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Sample records for oligomers neuroblastoma damaged

  1. Neuroblastoma

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy Neuroblastoma KidsHealth > For Parents > Neuroblastoma Print A A A ... infancy, the chance of recovery is good. About Neuroblastoma Neuroblastoma is a rare disease in which a ...

  2. Rare individual amyloid-β oligomers act on astrocytes to initiate neuronal damage.

    PubMed

    Narayan, Priyanka; Holmström, Kira M; Kim, Dong-Hyun; Whitcomb, Daniel J; Wilson, Mark R; St George-Hyslop, Peter; Wood, Nicholas W; Dobson, Christopher M; Cho, Kwangwook; Abramov, Andrey Y; Klenerman, David

    2014-04-22

    Oligomers of the amyloid-β (Aβ) peptide have been implicated in the neurotoxicity associated with Alzheimer's disease. We have used single-molecule techniques to examine quantitatively the cellular effects of adding well characterized Aβ oligomers to primary hippocampal cells and hence determine the initial pathway of damage. We found that even picomolar concentrations of Aβ (1-40) and Aβ (1-42) oligomers can, within minutes of addition, increase the levels of intracellular calcium in astrocytes but not in neurons, and this effect is saturated at a concentration of about 10 nM of oligomers. Both Aβ (1-40) and Aβ (1-42) oligomers have comparable effects. The rise in intracellular calcium is followed by an increase in the rate of ROS production by NADPH oxidase in both neurons and astrocytes. The increase in ROS production then triggers caspase-3 activation resulting in the inhibition of long-term potentiation. Our quantitative approach also reveals that only a small fraction of the oligomers are damaging and that an individual rare oligomer binding to an astrocyte can initiate the aforementioned cascade of responses, making it unlikely to be due to any specific interaction. Preincubating the Aβ oligomers with an extracellular chaperone, clusterin, sequesters the oligomers in long-lived complexes and inhibits all of the physiological damage, even at a ratio of 100:1, total Aβ to clusterin. To explain how Aβ oligomers are so damaging but that it takes decades to develop Alzheimer's disease, we suggest a model for disease progression where small amounts of neuronal damage from individual unsequestered oligomers can accumulate over time leading to widespread tissue-level dysfunction. PMID:24717093

  3. [Neuroblastoma].

    PubMed

    Sawada, T; Komatsu, H; Shirai, C; Yamamoto, S; Ishiwari, K; Ishida, H; Ohmizono, Y; Matsumura, T

    1995-01-01

    Neuroblastoma is the most common and highly malignant tumor. The 2-year survival rate for NB patients for 1970s was 32% in US and 29% in Japan. But, improvement of prognosis was observed by recent advances in surgery, chemotherapy and numerous other supportive therapies. We introduce the some treatment regimens to patients with neuroblastoma which should be selected by the age and the stage at diagnosis and other prognostic factors such as N-myc amplification, trk overexpression, chromosome anomalies (lp-. double minutes, homogeneous staining region) of neuroblastoma cells and histological pathology. As a general rules, patients under 1 year of age without unfavorable prognostic factors should be treated less intensive regimen, even their tumors are progressive stages. Conversely, patients with progressive stages over 1 year of age without unfavorable factors, it is necessary to treat with intensive protocol. Furthermore, to patients of all age group with unfavorable factors, they are given a very strong intensive treatment through advances in supportive therapies such as the new antiemetics, G-CSF, antibiotics, or IVH etc.. Recent treatment regimens to the patients with neuroblastoma are presented.

  4. Neuroblastoma.

    PubMed

    Duckett, J W; Koop, C E

    1977-06-01

    Neuroblastoma is the most common solid malignant tumor in children. The prognosis is poor, and despite varying chemotherapy and radiation regimens, its status has not been altered much in the past 20 years. Seventy per cent of the patients have abdominal neuroblastomas, which carry the worst prognosis of all the possible sites for the disease. Seventy per cent of the patients have metastases at the time of diagnosis. Survival is best in children under one year of age and in those patients (8 per cent) who are fortunate enough to have only stage I disease. Stage IV disease has only a 3 per cent survival rate. Surgical removal of the tumor is still the primary therapy; irradiation is of significant benefit in patients with stage III disease. Immunotherapy offers an optimistic modality for future improvement in survival rates.

  5. DNA-damaging drug-induced apoptosis sensitized by N-myc in neuroblastoma cells.

    PubMed

    Li, Tai; Wang, Lin; Ke, Xiao-Xue; Gong, Xue-Yang; Wan, Jian-Hua; Hao, Xiang-Wei; Xu, Man; Xiang, Zonghuai; Cui, Zhao-Bo; Cui, Hongjuan

    2012-04-01

    Neuroblastoma is one of the most common solid tumours in children (8-10% of all malignancies). Over 22% of cases have N-myc amplification associated with aggressively growing neuroblastomas. Oncogene-induced sensitization of cells to apoptosis is an important mechanism for suppression of tumorigenesis. Tumour suppressors often play a critical role in linking oncogenes to apoptotic machinery. For example, activated p53 then targets both intrinsic and extrinsic pathways to promote apoptosis through transcription-dependent and -independent mechanisms. Understanding of the involved mechanisms has important clinical implications. We have employed DNA-damaging drug-induced apoptosis sensitized by oncogene N-myc as a model. DNA damaging drugs trigger high levels of p53, leading to caspase-9 activation in neuroblastoma cells. Inactivation of p53 protects cells from drug-triggered apoptosis sensitized by N-myc. These findings thus define a molecular pathway for mediating DNA-damaging drug-induced apoptosis sensitized by oncogene, and suggest that inactivation of p53 or other components of this apoptotic pathway may confer drug resistance in neuroblastoma cells. The data also suggests that inactivation of apoptotic pathways through co-operating oncogenes may be necessary for the pathogenesis of neuroblastoma with N-myc amplification.

  6. MYCN sensitizes human neuroblastoma to apoptosis by HIPK2 activation through a DNA damage response.

    PubMed

    Petroni, Marialaura; Veschi, Veronica; Prodosmo, Andrea; Rinaldo, Cinzia; Massimi, Isabella; Carbonari, Maurizio; Dominici, Carlo; McDowell, Heather P; Rinaldi, Christian; Screpanti, Isabella; Frati, Luigi; Bartolazzi, Armando; Gulino, Alberto; Soddu, Silvia; Giannini, Giuseppe

    2011-01-01

    MYCN amplification occurs in approximately 20% of human neuroblastomas and is associated with early tumor progression and poor outcome, despite intensive multimodal treatment. However, MYCN overexpression also sensitizes neuroblastoma cells to apoptosis. Thus, uncovering the molecular mechanisms linking MYCN to apoptosis might contribute to designing more efficient therapies for MYCN-amplified tumors. Here we show that MYCN-dependent sensitization to apoptosis requires activation of p53 and its phosphorylation at serine 46. The p53(S46) kinase HIPK2 accumulates on MYCN expression, and its depletion by RNA interference impairs p53(S46) phosphorylation and apoptosis. Remarkably, MYCN induces a DNA damage response that accounts for the inhibition of HIPK2 degradation through an ATM- and NBS1-dependent pathway. Prompted by the rare occurrence of p53 mutations and by the broad expression of HIPK2 in our human neuroblastoma series, we evaluated the effects of the p53-reactivating compound Nutlin-3 on this pathway. At variance from other tumor histotypes, in MYCN-amplified neuroblastoma, Nutlin-3 further induced HIPK2 accumulation, p53(S46) phosphorylation, and apoptosis, and in combination with clastogenic agents purged virtually the entire cell population. Altogether, our data uncover a novel mechanism linking MYCN to apoptosis that can be triggered by the p53-reactivating compound Nutlin-3, supporting its use in the most difficult-to-treat subset of neuroblastoma.

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

    PubMed

    Murakami-Tonami, Yuko; Ikeda, Haruna; Yamagishi, Ryota; Inayoshi, Mao; Inagaki, Shiho; Kishida, Satoshi; Komata, Yosuke; Jan Koster; 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

  8. 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

  9. DNA damage promotes Herpes Simplex Virus-1 protein expression in a neuroblastoma cell line

    PubMed Central

    Volcy, Ketna; Fraser, Nigel W.

    2013-01-01

    Although the induction of the cellular DNA damage response by Herpes simplex virus-1 (HSV-1) infection of epithelial cells in tissue culture promotes productive infection, there has been no experimental observation of the effect of the cellular DNA damage response on HSV-1 infection in vivo or in neuronal derived cell lines in tissue culture. Thus, it has been speculated that the lack of cellular DNA damage induction during infection of neurons may promote latency in these cells. This work examines the profile of HSV-1 promoter induction and protein expression, in the absence or presence of infection; using cellular DNA damage inducing topoisomerase inhibitors (Camptothecin and Etoposide) on a neuroblastoma cell line (C1300) in which HSV-1 infection fails to induce the DNA damage response. In the absence of infection, a plasmid expressing the immediate early ICP0 promoter was the most induced by the DNA damage drug treatments compared to the early (RR) and late (VP16) gene promoters. Similarly, drug treatment of C1300 cells infected with HSV-1 virus showed enhanced protein expression for ICP0, but not ICP4 and VP16 proteins. However, when the cells were infected with a HSV-1 virus defective in the immediate early gene trans-activator VP16 (in814) and treated with the DNA damaging drugs, there was enhanced expression of immediate early and late HSV-1 proteins. Although, viral infection of the neuroblastoma cell alone did not induce DNA damage, cellular DNA damage induced by drug treatments facilitated viral promoter induction and viral protein expression. This implicates a mechanism by which HSV-1 viral genes in a quiescent or latent state may become induced by cellular DNA damage in neuronal cells to facilitate productive infection. PMID:23354549

  10. How Is Neuroblastoma Diagnosed?

    MedlinePlus

    ... and can provide a picture of the entire skeleton at once. Neuroblastoma often causes bone damage, which ... settles in areas of damaged bone throughout the skeleton over the course of a couple of hours. ...

  11. Aggressive human neuroblastomas show a massive increase in the numbers of autophagic vacuoles and damaged mitochondria.

    PubMed

    Samardzija, Gordana; Stevovic, Tamara Kravic; Djuricic, Slavisa; Djokic, Dragomir; Djurisic, Marina; Ciric, Darko; Martinovic, Tamara; Bumbasirevic, Vladimir; Vujic, Dragana

    2016-01-01

    Autophagy is activated in cancer cells in response to multiple stresses and has been demonstrated to promote tumor cell survival and drug resistance in neuroblastoma (NB). This study was conducted to analyze the ultrastructural features of peripheral neuroblastic tumors (pNTs) and identify the relation of the types of NTs, the proliferation rate, and MYCN gene amplification with a number of autophagic vacuoles. Our results indicate that aggressive human NBs show a massive increase in the number of autophagic vacuoles associated with proliferation rate and that alteration of the mitochondria might be an important factor for the induction of autophagy in NTs. PMID:27669398

  12. Aqueous dispersions of oligomer-grafted carbon nanomaterials with controlled surface charge and minimal framework damage

    PubMed Central

    Hu, Sheng; Chen, Shu; Menzel, Robert; Goode, Angela D.; Ryan, Mary P.; Porter, Alexandra E.; Shaffer, Milo S. P.

    2015-01-01

    Functionalised carbon nanomaterials (CNMs), with an undamaged carbon framework and controlled physiochemical properties, are desirable for a wide range of scientific studies and commercial applications. The use of a thermochemical grafting approach provides a versatile means to functionalise both multi-walled carbon nanotubes (MWCNTs) and carbon black (CB) nanoparticles without altering their inherent structure. The functionalisation process was investigated by employing various types of grafting monomers; to improve water solubility, reagents were chosen that introduced ionic character either intrinsically or after further chemical reaction. The degree of grafting for both MWCNTs and CB ranged from 3 to 27 wt%, as established by thermal gravimetric analysis (TGA). Raman spectroscopy confirmed that the structural framework of the MWNTs was unaffected by the thermochemical treatment. The effectiveness of the surface modification was demonstrated by significantly improved dispersibility and stability in water, and further quantified by zeta-potential analysis. The concentration of stable, individualised, grafted MWNTs in water ranged from 30 to 80 µg mL−1, whereas functionalised CB (CB) in water showed improved dispersibility up to ~460 µg mL−1 after centrifugation at 10, 000 g for 15 minutes. The successful preparation of structurally identical but differently functionalised nanoparticles panels, with high water compatibility and minimal framework damage, are useful for controlled experiments. For example, they can be used to explore the relationship between toxicological effects and specific physiochemical properties, such as surface charge and geometry. PMID:25254653

  13. Aqueous dispersions of oligomer-grafted carbon nanomaterials with controlled surface charge and minimal framework damage.

    PubMed

    Hu, Sheng; Chen, Shu; Menzel, Robert; Goode, Angela D; Ryan, Mary P; Porter, Alexandra E; Shaffer, Milo S P

    2014-01-01

    Functionalised carbon nanomaterials (CNMs), with an undamaged carbon framework and controlled physiochemical properties, are desirable for a wide range of scientific studies and commercial applications. The use of a thermochemical grafting approach provides a versatile means to functionalise both multi-walled carbon nanotubes (MWCNTs) and carbon black (CB) nanoparticles without altering their inherent structures. The functionalisation process was investigated by employing various types of grafting monomers; to improve water solubility, reagents were chosen that introduced an ionic character either intrinsically or after further chemical reactions. The degree of grafting for both MWCNTs and CB ranged from 3-27 wt%, as established by thermal gravimetric analysis (TGA). Raman spectroscopy confirmed that the structural framework of the MWCNTs was unaffected by the thermochemical treatment. The effectiveness of the surface modification was demonstrated by significantly improved dispersibility and stability in water, and further quantified by zeta-potential analysis. The concentration of stable, individualised and grafted MWCNTs in water ranged from ∼30 to 80 μg mL(-1) after centrifugation at 10 000 g for 15 min, whereas functionalised CB in water showed improved dispersibility up to ∼460 μg mL(-1). The successful preparation of structurally identical but differently functionalised nanoparticle panels, with high water compatibility and minimal framework damage, is useful for controlled experiments. For example, they can be used to explore the relationship between toxicological effects and specific physiochemical properties, such as surface charge and geometry.

  14. 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

  15. What Is Neuroblastoma?

    MedlinePlus

    ... are the key statistics 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 ...

  16. 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 ...

  17. 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

  18. Damage of neuroblastoma cell SH-SY5Y mediated by MPP+ inhibits proliferation of T-cell leukemia Jurkat by co-culture system.

    PubMed

    Wang, Fuli; Awan, Umer Farooq; Wang, Yuanyuan; Wang, Luna; Qing, Hong; Ma, Hong; Deng, Yulin

    2014-01-01

    The adaptive immune system has implications in pathology of Parkinson's disease (PD). Research data demonstrated that the peripheral CD4+ T-cell population decreased in pathogenesis of PD. The effect of damaged dopaminergic neurons on peripheral T cells of PD is still unknown. In this study, we constructed a neuronal and glial cells co-culture model by using human neuroblastoma cells SH-SY5Y and gliomas cells U87. After the co-culture cells were treated with neurotoxin 1-methyl-4-phenylpyridinium (MPP+) for 24 h, the conditioned media was harvested and used to cultivate T-cell leukemia Jurkat cells for another 24 h. We then analyzed the cell proliferation, cell cycle and necrosis effect of Jurkat cells. The results showed that co-culture medium of SH-SY5Y and U87 cells with MPP+ treatment inhibited the proliferation of Jurkat cells compared to control medium without MPP+, even though the same concentration of MPP+ had very little toxicity to the Jurkat cell. Furthermore, co-culture medium with low concentration of MPP+ (100 µM) arrested Jurkat cells cycle in G2/M phase through increasing cell cycle division 2 (CDC2) and CyclinB1 expression level, whereas co-culture medium with high concentration of MPP+ (500 µM) induced Jurkat cell necrosis through cellular swelling and membrane breakage. Our data implies that damaged dopamine neurons with glial cells can lead to the reduced number or inhibited proliferation activity of peripheral T cells. PMID:24933638

  19. 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.

  20. Cell Proliferation in Neuroblastoma

    PubMed Central

    Stafman, Laura L.; Beierle, Elizabeth A.

    2016-01-01

    Neuroblastoma, the most common extracranial solid tumor of childhood, continues to carry a dismal prognosis for children diagnosed with advanced stage or relapsed disease. This review focuses upon factors responsible for cell proliferation in neuroblastoma including transcription factors, kinases, and regulators of the cell cycle. Novel therapeutic strategies directed toward these targets in neuroblastoma are discussed. PMID:26771642

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

    PubMed

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

    2015-01-01

    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.

  2. 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

  3. 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

  4. 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.

  5. Immune therapies for neuroblastoma.

    PubMed

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

    2009-05-01

    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 four 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.

  6. 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

  7. Melatonin prevents cytosolic calcium overload, mitochondrial damage and cell death due to toxically high doses of dexamethasone-induced oxidative stress in human neuroblastoma SH-SY5Y cells.

    PubMed

    Suwanjang, Wilasinee; Abramov, Andrey Y; Charngkaew, Komgrid; Govitrapong, Piyarat; Chetsawang, Banthit

    2016-07-01

    Stressor exposure activates the hypothalamic-pituitary-adrenal (HPA) axis and causes elevations in the levels of glucocorticoids (GC) from the adrenal glands. Increasing evidence has demonstrated that prolonged exposure to high GC levels can lead to oxidative stress, calcium deregulation, mitochondrial dysfunction and apoptosis in a number of cell types. However, melatonin, via its antioxidant activity, exhibits a neuroprotective effect against oxidative stress-induced cell death. Therefore, in the present study, we explored the protective effect of melatonin in GC-induced toxicity in human neuroblastoma SH-SY5Y cells. Cellular treatment with the toxically high doses of the synthetic GC receptor agonist, dexamethasone (DEX) elicited marked decreases in the levels of glutathione and increases in ROS production, lipid peroxidation and cell death. DEX toxicity also induced increases in the levels of cytosolic calcium and mitochondrial fusion proteins (Mfn1 and Opa1) but decreases in the levels of mitochondrial fission proteins (Fis1 and Drp1). Mitochondrial damage was observed in large proportions of the DEX-treated cells. Pretreatment of the cells with melatonin substantially prevented the DEX-induced toxicity. These results suggest that melatonin might exert protective effects against oxidative stress, cytosolic calcium overload and mitochondrial damage in DEX-induced neurotoxicity. PMID:27155536

  8. 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.

  9. Structural studies on HCN oligomers.

    PubMed

    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.

  10. Anti-angiogenesis in neuroblastoma.

    PubMed

    Ribatti, Domenico

    2013-06-01

    The nature of the angiogenic balance in neuroblastoma is complex, and a spectrum of angiogenesis stimulators and inhibitors have been detected in neuroblastoma tumours. The complex relationships between angiogenic cascade and anti-angiogenic agents in the tumour vascular phase have indicated that anti-angiogenesis can be considered as a strategy for the adjuvant therapy of neuroblastoma. The major goal is to establish if inhibition of angiogenesis is a realistic therapeutic strategy for inhibiting tumour cell dissemination and the formation of metastasis in neuroblastoma.

  11. WIP1 phosphatase as a potential therapeutic target in neuroblastoma.

    PubMed

    Richter, Mark; Dayaram, Tajhal; Gilmartin, Aidan G; Ganji, Gopinath; Pemmasani, Sandhya Kiran; Van Der Key, Harjeet; Shohet, Jason M; Donehower, Lawrence A; Kumar, Rakesh

    2015-01-01

    The wild-type p53-induced phosphatase 1 (WIP1) is a serine/threonine phosphatase that negatively regulates multiple proteins involved in DNA damage response including p53, CHK2, Histone H2AX, and ATM, and it has been shown to be overexpressed or amplified in human cancers including breast and ovarian cancers. We examined WIP1 mRNA levels across multiple tumor types and found the highest levels in breast cancer, leukemia, medulloblastoma and neuroblastoma. Neuroblastoma is an exclusively TP53 wild type tumor at diagnosis and inhibition of p53 is required for tumorigenesis. Neuroblastomas in particular have previously been shown to have 17q amplification, harboring the WIP1 (PPM1D) gene and associated with poor clinical outcome. We therefore sought to determine whether inhibiting WIP1 with a selective antagonist, GSK2830371, can attenuate neuroblastoma cell growth through reactivation of p53 mediated tumor suppression. Neuroblastoma cell lines with wild-type TP53 alleles were highly sensitive to GSK2830371 treatment, while cell lines with mutant TP53 were resistant to GSK2830371. The majority of tested neuroblastoma cell lines with copy number gains of the PPM1D locus were also TP53 wild-type and sensitive to GSK2830371A; in contrast cell lines with no copy gain of PPM1D were mixed in their sensitivity to WIP1 inhibition, with the primary determinant being TP53 mutational status. Since WIP1 is involved in the cellular response to DNA damage and drugs used in neuroblastoma treatment induce apoptosis through DNA damage, we sought to determine whether GSK2830371 could act synergistically with standard of care chemotherapeutics. Treatment of wild-type TP53 neuroblastoma cell lines with both GSK2830371 and either doxorubicin or carboplatin resulted in enhanced cell death, mediated through caspase 3/7 induction, as compared to either agent alone. Our data suggests that WIP1 inhibition represents a novel therapeutic approach to neuroblastoma that could be integrated with

  12. 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.

  13. Monoclonal antibodies and neuroblastoma.

    PubMed

    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.

