (within 4 h) of thrombospondin (TSP) message which is independent of intervening protein synthesis and superinducible in the presence of cycloheximide. This suggests that TSP functions as a retinoic acid inducible immediate early response gene. A concomitant increase in both cell associated and soluble forms of TSP protein can be detected within 24 h of retinoic acid treatment. A functional role for TSP in SMH-KCNR differentiation was established in experiments which showed that exposure to anti-TSP monoclonal antibodies delay retinoic acid differentiation for 48 h. At the time the cells overcome the effects of TSP inhibition, laminin production becomes maximal. Treatment of the cells with a combination of anti-TSP and antilaminin antibodies results in complete inhibition of differentiation. Images PMID:1430209

  18. Aromatic oligomers that form hetero duplexes in aqueous solution.

    PubMed

    Gabriel, Gregory J; Iverson, Brent L

    2002-12-25

    The electron-deficient 1,4,5,8-naphthalenetetracarboxylic diimide (Ndi) and electron-rich 1,5-dialkoxynaphthalene (Dan) have been shown to complex strongly with each other in water due to the hydrophobic effect as modulated through the electrostatic complementarity of the stacked dimer. Previously, oligomers of alternating Ndi and Dan units, termed aedamers, were the first foldamers to employ intramolecular aromatic stacking to effect the formation of secondary structure of nonnatural chains in aqueous solution. Described here is the use of this aromatic-aromatic (or pi-pi) interaction, this time in an intermolecular format, to demonstrate the self-assembly of stable hetero duplexes from a set of molecular strands (1a-4a) and (1b-4b) incorporating Ndi and Dan units, respectively. A 1-to-1 binding stoichiometry was determined from NMR and isothermal titration calorimetry (ITC) investigations, and these experiments indicated that association is enthalpically favored with the tetra-Ndi (4a) and tetra-Dan (4b) strands forming hetero duplexes (4a:4b) with a stability constant of 350 000 M-1 at T = 318 K. Polyacrylamide gel electrophoresis (PAGE) also illustrated the strong interaction between 4a and 4b and support a 1-to-1 binding mode even when one component is in slight excess. Overall, this system is the first to utilize complementary aromatic units to drive discrete self-assembly in aqueous solution. This new approach for designing assemblies is encouraging for future development of duplex systems with highly programmable modes of binding in solution or on surfaces.

  19. Genome-wide DNA methylation analysis identifies MEGF10 as a novel epigenetically repressed candidate tumor suppressor gene in neuroblastoma.

    PubMed

    Charlet, Jessica; Tomari, Ayumi; Dallosso, Anthony R; Szemes, Marianna; Kaselova, Martina; Curry, Thomas J; Almutairi, Bader; Etchevers, Heather C; McConville, Carmel; Malik, Karim T A; Brown, Keith W

    2017-04-01

    Neuroblastoma is a childhood cancer in which many children still have poor outcomes, emphasising the need to better understand its pathogenesis. Despite recent genome-wide mutation analyses, many primary neuroblastomas do not contain recognizable driver mutations, implicating alternate molecular pathologies such as epigenetic alterations. To discover genes that become epigenetically deregulated during neuroblastoma tumorigenesis, we took the novel approach of comparing neuroblastomas to neural crest precursor cells, using genome-wide DNA methylation analysis. We identified 93 genes that were significantly differentially methylated of which 26 (28%) were hypermethylated and 67 (72%) were hypomethylated. Concentrating on hypermethylated genes to identify candidate tumor suppressor loci, we found the cell engulfment and adhesion factor gene MEGF10 to be epigenetically repressed by DNA hypermethylation or by H3K27/K9 methylation in neuroblastoma cell lines. MEGF10 showed significantly down-regulated expression in neuroblastoma tumor samples; furthermore patients with the lowest-expressing tumors had reduced relapse-free survival. Our functional studies showed that knock-down of MEGF10 expression in neuroblastoma cell lines promoted cell growth, consistent with MEGF10 acting as a clinically relevant, epigenetically deregulated neuroblastoma tumor suppressor gene. © 2016 The Authors. Molecular Carcinogenesis Published by Wiley Periodicals, Inc.

  20. COX/mPGES-1/PGE2 pathway depicts an inflammatory-dependent high-risk neuroblastoma subset.

    PubMed

    Larsson, Karin; Kock, Anna; Idborg, Helena; Arsenian Henriksson, Marie; Martinsson, Tommy; Johnsen, John I; Korotkova, Marina; Kogner, Per; Jakobsson, Per-Johan

    2015-06-30

    The majority of solid tumors are presented with an inflammatory microenvironment. Proinflammatory lipid mediators including prostaglandin E2 (PGE2) contribute to the establishment of inflammation and have been linked to tumor growth and aggressiveness. Here we show that high-risk neuroblastoma with deletion of chromosome 11q represents an inflammatory subset of neuroblastomas. Analysis of enzymes involved in the production of proinflammatory lipid mediators showed that 11q-deleted neuroblastoma tumors express high levels of microsomal prostaglandin E synthase-1 (mPGES-1) and elevated levels of PGE2. High mPGES-1 expression also corresponded to poor survival of neuroblastoma patients. Investigation of the tumor microenvironment showed high infiltration of tumor-promoting macrophages with high expression of the M2-polarization markers CD163 and CD206. mPGES-1-expressing cells in tumors from different subtypes of neuroblastoma showed differential expression of one or several cancer-associated fibroblast markers such as vimentin, fibroblast activation protein α, α smooth muscle actin, and PDGF receptor β. Importantly, inhibition of PGE2 production with diclofenac, a nonselective COX inhibitor, resulted in reduced tumor growth in an in vivo model of 11q-deleted neuroblastoma. Collectively, these results suggest that PGE2 is involved in the tumor microenvironment of specific neuroblastoma subgroups and indicate that therapeutic strategies using existing anti-inflammatory drugs in combination with current treatment should be considered for certain neuroblastomas.