  14. Mechanisms of neuroblastoma regression

    PubMed Central

    Brodeur, Garrett M.; Bagatell, Rochelle

    2014-01-01

    Recent genomic and biological studies of neuroblastoma have shed light on the dramatic heterogeneity in the clinical behaviour of this disease, which spans from spontaneous regression or differentiation in some patients, to relentless disease progression in others, despite intensive multimodality therapy. This evidence also suggests several possible mechanisms to explain the phenomena of spontaneous regression in neuroblastomas, including neurotrophin deprivation, humoral or cellular immunity, loss of telomerase activity and alterations in epigenetic regulation. A better understanding of the mechanisms of spontaneous regression might help to identify optimal therapeutic approaches for patients with these tumours. Currently, the most druggable mechanism is the delayed activation of developmentally programmed cell death regulated by the tropomyosin receptor kinase A pathway. Indeed, targeted therapy aimed at inhibiting neurotrophin receptors might be used in lieu of conventional chemotherapy or radiation in infants with biologically favourable tumours that require treatment. Alternative approaches consist of breaking immune tolerance to tumour antigens or activating neurotrophin receptor pathways to induce neuronal differentiation. These approaches are likely to be most effective against biologically favourable tumours, but they might also provide insights into treatment of biologically unfavourable tumours. We describe the different mechanisms of spontaneous neuroblastoma regression and the consequent therapeutic approaches. PMID:25331179

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

    PubMed

    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

    2016-01-01

    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. PMID:27346247

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

    PubMed Central

    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

    2016-01-01

    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. PMID:27346247

  17. 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.

  18. 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.

  19. Promising therapeutic targets in neuroblastoma.

    PubMed

    Matthay, Katherine K; George, Rani E; Yu, Alice L

    2012-05-15

    Neuroblastoma, the most common extracranial solid tumor in children, is derived from neural crest cells. Nearly half of patients present with metastatic disease and have a 5-year event-free survival of <50%. New approaches with targeted therapy may improve efficacy without increased toxicity. In this review we evaluate 3 promising targeted therapies: (i) (131)I-metaiodobenzylguanidine (MIBG), a radiopharmaceutical that is taken up by human norepinephrine transporter (hNET), which is expressed in 90% of neuroblastomas; (ii) immunotherapy with monoclonal antibodies targeting the GD2 ganglioside, which is expressed on 98% of neuroblastoma cells; and (iii) inhibitors of anaplastic lymphoma kinase (ALK), a tyrosine kinase that is mutated or amplified in ~10% of neuroblastomas and expressed on the surface of most neuroblastoma cells. Early-phase trials have confirmed the activity of (131)I-MIBG in relapsed neuroblastoma, with response rates of ~30%, but the technical aspects of administering large amounts of radioactivity in young children and limited access to this agent have hindered its incorporation into treatment of newly diagnosed patients. Anti-GD2 antibodies have also shown activity in relapsed disease, and a recent phase III randomized trial showed a significant improvement in event-free survival for patients receiving chimeric anti-GD2 (ch14.18) combined with cytokines and isotretinoin after myeloablative consolidation therapy. A recently approved small-molecule inhibitor of ALK has shown promising preclinical activity for neuroblastoma and is currently in phase I and II trials. This is the first agent directed to a specific mutation in neuroblastoma, and marks a new step toward personalized therapy for neuroblastoma. Further clinical development of targeted treatments offers new hope for children with neuroblastoma.

  20. Promising therapeutic targets in neuroblastoma

    PubMed Central

    Matthay, Katherine K.; George, Rani E.; Yu, Alice L.

    2012-01-01

    Neuroblastoma, the most common extra- cranial solid tumor in children, is derived from neural crest cells. Nearly half of patients present with metastatic disease, and have 5-year EFS of less than 50%. New approaches with targeted therapy may improve efficacy without increased toxicity. The current review will evaluate three promising targeted therapies, including 131I-metaiodobenzylguanidine (MIBG), a radiopharmaceutical taken up by the human norepinephrine transporter expressed in 90% of neuroblastomas, immunotherapy with monoclonal antibodies targeting the GD2 ganglioside, expressed on 98% of neuroblastoma cells, and inhibitors of ALK, a tyrosine kinase which is mutated or amplified in approximately 10% of neuroblastoma and expressed on the surface of most neuroblastoma cells. Early phase trials have confirmed the activity of 131I-MIBG in relapsed neuroblastoma, with response rates of about 30%, but the technical aspects of administration of large amounts of radioactivity in young children and the limited access have hindered incorporation into treatment of newly diagnosed patients. Anti-GD2 antibodies have also demonstrated activity in relapsed disease, and a recent phase III randomized trial showed a significant improvement in event-free survival for patients receiving chimeric anti-GD2 (ch14.18) combined with cytokines and isotretinoin after myeloablative consolidation therapy. A recently approved small molecule inhibitor of ALK has promising pre-clinical activity for neuroblastoma, and is currently in phase I and II trials. This is the first agent directed to a specific mutation in neuroblastoma, and marks a new step toward personalized therapy for neuroblastoma. Further clinical development of targeted treatments offers new hope for children with neuroblastoma. PMID:22589483

  1. Apoptosis pathways and neuroblastoma therapy.

    PubMed

    Fulda, S

    2009-01-01

    Evasion of apoptosis, the cell's intrinsic death program, is a hallmark of human cancers including neuroblastoma. Also, failure to undergo apoptosis may cause treatment resistance, since the cytotoxic activity of anticancer therapies commonly used in the clinic, e.g. chemotherapy, gamma-irradiation or immunotherapy, is predominantly mediated by triggering apoptosis in tumor cells. Therefore, a better understanding of the signaling pathways and molecules that govern apoptosis in neuroblastoma cells is expected to open new avenues for the design of molecular targeted therapies for neuroblastoma.

  2. Apoptosis pathways in neuroblastoma therapy.

    PubMed

    Fulda, Simone; Debatin, Klaus Michael

    2003-07-18

    Apoptosis, the cell's intrinsic death program, plays a crucial role in the regulation of tissue homeostasis, and an imbalance between cell death and proliferation may result in tumor formation. Also, killing of tumor cells by diverse cytotoxic approaches such as anticancer drugs, gamma-irradiation, suicide genes or immunotherapy, is predominantly mediated through induction of apoptosis. Failure to activate apoptotic pathways in response to drug treatment may lead to resistance of neuroblastoma cells to anticancer therapies. Understanding the molecular events that regulate apoptosis induced by cytotoxic therapies and how neuroblastoma cells evade apoptotic events may provide a new paradigm for neuroblastoma therapy. Thus, novel strategies targeting resistance of neuroblastoma cells will be based on insights into the molecular mechanisms of apoptosis as well as other forms of cell death.

  3. Neuroblastoma and dendritic cell function.

    PubMed

    Redlinger, Richard E; Mailliard, Robbie B; Barksdale, Edward M

    2004-02-01

    Neuroblastoma, the most common extracranial solid tumor of childhood, remains a challenge for clinicians and investigators in pediatric surgical oncology. The absence of effective conventional therapies for most patients with neuroblastoma justifies the application of novel, biology-based, experimental approaches to the treatment of this deadly disease. The observation that some aggressive neuroblastomas, particularly in infants, may spontaneously regress suggested that immune-mediated mechanisms may be important in the biology of this disease. Advances in the understanding of the cognate interactions between T cells, antigen-presenting cells and tumors have demonstrated the sentinel role of dendritic cells (DC), the most potent antigen presenting cells, in initiating the cellular immune response to cancer. Until recently the function of DC in pediatric solid tumors, especially neuroblastoma, had not been extensively studied. This review discusses the role of DC in initiating and coordinating the immune response against cancer, the ability of neuroblastoma to induce DC dysregulation at multiple levels by inhibiting DC maturation and function, and the current vaccine strategies being designed to employ the unique ability of DC to promote neuroblastoma regression.

  4. 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

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

    MedlinePlus

    ... treatment Next Topic Additional resources for 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 ...

  6. Immunology and Immunotherapy of Neuroblastoma

    PubMed Central

    Seeger, Robert C.

    2012-01-01

    Purpose This review demonstrates the importance of immunobiology and immunotherapy research for understanding and treating neuroblastoma. Principal results The first suggestions of immune system-neuroblastoma interactions came from in vitro experiments showing that lymphocytes from patients were cytotoxic for their own tumor cells and from evaluations of tumors from patients that showed infiltrations of immune system cells. With the development of monoclonal antibody (mAb) technology, a number of mAbs were generated against neuroblastoma cells lines and were used to define tumor associated antigens. Disialoganglioside (GD2) is one such antigen that is highly expressed by virtually all neuroblastoma cells and so is a useful target for both identification and treatment of tumor cells with mAbs. Preclinical research using in vitro and transplantable tumor models of neuroblastoma has demonstrated that cytotoxic T lymphocytes (CTLs) can specifically recognize and kill tumor cells as a result of vaccination or of genetic engineering that endows them with chimeric antigen receptors. However, CTL based clinical trials have not progressed beyond pilot and phase I studies. In contrast, anti-GD2 mAbs have been extensively studied and modified in pre-clinical experiments and have progressed from phase I through phase III clinical trials. Thus, the one proven beneficial immunotherapy for patients with high-risk neuroblastoma uses a chimeric anti-GD2 mAb combined with IL-2 and GM-CSF to treat patients after they have received intensive cyto-reductive chemotherapy, irradiation, and surgery. Ongoing pre-clinical and clinical research emphasizes vaccine, adoptive cell therapy, and mAb strategies. Recently it was shown that the neuroblastoma microenvironment is immunosuppressive and tumor growth promoting, and strategies to overcome this are being developed to enhance anti-tumor immunotherapy. Conclusions Our understanding of the immunobiology of neuroblastoma has increased

  7. Disialoganglioside directed immunotherapy of neuroblastoma.

    PubMed

    Modak, Shakeel; Cheung, Nai-Kong V

    2007-02-01

    Achieving a cure for metastatic neuroblastoma remains a challenge despite sensitivity to chemotherapy and radiotherapy. Most patients achieve remission, but a failure to eliminate minimal residual disease (MRD) often leads to relapse. Immunotherapy is potentially useful for chemotherapy-resistant disease and may be particularly effective for low levels of MRD that are below the threshold for detection by routine radiological and histological methods. Disialoganglioside (GD2), a surface glycolipid antigen that is ubiquitous and abundant on neuroblastoma cells is an ideal target for immunotherapy. Anti-GD2 monoclonal antibodies currently form the mainstay of neuroblastoma immunotherapy and their safety profile has been well-established. Although responses in patients with gross disease have been observed infrequently, histologic responses of bone marrow disease are consistently achieved in >75 percent of patients with primary refractory neuroblastoma. The advent of highly sensitive and specific molecular assays to measure MRD has confirmed the efficacy anti-GD2 antibody immunotherapy in patients with subclinical disease. Such markers will allow further optimization of other anti-MRD therapies. We review the current status of anti-GD2 clinical trials for neuroblastoma and novel preclinical GD2-targeted strategies for this rare but often lethal childhood cancer.

  8. RESEARCH ADVANCES IN NEUROBLASTOMA IMMUNOTHERAPY.

    PubMed

    Booker, Latania Y; Ishola, Titilope A; Bowen, Kanika A; Chung, Dai H

    2009-05-01

    Neuroblastoma is the third most common pediatric cancer in the United States and is responsible for 15% of pediatric cancer-related deaths. Despite major advances in multimodal therapy, the clinical outcome for several patients remains poor. Due to the desperate need for innovativation and improved success in the treatment and management of neuroblastoma, research interests in immunotherapy have been on the rise in recent years. Current immunotherapeutic approaches under investigation include antibodies targeting the neuroblastoma antigen GD2, cytokine stimulation of immune cells, use of immunocytokine conjugates, radioimmunotherapy, and tumor-primed dendritic cells. Immunotherapy could serve as a safe alternative or adjunct to current therapeutic protocols and would presumptively have fewer deleterious effects making it more favorable to patients.

  9. Locoregional MYCN-amplified neuroblastoma.

    PubMed

    Morales La Madrid, Andres; Volchenboum, Samuel; Gastier-Foster, Julie M; Pyatt, Robert; Liu, Don; Pytel, Peter; Lavarino, Cinzia; Rodriguez, Eva; Cohn, Susan L

    2012-10-01

    MYCN-amplification is strongly associated with other high-risk prognostic factors and poor outcome in neuroblastoma. Infrequently, amplification of MYCN has been identified in localized tumors with favorable biologic features. Outcome for these children is difficult to predict and optimal treatment strategies remain unclear. We report a 5-month-old who presented with an MYCN-amplified INSS stage 3, pelvic neuroblastoma. The tumor had favorable histology, hyperdiploidy, and lacked 1p36 and 11q23 aberrations. Although the patient met the criteria for high-risk neuroblastoma, because of the discordant prognostic markers we elected to treat her according to an intermediate-risk protocol. She remains event-free more than 18 months.

  10. 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.

  11. 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. PMID:27165366

  12. Inconspicuous Presentation of Metastatic Neuroblastoma.

    PubMed

    Hatten, James; McGuffin, Aaron; Mogul, Mark

    2016-01-01

    Neuroblastoma is a malignant tumor arising from nerve tissue that accounts for approximately 15 percent of pediatric cancer fatalities. Primary tumors most commonly arise in sympathetic nervous tissue of the abdomen and metastasize to the bone marrow, liver, and lymph nodes. This case report depicts a 3-year-old girl who presented with a recurring fever, runny nose, and a positive test for rhinovirus suggesting a simple case of the common cold. Further investigation, however, revealed stage 4 neuroblastoma. This patient experience emphasizes the importance of having a high level of suspicion to rule out more serious underlying pathology in a seemingly unremarkable patient presentation. PMID:27491101

  13. Immunogenicity of human neuroblastoma.

    PubMed

    Prigione, Ignazia; Corrias, Maria Valeria; Airoldi, Irma; Raffaghello, Lizzia; Morandi, Fabio; Bocca, Paola; Cocco, Claudia; Ferrone, Soldano; Pistoia, Vito

    2004-12-01

    Neuroblastoma (NB) is a neuroectodermal tumor that affects children in the first years of life. Half of NB cases present with metastatic disease at diagnosis and have a poor prognosis, in spite of the most advanced chemotherapeutic protocols combined with autologous hematopoietic stem cell transplantation. Among the new avenues for NB treatment that are being explored, immunotherapy has attracted much interest. Emphasis has been placed on monoclonal antibodies directed to tumor-associated antigens--in particular the disialoganglioside GD2--that have been tested in the clinical setting with promising results. In addition, stimulation of cell-mediated antitumor effector mechanisms have been attempted-for example, by recombinant interleukin (IL)-2 administration. Nonetheless, the issue of the immunogenicity of human NB cells has never been thoroughly addressed. Here we shall review the work carried out in our lab in recent years and show that NB cells express tumor-associated antigens, such as MAGE-3, but lack constitutive expression of costimulatory molecules and surface HLA class I and II molecules. As such, NB cells are likely to be ignored by the host T cell compartment, since expression of HLA and costimulatory molecules on antigen presenting cells are sine qua non conditions for efficient peptide presentation to T cells and for the subsequent activation and clonal expansion of the latter cells. Notably, in vitro experiments with NB cell lines demonstrated that surface HLA class I molecules and the CD40 costimulatory molecule were upregulated following cell incubation with recombinant interferon-gamma. Interaction of CD40 with recombinant CD40 ligand induced apoptosis of NB cells through a caspase 8-dependent mechanism. Collectively, these results indicate that the immunogenicity of human NB cells is very low but suggest that manipulation by cytokine administration or gene transfer can increase their immunogenic potential. On the other hand, NB cells represent an

  14. Conformational Dynamics of Specific Aβ Oligomers Govern Their Ability To Replicate and Induce Neuronal Apoptosis.

    PubMed

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

    2016-04-19

    Oligomers of amyloid-β (Aβ) have emerged as the primary toxic agents responsible for early synaptic dysfunction and neuronal death in Alzheimer's disease (AD). Characterization of oligomers is an important step in the progress toward delineating the complex molecular mechanisms involved in AD pathogenesis. In our previous reports, we established that a distinct 12-24mer neurotoxic oligomer of Aβ42, called Large Fatty Acid derived Oligomers (LFAOs), exhibits a unique property of replication in which LFAOs directly duplicate to quantitatively larger amounts upon interacting with monomers. This self-propagative process of replication is somewhat reminiscent of prion propagation. In this report, we sought to investigate the concentration-dependent conformational dynamics LFAOs undergo and how such transitions manifest in their ability to replicate and induce neuronal apoptosis. The results indicate that LFAOs undergo a concentration-dependent transition between 12mers and disperse 12-24mers with a dissociation constant (Kd) of 0.1 μM. The two species differ in their respective tertiary/quaternary structures but not their secondary structures. This conformational dynamics of LFAOs correlates with their ability to replicate and to induce apoptosis in SH-SY5Y human neuroblastoma cells, with 12mers being more neurotoxic and prone to replication than 12-24mers. The latter result implicates the replication process dominates at low physiological concentrations. The observations made in this report may have profound significance in deciphering the elusive roles of Aβ oligomer phenotypes and in determining their prion-type behavior in AD pathology.

  15. Nuclear medicine therapy of neuroblastoma.

    PubMed

    Hoefnagel, C A

    1999-12-01

    Specific targeting of radionuclides to neuroblastoma, a neural crest tumour occurring predominantly in young children and associated with a relatively poor prognosis, may be achieved via the metabolic route (MIBG), receptor binding (peptides) or immunological approach (antibodies). The clinical role of 131I-MIBG therapy and radioimmunotherapy in neuroblastoma is discussed. In recurrent or progressive metastatic disease after conventional treatment modalities have failed, 131I-MIBG therapy, with an overall objective response rate of 35%, is probably the best palliative treatment, as the invasiveness and toxicity of this therapy compare favourably with that of chemotherapy, immunotherapy and external beam radiotherapy. In patients presenting with inoperable stage III and IV neuroblastoma, 131I-MIBG therapy at diagnosis is at least as effective as combination chemotherapy but is associated with much less toxicity. In patients with recurrent disease 131I-MIBG therapy in combination with hyperbaric oxygen therapy proved feasible and encouraging effects on survival have been observed. Attempts to intensify the treatment in relapsed patients by combination of 131I-MIBG therapy with high dose chemotherapy and/or total body irradiation have met with considerable toxicity. Developments in MIBG therapy aiming at improving the therapeutic index are mentioned. Early results of radioimmunotherapy using 131I-UJ13A or 131I-3F8 monoclonal antibodies have shown moderate objective response and considerable side effects in patients with stage IV neuroblastoma, who had relapsed or failed conventional therapy. New developments in radioimmunotherapy of neuroblastoma include the use of chimaeric antibodies, the enhancement of tumour uptake by modulation of antigen expression or by increasing the tumour perfusion/vascularity/permeability, the use of other labels and multistep targeting techniques, e.g. using bispecific monoclonal antibodies.

  16. 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.

  17. 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.

  18. Ballistic Energy Transport in Oligomers.

    PubMed

    Rubtsova, Natalia I; Qasim, Layla N; Kurnosov, Arkady A; Burin, Alexander L; Rubtsov, Igor V

    2015-09-15

    The development of nanocomposite materials with desired heat management properties, including nanowires, layered semiconductor structures, and self-assembled monolayer (SAM) junctions, attracts broad interest. Such materials often involve polymeric/oligomeric components and can feature high or low thermal conductivity, depending on their design. For example, in SAM junctions made of alkane chains sandwiched between metal layers, the thermal conductivity can be very low, whereas the fibers of ordered polyethylene chains feature high thermal conductivity, exceeding that of many pure metals. The thermal conductivity of nanostructured materials is determined by the energy transport between and within each component of the material, which all need to be understood for optimizing the properties. For example, in the SAM junctions, the energy transport across the metal-chain interface as well as the transport through the chains both determine the overall heat conductivity, however, to separate these contributions is difficult. Recently developed relaxation-assisted two-dimensional infrared (RA 2DIR) spectroscopy is capable of studying energy transport in individual molecules in the time domain. The transport in a molecule is initiated by exciting an IR-active group (a tag); the method records the influence of the excess energy on another mode in the molecule (a reporter). The energy transport time can be measured for different reporters, and the transport speed through the molecule is evaluated. Various molecules were interrogated by RA 2DIR: in molecules without repeating units (disordered), the transport mechanism was expected and found to be diffusive. The transport via an oligomer backbone can potentially be ballistic, as the chain offers delocalized vibrational states. Indeed, the transport regime via three tested types of oligomers, alkanes, polyethyleneglycols, and perfluoroalkanes was found to be ballistic, whereas the transport within the end groups was diffusive

  19. Immunotherapy. Neuroblastoma as a model.

    PubMed

    Cheung, N K

    1991-04-01

    Combinations of aggressive therapy and radiotherapy directed at the primary tumor site as well as dose intensive chemotherapy against metastases can effectively induce complete remissions in patients with stage IV neuroblastomas. By virtue of its tumor specificity, the use of immunotherapy at the time when microscopic residual disease is present holds great promise in eradicating the tumors permanently. Monoclonal antibodies can accumulate selectively and at high concentrations in neuroblastomas. They have the potential of initiating complement activation and inflammation at the tumor site. Hematopoietic factors and cytokines can reinforce the body with tumoricidal leukocytes. Ex vivo activation of autologous white cells as well as arming by genetic manipulation can also produce tumor-seeking vehicles that may be therapeutically useful. As the knowledge of tumor and host immunobiology accumulates, the optimal combination of these approaches will become apparent.

  20. Targeted cytokine delivery to neuroblastoma.

    PubMed

    Dehal, P K; Embleton, M J; Kemshead, J T; Hawkins, R E

    2002-08-01

    The aim of this study was to construct a fusion protein from the cytokine granulocyte/macrophage colony-stimulating factor (GM-CSF) and a single-chain Fv fragment (scFv D29) and to investigate its potential to activate cells of the immune system against neuroblastoma cells expressing neural cell adhesion molecule (NCAM). Mammalian cell expression of the scFv D29-GM-CSF fusion protein was compared using a number of vectors, including retroviral and adenoviral vectors. The resultant fusion protein, expressed by HeLa cells, was found by ELISA to bind immobilized recombinant NCAM. Moreover, FACS analysis confirmed binding to the human neuroblastoma cell line SKNBE and a murine neuroblastoma cell line engineered to express the glycosylphosphatidylinositol form of human NCAM (N2A-rKNIE). The fusion protein was also found to stimulate the proliferation of the FDC-P1 haemopoietic cell line, which is dependent on GM-CSF (or interleukin 3) for continued growth. In vitro clonogenic assays indicated that scFv-GM-CSF could selectively induce growth inhibition of SKNBE cells by murine lymphoid cells.

  1. [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. PMID:15105902

  2. Role of radiation therapy in the treatment of olfactory neuroblastoma

    SciTech Connect

    Ahmad, K.; Fayos, J.V.

    1980-03-01

    Nine patients with olfactory neuroblastoma were treated at the Radiation Therapy Service of the University of Michigan Medical Center (UMMC); their case histories are presented. There was a slight female predominance and the peak age distribution was between 60 to 69 years (4 patients). One patient developed sudden visual loss in one eye and partial loss in the other resulting from a hematoma at the optic chiasmal region. We have ascribed it to radiation damage. Our results show that this tumor is radiocontrollable; control at primary site occurs in 66.6% of patients. We recommend postoperative irradiation in all tumors that are extensive initially.

  3. The effect of explosive blast loading on human neuroblastoma cells.

    PubMed

    Zander, Nicole E; Piehler, Thuvan; Banton, Rohan; Boggs, Mary

    2016-07-01

    Diagnosis of mild to moderate traumatic brain injury is challenging because brain tissue damage progresses slowly and is not readily detectable by conventional imaging techniques. We have developed a novel in vitro model to study primary blast loading on dissociated neurons using nitroamine explosives such as those used on the battlefield. Human neuroblastoma cells were exposed to single and triple 50-psi explosive blasts and single 100-psi blasts. Changes in membrane permeability and oxidative stress showed a significant increase for the single and triple 100-psi blast conditions compared with single 50-psi blast and controls.

  4. How does ethanol induce apoptotic cell death of SK-N-SH neuroblastoma cells.

    PubMed

    Moon, Yong; Kwon, Yongil; Yu, Shun

    2013-07-15

    A body of evidence suggests that ethanol can lead to damage of neuronal cells. However, the mechanism underlying the ethanol-induced damage of neuronal cells remains unclear. The role of mitogen-activated protein kinases in ethanol-induced damage was investigated in SK-N-SH neuroblastoma cells. 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide cell viability assay, DNA fragmentation detection, and flow cytometric analysis showed that ethanol induced apoptotic cell death and cell cycle arrest, characterized by increased caspase-3 activity, DNA fragmentation, nuclear disruption, and G1 arrest of cell cycle of the SK-N-SH neuroblastoma cells. In addition, western blot analysis indicated that ethanol induced a lasting increase in c-Jun N-terminal protein kinase activity and a transient increase in p38 kinase activity of the neuroblastoma cells. c-Jun N-terminal protein kinase or p38 kinase inhibitors significantly reduced the ethanol-induced cell death. Ethanol also increased p53 phosphorylation, followed by an increase in p21 tumor suppressor protein and a decrease in phospho-Rb (retinoblastoma) protein, leading to alterations in the expressions and activity of cyclin dependent protein kinases. Our results suggest that ethanol mediates apoptosis of SK-N-SH neuroblastoma cells by activating p53-related cell cycle arrest possibly through activation of the c-Jun N-terminal protein kinase-related cell death pathway. PMID:25206494

  5. Stem cell transplantation for neuroblastoma.

    PubMed

    Fish, J D; Grupp, S A

    2008-01-01

    High-risk neuroblastoma is a childhood malignancy with a poor prognosis. Gradual improvements in survival have correlated with therapeutic intensity, and the ability to harvest, process and store autologous hematopoietic stem cells has allowed for dose intensification beyond marrow tolerance. The use of high-dose chemotherapy with autologous hematopoietic stem cell rescue in consolidation has resulted in improvements in survival, although further advances are still needed. Newer approaches to SCT and supportive care, most notably the transition to PBSC, have resulted in further improvement in survival and decreases in treatment-related mortality. Research into experimental approaches to hematopoietic SCT is ongoing.

  6. Neuroblastoma: paradigm for precision medicine.

    PubMed

    Irwin, Meredith S; Park, Julie R

    2015-02-01

    Neuroblastoma (NB) is the third most common pediatric cancer. Although NB accounts for 7% of pediatric malignancies, it is responsible for more than 10% of childhood cancer-related mortality. Prognosis and treatment are determined by clinical and biological risk factors. Estimated 5-year survival rates for patients with non-high-risk and high-risk NB are more than 90% and less than 50%, respectively. Recent clinical trials have continued to reduce therapy for patients with non-high-risk NB, including the most favorable subsets who are often followed with observation approaches. In contrast, high-risk patients are treated aggressively with chemotherapy, radiation, surgery, and myeloablative and immunotherapies.

  7. 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.

  8. 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.

  9. Therapeutic strategies for the treatment of neuroblastoma.

    PubMed

    Izbicka, Elzbieta; Izbicki, Tadeusz

    2005-12-01

    Neuroblastoma, the most common extracranial solid tumor in children, has a highly heterogeneous clinical presentation and course. Current risk-based therapy is usually effective in patients who have intermediate risk features, however, intensive treatment of advanced neuroblastoma in children over two years of age is far from satisfactory. Current therapeutic approaches include the optimization of pharmacokinetic and pharmacodynamic properties of conventional agents, as well as the development of novel targeted drugs, such as signal transduction and angiogenesis inhibitors, apoptosis/differentiation stimulators and immunotherapeutics. This review provides an overview of current treatment options and future perspectives for the therapy and prevention of neuroblastoma.

  10. Immunotherapy of neuroblastoma: present, past and future.

    PubMed

    Raffaghello, Lizzia; Pistoia, Vito

    2006-04-01

    Neuroblastoma is a neuroectodermal tumor of childhood with poor prognosis and low survival in patients with advanced-stage disease who respond to conventional therapies but unfortunately, often present relapse. Therefore, the search for novel therapeutic strategies is warranted and represents the objective of many investigators. Among the new, innovative approaches, immunotherapy has attracted much interest. However, until recently, little information was available about the immunogenicity of human neuroblastoma.

  11. Neuroblastoma: developmental biology, cancer genomics and immunotherapy.

    PubMed

    Cheung, Nai-Kong V; Dyer, Michael A

    2013-06-01

    Neuroblastoma is a solid tumour that arises from the developing sympathetic nervous system. Over the past decade, our understanding of this disease has advanced tremendously. The future challenge is to apply the knowledge gained to developing risk-based therapies and, ultimately, improving outcome. In this Review we discuss the key discoveries in the developmental biology, molecular genetics and immunology of neuroblastoma, as well as new translational tools for bringing these promising scientific advances into the clinic.

  12. Neuroblastoma: Developmental Biology, Cancer Genomics, and Immunotherapy

    PubMed Central

    Cheung, Nai-Kong V.; Dyer, Michael A.

    2015-01-01

    Neuroblastoma is a solid tumor that arises from the developing sympathetic nervous system. Over the past decade, our understanding of this disease has advanced tremendously. The future challenge is to apply the knowledge gained toward developing risk-based therapies and ultimately improving outcome. Here we review the key discoveries in the developmental biology, molecular genetics, and immunology of neuroblastoma, as well as new translational tools to bring these promising scientific advances into the clinic. PMID:23702928

  13. Neuroblastoma and pediatric delirium: a case series.

    PubMed

    Traube, Chani; Augenstein, Julie; Greenwald, Bruce; LaQuaglia, Michael; Silver, Gabrielle

    2014-06-01

    Delirium occurs frequently in critically ill children, and children with neuroblastoma may be at particular risk. Early diagnosis and treatment may improve short- and long-term outcomes. In this case series, we present four critically ill children with neuroblastoma who were diagnosed with delirium in the post-operative period. In all four patients, the diagnosis of delirium facilitated targeted intervention and improvement. Heightened awareness by pediatric oncologists, surgeons, and intensivists may lead to earlier diagnosis and improvement in clinical outcomes.

  14. 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

  15. Induced differentiation inhibits sphere formation in neuroblastoma.

    PubMed

    Craig, Brian T; Rellinger, Eric J; Alvarez, Alexandra L; Dusek, Haley L; Qiao, Jingbo; Chung, Dai H

    2016-08-19

    Neuroblastoma arises from the neural crest, the precursor cells of the sympathoadrenal axis, and differentiation status is a key prognostic factor used for clinical risk group stratification and treatment strategies. Neuroblastoma tumor-initiating cells have been successfully isolated from patient tumor samples and bone marrow using sphere culture, which is well established to promote growth of neural crest stem cells. However, accurate quantification of sphere-forming frequency of commonly used neuroblastoma cell lines has not been reported. Here, we show that MYCN-amplified neuroblastoma cell lines form spheres more frequently than non-MYCN-amplified cell lines. We also show that sphere formation is directly sensitive to cellular differentiation status. 13-cis-retinoic acid is a clinically used differentiating agent that induces a neuronal phenotype in neuroblastoma cells. Induced differentiation nearly completely blocked sphere formation. Furthermore, sphere formation was specifically FGF-responsive and did not respond to increasing doses of EGF. Taken together, these data suggest that sphere formation is an accurate method of quantifying the stemness phenotype in neuroblastoma. PMID:27297102

  16. Neuroblastoma

    MedlinePlus

    ... rare type of cancerous tumor that develops from nerve tissue. It usually occurs in infants and children. ... areas of the body. It develops from the tissues that form the sympathetic nervous system. This is the part of the nervous ...

  17. Neuroprotective effect of Chunghyuldan from amyloid beta oligomer induced neuroinflammation in vitro and in vivo.

    PubMed

    Kim, Hyo Geun; Kim, Ji-Young; Whang, Wei-Wan; Oh, Myung Sook

    2014-06-01

    Microglia-mediated inflammation is a major pathological mechanism contributing to Alzheimer's disease (AD), and has been proposed as a potential therapeutic target. Chunghyuldan (CHD; Qingxue-dan in Chinese and Daio-Orengedokuto in Japanese) possesses wide-ranging biological effects, including anti-hyperlipidemic, anti-stroke, anti-inflammatory, and antioxidant activities that could affect neurological functions. In this study, we examined the effects of CHD in in-vitro and in-vivo models of AD induced by the oligomeric form of amyloid-beta (Aβ oligomer), which acts directly on microglia-mediated neuroinflammation to result in neuronal damage and cognitive impairment. CHD at 0.1-100 μg·mL(-1) significantly protected PC12 cells and rat primary hippocampal cells from Aβ oligomer1-42 toxicity. In addition, CHD at 1-10 μg·mL(-1) inhibited Aβ oligomer1-42 induced production of nitric oxide, tumor necrosis factor-α, and interleukin-1β in microglial cells. In an in-vivo AD model, administration of CHD (50 mg·(kg body mass)(-1), for 5 days, per oral) inhibited the activation of astrocytes and microglia in the dentate gyrus and neuronal damage in the CA1 of the ipsilateral hippocampus. Moreover, CHD ameliorated cognitive impairment induced by Aβ oligomer1-42 toxicity. These results demonstrate the neuroprotective effects of CHD through inhibition of microglia-mediated neuroinflammation in in-vitro and in-vivo AD-like models induced by Aβ oligomer1-42 toxicity.

  18. Occult orbital neuroblastoma detected after administration of an antitumor vaccine.

    PubMed

    Wilson, Matthew W; Moshfeghi, Darius M; Haik, Barrett G; Haight, Ann E; Hill, D Ashley; Davidoff, Andrew M; Rousseau, Raphael F; Bowman, Laura C

    2003-01-01

    A 6-year-old girl with neuroblastoma developed swelling and erythema of her right upper eyelid following administration of an interleukin-2 and lymphotactin gene-modified allogeneic neuroblastoma cell vaccine. Computed tomography demonstrated a cystic lesion in the subperiosteal space. A biopsy of the mass showed necrotic neuroblastoma with minimal associated inflammation. To our knowledge, this case represents the first description of occult orbital metastases in a patient with neuroblastoma detected after administration of an antitumor vaccine.

  19. Nucleolar protein PES1 is a marker of neuroblastoma outcome and is associated with neuroblastoma differentiation

    PubMed Central

    Nakaguro, Masato; Kiyonari, Shinichi; Kishida, Satoshi; Cao, Dongliang; Murakami-Tonami, Yuko; Ichikawa, Hitoshi; Takeuchi, Ichiro; Nakamura, Shigeo; Kadomatsu, Kenji

    2015-01-01

    Neuroblastoma (NB) is a childhood malignant tumor that arises from precursor cells of the sympathetic nervous system. Spontaneous regression is a phenomenon unique to NBs and is caused by differentiation of tumor cells. PES1 is a multifunctional protein with roles in both neural development and ribosome biogenesis. Various kinds of models have revealed the significance of PES1 in neurodevelopment. However, the roles of PES1 in NB tumorigenesis and differentiation have remained unknown. Here we show that NB cases with MYCN amplification and clinically unfavorable stage (INSS stage 4) express higher levels of PES1. High PES1 expression was associated with worse overall and relapse-free survival. In NB cell lines, PES1 knockdown suppressed tumor cell growth and induced apoptosis. This growth inhibition was associated with the expression of NB differentiation markers. However, when the differentiation of NB cell lines was induced by the use of all-trans retinoic acid, there was a corresponding decrease in PES1 expression. Pes1 expression of tumorspheres originated from MYCN transgenic mice also diminished after the induction of differentiation with growth factors. We also reanalyzed the distribution of PES1 in the nucleolus. PES1 was localized in the dense fibrillar component, but not in the granular component of nucleoli. After treatment with the DNA-damaging agent camptothecin, this distribution was dramatically changed to diffuse nucleoplasmic. These data suggest that PES1 is a marker of NB outcome, that it regulates NB cell proliferation, and is associated with NB differentiation. PMID:25557119

  20. Stabilization, Characterization, and Selective Removal of Cystatin C Amyloid Oligomers*

    PubMed Central

    Östner, Gustav; Lindström, Veronica; Hjort Christensen, Per; Kozak, Maciej; Abrahamson, Magnus; Grubb, Anders

    2013-01-01

    The pathophysiological process in amyloid disorders usually involves the transformation of a functional monomeric protein via potentially toxic oligomers into amyloid fibrils. The structure and properties of the intermediary oligomers have been difficult to study due to their instability and dynamic equilibrium with smaller and larger species. In hereditary cystatin C amyloid angiopathy, a cystatin C variant is deposited in arterial walls and cause brain hemorrhage in young adults. In the present investigation, we use redox experiments of monomeric cystatin C, stabilized against domain swapping by an intramolecular disulfide bond, to generate stable oligomers (dimers, trimers, tetramers, decamers, and high molecular weight oligomers). These oligomers were characterized concerning size by gel filtration, polyacrylamide gel electrophoresis, and mass spectrometry, shape by electron and atomic force microscopy, and, function by assays of their capacity to inhibit proteases. The results showed the oligomers to be highly ordered, domain-swapped assemblies of cystatin C and that the oligomers could not build larger oligomers, or fibrils, without domain swapping. The stabilized oligomers were used to induce antibody formation in rabbits. After immunosorption, using immobilized monomeric cystatin C, and elution from columns with immobilized cystatin C oligomers, oligomer-specific antibodies were obtained. These could be used to selectively remove cystatin C dimers from biological fluids containing both dimers and monomers. PMID:23629649

  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. 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.

  3. New insights into the genetics of neuroblastoma.

    PubMed

    Sridhar, Srishma; Al-Moallem, Batool; Kamal, Hawra; Terrile, Marta; Stallings, Raymond L

    2013-04-01

    Neuroblastoma is a genetically and clinically heterogeneous tumor of childhood, arising from precursor cells of the sympathetic nervous system. It is still a challenging cancer for pediatric oncology, as some tumors will spontaneously regress, while others will become refractory to all forms of therapy. The clinical course of this disease is greatly influenced by both patient age and the genetic abnormalities that occur within the tumors. MYCN (v-myc myelocytomatosis viral related oncogene, neuroblastoma derived (avian)) amplification and loss of chromosome 11q heterozygosity have been known to be indicative of poor prognosis. In this article, we review how mutations and structural alterations in specific genes contribute to inheritable predisposition to neuroblastoma and/or to aggressive disease pathogenesis, as well as implications for diagnosis and therapy. These genes include PHOX2B (paired-like homeobox 2b), ALK (anaplastic lymphoma receptor tyrosine kinase), and ATRX (alpha thalassemia/mental retardation syndrome X-linked).

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Formation of domain-swapped oligomer of cytochrome C from its molten globule state oligomer.

    PubMed

    Deshpande, Megha Subhash; Parui, Partha Pratim; Kamikubo, Hironari; Yamanaka, Masaru; Nagao, Satoshi; Komori, Hirofumi; Kataoka, Mikio; Higuchi, Yoshiki; Hirota, Shun

    2014-07-22

    Many proteins, including cytochrome c (cyt c), have been shown to form domain-swapped oligomers, but the factors governing the oligomerization process remain unrevealed. We obtained oligomers of cyt c by refolding cyt c from its acid molten globule state to neutral pH state under high protein and ion concentrations. The amount of oligomeric cyt c obtained depended on the nature of the anion (chaotropic or kosmotropic) in the solution: ClO4(-) (oligomers, 11% ± 2% (heme unit)), SCN(-) (10% ± 2%), I(-) (6% ± 2%), NO3(-) (3% ± 1%), Br(-) (2% ± 1%), Cl(-) (2% ± 1%), and SO4(2-) (3% ± 1%) for refolding of 2 mM cyt c (anion concentration 125 mM). Dimeric cyt c obtained by refolding from the molten globule state exhibited a domain-swapped structure, in which the C-terminal α-helices were exchanged between protomers. According to small-angle X-ray scattering measurements, approximately 25% of the cyt c molecules were dimerized in the molten globule state containing 125 mM ClO4(-). These results indicate that a certain amount of molten globule state oligomers of cyt c convert to domain-swapped oligomers during refolding and that the intermolecular interactions necessary for domain swapping are present in the molten globule state. PMID:24981551

  9. Overview of current treatment of neuroblastoma.

    PubMed

    Philip, T

    1992-05-01

    Neuroblastoma is the second most common solid tumor in infants and children. Improvement of therapy for stage IV patients remains the major goal of research in treatment of neuroblastoma. New approaches under study are focused in four main areas: (a) phase II studies; (b) mega-therapy procedures; (c) targeted therapy; and (d) immunotherapy. Future approaches will be closely linked to progress in laboratory investigation and more efficient use of currently available drugs. Of all the childhood malignancies, this is the one tumor where such an approach is most likely to be effective.

  10. Immunotherapy and chemotherapy in children with neuroblastoma.

    PubMed

    Nesbit, M E; Kersey, J; Finklestein, J; Weiner, J; Simmons, R

    1976-09-01

    Recent advances with immunotherapy in animal tumors suggested that trials with a combination of chemotherapy and immunotherapy in human malignant tumors might be worthwhile. A pilot program with Vibrio cholera neuraminidase-treated tumor cells plus BCG was tested in 3 patients who had had chemotherapy for disseminated neuroblastoma. Two of these children were in "complete remission" after radiation therapy and chemotherapy before the administration of immunotherapy. Relapse occurred in 5-6 months in all 3 patients. These disappointing results are discussed in relation to problems of current chemotherapy in disseminated neuroblastoma including results obtained at second-look operations in patients obtaining "complete remission."

  11. Kinetics of ligation of fibrin oligomers.

    PubMed

    Nelb, G W; Kamykowski, G W; Ferry, J D

    1980-07-10

    Human fibrinogen was treated with thrombin in the presence of fibrinoligase and calcium ion at pH 8.5, ionic strength 0.45, and the ensuring polymerization was interrupted at various time intervals (t) both before and after the clotting time (tc) by solubilization with a solution of sodium dodecyl sulfate and urea. Aliquots of the solubilized protein were subjected to gel electrophoresis on polyacrylamide gels after disulfide reduction by dithiothreitol and on agarose gels without reduction. The degree of gamma-gamma ligation was determined from the former and the size distribution of ligated oligomers, for degree of polymerization x from 1 to 10, from the latter. The degree of gamma-gamma ligation was calculated independently from the size distribution with the assumption that every junction between two fibrin monomers remaining intact after solubilization is ligated, and this agreed well with the direct determination. The size distribution at t/tc = 1.3 to 1.6 differed somewhat from that calculated by the classical theory of linear polycondensation on the assumption that all reactive sites react with equal probability and rate. Analysis of the difference suggests that ligation of a fibrin digomer is not a random process; the probability of ligation of a given junction between two monomers increases with the oligomer length. The number-average degree of polymerization, xn, of ligated oligomers increases approximately linearly with time up to a value of 1.6. PMID:7391026

  12. Cellular uptake of neutral phosphorodiamidate morpholino oligomers.

    PubMed

    Iversen, Patrick L; Aird, Katherine M; Wu, Rebecca; Morse, Michael M; Devi, Gayathri R

    2009-09-01

    Phosphorodiamidate morpholino oligomers (PMO), which have a neutral chemistry, are extensively being used as tools for selective inhibition of gene expression in cell culture models and are currently in human clinical trials. Unlike phosphorothioates (PS ODN) and other charged oligonucleotides, little is known about the uptake characteristics of neutral oligomers. The purpose of this study was to understand the kinetics of PMO transport in cells and correlate with antisense activity. In contrast to primary cells and some transformed cell lines which were uptake permissive, established cancer cell lines showed very poor uptake with an occasional diffuse intracellular pattern. Differential PMO uptake was also observed in immune cells, with dendritic cells and monocytes showing highest uptake compared to T and B cells. In addition, PMO localization was observed to be heterogeneous within a population of uptake permissive cells. Unassisted PMO delivery targeting specific genes was correlated with functional antisense efficacy in experiments showing correction of pre-mRNA missplicing and inhibition of target enzyme activity in cells in culture. PMO internalization in uptake-permissive cells was identified to be specific, saturable, and energy-dependent, suggesting a receptor mediated uptake mechanism. Understanding PMO transport should facilitate the design of more effective synthetic antisense oligomers as therapeutic agents.

  13. New aspects of neuroblastoma treatment: ASPHO 2011 symposium review.

    PubMed

    Zage, Peter E; Louis, Chrystal U; Cohn, Susan L

    2012-07-01

    Neuroblastoma is the most common extracranial solid tumor of childhood, and the outcomes for children with high-risk and relapsed disease remain poor. However, new international strategies for risk stratification and for treatment based on novel tumor targets and including immunotherapy are being employed in attempts to improve the outcomes of children with neuroblastoma. A new international neuroblastoma risk classification system has been developed which is being incorporated into cooperative group clinical trials in North America, Japan, and Europe, resulting in standardized approaches for the initial evaluation and treatment stratification of neuroblastoma patients. Furthermore, novel treatment regimens are being developed based on improved understanding of neuroblastoma biology and on the recruitment of the immune system to specifically target neuroblastoma tumors. These approaches will lead to new therapeutic strategies that likely will improve the outcomes for children with neuroblastoma worldwide.

  14. New Aspects of Neuroblastoma Treatment: ASPHO 2011 Symposium Review

    PubMed Central

    Zage, Peter E.; Louis, Chrystal U.; Cohn, Susan L.

    2014-01-01

    Neuroblastoma is the most common extracranial solid tumor of childhood, and the outcomes for children with high-risk and relapsed disease remain poor. However, new international strategies for risk stratification and for treatment based on novel tumor targets and including immunotherapy are being employed in attempts to improve the outcomes of children with neuroblastoma. A new international neuroblastoma risk classification system has been developed which is being incorporated into cooperative group clinical trials in North America, Japan, and Europe, resulting in standardized approaches for the initial evaluation and treatment stratification of neuroblastoma patients. Furthermore, novel treatment regimens are being developed based on improved understanding of neuroblastoma biology and on the recruitment of the immune system to specifically target neuroblastoma tumors. These approaches will lead to new therapeutic strategies that likely will improve the outcomes for children with neuroblastoma worldwide. PMID:22378620

  15. Amyloid β oligomers in Alzheimer's disease pathogenesis, treatment, and diagnosis.

    PubMed

    Viola, Kirsten L; Klein, William L

    2015-02-01

    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 Ca(2+) 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, they

  16. 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.

  17. Unlikely suspects identified in neuroblastoma conspiracy.

    PubMed

    Bernards, Rene

    2014-04-01

    KIF1B is a candidate tumor-suppressor gene in neuroblastoma whose function is to mediate apoptosis when nerve growth factor becomes limiting in the developing nervous system. Chen and colleagues now provide mechanistic insight into how one of the protein products of this locus, KIF1Bβ, induces apoptosis. PMID:24706657

  18. 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.

  19. Malignant adrenal neuroblastoma in a young dog

    PubMed Central

    2004-01-01

    Abstract A 1.5-year-old dog was evaluated for abnormal mentation, collapse, and weight loss. Radiographs and ultrasonographs revealed soft tissue masses in the mid abdomen. Ultrasound-guided fine-needle aspirates provided a diagnosis of malignant epithelial or round cell neoplasia. Histopathologic and immunohistochemical findings on the tumors were consistent with a primitive neuroblastoma. PMID:15510689

  20. 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.

  1. p53 Cellular Localization and Function in Neuroblastoma

    PubMed Central

    Tweddle, Deborah A.; Malcolm, Archie J.; Cole, Michael; Pearson, Andrew D.J.; Lunec, John

    2001-01-01

    This study investigated the hypothesis that p53 accumulation in neuroblastoma, in the absence of mutation, is associated with functional inactivation, which interferes with downstream mediators of p53 function. To test this hypothesis, p53 expression, location, and functional integrity was examined in neuroblastoma by irradiating 6 neuroblastoma cell lines and studying the effects on p53 transcriptional function, cell cycle arrest, and induction of apoptosis, together with the transcriptional function of p53 after irradiation in three ex vivo primary, untreated neuroblastoma tumors. p53 sequencing showed five neuroblastoma cell lines, two of which were MYCN-amplified, and that all of the tumors were wild-type for p53. p53 was found to be predominantly nuclear before and after irradiation and to up-regulate the p53 responsive genes WAF1 and MDM2 in wild-type p53 cell lines and a poorly-differentiated neuroblastoma, but not a differentiating neuroblastoma or the ganglioneuroblastoma part of a nodular ganglioneuroblastoma in short term culture. This suggests intact p53 transcriptional activity in proliferating neuroblastoma. Irradiation of wild-type p53 neuroblastoma cell lines led to G1 cell cycle arrest in cell lines without MYCN amplification, but not in those with MYCN amplification, despite induction of WAF1. This suggests MYCN amplification may alter downstream mediators of p53 function in neuroblastoma. PMID:11395384

  2. Development of treatment strategies for advanced neuroblastoma.

    PubMed

    Hara, Junichi

    2012-06-01

    Neuroblastoma is the most common cancer in childhood. The majority of patients with neuroblastoma are assigned to the high-risk group based on age at diagnosis, stage, histology, MYCN status, and DNA ploidy. Their prognosis remains unsatisfactory; the 5-year event-free survival (EFS) rate is generally 40 %. During the past 20 years, much effort has been made to reinforce chemotherapy, including the introduction of high-dose chemotherapy with autologous stem cell rescue, resulting in a 5-year EFS rate of around 30 %. Subsequently, maintenance therapy aimed at eradicating residual tumors after induction and consolidation therapies was introduced, consisting of differentiation-inducing agents, retinoids, and immunotherapy using anti-GD2 antibodies combined with cytokines. However, such additional treatment provided benefit to only 10-20 % of patients, while the prognosis of about half the patients remains poor. Currently, novel targeted agents are under development. Among them, anaplastic lymphoma kinase (ALK) inhibitors and aurora kinase A inhibitors are promising. ALK somatic mutation or gene amplification predisposing neuroblastoma development occurs in up to 15 % of neuroblastomas. Crizotinib is a dual-specific inhibitor of ALK/Met and inhibits proliferation of neuroblastoma cells harboring R1275Q-mutated ALK or amplified wild-type ALK, but not cells harboring F1174L. Instead, cells with F1174L are sensitive to another small molecule ALK inhibitor, TAE684. Aurora kinase A plays a pivotal role in centrosome maturation and spindle formation during mitosis. MLN8237 (alisertib) is a small molecule inhibitor of aurora kinase A that is currently in early-phase clinical testing. Future treatment will be individually planned, adapting targeted agents based on personal biological tumor characteristics.

  3. Alpha synuclein oligomers oppose long-term potentiation and impair memory through a calcineurin-dependent mechanism: relevance to human synucleopathic diseases

    PubMed Central

    Martin, Zane S.; Neugebauer, Volker; Dineley, Kelly T.; Kayed, Rakez; Zhang, Wenru; Reese, Lindsay C.; Taglialatela, Giulio

    2011-01-01

    Intracellular deposition of fibrillar aggregates of alpha synuclein (αSyn) characterizes neurodegenerative diseases such as Parkinson’s disease (PD) and dementia with Lewy bodies (DLB). However, recent evidence indicates that small αSyn oligomeric aggregates that precede fibril formation may be the most neurotoxic species and can be found extracellularly. This new evidence has changed the view of pathological αSyn aggregation from a self-contained cellular phenomenon to an extracellular event and prompted investigation of the putative effects of extracellular αSyn oligomers. Here, we report that extracellular application of αSyn oligomers detrimentally impacts neuronal welfare and memory function. We found that oligomeric αSyn increased intracellular Ca2+ levels, induced calcineurin (CaN) activity, decreased cAMP response element binding protein (CREB) transcriptional activity and resulted in calcineurin-dependent death of human neuroblastoma cells. Similarily, CaN induction and CREB inhibition were observed when αSyn oligomers were applied to organotypic brain slices, which opposed hippocampal long-term potentiation (LTP). Furthermore, αSyn oligomers induced CaN, inhibited CREB and evoked memory impairments in mice that received acute intracerebroventricular injections. Notably, all these events were reversed by pharmacological inhibition of CaN. Moreover, we found decreased active calcineurin (CaN) and reduced levels of phosphorylated CREB in autopsy brain tissue from patients affected by DLB, which is characterized by deposition of αSyn aggregates and progressive cognitive decline. These results indicate that exogenously-applied αSyn oligomers impact neuronal function and produce memory deficits through mechanisms that involve CaN activation. PMID:22060133

  4. 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.

  5. Mx oligomer: a novel capsid pattern sensor?

    PubMed

    Kong, Jia; Ma, Min; He, Shuangyi; Qin, Xiaohong

    2016-08-01

    Myxovirus resistance proteins represent a family of interferon-induced restriction factors of the innate and adaptive immune system. Human MxB acts as a novel restriction factor with antiviral activity against a range of HIV-1 and other retroviruses mainly by inhibiting the uncoating process after reverse transcription but prior to integration. Based on published data and conservation analysis, we propose a novel hypothesis, in which MxB dimers form higher order oligomers that restrict retroviral replication by binding to the viral capsid. Insights into the mechanistic basis of structural and functional characteristics of MxB will greatly advance our understanding of MxB. PMID:27492442

  6. Macrocyclic 2,7-Anthrylene Oligomers.

    PubMed

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

    2016-05-01

    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.

  7. Tolfenamic acid inhibits neuroblastoma cell proliferation and induces apoptosis: a novel therapeutic agent for neuroblastoma.

    PubMed

    Eslin, Don; Sankpal, Umesh T; Lee, Chris; Sutphin, Robert M; Maliakal, Pius; Currier, Erika; Sholler, Giselle; Khan, Moeez; Basha, Riyaz

    2013-05-01

    Current therapeutic options for recurrent neuroblastoma have poor outcomes that warrant the development of novel therapeutic strategies. Specificity protein (Sp) transcription factors regulate several genes involved in cell proliferation, survival, and angiogenesis. Sp1 regulates genes believed to be important determinants of the biological behavior of neuroblastoma. Tolfenamic acid (TA), a non-steroidal anti-inflammatory drug, is known to induce the degradation of Sp proteins and may serve as a novel anti-cancer agent. The objective of this investigation was to examine the anti-cancer activity of TA using established human neuroblastoma cell lines. We tested the anti-proliferative effect of TA using SH-SY5Y, CHLA90, LA1 55n, SHEP, Be2c, CMP 13Y, and SMS KCNR cell lines. Cells were treated with TA (0/25/50/100 µM) and cell viability was measured at 24, 48, and 72 h post-treatment. Selected neuroblastoma cell lines were treated with 50 µM TA for 24 and 48 h and tested for cell apoptosis using Annexin-V staining. Caspase activity was measured with caspase 3/7 Glo kit. Cell lysates were prepared and the expression of Sp1, survivin, and c-PARP were evaluated through Western blot analysis. TA significantly inhibited the growth of neuroblastoma cells in a dose/time-dependent manner and significantly decreased Sp1 and survivin expression. Apart from cell cycle (G0/G1) arrest, TA caused significant increase in the apoptotic cell population, caspase 3/7 activity, and c-PARP expression. These results show that TA effectively inhibits neuroblastoma cell growth potentially through suppressing mitosis, Sp1, and survivin expression, and inducing apoptosis. These results show TA as a novel therapeutic agent for neuroblastoma.

  8. Ataxia induced by a thymic neuroblastoma in the elderly patient.

    PubMed

    Wiesel, Ory; Bhattacharyya, Shamik; Vaitkevicius, Henrikas; Prasad, Sashank; McNamee, Ciaran

    2015-05-12

    Thymic neuroblastoma is a rare tumor with only few reports in modern literature. Whereas most data is taken from childhood neuroblastoma, little is known about the characteristics of the disease in the adult and elderly population. There are significant differences between adult and childhood neuroblastoma which are reviewed below. We report a case of a 62-year-old male who presented with neurological symptoms of ataxia and opsoclonus and an anterior mediastinal mass. Ultimately, the patient underwent a resection of the mass and pathologic review identified a thymic neuroblastoma. This is the first case of thymic neuroblastoma associated with symptomatic central nervous system disease; it is presented with an up-to-date review of the previous cases in the field as well with a review of the literature of post adolescent neuroblastoma.

  9. More than the genes, the tumor microenvironment in neuroblastoma.

    PubMed

    Borriello, Lucia; Seeger, Robert C; Asgharzadeh, Shahab; DeClerck, Yves A

    2016-09-28

    Neuroblastoma is the second most common solid tumor in children. Since the seminal discovery of the role of amplification of the MYCN oncogene in the pathogenesis of neuroblastoma in the 1980s, much focus has been on the contribution of genetic alterations in the progression of this cancer. However it is now clear that not only genetic events play a role but that the tumor microenvironment (TME) substantially contributes to the biology of neuroblastoma. In this article, we present a comprehensive review of the literature on the contribution of the TME to the ten hallmarks of cancer in neuroblastoma and discuss the mechanisms of communication between neuroblastoma cells and the TME that underlie the influence of the TME on neuroblastoma progression. We end our review by discussing how the knowledge acquired over the last two decades in this field is now leading to new clinical trials targeting the TME.

  10. More than the genes, the tumor microenvironment in neuroblastoma.

    PubMed

    Borriello, Lucia; Seeger, Robert C; Asgharzadeh, Shahab; DeClerck, Yves A

    2016-09-28

    Neuroblastoma is the second most common solid tumor in children. Since the seminal discovery of the role of amplification of the MYCN oncogene in the pathogenesis of neuroblastoma in the 1980s, much focus has been on the contribution of genetic alterations in the progression of this cancer. However it is now clear that not only genetic events play a role but that the tumor microenvironment (TME) substantially contributes to the biology of neuroblastoma. In this article, we present a comprehensive review of the literature on the contribution of the TME to the ten hallmarks of cancer in neuroblastoma and discuss the mechanisms of communication between neuroblastoma cells and the TME that underlie the influence of the TME on neuroblastoma progression. We end our review by discussing how the knowledge acquired over the last two decades in this field is now leading to new clinical trials targeting the TME. PMID:26597947

  11. SAXS fingerprints of aldehyde dehydrogenase oligomers

    PubMed Central

    Tanner, John J.

    2015-01-01

    Enzymes of the aldehyde dehydrogenase (ALDH) superfamily catalyze the nicotinamide adenine dinucleotide-dependent oxidation of aldehydes to carboxylic acids. ALDHs are important in detoxification of aldehydes, amino acid metabolism, embryogenesis and development, neurotransmission, oxidative stress, and cancer. Mutations in genes encoding ALDHs cause metabolic disorders, including alcohol flush reaction (ALDH2), Sjögren–Larsson syndrome (ALDH3A2), hyperprolinemia type II (ALDH4A1), γ-hydroxybutyric aciduria (ALDH5A1), methylmalonic aciduria (ALDH6A1), pyridoxine dependent epilepsy (ALDH7A1), and hyperammonemia (ALDH18A1). We previously reported crystal structures and small-angle X-ray scattering (SAXS) analyses of ALDHs exhibiting dimeric, tetrameric, and hexameric oligomeric states (Luo et al., Biochemistry 54 (2015) 5513–5522; Luo et al., J. Mol. Biol. 425 (2013) 3106–3120). Herein I provide the SAXS curves, radii of gyration, and distance distribution functions for the three types of ALDH oligomer. The SAXS curves and associated analysis provide diagnostic fingerprints that allow rapid identification of the type of ALDH oligomer that is present in solution. The data sets provided here serve as a benchmark for characterizing oligomerization of ALDHs. PMID:26693506

  12. Cooperative Switching in Nanofibers of Azobenzene Oligomers

    PubMed Central

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

    2016-01-01

    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. PMID:27161608

  13. 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.

  14. Equilibrium polymerization of cyclic carbonate oligomers

    NASA Astrophysics Data System (ADS)

    Ballone, P.; Jones, R. O.

    2001-08-01

    A model of the polymerization of ring oligomers of bisphenol A polycarbonate (BPA-PC) is used to investigate the influence of dimensionality (2D or 3D), density and temperature on the size distribution of the polymer chains. The polymerization step is catalyzed by a single active particle, conserves the number and type of the chemical bonds, and occurs without a significant gain in either potential energy or configurational entropy. Monte Carlo and molecular dynamics simulations show that polymerization of cyclic oligomers occurs readily at high density and is driven by the entropy associated with the distribution of interparticle bonds. Polymerization competes at lower densities with long range diffusion, which favors small molecular species, and is prevented if the system is sufficiently dilute. Polymerization occurs in 2D via a weakly first order transition as a function of density and is characterized by low hysteresis and large fluctuations in the size of polymer chains. Polymerization occurs more readily in 3D than in 2D, and is favored by increasing temperature, as expected for an entropy-driven process.

  15. SAXS fingerprints of aldehyde dehydrogenase oligomers.

    PubMed

    Tanner, John J

    2015-12-01

    Enzymes of the aldehyde dehydrogenase (ALDH) superfamily catalyze the nicotinamide adenine dinucleotide-dependent oxidation of aldehydes to carboxylic acids. ALDHs are important in detoxification of aldehydes, amino acid metabolism, embryogenesis and development, neurotransmission, oxidative stress, and cancer. Mutations in genes encoding ALDHs cause metabolic disorders, including alcohol flush reaction (ALDH2), Sjögren-Larsson syndrome (ALDH3A2), hyperprolinemia type II (ALDH4A1), γ-hydroxybutyric aciduria (ALDH5A1), methylmalonic aciduria (ALDH6A1), pyridoxine dependent epilepsy (ALDH7A1), and hyperammonemia (ALDH18A1). We previously reported crystal structures and small-angle X-ray scattering (SAXS) analyses of ALDHs exhibiting dimeric, tetrameric, and hexameric oligomeric states (Luo et al., Biochemistry 54 (2015) 5513-5522; Luo et al., J. Mol. Biol. 425 (2013) 3106-3120). Herein I provide the SAXS curves, radii of gyration, and distance distribution functions for the three types of ALDH oligomer. The SAXS curves and associated analysis provide diagnostic fingerprints that allow rapid identification of the type of ALDH oligomer that is present in solution. The data sets provided here serve as a benchmark for characterizing oligomerization of ALDHs. PMID:26693506

  16. Cooperative Switching in Nanofibers of Azobenzene Oligomers.

    PubMed

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

    2016-01-01

    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. PMID:27161608

  17. 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.

  18. Childhood neuroblastoma masquerading as pheochromocytoma: case report.

    PubMed

    Moon, Suk-Bae

    2016-01-01

    Neuroblastoma is the most common extracranial solid tumor in children. Mild hypertension is a frequent symptom, presumably an effect of catecholamines that tumors release. Reported herein is the rare occurrence of severe hypertension and subsequent heart failure attributable to adrenal gland neuroblastoma. A 3-year-old boy presented with anterior chest wall protrusion. Physical examination revealed severe hypertension, and left-sided cardiac failure was evident by echocardiography. Catecholamine metabolite (norepinephrine) levels were increased in serum (>2,000 pg/mL) and in urine (1,350.5 µg/day). Abdominal computed tomography scan showed a 7 cm solid mass arising from right adrenal gland. Oral phenoxybenzamine was given for hemodynamic stabilization, and right adrenalectomy was performed to remove an apparent pheochromocytoma. Ultimately, the pathologic diagnosis was ganglioneuroblastoma. Both hypertension and cardiac failure resolved postoperatively.

  19. Immunotherapy for neuroblastoma: turning promise into reality.

    PubMed

    Gray, Juliet C; Kohler, Janice A

    2009-12-01

    Neuroblastoma is one of the commonest and most aggressive paediatric malignancies. The majority of children present with metastatic disease for which long-term survival remains poor despite intensive multi-modal therapies. Toxicity from current treatment regimes is already significant, and there is little room to further intensify therapy. Alternative treatment strategies are therefore needed in order to improve survival. Immunotherapy is an attractive therapeutic option for these children as it potentially offers a much more specific and less toxic treatment than conventional therapies. This review discusses the different immunotherapy strategies that may be useful in neuroblastoma, their advantages and disadvantages and the challenges that need to be overcome to successfully use them clinically.

  20. Ten challenges in the management of neuroblastoma.

    PubMed

    Gains, Jennifer; Mandeville, Henry; Cork, Nicholas; Brock, Penelope; Gaze, Mark

    2012-07-01

    Neuroblastoma is a complex disease with many contradictions and challenges. It is, by and large, a cancer of babies and preschool children, but it does occur, albeit increasingly rarely, in older children, adolescents and young adults. The prognosis is very variable, with outcome related to age, stage and molecular pathology. Neuroblastoma may behave in an almost benign way, with spontaneous regression in some infants, but the majority of older patients have high-risk disease, which is usually fatal, despite best current treatments. As a rare disease, international collaboration is essential to run clinical trials of adequate statistical power to answer important questions in a reasonable time frame. High-risk disease requires multimodality therapy including chemotherapy, surgery and radiotherapy as well as biological and immunological treatments for optimal outcomes. Innovative treatment approaches, sometimes associated with appreciable toxicity, offer hope for the future but, despite parental wishes, cannot be generally implemented without adequate assessment in clinical trials.

  1. The genetics of splicing in neuroblastoma

    PubMed Central

    Chen, Justin; Hackett, Christopher S.; Zhang, Shile; Song, Young K.; Bell, Robert J.A.; Molinaro, Annette M.; Quigley, David A.; Balmain, Allan; Song, Jun S.; Costello, Joseph F.; Gustafson, W. Clay; Dyke, Terry Van; Kwok, Pui-Yan; Khan, Javed; Weiss, William A.

    2015-01-01

    Regulation of mRNA splicing, a critical and tightly regulated cellular function, underlies the majority of proteomic diversity, and is frequently disrupted in disease. Using an integrative genomics approach, we combined both genome and exon level transcriptome data in two somatic tissues (cerebella and peripheral ganglia) from a transgenic mouse model of neuroblastoma, a tumor that arises from peripheral neural crest. Here we describe splicing quantitative trait loci (sQTL) associated with differential splicing across the genome that we use to identify genes with previously unknown functions within the splicing pathway and to define de novo intronic splicing motifs that influence splicing from hundreds of bases away. Our results show that these splicing motifs represent sites for functional recurrent mutations and highlight novel candidate genes in human cancers, including childhood neuroblastoma. PMID:25637275

  2. Childhood neuroblastoma masquerading as pheochromocytoma: case report

    PubMed Central

    Moon, Suk-Bae

    2016-01-01

    Neuroblastoma is the most common extracranial solid tumor in children. Mild hypertension is a frequent symptom, presumably an effect of catecholamines that tumors release. Reported herein is the rare occurrence of severe hypertension and subsequent heart failure attributable to adrenal gland neuroblastoma. A 3-year-old boy presented with anterior chest wall protrusion. Physical examination revealed severe hypertension, and left-sided cardiac failure was evident by echocardiography. Catecholamine metabolite (norepinephrine) levels were increased in serum (>2,000 pg/mL) and in urine (1,350.5 µg/day). Abdominal computed tomography scan showed a 7 cm solid mass arising from right adrenal gland. Oral phenoxybenzamine was given for hemodynamic stabilization, and right adrenalectomy was performed to remove an apparent pheochromocytoma. Ultimately, the pathologic diagnosis was ganglioneuroblastoma. Both hypertension and cardiac failure resolved postoperatively. PMID:27051319

  3. 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

  4. 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

  5. Monoclonal antibody-based therapy of neuroblastoma.

    PubMed

    Cheung, N K; Kushner, B H; Kramer, K

    2001-10-01

    The curative potential of mAbs in the treatment of patients with metastatic neuroblastoma is increasingly evident. The idiotype network appears to represent one component of a complex mechanism for success with mAb-based immunotherapy. Ongoing strategies to modify or reconstruct mAbs, to engage them with cytokines, or to unite them with T cells open new avenues for harnessing the unique forces of the immune system against some of the most deadly pediatric cancers.

  6. Neuroblastoma: Therapeutic strategies for a clinical enigma.

    PubMed

    Modak, Shakeel; Cheung, Nai-Kong V

    2010-06-01

    Neuroblastoma, the most common extracranial pediatric solid tumor remains a clinical enigma with outcomes ranging from cure in >90% of patients with locoregional tumors with little to no cytotoxic therapy, to <30% for those >18months of age at diagnosis with metastatic disease despite aggressive multimodality therapy. Age, stage and amplification of the MYCN oncogene are the most validated prognostic markers. Recent research has shed light on the biology of neuroblastoma allowing more accurate stratification of patients which has permitted reducing or withholding cytotoxic therapy without affecting outcome for low-risk patients. However, for children with high-risk disease, the development of newer therapeutic strategies is necessary. Current surgery and radiotherapy techniques in conjunction with induction chemotherapy have greatly reduced the risk of local relapse. However, refractory or recurrent osteomedullary disease occurs in most patients with high-risk neuroblastoma. Toxicity limits for high-dose chemotherapy appear to have been reached without further clinical benefit. Neuroblastoma is the first pediatric cancer for which monoclonal-antibody-based immunotherapy has been shown to be effective, particularly for metastatic osteomedullary disease. Radioimmunotherapy appears to be a critical component of a recent, successful regimen for treating patients who relapse in the central nervous system, a possible sanctuary site. Efforts are under way to refine and enhance antibody-based immunotherapy and to determine its optimal use. The identification of newer tumor targets and the harnessing of cell-mediated immunotherapy may generate novel therapeutic approaches. It is likely that a combination of therapeutic modalities will be required to improve survival and cure rates.

  7. DNA minigene vaccination for adjuvant neuroblastoma therapy.

    PubMed

    Lode, Holger N; Huebener, Nicole; Zeng, Yan; Fest, Stefan; Weixler, S; Gaedicke, Gerhard

    2004-12-01

    The disruption of self-tolerance against neuroblastoma is the ultimate goal of an effective DNA-vaccine. We demonstrate the induction of protective immunity against syngeneic murine NXS2 neuroblastoma in A/J mice following vaccination with tyrosine hydroxylase (TH)-derived antigens. Oral gene delivery was accomplished using an attenuated strain of Salmonella typhimurium as a carrier harboring vectors encoding for mouse tyrosine hydroxylase (mTH) antigens. Vaccination was effective in protecting animals from a lethal challenge with wild-type NXS2 tumor cells. These findings were extended by comparing efficacy of mTH minigene vaccines with a minigene vaccine comprising three novel epitopes isolated fom NXS2 neuroblastoma cells. For this purpose, MHC class I was immunoprecipitated from NXS2 cell lysates, and peptides were eluted and examined in tandem-mass spectrometry analysis. This led to the identification of three novel natural MHC class I peptide ligands: TEALPVKLI, from ribonucleotide reductase M2; NEYIMSLI, from Ser/Thr protein phosphatase 2A; and FEMVSTLI, of unknown origin. Two minigenes were constructed, one encoding for the three novel epitopes and the second for three known mTH-derived epitopes with high predicted binding affinity to MHC class I, by cloning them into the mammalian expression vector pCMV-3FUB. Immunized mice showed a reduction in primary tumor growth and the absence of spontaneous liver metastasis in the majority of animals. Importantly, there was no significant difference between the two minigenes, suggesting that, compared with tumor peptide isolation, mTH epitope prediction is similarly effective for designing efficient DNA-minigene vaccines. In summary, these findings establish proof of the concept that disruption of self-tolerance against neuroblastoma-associated epitopes may be an effective adjuvant therapeutic strategy.

  8. [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.

  9. 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

  10. 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

  11. Immunosuppressive activity of human neuroblastoma tumor gangliosides.

    PubMed

    Floutsis, G; Ulsh, L; Ladisch, S

    1989-01-15

    Gangliosides are shed in substantial amounts by some tumors, including human neuroblastoma, and these molecules modulate experimental tumor formation in vivo. We now demonstrate that neuroblastoma tumor gangliosides have potent immunoregulatory activity. Gangliosides of every one of 17 tumors studied were highly inhibitory for the normal in vitro human lymphoproliferative responses to the soluble antigen, tetanus toxoid; 30 nmol ganglioside/ml caused 43% to greater than 99% inhibition and the mean concentration causing 50% inhibition was only 17.3 nmol/ml. Furthermore, gangliosides isolated from clinically more aggressive tumors (Stage III or IV) were up to twice as immunosuppressive as those of the generally less aggressive tumors (Stage I or II) (p less than 0.05). Taken together with the lack of immunosuppressive activity of normal plasma gangliosides, the potent activity of neuroblastoma gangliosides supports the hypothesis that one mechanism by which these shed molecules may act to enhance tumor formation in vivo is through abrogation of the host cellular immune response at the site of tumor formation.

  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. PMID:1734220

  13. Deciphering aggregates, prefibrillar oligomers and protofibrils of cytochrome c.

    PubMed

    Amani, Samreen; Naeem, Aabgeena

    2014-08-01

    Aggregation of protein into insoluble intracellular complexes and inclusion bodies underlies the pathogenesis of human neurodegenerative diseases. Importance of cytochrome c (cyt c) arises from its involvement in apoptosis, sequence homology and for studying molecular evolution. A systemic investigation of polyethylene glycol (PEG) and trifluoroethanol (TFE) on the conformational stability of cyt c as a model hemeprotein was made using multi-methodological approach. Cyt c exists as molten globule (MG) at 60% PEG-400 and 40% TFE as confirmed by far-UV CD, attenuated total reflection Fourier transform infrared spectroscopy, Trp environment, 8-anilino-1-naphthalene-sulfonic acid (ANS) binding and blue shift in the soret band. Q-band splitting in MG states specifies conformational changes in the hydrophobic heme-binding pocket. Aggregates were detected at 90% PEG-400 and 50% TFE as confirmed by increase thioflavin T and ANS fluorescence and shift in Congo red absorbance. Detection of prefibrils and protofibrils at 90% PEG-400 and 50% TFE was possible after 72-h incubation. Single cell gel electrophoresis of prefibrils and protofibrils showed DNA damage confirming their toxicity and potential health hazards. Scanning electron microscopy and XRD analysis confirmed prefibrillar oligomers and protofibrils of cyt c. PMID:24729012

  14. Soluble Aβ oligomer production and toxicity.

    PubMed

    Larson, Megan E; Lesné, Sylvain E

    2012-01-01

    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.

  15. Rectification mechanism in diblock oligomer molecular diodes.

    PubMed

    Oleynik, I I; Kozhushner, M A; Posvyanskii, V S; Yu, L

    2006-03-10

    We investigated a mechanism of rectification in diblock oligomer diode molecules that have recently been synthesized and showed a pronounced asymmetry in the measured I-V spectrum. The observed rectification effect is due to the resonant nature of electron transfer in the system and the localization properties of bound state wave functions of resonant states of the tunneling electron interacting with an asymmetric molecule in an electric field. The asymmetry of the tunneling wave function is enhanced or weakened depending on the polarity of the applied bias. The conceptually new theoretical approach, the Green's function theory of sub-barrier scattering, is able to provide a physically transparent explanation of this rectification effect based on the concept of the bound state spectrum of a tunneling electron. The theory predicts the characteristic features of the I-V spectrum in qualitative agreement with experiment. PMID:16606295

  16. First-principles simulations of thiophene oligomers

    NASA Astrophysics Data System (ADS)

    Scherlis, Damian; Marzari, Nicola

    2003-03-01

    Conducting polymers, extensively investigated for their use in electronic and nanotechnology applications, have recently gained prominence for their possible use as molecular actuators in mechanical and bioengineering devices. We have focused our efforts on thiophene-based compounds, a class of materials that can be designed for high stress generation and large linear displacement (actuation strain), ideally outperforming mammalian muscle. Key features for the development of these materials are the microscopic binding properties of thiophene and thiophene oligomers stacks, where applied electric fields lead to oxidation and enhanced pi-pi bonding. We have completed the structural studies of neutral and charged oligothiophene dimers, in the search for efficient dimerization mechanisms. A comparison between different density-functional and quantum-chemistry approaches is critically presented, as are solvation effects, described in this work with a combination of first-principles molecular dynamics and a QM/MM approach for the solvating medium.

  17. 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.

  18. Protection against the synaptic targeting and toxicity of Alzheimer's-associated Aβ oligomers by insulin mimetic chiro-inositols

    PubMed Central

    Pitt, Jason; Thorner, Michael; Brautigan, David; Larner, Joseph; Klein, William L.

    2013-01-01

    Alzheimer's disease (AD) is a progressive dementia that correlates highly with synapse loss. This loss appears due to the synaptic accumulation of toxic Aβ oligomers (ADDLs), which damages synapse structure and function. Although it has been reported that oligomer binding and toxicity can be prevented by stimulation of neuronal insulin signaling with PPARγ agonists, these agonists have problematic side effects. We therefore investigated the therapeutic potential of chiro-inositols, insulin-sensitizing compounds safe for human consumption. Chiro-inositols have been studied extensively for treatment of diseases associated with peripheral insulin resistance, but their insulin mimetic function in memory-relevant central nervous system (CNS) cells is unknown. Here we demonstrate that mature cultures of hippocampal neurons respond to d-chiro-inositol (DCI), pinitol (3-O-methyl DCI), and the inositol glycan INS-2 (pinitol β-1-4 galactosamine) with increased phosphorylation in key upstream components in the insulin-signaling pathway (insulin receptor, insulin receptor substrate-1, and Akt). Consistent with insulin stimulation, DCI treatment promotes rapid withdrawal of dendritic insulin receptors. With respect to neuroprotection, DCI greatly enhances the ability of insulin to prevent ADDL-induced synapse damage (EC50 of 90 nM). The mechanism comprises inhibition of oligomer binding at synapses and requires insulin/IGF signaling. DCI showed no effects on Aβ oligomerization. We propose that inositol glycans and DCI, a compound already established as safe for human consumption, have potential as AD therapeutics by protecting CNS synapses against Aβ oligomers through their insulin mimetic activity.—Pitt, J., Thorner, M., Brautigan, D., Larner, J., Klein, W. L. Protection against the synaptic targeting and toxicity of Alzheimer's-associated Aβ oligomers by insulin mimetic chiro-inositols. PMID:23073831

  19. Elucidating Molecular Mass and Shape of a Neurotoxic Aβ Oligomer

    PubMed Central

    2015-01-01

    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. PMID:25343357

  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. 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

  2. Antiparallel Triple-strand Architecture for Prefibrillar Aβ42 Oligomers*

    PubMed Central

    Gu, Lei; Liu, Cong; Stroud, James C.; Ngo, Sam; Jiang, Lin; Guo, Zhefeng

    2014-01-01

    Aβ42 oligomers play key roles in the pathogenesis of Alzheimer disease, but their structures remain elusive partly due to their transient nature. Here, we show that Aβ42 in a fusion construct can be trapped in a stable oligomer state, which recapitulates characteristics of prefibrillar Aβ42 oligomers and enables us to establish their detailed structures. Site-directed spin labeling and electron paramagnetic resonance studies provide structural restraints in terms of side chain mobility and intermolecular distances at all 42 residue positions. Using these restraints and other biophysical data, we present a novel atomic-level oligomer model. In our model, each Aβ42 protein forms a single β-sheet with three β-strands in an antiparallel arrangement. Each β-sheet consists of four Aβ42 molecules in a head-to-tail arrangement. Four β-sheets are packed together in a face-to-back fashion. The stacking of identical segments between different β-sheets within an oligomer suggests that prefibrillar oligomers may interconvert with fibrils via strand rotation, wherein β-strands undergo an ∼90° rotation along the strand direction. This work provides insights into rational design of therapeutics targeting the process of interconversion between toxic oligomers and non-toxic fibrils. PMID:25118290

  3. Macroautophagy-generated increase of lysosomal amyloid β-protein mediates oxidant-induced apoptosis of cultured neuroblastoma cells

    PubMed Central

    Terman, Alexei; Hallbeck, Martin; Dehvari, Nodi; Cowburn, Richard F.; Benedikz, Eirikur; Kågedal, Katarina; Cedazo-Minguez, Angel; Marcusson, Jan

    2011-01-01

    Increasing evidence suggests the toxicity of intracellular amyloid β-protein (Aβ) to neurons, as well as the involvement of oxidative stress in Alzheimer disease (AD). Here we show that normobaric hyperoxia (exposure of cells to 40% oxygen for five days), and consequent activation of macroautophagy and accumulation of Aβ within lysosomes, induced apoptosis in differentiated SH-SY5Y neuroblastoma cells. Cells under hyperoxia showed: (1) increased numbers of autophagic vacuoles that contained amyloid precursor protein (APP) as well as Aβ monomers and oligomers, (2) increased reactive oxygen species production, and (3) enhanced apoptosis. Oxidant-induced apoptosis positively correlated with cellular Aβ production, being the highest in cells that were stably transfected with APP Swedish KM670/671NL double mutation. Inhibition of γ-secretase, prior and/or in parallel to hyperoxia, suggested that the increase of lysosomal Aβ resulted mainly from its autophagic uptake, but also from APP processing within autophagic vacuoles. The oxidative stress-mediated effects were prevented by macroautophagy inhibition using 3-methyladenine or ATG5 downregulation. Our results suggest that upregulation of macroautophagy and resulting lysosomal Aβ accumulation are essential for oxidant-induced apoptosis in cultured neuroblastoma cells and provide additional support for the interactive role of oxidative stress and the lysosomal system in AD-related neurodegeneration. PMID:22108004

  4. 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.

  5. Artemisinin reduces cell proliferation and induces apoptosis in neuroblastoma.

    PubMed

    Zhu, Shunqin; Liu, Wanhong; Ke, Xiaoxue; Li, Jifu; Hu, Renjian; Cui, Hongjuan; Song, Guanbin

    2014-09-01

    Artemisinin, a natural product from the Chinese medicinal plant, Artemisia annua L., is commonly used in the treatment of malaria, and has recently been reported to have potent anticancer activity in various types of human tumors. Yet, the effect of artemisinin on neuroblastoma is still unclear. In the present study, we aimed to investigate the effects of artemisinin on neuroblastoma cells. We observed that artemisinin significantly inhibited cell growth and proliferation, and caused cell cycle arrest in the G1 phase in neuroblastoma cell lines. Annexin V-FITC/PI staining assay revealed that artemisinin markedly induced apoptosis. Soft agar assays revealed that artemisinin suppressed the ability of clonogenic formation of neuroblastoma cells and a xenograft study in NOD/SCID mice showed that artemisinin inhibited tumor growth and development in vivo. Therefore, our results suggest that the Chinese medicine artemisinin could serve as a novel potential therapeutic agent in the treatment of neuroblastoma. PMID:25017372

  6. Artemisinin reduces cell proliferation and induces apoptosis in neuroblastoma.

    PubMed

    Zhu, Shunqin; Liu, Wanhong; Ke, Xiaoxue; Li, Jifu; Hu, Renjian; Cui, Hongjuan; Song, Guanbin

    2014-09-01

    Artemisinin, a natural product from the Chinese medicinal plant, Artemisia annua L., is commonly used in the treatment of malaria, and has recently been reported to have potent anticancer activity in various types of human tumors. Yet, the effect of artemisinin on neuroblastoma is still unclear. In the present study, we aimed to investigate the effects of artemisinin on neuroblastoma cells. We observed that artemisinin significantly inhibited cell growth and proliferation, and caused cell cycle arrest in the G1 phase in neuroblastoma cell lines. Annexin V-FITC/PI staining assay revealed that artemisinin markedly induced apoptosis. Soft agar assays revealed that artemisinin suppressed the ability of clonogenic formation of neuroblastoma cells and a xenograft study in NOD/SCID mice showed that artemisinin inhibited tumor growth and development in vivo. Therefore, our results suggest that the Chinese medicine artemisinin could serve as a novel potential therapeutic agent in the treatment of neuroblastoma.

  7. Modification of growth of neuroblastoma cells in syngeneic mice by aldehyde-treated neuroblastoma cells.

    PubMed

    Bertolini, L; Diamond, L; Revoltella, R

    1976-06-01

    Pretreatment of syngeneic strain A mice with aldehyde-fixed neuroblastoma cells (clone NB6R) almost completely protected the mice against challenge with viable NB6R cells. In contrast, tumor growth was enhanced in mice treated with fixed cells after challenge with viable cells.

  8. The Slowly Aggregating Salmon Calcitonin: A Useful Tool for the Study of the Amyloid Oligomers Structure and Activity

    PubMed Central

    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. PMID:22272133

  9. 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

  10. 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

    2016-01-01

    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 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. PMID:27619987

  11. An anti-Aβ (amyloid β) single-chain variable fragment prevents amyloid fibril formation and cytotoxicity by withdrawing Aβ oligomers from the amyloid pathway.

    PubMed

    Marín-Argany, Marta; Rivera-Hernández, Geovanny; Martí, Joaquim; Villegas, Sandra

    2011-07-01

    Aβ (amyloid β) immunotherapy has been revealed as a possible tool in Alzheimer's disease treatment. In contrast with complete antibodies, the administration of scFvs (single-chain variable fragments) produces neither meningoencephalitis nor cerebral haemorrhage. In the present study, the recombinant expression of scFv-h3D6, a derivative of an antibody specific for Aβ oligomers, is presented, as well as the subsequent proof of its capability to recover the toxicity induced by the Aβ1-42 peptide in the SH-SY5Y neuroblastoma cell line. To gain insight into the conformational changes underlying the prevention of Aβ toxicity by this antibody fragment, the conformational landscape of scFv-h3D6 upon temperature perturbation is also described. Heating the native state does not lead to any extent of unfolding, but rather directly to a β-rich intermediate state which initiates an aggregation pathway. This aggregation pathway is not an amyloid fibril pathway, as is that followed by the Aβ peptide, but rather a worm-like fibril pathway which, noticeably, turns out to be non-toxic. On the other hand, this pathway is thermodynamically and kinetically favoured when the scFv-h3D6 and Aβ1-42 oligomers form a complex in native conditions, explaining how the scFv-h3D6 withdraws Aβ1-42 oligomers from the amyloid pathway. To our knowledge, this is the first description of a conformational mechanism by which a scFv prevents Aβ-oligomer cytotoxicity.

  12. Chirality organization of aniline oligomers through hydrogen bonds of amino acid moieties.

    PubMed

    Ohmura, Satoshi D; Moriuchi, Toshiyuki; Hirao, Toshikazu

    2010-11-19

    Aniline oligomers bearing amino acid moieties were designed by the introduction of L/D-Ala-OMe into aniline oligomers to induce chirality organization of the π-conjugated aniline oligomer moieties, wherein the formation of intramolecular hydrogen bonds was demonstrated to play an important role to regulate the aniline oligomer moieties conformationally.

  13. Non-Amyloid-β Component of Human α-Synuclein Oligomers Induces Formation of New Aβ Oligomers: Insight into the Mechanisms That Link Parkinson's and Alzheimer's Diseases.

    PubMed

    Atsmon-Raz, Yoav; Miller, Yifat

    2016-01-20

    Parkinson's disease (PD) is characterized by the formation of Lewy bodies (LBs), of which their major component is the non-amyloid-β component (NAC) of α-synuclein (AS). Clinical studies have identified a link between PD and Alzheimer's disease (AD), but the question of why PD patients are at risk to develop various types of dementia, such as AD, is still elusive. In vivo studies have shown that Aβ can act as a seed for NAC/AS aggregation, promoting NAC/AS aggregation and thus contributing to the etiology of PD. However, the mechanisms by which NAC/AS oligomers interact with Aβ oligomers are still elusive. This work presents the interactions between NAC oligomers and Aβ oligomers at atomic resolution by applying extensive molecular dynamics simulations for an ensemble of cross-seeded NAC-Aβ(1-42) oligomers. The main conclusions of this study are as follows: first, the cross-seeded NAC-Aβ(1-42) oligomers represent polymorphic states, yet NAC oligomers prefer to interact with Aβ(1-42) oligomers to form double-layer over single-layer conformations due to electrostatic/hydrophobic interactions; second, among the single-layer conformations, the NAC oligomers induce formation of new β-strands in Aβ(1-42) oligomers, thus leading to new Aβ oligomer structures; and third, NAC oligomers stabilize the cross-β structure of Aβ oligomers, i.e., yielding compact Aβ fibril-like structures.

  14. 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.

  15. Breaking the Code of Amyloid-β Oligomers

    PubMed Central

    Lesné, Sylvain E.

    2013-01-01

    Departing from the original postulates that defined various neurodegenerative disorders, accumulating evidence supports a major role for soluble forms of amyloid proteins as initiator toxins in Alzheimer's disease, Parkinson's disease, frontotemporal dementias, and prion diseases. Soluble multimeric assemblies of amyloid-β, tau, α-synuclein, and the prion protein are generally englobed under the term oligomers. Due to their biophysical properties, soluble amyloid oligomers can adopt multiple conformations and sizes that potentially confer differential biological activities. Therein lies the problem: with sporadic knowledge and limited tools to identify, characterize, and study amyloid oligomers, how can we solve the enigma of their respective role(s) in the pathogenesis of neurodegenerative disorders? To further our understanding of these devastating diseases, the code of the amyloid oligomers must be broken. PMID:24072999

  16. 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

  17. Clinical strategies for the treatment of neuroblastoma.

    PubMed

    Niethammer, D; Handgretinger, R

    1995-01-01

    Neuroblastoma is the most common solid extracranial tumour in childhood. In spite of intensive efforts of clinicians and scientists the prognosis for advanced disease is still poor. This paper presents a short review of the state-of-the-art in conventional treatment including surgery, chemotherapy, and radiation. This is followed by a review of the treatment attempts with high dose chemotherapy followed by autologous bone marrow or stem cell transplantation. One of the main problems with this approach is the contaminating tumour cells. Finally the various immunotherapeutic strategies are summarised which are used to remove minimal residual disease. Later, our new approach, combining various treatment modalities, is described.

  18. Refractory dilated cardiomyopathy associated with metastatic neuroblastoma.

    PubMed

    Carlson, Peter; Jefferies, John L; Kearney, Debra; Russell, Heidi

    2010-10-01

    A 2-year-old African American male presented with heart failure and an abdominal mass. Computerized tomography (CT) scan revealed a 7 cm adrenal lesion, confirmed as poorly differentiated neuroblastoma (NB). CT and meta-iodobenzoguanidine (MIBG) scans identified multiple metastases, but cardiac MIBG imaging was absent. Cardiac ejection fraction (EF) was 8% with 7% shortening fraction. The patient underwent six cycles of chemotherapy and investigational immunotherapy. Cardiac function improved to 26% EF. However, the tumor proved unresponsive to treatment. The patient died from stage IV congestive heart failure (CHF) and progressive NB. Autopsy confirmed dilated cardiomyopathy with endocardial fibroelastosis.

  19. 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.

  20. [Neuroblastoma. Current clinical and therapeutic aspects. Contributions of modern biology].

    PubMed

    Hartmann, O; Favrot, M C

    1993-11-01

    Neuroblastoma is a malignant tumour of the sympathetic tissue observed in children, generally before 6 years and before 1 year in one-third of the cases. In most cases the primary tumour lies in the retroperitoneal region, and in particular in the adrenal gland. Metastases affect the bones and bone-marrow after the age of 1 year and the liver in infants. Children whose metastases are present at the time of diagnosis are the most numerous. The therapeutic problems posed by non-metastatic forms are almost exclusively due to the difficulties encountered in complete excision of the tumour. For this reason, tumour reduction by preoperative chemotherapy plays a large role in the therapeutic approach. The prognosis of metastatic forms is totally different in infants and in older children: in infants, hepatic metastases without bone lesions have a favourable prognosis as a rule and sometimes regress without treatment. In older children, the usual osteomedullary damage still has a very sombre prognosis despite the recent therapeutic advances due to high-dose chemotherapy with bone-marrow transplantation. Cytogenetic studies and molecular biology have improved our understanding of these differences in the outcome of the disease. Amplification of Nmy cellular oncogene, ploidy and chromosome 1 short-arm deletion are essential prognostic factors in this particular tumour.

  1. Distinct cytotoxicity against neuroblastoma cells of peripheral blood and tumor-infiltrating lymphocytes from patients with neuroblastoma.

    PubMed

    Kataoka, Y; Matsumura, T; Yamamoto, S; Sugimoto, T; Sawada, T

    1993-09-15

    The cytotoxicity against neuroblastoma cells of IL-2-activated peripheral blood (PBL) and tumor-infiltrating lymphocytes (TIL) was evaluated in seventeen patients with neuroblastoma. Regional lymph node lymphocytes (LNL) were similarly studied in some patients. Three allogeneic neuroblastoma cell lines, LA2D2, LA2B4 and SIFA, established from the different metastases of the same patient were used as targets. Of the three neuroblastoma lines, LA2D2, with low CD56 expression, was the most susceptible to IL-2-activated lymphocytes, while SIFA, with high CD56 expression, was resistant in the greatest degree. LA2B4 showed moderate susceptibility. Although TIL (73.9 +/- 2.1%), LNL (81.0%) and PBL (76.2 +/- 3.1%) revealed similar cytotoxic activity to K562, they demonstrated distinct cytotoxic activities to each neuroblastoma cell line, as follows: against LA2D2: TIL 56.3 +/- 4.2%, LNL 52.1%, PBL 33.6 +/- 4.9% (P < 0.01); against LA2B4: TIL 47.3 +/- 3.3%, LNL 37.8%, PBL 33.7 +/- 4.8% (P < 0.05); against SIFA: TIL 27.0 +/- 6.2%, LNL 20.7%, PBL 13.9 +/- 2.4% (P = 0.056). TIL always showed higher cytotoxic activity against neuroblastoma cells than those of LNL and PBL, whereas LNL were more cytotoxic than PBL. This data showed that TIL from neuroblastoma patients preferentially killed neuroblastoma cells. It was suggested that lymphocytes in the tumor site and regional lymph node could have been sensitized with neuroblastoma-related antigens and exert preferential killing activity against neuroblastoma cells. Phenotypical analysis revealed that TIL had a larger population of CD56+ cells than PBL. Conversely, PBL had a higher population of CD16+ cells than TIL. The cytotoxic activity of TIL significantly decreased by the depletion of CD56+ cells (10.9 +/- 6.2 from 49.9 +/- 5.9% against LA2D2, P < 0.001). These results indicated that CD56+ cells were most responsible for the killing of neuroblastoma cells, and that TIL, with a high proportion of CD56+ cells with strong

  2. Monoclonal antibody-based therapy for neuroblastoma.

    PubMed

    Cheung, N K

    2000-11-01

    Dose-intensive combination chemotherapy can improve the clinical response of many pediatric solid tumors. However, cure remains elusive. Stage 4 neuroblastoma stands out as an exception. Part of this success is a result of antibody-based strategies, which include immunomagnetic purging of autologous marrow prior to autologous marrow transplantation and immunotherapy directed at minimal residual disease. It is striking that treatment with monoclonal antibodies, even when targeted at a single antigen, namely, ganglioside G(D2), can affect long-term progression-free survival among these patients. The potential role of the idiotype network in tumor control can be exploited clinically. The genetic engineering of these antibodies into novel forms holds great promise for more specific and effective targeting possibilities, including the delivery of cytokines and cells. Preclinical results are also promising. It is expected that the availability of novel antibodies directed at a broader spectrum of pediatric solid tumors will facilitate the successful application of this approach to more patients. Experience with metastatic neuroblastoma has provided proof of this principle. It is likely that other tumors will fall.

  3. High-risk neuroblastoma: a therapy in evolution.

    PubMed

    Fong, Abraham; Park, Julie R

    2009-11-01

    High-risk neuroblastoma remains a therapeutic challenge for pediatric oncologists. It is becoming increasingly evident that conventional chemotherapeutics are approaching or perhaps have already attained their maximum therapeutic potential. The focus of this review is to summarize current therapies and bring to light some of the novel strategies for treating high-risk neuroblastoma. These rationally designed therapies include molecular- and immune-targeted agents in an attempt to exploit the biology of the neuroblastoma cell. These novel therapies are likely to pose a whole new set of challenges and questions and emphasize the need for continued enrollment of patients in therapeutic studies.

  4. A Dilated Cardiomyopathy Revealing a Neuroblastoma: Which Link?

    PubMed

    Duhil de Bénazé, Gwenaelle; Iserin, Franck; Durand, Philippe; Schleiermacher, Gudrun; Orbach, Daniel

    2016-10-01

    Acute cardiac dysfunctions associated to neuroblastoma have rarely been reported. Cases already described are mainly related to high blood pressure, and rarely to an "acute catecholamine cardiomyopathy" more frequently found in adults with pheochromocytoma or secreting paraganglioma. We here report a case of an 8-month-old infant with severe acute cardiac failure with dilated cardiomyopathy and moderate ischemic myocardial signs, revealing a favorable histoprognosis neuroblastoma. After specific treatment, evolution was favorable, and cardiac function completely recovered. The association of reversible ischemic signs with high plasmatic level of catecholamines suggests the existence of a catecholamine-induced acute cardiac dysfunction which imitates a Tako-Tsubo syndrome in neuroblastoma.

  5. A Dilated Cardiomyopathy Revealing a Neuroblastoma: Which Link?

    PubMed

    Duhil de Bénazé, Gwenaelle; Iserin, Franck; Durand, Philippe; Schleiermacher, Gudrun; Orbach, Daniel

    2016-10-01

    Acute cardiac dysfunctions associated to neuroblastoma have rarely been reported. Cases already described are mainly related to high blood pressure, and rarely to an "acute catecholamine cardiomyopathy" more frequently found in adults with pheochromocytoma or secreting paraganglioma. We here report a case of an 8-month-old infant with severe acute cardiac failure with dilated cardiomyopathy and moderate ischemic myocardial signs, revealing a favorable histoprognosis neuroblastoma. After specific treatment, evolution was favorable, and cardiac function completely recovered. The association of reversible ischemic signs with high plasmatic level of catecholamines suggests the existence of a catecholamine-induced acute cardiac dysfunction which imitates a Tako-Tsubo syndrome in neuroblastoma. PMID:27571126

  6. Cross-linking of glycoprotein oligomers during herpes simplex virus type 1 entry.

    PubMed

    Handler, C G; Cohen, G H; Eisenberg, R J

    1996-09-01

    Herpes simplex virus (HSV) has 10 glycoproteins in its envelope. Glycoprotein B (gB), gC, gD, gH, and gL have been implicated in virus entry. We previously used chemical cross-linking to show that these five glycoproteins were close enough to each other to be cross-linked into homodimeric and hetero-oligomeric forms; hetero-oligomers of gB-gC, gC-gD, gD-gB, gH-gL, gC-gL and gD-gL were found in purified virions. To better understand the roles of these glycoproteins in viral entry, we have modified a standard HSV penetration assay to include cross-linkers. This allowed us to examine changes in associations of viral glycoproteins during the entry process. HSV-1(KOS) was adsorbed at 4 degrees C to human neuroblastoma cells (SY5Y). The temperature was raised to 37 degrees C and cells were treated with cross-linker at various times after the temperature shift. Cytoplasmic extracts were examined by Western blotting (immunoblotting) for viral glycoproteins. We found that (i) as in virus alone, the length and concentration of the cross-linking agent affected the number of specific complexes isolated; (ii) the same glycoprotein patterns found in purified virions were also present after attachment of virions to cells; and (iii) the ability to cross-link HSV glycoproteins changed as virus penetration proceeded, e.g., gB and gD complexes which were present during attachment disappeared with increasing time, and their disappearance paralleled the kinetics of penetration. However, this phenomenon appeared to be selective since it was not observed with gC oligomers. In addition, we examined the cross-linking patterns of gB and gD in null viruses K082 and KOSgD beta. Neither of these mutants, which attach but cannot penetrate, showed changes in glycoprotein cross-linking over time. We speculate that these changes are due to conformational changes which preclude cross-linking or spatial alterations which dissociate the glycoprotein interactions during the penetration events. PMID

  7. Antibody-based immunotherapy in high-risk neuroblastoma.

    PubMed

    Johnson, Erik; Dean, Shannon M; Sondel, Paul M

    2007-01-01

    Although great advances have been made in the treatment of low- and intermediate-risk neuroblastoma in recent years, the prognosis for advanced disease remains poor. Therapies based on monoclonal antibodies that specifically target tumour cells have shown promise for treatment of high-risk neuroblastoma. This article reviews the use of monoclonal antibodies either as monotherapy or as part of a multifaceted treatment approach for advanced neuroblastoma, and explains how toxins, cytokines, radioactive isotopes or chemotherapeutic drugs can be conjugated to antibodies to enhance their effects. Tumour resistance, the development of blocking antibodies, and other problems hindering the effectiveness of monoclonal antibodies are also discussed. Future therapies under investigation in the area of immunotherapy for neuroblastoma are considered.

  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. Anti-GD2 Strategy in the Treatment of Neuroblastoma

    PubMed Central

    Yang, Richard K.; Sondel, Paul M.

    2010-01-01

    The prognosis for advanced neuroblastoma remains poor with high risk of recurrence after consolidation. Therapies based on monoclonal antibodies that specifically target disialoganglioside GD2 on tumor cells are improving treatment results for high-risk neuroblastoma. This article reviews the use of anti-GD2 antibodies either as monotherapy or as part of a larger and more complex treatment approach for advanced neuroblastoma. We review how anti-GD2 antibodies can be combined with other treatments or strategies to enhance their clinical effects. Tumor resistance and other problems that decrease the efficacy of anti-GD2 antibodies are discussed. Future developments in the area of anti-GD2 immunotherapies for neuroblastoma are also addressed. PMID:21037966

  10. 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.

  11. Degradation of a Sodium Acrylate Oligomer by an Arthrobacter sp

    PubMed Central

    Hayashi, Takaya; Mukouyama, Masaharu; Sakano, Kouichi; Tani, Yoshiki

    1993-01-01

    Arthrobacter sp. strain NO-18 was first isolated from soil as a bacterium which could degrade the sodium acrylate oligomer and utilize it as the sole source of carbon. When 0.2% (wt/wt) oligomer was added to the culture medium, the acrylate oligomer was found to be degraded by 70 to 80% in 2 weeks, using gel permeation chromatography. To determine the maximum molecular weight for biodegradation, the degradation test was done with the hexamer, heptamer, and octamer, which were separated from the oligomer mixture by fractional gel permeation chromatography. The hexamer and heptamer were consumed to the extents of 58 and 36%, respectively, in 2 weeks, but the octamer was not degraded. Oligomers with three different terminal groups were synthesized to examine the effect of the different terminal groups on biodegradation, but few differences were found. Arthrobacter sp. NO-18 assimilated acrylic acid, propionic acid, glutaric acid, 2-methylglutaric acid, and 1,3,5-pentanetricarboxylic acid. Degradation of the acrylic unit structure by this strain is discussed. PMID:8517751

  12. 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.

  13. 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.

  14. Biodistribution of 99mTc Tricarbonyl Glycine Oligomers

    PubMed Central

    Jang, Beom-Su; Lee, Joo-Sang; Rho, Jong Kook

    2012-01-01

    99mTc tricarbonyl glycine monomers, trimers, and pentamers were synthesized and evaluated for their radiolabeling and in vivo distribution characteristics. We synthesized a 99mTc-tricarbonyl precursor with a low oxidation state (I). 99mTc(CO)3(H2O)3 + was then made to react with monomeric and oligomeric glycine for the development of bifunctional chelating sequences for biomolecules. Labeling yields of 99mTc-tricarbonyl glycine monomers and oligomers were checked by high-performance liquid chromatography. The labeling yields of 99mTc-tricarbonyl glycine and glycine oligomers were more than 95%. We evaluated the characteristics of 99mTc-tricarbonyl glycine oligomers by carrying out a lipophilicity test and an imaging study. The octanol-water partition coefficient of 99mTc tricarbonyl glycine oligomers indicated hydrophilic properties. Single-photon emission computed tomography imaging of 99mTc-tricarbonyl glycine oligomers showed rapid renal excretion through the kidneys with a low uptake in the liver, especially of 99mTc tricarbonyl triglycine. Furthermore, we verified that the addition of triglycine to prototype biomolecules (AGRGDS and RRPYIL) results in the improvement of radiolabeling yield. From these results, we conclude that triglycine has good characteristics for use as a bifunctional chelating sequence for a 99mTc-tricarbonyl- based biomolecular imaging probe. PMID:24278615

  15. Immune response to racotumomab in a child with relapsed neuroblastoma.

    PubMed

    Sampor, C; Guthmann, M D; Scursoni, A; Cacciavillano, W; Torbidoni, A; Galluzzo, L; Camarero, S; Lopez, J; de Dávila, M T G; Fainboim, L; Chantada, G L

    2012-01-01

    Immunotherapy targeting ganglioside antigens is a powerful tool for the treatment of high risk neuroblastoma. However, only treatment with anti-GD2 antibodies has been used in clinical practice and other options may be pursued. We report the use of racotumomab, an anti-idiotype vaccine against N-glycolyl neuraminic acid (NeuGc)- containing gangliosides, eliciting an immune response in a child with relapsed neuroblastoma expressing the NeuGcGM3 ganglioside.

  16. 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

  17. Cytokines in neuroblastoma: from pathogenesis to treatment.

    PubMed

    Pistoia, Vito; Bianchi, Giovanna; Borgonovo, Giacomo; Raffaghello, Lizzia

    2011-07-01

    Cytokines released by cancer cells or by cells of the tumor microenvironment stimulate angiogenesis, act as autocrine or paracrine growth factors for malignant cells, promote tumor cell migration and metastasis or create an immunosuppressive microenvironment. These tumor-promoting effects of cytokines also apply to neuroblastoma (NB), a pediatric neuroectodermal malignancy with frequent metastatic presentation at diagnosis and poor prognosis. IL-6 and VEGF are the best characterized cytokines that stimulated tumor growth and metastasis, while others such as IFN-γ can exert anti-NB activity by inducing tumor cell apoptosis and inhibiting angiogenesis. On the other hand, cytokines are part of the anti-NB therapeutic armamentarium, as exemplified by IL-2 and granulocyte-macrophage colony stimulating factor that potentiate the activity of anti-NB antibodies. These recent results raise hope for more efficacious treatment of this ominous pediatric malignancy.

  18. Immunocombination therapy for high-risk neuroblastoma.

    PubMed

    Kroesen, Michiel; Lindau, Dennis; Hoogerbrugge, Peter; Adema, Gosse J

    2012-02-01

    Neuroblastoma (NBL) is an aggressive malignancy of the sympathetic nervous system. Advanced-stage NBLs prove fatal in approximately 50% of patients within 5 years. Therefore, new treatment modalities are urgently needed. Immunotherapy is a treatment modality that can be combined with established forms of treatment. Administration of monoclonal antibodies or dendritic cell-based therapies alone can lead to favorable clinical outcomes in individual cancer patients; for example patients with melanoma, lymphoma and NBL. However, clinical benefit is still limited to a minority of patients, and further improvements are clearly needed. In this article, we review the most commonly used approaches to treat patients with NBL and highlight the prerequisites and opportunities of cell-based immunotherapy, involving both innate and adaptive immune-effector cells. Furthermore, we discuss the potential of the combined application of immunotherapy and novel tumor-targeted therapies for the treatment of both cancer in general and NBL in particular.

  19. PHOX2B is a suppressor of neuroblastoma metastasis

    PubMed Central

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

    2016-01-01

    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. PMID:26840262

  20. 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.

  1. Postoperative immunotherapy of murine C1300-neuroblastoma.

    PubMed

    Fowler, C L; Brooks, S P; Rossman, J E; Cooney, D R

    1990-02-01

    Low-dose cyclophosphamide (CY) is an immunomodulating agent that down-regulates T suppressor cell function. This study investigates postoperative immunotherapy with CY as an alternate treatment for advanced immunogenic tumors such as neuroblastoma that typically respond poorly to traditional high-dose chemotherapy. A/J mice with 1.5-cm subcutaneous C1300-neuroblastoma (C1300-NB) tumors were divided into the following treatment groups: I, untreated (n = 14); II, 85% tumor resection (n = 18); III, sham-operated (n = 18); IV, multiple-dose CY (n = 6); V, 85% resection and single-dose CY (n = 14); VI, 85% resection and multiple-dose CY (n = 14). CY (100 mg/kg, intraperitoneally) was given initially 24 hours post-operatively to groups IV, V, and VI. Groups IV and VI also received weekly maintenance doses of 25 mg/kg CY. Results showed significantly increased survival (log-rank test) in CY-treated groups (IV, V, VI) compared with control groups (I,II,III). Cures were observed only in groups receiving partial resection plus CY (V, 7%; VI, 29%). Although surgical debulking of tumor alone (II) did not enhance survival, the procedure normalized depressed total lymphocyte counts and the subpopulation of Lyt 2,3+ (T suppressor/cytolytic cells) in the immediate postoperative period during which immunotherapy with CY was instigated. This may have contributed to the success of CY immunotherapy. To characterize the tumor-host immune interaction, additional studies were performed. Results showed the following. (1) Mice cured by debulking plus CY (from groups V and VI) could not be successfully reimplanted with C1300-NB, demonstrating immunologic mediation by CY.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Probing the stability of insulin oligomers using electrospray ionization ion mobility mass spectrometry.

    PubMed

    Boga Raja, Uday Kumar; Injeti, Srilakshmi; Culver, Tiffany; McCabe, Jacob W; Angel, Laurence A

    2015-01-01

    The peptide hormone insulin is central to regulating carbohydrate and fat metabolism in the body by controlling blood sugar levels. Insulin's most active form is the monomer and the extent of insulin oligomerization is related to insulin's activity of controlling blood sugar levels. Electrospray ionization (ESI) of human insulin produced a series of oligomers from the monomer to the undecamer identified using quadrupole ion mobility time-of-flight mass spectrometry. Previous research suggested that only the monomer, dimer and hexamer are native forms of insulin in solution and the range of oligomers observed in the gas-phase are ESI artifacts. Here the properties of three distinct oligomer bands I, II and III, where both the charge state and number of insulin units of the oligomer increase incrementally, were investigated. When Zn(ii) was added to the insulin sample the same oligomers were observed but with 0-6 Zn(ii) ions bound to each of the oligomers. The oligomers of bands I, II and III were characterized by comparing their drift times, collision cross- sections, relative intensities, collision-induced dissociation (CID) patterns and relative breakdown energies. Insulin oligomers of band I dissociated primarily by releasing either the 2+ or 3+ monomer accompanied by an oligomer that conserved the mass, charge and Zn(ii) of the precursor. Insulin oligomers of bands II and III dissociated primarily by releasing the 2+ monomer accompanied by an oligomer which conserved the mass, charge and Zn(ii) of the precursor. Comparison of CID patterns and breakdown energies showed all the oligomers in band II required higher collision energies to dissociate than the oligomers in band I, and the oligomers of band III required higher energies to dissociate than oligomers of band II. These results show that the amount of excess charge on the oligomer in respect to the number of insulin monomers in the oligomer affects their stability. PMID:26764306

  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

    2015-11-01

    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. Mutations in PIK3CA are infrequent in neuroblastoma

    PubMed Central

    Dam, Vincent; Morgan, Brian T; Mazanek, Pavel; Hogarty, Michael D

    2006-01-01

    Background Neuroblastoma is a frequently lethal pediatric cancer in which MYCN genomic amplification is highly correlated with aggressive disease. Deregulated MYC genes require co-operative lesions to foster tumourigenesis and both direct and indirect evidence support activated Ras signaling for this purpose in many cancers. Yet Ras genes and Braf, while often activated in cancer cells, are infrequent targets for activation in neuroblastoma. Recently, the Ras effector PIK3CA was shown to be activated in diverse human cancers. We therefore assessed PIK3CA for mutation in human neuroblastomas, as well as in neuroblastomas arising in transgenic mice with MYCN overexpressed in neural-crest tissues. In this murine model we additionally surveyed for Ras family and Braf mutations as these have not been previously reported. Methods Sixty-nine human neuroblastomas (42 primary tumors and 27 cell lines) were sequenced for PIK3CA activating mutations within the C2, helical and kinase domain "hot spots" where 80% of mutations cluster. Constitutional DNA was sequenced in cases with confirmed alterations to assess for germline or somatic acquisition. Additionally, Ras family members (Hras1, Kras2 and Nras) and the downstream effectors Pik3ca and Braf, were sequenced from twenty-five neuroblastomas arising in neuroblastoma-prone transgenic mice. Results We identified mutations in the PIK3CA gene in 2 of 69 human neuroblastomas (2.9%). Neither mutation (R524M and E982D) has been studied to date for effects on lipid kinase activity. Though both occurred in tumors with MYCN amplification the overall rate of PIK3CA mutations in MYCN amplified and single-copy tumors did not differ appreciably (2 of 31 versus 0 of 38, respectively). Further, no activating mutations were identified in a survey of Ras signal transduction genes (including Hras1, Kras2, Nras, Pik3ca, or Braf genes) in twenty-five neuroblastic tumors arising in the MYCN-initiated transgenic mouse model. Conclusion These data

  5. Solution Structure of Apoptotic BAX Oligomer: Oligomerization Likely Precedes Membrane Insertion.

    PubMed

    Sung, Tai-Ching; Li, Ching-Yu; Lai, Yei-Chen; Hung, Chien-Lun; Shih, Orion; Yeh, Yi-Qi; Jeng, U-Ser; Chiang, Yun-Wei

    2015-10-01

    Proapoptotic BAX protein is largely cytosolic in healthy cells, but it oligomerizes and translocates to mitochondria upon receiving apoptotic stimuli. A long-standing challenge has been the inability to capture any structural information beyond the onset of activation. Here, we present solution structures of an activated BAX oligomer by means of spectroscopic and scattering methods, providing details about the monomer-monomer interfaces in the oligomer and how the oligomer is assembled from homodimers. We show that this soluble oligomer undergoes a direct conversion into membrane-inserted oligomer, which has the ability of inducing apoptosis and structurally resembles a membrane-embedded oligomer formed from BAX monomers in lipid environment. Structural differences between the soluble and the membrane-inserted oligomers are manifested in the C-terminal helices. Our data suggest an alternative pathway of apoptosis in which BAX oligomer formation occurs prior to membrane insertion.

  6. Biophysical characterization data on Aβ soluble oligomers produced through a method enabling prolonged oligomer stability and biological buffer conditions

    PubMed Central

    Crisostomo, Amanda C.; Dang, Loan; Digambaranath, Jyothi L.; Klaver, Andrea C.; Loeffler, David A.; Payne, Jeremiah J.; Smith, Lynnae M.; Yokom, Adam L.; Finke, John M.

    2015-01-01

    The data here consists of time-dependent experimental parameters from chemical and biophysical methods used to characterize Aβ monomeric reactants as well as soluble oligomer and amyloid fibril products from a slow (3–4 week) assembly reaction under biologically-relevant solvent conditions. The data of this reaction are both of a qualitative and quantitative nature, including gel images from chemical cross-linking and Western blots, fractional solubility, thioflavin T binding, size exclusion chromatograms, transmission electron microscopy images, circular dichroism spectra, and fluorescence resonance energy transfer efficiencies of donor–acceptor pair labels in the Aβ chain. This data enables future efforts to produce the initial monomer and eventual soluble oligomer and amyloid fibril states by providing reference benchmarks of these states pertaining to physical properties (solubility), ligand-binding (thioflavin T binding), mesoscopic structure (electron microscopy, size exclusion chromatography, cross-linking products, SDS and native gels) and molecular structure (circular dichroism, FRET donor-acceptor distance). Aβ1-40 soluble oligomers are produced that are suitable for biophysical studies requiring sufficient transient stability to exist in their “native” conformation in biological phosphate-saline buffers for extended periods of time. The production involves an initial preparation of highly monomeric Aβ in a phosphate saline buffer that transitions to fibrils and oligomers through time incubation alone, without added detergents or non-aqueous chemicals. This criteria ensures that the only difference between initial monomeric Aβ reactant and subsequent Aβ oligomer products is their degree of peptide assembly. A number of chemical and biophysical methods were used to characterize the monomeric reactants and soluble oligomer and amyloid fibril products, including chemical cross-linking, Western blots, fraction solubility, thioflvain T binding

  7. 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

  8. 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

  9. Surface antigen expression and complement susceptibility of differentiated neuroblastoma clones.

    PubMed

    Chen, S; Caragine, T; Cheung, N K; Tomlinson, S

    2000-03-01

    Human neuroblastoma cell lines typically consist of heterogenous subpopulations of cells that are morphologically and biochemically distinct. The cell types are characterized as neuroblastic (N-type), substrate-adherent Schwann-like (S-type), or intermediate (I). These cell types can undergo spontaneous or induced transdifferentiation in vitro. We investigated the complement sensitivity of different neuroblastoma cell lines and of matched sets of cloned N- and S-type neuroblastoma cell lines. Human neuroblastoma cell lines that consisted predominantly of a neuroblastic phenotype were shown to be significantly more susceptible to human complement-mediated lysis than cell lines of other cancer types. Complement sensitivity of neuroblastoma cell lines was correlated with low levels of CD59, decay-accelerating factor, and membrane cofactor protein expression. We found that cloned S-type neuroblastoma cells were much more resistant to complement-mediated lysis than cloned N-type cells. The increased complement resistance of S-type cells was shown to be due to increased expression of membrane-bound complement inhibitors. CD59 was the single most important protein in providing S-type cells with protection from complement lysis. S-type cells were also found to express lower levels of GD2, a target antigen for a complement activating monoclonal antibody currently in clinical trials for neuroblastoma immunotherapy. The ability of S-type cells to evade complement, and the ability of S-type cells to differentiate into the more tumorigenic N-type cells, may represent a mechanism of tumor survival and regrowth, a phenomenon often observed with this cancer.

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

    PubMed Central

    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; Glöckner, 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

    2016-01-01

    Neuroblastoma is a malignant paediatric tumour of the sympathetic nervous system1. 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 elusive2–4. 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 type1,2,5. 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. PMID:26466568

  11. Response of mature mice to challenge with neuroblastoma after inoculation with neuroblastoma cells as neonates.

    PubMed

    Schengrund, C L; Repman, M A; Sheffler, B A

    1982-01-01

    Injection (s.c.) of 2 X 10(5) S20Y neuroblastoma cells into adult A/J strain mice regularly produced a higher incidence of progressive, lethal tumor growth. In contrast, successful tumor growth was significantly less frequent (P less than 0.001) when the same number of tumor cells were injected into neonatal A/J mice. A significant number (P less than 0.001) of matured mice that had rejected the initial S20Y cell inoculum as neonates were able to reject 2 subsequent challenges with S20Y cells.

  12. A PCNA-Derived Cell Permeable Peptide Selectively Inhibits Neuroblastoma Cell Growth

    PubMed Central

    Gu, Long; Smith, Shanna; Li, Caroline; Hickey, Robert J.; Stark, Jeremy M.; Fields, Gregg B.; Lang, Walter H.; Sandoval, John A.; Malkas, Linda H.

    2014-01-01

    Proliferating cell nuclear antigen (PCNA), through its interaction with various proteins involved in DNA synthesis, cell cycle regulation, and DNA repair, plays a central role in maintaining genome stability. We previously reported a novel cancer associated PCNA isoform (dubbed caPCNA), which was significantly expressed in a broad range of cancer cells and tumor tissues, but not in non-malignant cells. We found that the caPCNA-specific antigenic site lies between L126 and Y133, a region within the interconnector domain of PCNA that is known to be a major binding site for many of PCNA's interacting proteins. We hypothesized that therapeutic agents targeting protein-protein interactions mediated through this region may confer differential toxicity to normal and malignant cells. To test this hypothesis, we designed a cell permeable peptide containing the PCNA L126-Y133 sequence. Here, we report that this peptide selectively kills human neuroblastoma cells, especially those with MYCN gene amplification, with much less toxicity to non-malignant human cells. Mechanistically, the peptide is able to block PCNA interactions in cancer cells. It interferes with DNA synthesis and homologous recombination-mediated double-stranded DNA break repair, resulting in S-phase arrest, accumulation of DNA damage, and enhanced sensitivity to cisplatin. These results demonstrate conceptually the utility of this peptide for treating neuroblastomas, particularly, the unfavorable MYCN-amplified tumors. PMID:24728180

  13. 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

  14. Enhanced cell cycle perturbation and apoptosis mediate the synergistic effects of ST1926 and ATRA in neuroblastoma preclinical models.

    PubMed

    Di Francesco, Angela Maria; Ubezio, Paolo; Torella, Anna Rita; Meco, Daniela; Pierri, Filomena; Barone, Giuseppe; Cusano, Gabriella; Pisano, Claudio; D'Incalci, Maurizio; Riccardi, Riccardo

    2012-08-01

    Retinoic acid therapy is nowadays an important component of treatment for residual disease of stage IV neuroblastoma after multimodal therapy. Nevertheless, arising resistance and treatment toxicity could represent relevant limiting factors. In the present study, we show that retinoic acid enhances the cytostatic and apoptogenic properties of the novel adamantyl retinoid ST1926 in a panel of neuroblastoma cells with different p53 status and caspase 8 expression, resulting in synergistic effects as assessed by Combination Index and Isobologram analysis. Under conditions where the two drugs alone produced no toxic effects, their combination resulted in enhanced G2-M arrest and sub-G1 population as shown by BrdU pulse-chase and labeling experiments. PARP cleavage, caspase 3, 8 and 9 activation and modulation of DR4 and FAS were indicative of enhanced apoptosis triggered by the co-incubation of the two drugs whereas neither ST1926-mediated genotoxic damage nor ATRA-differentiating effects were affected by the combined treatment. Caspase-3 and 8-mediated apoptosis appeared to play an important role in the drugs synergism. In fact, the addition of a pan-caspase inhibitor ZVAD-FMK reverted this effect in SK-N-DZ cells, and synergism was confined to limited drugs doses in HTLA cells not expressing caspase-8. Although not modulated, p53 appeared to enhance cells responsiveness to retinoid/ATRA combination. In vivo studies in the most sensitive neuroblastoma model SK-N-DZ, confirmed enhanced activity of the drugs combination vs single treatments. The study provides important lines of evidence that such a drugs combination could represent a less toxic and more effective approach for maintenance treatment in children with neuroblastoma.

  15. Microdroplet temperature calibration via thermal dissociation of quenched DNA oligomers.

    PubMed

    Hall, Eric W; Faris, Gregory W

    2014-03-01

    The development of microscale analytical techniques has created an increasing demand for reliable and accurate heating at the microscale. Here, we present a novel method for calibrating the temperature of microdroplets using quenched, fluorescently labeled DNA oligomers. Upon melting, the 3' fluorophore of the reporter oligomer separates from the 5' quencher of its reverse complement, creating a fluorescent signal recorded as a melting curve. The melting temperature for a given oligomer is determined with a conventional quantitative polymerase chain reaction (qPCR) instrument and used to calibrate the temperature within a microdroplet, with identical buffer concentrations, heated with an infrared laser. Since significant premelt fluorescence prevents the use of a conventional (single-term) sigmoid or logistic function to describe the melting curve, we present a three-term sigmoid model that provides a very good match to the asymmetric fluorescence melting curve with premelting. Using mixtures of three oligomers of different lengths, we fit multiple three-term sigmoids to obtain precise comparison of the microscale and macroscale fluorescence melting curves using "extrapolated two-state" melting temperatures.

  16. Small Glycosylated Lignin Oligomers Are Stored in Arabidopsis Leaf Vacuoles

    PubMed Central

    Dima, Oana; Morreel, Kris; Vanholme, Bartel; Kim, Hoon; Ralph, John; Boerjan, Wout

    2015-01-01

    Lignin is an aromatic polymer derived from the combinatorial coupling of monolignol radicals in the cell wall. Recently, various glycosylated lignin oligomers have been revealed in Arabidopsis thaliana. Given that monolignol oxidation and monolignol radical coupling are known to occur in the apoplast, and glycosylation in the cytoplasm, it raises questions about the subcellular localization of glycosylated lignin oligomer biosynthesis and their storage. By metabolite profiling of Arabidopsis leaf vacuoles, we show that the leaf vacuole stores a large number of these small glycosylated lignin oligomers. Their structural variety and the incorporation of alternative monomers, as observed in Arabidopsis mutants with altered monolignol biosynthesis, indicate that they are all formed by combinatorial radical coupling. In contrast to the common believe that combinatorial coupling is restricted to the apoplast, we hypothesized that the aglycones of these compounds are made within the cell. To investigate this, leaf protoplast cultures were cofed with 13C6-labeled coniferyl alcohol and a 13C4-labeled dimer of coniferyl alcohol. Metabolite profiling of the cofed protoplasts provided strong support for the occurrence of intracellular monolignol coupling. We therefore propose a metabolic pathway involving intracellular combinatorial coupling of monolignol radicals, followed by oligomer glycosylation and vacuolar import, which shares characteristics with both lignin and lignan biosynthesis. PMID:25700483

  17. Liquid chromatographic fractionations of mixtures of polystyrene oligomers

    SciTech Connect

    Curtis, M A; Webb, J W; Warren, D C; Brandt, V O; Gerberich, F G; Raut, K B; Rogers, L B

    1980-05-24

    Oligomer mixtures of 800, 2200, and 4000 molecular weight polystyrene have been fractionated using silica and bonded phase columns under similar conditions of solvent gradient and flow rate. Using a hexane/tetrahydrofuran gradient, the silica and nitro phases were best in that they separated 41 and 43 oligomers, respectively. At the other extreme, a phenyl bonded phase column gave virtually no resolution using a water/THF gradient and a cyano bonded phase column, using the earlier hexane/tetrahydrofuran system, resolved only 10 oligomers. Amino and octadecyl bonded phase columns gave results intermediate between these two extremes. The strength of the solvent used to dissolve the sample was found to be of critical importance. Use of too good a sample solvent seriously degraded the attainable resolution. When number average and weight average molecular weights for an 800 molecular weight polystyrene sample were calculated from the oligomer distribution, the silica column gave values which were most consistent with those reported from other methods.

  18. Microdroplet temperature calibration via thermal dissociation of quenched DNA oligomers.

    PubMed

    Hall, Eric W; Faris, Gregory W

    2014-03-01

    The development of microscale analytical techniques has created an increasing demand for reliable and accurate heating at the microscale. Here, we present a novel method for calibrating the temperature of microdroplets using quenched, fluorescently labeled DNA oligomers. Upon melting, the 3' fluorophore of the reporter oligomer separates from the 5' quencher of its reverse complement, creating a fluorescent signal recorded as a melting curve. The melting temperature for a given oligomer is determined with a conventional quantitative polymerase chain reaction (qPCR) instrument and used to calibrate the temperature within a microdroplet, with identical buffer concentrations, heated with an infrared laser. Since significant premelt fluorescence prevents the use of a conventional (single-term) sigmoid or logistic function to describe the melting curve, we present a three-term sigmoid model that provides a very good match to the asymmetric fluorescence melting curve with premelting. Using mixtures of three oligomers of different lengths, we fit multiple three-term sigmoids to obtain precise comparison of the microscale and macroscale fluorescence melting curves using "extrapolated two-state" melting temperatures. PMID:24688810

  19. Immunological activity difference between native calreticulin monomers and oligomers.

    PubMed

    He, Mi-chun; Wang, Jun; Wu, Jian; Gong, Fang-yuan; Hong, Chao; Xia, Yun; Zhang, Li-juan; Bao, Wan-rong; Gao, Xiao-Ming

    2014-01-01

    We have recently demonstrated that the greatly increased immunological activities of recombinant murine calreticulin (rCRT) are largely attributed to its self-oligomerization. Although native CRT (nCRT) can also oligomerize under stress conditions in vitro, whether this phenomenon could occur inside cells and the immunological activity difference between nCRT monomers and oligomers remained unclear. In this study, we illustrated the formation of CRT oligomers in tranfectant cells under "heat & low pH" (42°C/pH 6.5) condition. The mixture of nCRT oligomers and monomers (OnCRT) was obtained after 3 hr treatment of murine monomeric nCRT (MnCRT) under similar condition (42°C/pH 5.0) in vitro. The OnCRT thus obtained was better recognized by 2 monoclonal Abs from mice that had been immunized with oligomeric rCRT. Unlike MnCRT, OnCRT was able to elicit CRT-specific IgG production in mice. OnCRT also stimulated bone-marrow derived dendritic cells (BMDCs) to secrete significantly higher levels of TNF-α, IL-6 and IL-12p40 than did MnCRT in vitro. We postulate that oligomerization of soluble CRT may occur under certain pathophysiological conditions (e.g. ultrahyperpyrexia) and the resultant oligomers may exhibit exaggerated immunostimulating activities, thereby affiliating the inflammatory responses in vivo.

  20. Enhanced resection and improved survival in murine neuroblastoma (C1300-NB) after preoperative immunotherapy.

    PubMed

    Fowler, C L; Brooks, S P; Squire, R; Rich, G A; Rossman, J E; Finegold, M J; Allen, J E; Cooney, D R

    1991-04-01

    Advanced neuroblastoma treated with standard chemotherapy has a poor prognosis. Combination immunotherapy for murine neuroblastoma with retinyl palmitate, low-dose cyclophosphamide, and interleukin-2 resulted in increased survival, impaired tumor growth, easier surgical resection, and increased class I expression or tumor cells. Preoperative immunotherapy may be useful in treatment of advanced human neuroblastoma.

  1. 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.

  2. Montmorillonite Clay-Catalyzed Synthesis of RNA Oligomers

    NASA Astrophysics Data System (ADS)

    Ferris, J. P.; Miyakawa, S.; Huang, W.; Joshi, P.

    2005-12-01

    It is proposed that catalysis had a central role in the origins of life. This will be illustrated using the montmorillonite clay-catalyzed synthesis of oligomers of RNA from activated monomers, (Ferris and Ertem, 1993) a possible step in the origin of the RNA world (Ferris, 2005). Structural analysis of oligomers formed in the reaction of the activated monomer of 5'-AMP with that of 5'-CMP demonstrated that the oligomers formed were not produced by random synthesis but rather the sequences observed were directed by the montmorillonite catalyst (Miyakawa and Ferris, 2003). RNA oligomers containing up to 40 mers have been synthesized in reactions performed in water at 25 oC in the presence of montmorillonite (Huang and Ferris, 2003). Analysis of the structure elements in these oligomers from the 7 to 39 mers showed that they did not vary. Reaction of D, L-mixtures of the activated monomers of A and U resulted in the formation of greater amounts of the homochiral amounts of dimers and trimers of A than would be expected if there was no selectivity in the reaction. A limited number of the dimers and trimers of U were also formed but here the selectivity was for the formation of an excess of heterochiral products (Joshi et al., 2000). A postulate that explains why homochiral trimers of U are not formed and the significance of catalysis in prebiotic synthesis will be discussed. Ferris, J.P. (2005) Origins of life, molecular basis of. In R.A. Meyers, Ed. Encyclopedia of Molecular Cell Biology and Molecular Medicine, 10. Wiley-VCH Verlag, Weinheim, Germany. Ferris, J.P., and Ertem, G. (1993) Montmorillonite catalysis of RNA oligomer formation in aqueous solution. A model for the prebiotic formation of RNA. J. Am. Chem. Soc., 115, 12270-12275. Huang, W., and Ferris, J.P. (2003) Synthesis of 35-40 mers of RNA oligomers from unblocked monomers. A simple approach to the RNA world. Chem. Commun., 1458-1459. Joshi, P.C., Pitsch, S., and Ferris, J.P. (2000) Homochiral selection

  3. Nicotine prevents synaptic impairment induced by amyloid-β oligomers through α7-nicotinic acetylcholine receptor activation.

    PubMed

    Inestrosa, Nibaldo C; Godoy, Juan A; Vargas, Jessica Y; Arrazola, Macarena S; Rios, Juvenal A; Carvajal, Francisco J; Serrano, Felipe G; Farias, Ginny G

    2013-09-01

    An emerging view on Alzheimer disease's (AD) pathogenesis considers amyloid-β (Aβ) oligomers as a key factor in synaptic impairment and rodent spatial memory decline. Alterations in the α7-nicotinic acetylcholine receptor (α7-nAChR) have been implicated in AD pathology. Herein, we report that nicotine, an unselective α7-nAChR agonist, protects from morphological and synaptic impairments induced by Aβ oligomers. Interestingly, nicotine prevents both early postsynaptic impairment and late presynaptic damage induced by Aβ oligomers through the α7-nAChR/phosphatidylinositol-3-kinase (PI3K) signaling pathway. On the other hand, a cross-talk between α7-nAChR and the Wnt/β-catenin signaling pathway was revealed by the following facts: (1) nicotine stabilizes β-catenin, in a concentration-dependent manner; (2) nicotine prevents Aβ-induced loss of β-catenin through the α7-nAChR; and (3) activation of canonical Wnt/β-catenin signaling induces α7-nAChR expression. Analysis of the α7-nAChR promoter indicates that this receptor is a new Wnt target gene. Taken together, these results demonstrate that nicotine prevents memory deficits and synaptic impairment induced by Aβ oligomers. In addition, nicotine improves memory in young APP/PS1 transgenic mice before extensive amyloid deposition and senile plaque development, and also in old mice where senile plaques have already formed. Activation of the α7-nAChR/PI3K signaling pathway and its cross-talk with the Wnt signaling pathway might well be therapeutic targets for potential AD treatments.

  4. 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.

  5. Development and characterization of a human orthotopic neuroblastoma xenograft

    PubMed Central

    Stewart, Elizabeth; Shelat, Anang; Bradley, Cori; Chen, Xiang; Federico, Sara; Thiagarajan, Suresh; Shirinifard, Abbas; Bahrami, Armita; Pappo, Alberto; Qu, Chunxu; Finkelstein, David; Sablauer, Andras; Dyer, Michael A.

    2016-01-01

    Neuroblastoma is a pediatric cancer of the developing sympathoadrenal lineage. The tumors are known to develop from the adrenal gland or paraspinal ganglia and have molecular and cellular features of sympathetic neurons such as dense core vesicles and catecholamine production. Here we present the detailed molecular, cellular, genetic and epigenetic characterization of an orthotopic xenograft derived from a high-risk stage 4 neuroblastoma patient. Overall, the xenografted tumor retained the high risk features of the primary tumor and showed aggressive growth and metastasis in the mouse. Also, the genome was preserved with no additional copy number variations, structural variations or aneuploidy. There were 13 missense mutations identified in the xenograft that were not present in the patient’s primary tumor and there were no new nonsense mutations. None of the missense mutations acquired in the xenograft were in known cancer genes. We also demonstrate the feasibility of using the orthotopic neuroblastoma xenograft to test standard of care chemotherapy and molecular targeted therapeutics. Finally, we optimized a new approach to produce primary cultures of the neuroblastoma xenografts for high-throughput drug screening which can be used to test new combinations of therapeutic agents for neuroblastoma. PMID:25863122

  6. Targeting ALK in neuroblastoma--preclinical and clinical advancements.

    PubMed

    Carpenter, Erica L; Mossé, Yael P

    2012-07-01

    Despite improvements in cancer therapies in the past 50 years, neuroblastoma remains a devastating clinical problem and a leading cause of childhood cancer deaths. Advances in treatments for children with high-risk neuroblastoma have, until recently, involved addition of cytotoxic therapy to dose-intensive regimens. In this era of targeted therapies, substantial efforts have been made to identify optimal targets for different types of cancer. The discovery of hereditary and somatic activating mutations in the oncogene ALK has now placed neuroblastoma among other cancers, such as melanoma and non-small-cell lung cancer (NSCLC), which benefit from therapies with oncogene-specific small-molecule tyrosine kinase inhibitors. Crizotinib, a small-molecule inhibitor of ALK, has transformed the landscape for the treatment of NSCLC harbouring ALK translocations and has demonstrated activity in preclinical models of ALK-driven neuroblastomas. However, inhibition of mutated ALK is complex when compared with translocated ALK and remains a therapeutic challenge. This Review discusses the biology of ALK in the development of neuroblastoma, preclinical and clinical progress with the use of ALK inhibitors and immunotherapy, challenges associated with resistance to such therapies and the steps being taken to overcome some of these hurdles.

  7. [The role of interferons in neuroblastoma. 2: Immunomodulatory effects].

    PubMed

    Handgretinger, R; Bruchelt, G; Daurer, B; Lang, P; Dopfer, R; Reisfeld, R A; Treuner, J; Niethammer, D

    1990-01-01

    The role of Interferon-gamma (IFN-gamma) in the immunotherapy of neuroblastoma was investigated. In vitro experiments showed that IFN-gamma augments the cytotoxicity of Natural Killer (NK) cells and of interleukin 2 (IL-2)-activated NK (LAK) cells against neuroblastoma target cells. Incubation of the neuroblastoma cells with IFN-gamma resulted in an increased susceptibility of these target cells to NK and LAK cells. Additionally, the IFN-gamma-treated neuroblastoma cells showed an increased susceptibility to the antibody-dependent cellular cytotoxicity (ADCC). In patients who have been treated with continuous infusions of IL-2, IL-2-induced secretion of IFN-gamma was detected by measuring the elevation of the 2-5 A synthetase activity in peripheral mononuclear cells or the 2-5 A oligoadenylates in the serum, although IFN-gamma itself was not detectable. From these results we conclude that IFN-gamma may play an important role in the immunotherapy of neuroblastoma in combination with IL-2 and/or with monoclonal antibodies.

  8. 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. PMID:26304901

  9. 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

  10. 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.

  11. Self-assembly of 33-mer gliadin peptide oligomers.

    PubMed

    Herrera, M G; Benedini, L A; Lonez, C; Schilardi, P L; Hellweg, T; Ruysschaert, J-M; Dodero, V I

    2015-11-28

    The 33-mer gliadin peptide, LQLQPF(PQPQLPY)3PQPQPF, is a highly immunogenic peptide involved in celiac disease and probably in other immunopathologies associated with gliadin. Herein, dynamic light scattering measurements showed that 33-mer, in the micromolar concentration range, forms polydisperse nano- and micrometer range particles in aqueous media. This behaviour is reminiscent of classical association of colloids and we hypothesized that the 33-mer peptide self-assembles into micelles that could be the precursors of 33-mer oligomers in water. Deposition of 33-mer peptide aqueous solution on bare mica generated nano- and microstructures with different morphologies as revealed by atomic force microscopy. At 6 μM, the 33-mer is organised in isolated and clusters of spherical nanostructures. In the 60 to 250 μM concentration range, the spherical oligomers associated mainly in linear and annular arrangements and structures adopting a "sheet" type morphology appeared. At higher concentrations (610 μM), mainly filaments and plaques immersed in a background of nanospherical structures were detected. The occurrence of different morphologies of oligomers and finally the filaments suggests that the unique specific geometry of the 33-mer oligomers has a crucial role in the subsequent condensation and organization of their fractal structures into the final filaments. The self-assembly process on mica is described qualitatively and quantitatively by a fractal diffusion limited aggregation (DLA) behaviour with the fractal dimension in the range of 1.62 ± 0.02 to 1.73 ± 0.03. Secondary structure evaluation of the oligomers by Attenuated Total Reflection FTIR spectroscopy (ATR-FTIR) revealed the existence of a conformational equilibrium of self-assembled structures, from an extended conformation to a more folded parallel beta elongated structures. Altogether, these findings provide structural and morphological information about supramolecular organization of the 33-mer

  12. Unique Properties of the Rabbit Prion Protein Oligomer.

    PubMed

    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

  13. 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

  14. Treatment of high-risk neuroblastoma.

    PubMed

    Sung, Ki Woong

    2012-04-01

    Although high-dose chemotherapy and autologous stem cell transplantation (HDCT/autoSCT) have improved the prognosis for patients with high-risk neuroblastoma (NB), event-free survival rates remain in the range of 30 to 40%, which is unsatisfactory. To further improve outcomes, several clinical trials, including tandem HDCT/autoSCT, high-dose (131)I-metaiodobenzylguanidine treatment, and immunotherapy with NB specific antibody, have been undertaken and pilot studies have reported encouraging results. Nonetheless, about half of high-risk NB patients still experience treatment failure and have no realistic chance for cure with conventional treatment options alone after relapse. Therefore, a new modality of treatment is warranted for these patients. In recent years, several groups of investigators have examined the feasibility and effectiveness of reduced-intensity allogeneic stem cell transplantation (RI alloSCT) for the treatment of relapsed/progressed NB. Although a graft-versus-tumor effect has not yet been convincingly demonstrated in the setting of relapsed NB, the strategy of employing RI alloSCT has provided hope that treatment-related mortality will be reduced and a therapeutic benefit will emerge. However, alloSCT for NB is still investigational and there remain many issues to be elucidated in many areas. At present, alloSCT is reserved for specific clinical trials testing the immunomodulatory effect against NB.

  15. 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.

  16. Children's Oncology Group's 2013 blueprint for research: neuroblastoma.

    PubMed

    Park, Julie R; Bagatell, Rochelle; London, Wendy B; Maris, John M; Cohn, Susan L; Mattay, Katherine K; Mattay, Katherine M; Hogarty, Michael

    2013-06-01

    Estimated 5-year survival rates for patients with non-high-risk and high-risk neuroblastoma are 90% and 50%, respectively. Recent clinical trials have shown excellent outcomes with reduced therapy for non-high-risk disease. For patients with high-risk neuroblastoma treated with chemoradiotherapy, surgery, and stem cell transplantation, the addition of anti-disialoganglioside (GD2) immunotherapy plus cytokines improves survival. Upcoming trials will study the incorporation of targeted radionuclide therapy prior to myeloablative chemotherapy into high-risk treatment. Phase 2 trials will investigate druggable target(s) including mTOR inhibition and GD2-directed therapy in combination with chemotherapy for patients with recurrent neuroblastoma, and ALK inhibition for those with ALK-aberrant tumors.

  17. Modulation of cell-surface antigens of a murine neuroblastoma.

    PubMed

    Akeson, R; Herschman, H R

    1974-01-01

    Antisera were produced in rabbits to morphologically differentiated cells from the C1300 murine neuroblastoma (i.e., cells in which process formation was induced by maintenance on serum-free medium for 5 days). These antisera reacted more strongly in the complement fixation reaction with such "differentiated" cells than with "undifferentiated" (nonprocess-bearing) neuroblastoma cells. Adsorption of the antisera with undifferentiated cells removed the reactivity to cells without processes, while the reactivity with serum-free cells which possess processes was retained. Indirect immunofluorescence studies confirmed the results obtained by complement fixation and demonstrated that antibodies to the surface antigens of process-bearing cells could be adsorbed by particulate preparations from brain but not liver, spleen, or kidney. This is the first description of neural-associated cell-surface changes that correlate with the morphological differentiation in culture of neuroblastoma cells.

  18. Expression of GD2 ganglioside by untreated primary human neuroblastomas.

    PubMed

    Wu, Z L; Schwartz, E; Seeger, R; Ladisch, S

    1986-01-01

    Primary neuroblastomas obtained before therapy from 36 patients were studied to determine the frequency of tumors expressing a specific glycosphingolipid, GD2 ganglioside. Total tissue gangliosides were purified by a new partition method, quantitated, and analyzed by high-performance thin-layer chromatography. All 36 neuroblastoma tumors, representing all clinical stages, contained GD2 ganglioside. The mean relative and absolute concentrations of GD2 were substantial (12% of the total tissue gangliosides and 50 nmol/g of tissue) and were independent of the clinical stage of the tumor. In contrast, 6 samples of related but more differentiated tumors (ganglioneuroblastoma and ganglioneuroma) had little or no detectable GD2 (less than or equal to 1.5% of total gangliosides and less than or equal to 4 nmol/g of tissue). These results suggest that GD2 is a sensitive marker for neuroblastoma tissue and may be an excellent target antigen for immunotherapy of this tumor.

  19. 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

  20. Quaternary structure defines a large class of amyloid-β oligomers neutralized by sequestration

    PubMed Central

    Liu, Peng; Reed, Miranda N.; Kotilinek, Linda A.; Grant, Marianne K.O.; Forster, Colleen L.; Qiang, Wei; Shapiro, Samantha L.; Reichl, John H.; Chiang, Angie C.A.; Jankowsky, Joanna L.; Wilmot, Carrie M.; Cleary, James P.; Zahs, Kathleen R.; Ashe, Karen H.

    2015-01-01

    Summary The accumulation of amyloid-β (Aβ) as amyloid fibrils and toxic oligomers is an important step in the development of Alzheimer's disease (AD). However, there are numerous potentially toxic oligomers and little is known about their neurological effects when generated in the living brain. Here, we show that Aβ oligomers can be assigned to one of at least two classes (Type 1 and Type 2) based on their temporal, spatial and structural relationships to amyloid fibrils. The Type 2 oligomers are related to amyloid fibrils and represent the majority of oligomers generated in vivo, but remain confined to the vicinity of amyloid plaques and do not impair cognition at levels relevant to AD. Type 1 oligomers are unrelated to amyloid fibrils and may have greater potential to cause global neural dysfunction in AD because they are dispersed. These results refine our understanding of the pathogenicity of Aβ oligomers in vivo. PMID:26051935

  1. Rituximab for treatment of opsoclonus-myoclonus syndrome in neuroblastoma.

    PubMed

    Burke, Michael J; Cohn, Susan L

    2008-03-01

    Opsoclonus-myoclonus syndrome (OMS) is a rare paraneoplastic syndrome that occurs in 2%-3% of patients with neuroblastoma. The cause of this syndrome is believed to be immune mediated, but the exact mechanism still remains unclear. There is an urgent need to improve our current strategies for treating patients with OMS, as many patients have significant long-term neurologic deficits and behavior disorders with current treatment approaches. Therapies that have shown to improve symptoms in these patients have ranged from ACTH and corticosteroids, to intravenous gammaglobulin and plasmapheresis. We report our experience with Rituximab in a patient with neuroblastoma and OMS.

  2. 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. PMID:26963048

  3. 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

  4. Dehydroepiandrosterone protects male and female hippocampal neurons and neuroblastoma cells from glucose deprivation.

    PubMed

    Vieira-Marques, Claudia; Arbo, Bruno Dutra; Ruiz-Palmero, Isabel; Ortiz-Rodriguez, Ana; Ghorbanpoor, Samar; Kucharski, Luiz Carlos; Arevalo, Maria A; Garcia-Segura, Luis Miguel; Ribeiro, Maria Flávia M

    2016-08-01

    Dehydroepiandrosterone (DHEA) modulates neurogenesis, neuronal function, neuronal survival and metabolism, enhancing mitochondrial oxidative capacity. Glucose deprivation and hypometabolism have been implicated in the mechanisms that mediate neuronal damage in neurological disorders, and some studies have shown that these mechanisms are sexually dimorphic. It was also demonstrated that DHEA is able to attenuate the hypometabolism that is related to some neurodegenerative diseases, eliciting neuroprotective effects in different experimental models of neurodegeneration. The aim of this study was to evaluate the effect of DHEA on the viability of male and female hippocampal neurons and SH-SY5Y neuroblastoma cells exposed to glucose deprivation. It was observed that after 12h of pre-treatment, DHEA was able to protect SH-SY5Y cells from glucose deprivation for 6h (DHEA 10(-12), 10(-8) and 10(-6)M) and 8h (DHEA 10(-8)M). In contrast, DHEA was not neuroprotective against glucose deprivation for 12 or 24h. DHEA (10(-8)M) also protected SH-SY5Y cells when added together or even 1h after the beginning of glucose deprivation (6h). Furthermore, DHEA (10(-8)M) also protected primary neurons from both sexes against glucose deprivation. In summary, our findings indicate that DHEA is neuroprotective against glucose deprivation in human neuroblastoma cells and in male and female mouse hippocampal neurons. These results suggest that DHEA could be a promising candidate to be used in clinical studies aiming to reduce neuronal damage in people from both sexes. PMID:27174000

  5. Energy metabolism in neuroblastoma and Wilms tumor.

    PubMed

    Aminzadeh, Sepideh; Vidali, Silvia; Sperl, Wolfgang; Kofler, Barbara; Feichtinger, René G

    2015-01-01

    To support high proliferation, the majority of cancer cells undergo fundamental metabolic changes such as increasing their glucose uptake and shifting to glycolysis for ATP production at the expense of far more efficient mitochondrial energy production by oxidative phosphorylation (OXPHOS), which at first glance is a paradox. This phenomenon is known as the Warburg effect. However, enhanced glycolysis is necessary to provide building blocks for anabolic growth. Apart from the generation of ATP, intermediates of glycolysis serve as precursors for a variety of biosynthetic pathways essential for cell proliferation. In the last 10-15 years the field of tumor metabolism has experienced an enormous boom in interest. It is now well established that tumor suppressor genes and oncogenes often play a central role in the regulation of cellular metabolism. Therefore, they significantly contribute to the manifestation of the Warburg effect. While much attention has focused on adult solid tumors, so far there has been comparatively little effort directed at elucidation of the mechanism responsible for the Warburg effect in childhood cancers. In this review we focus on metabolic pathways in neuroblastoma (NB) and Wilms tumor (WT), the two most frequent solid tumors in children. Both tumor types show alterations of the OXPHOS system and glycolytic features. Chromosomal alterations and activation of oncogenes like MYC or inactivation of tumor suppressor genes like TP53 can in part explain the changes of energy metabolism in these cancers. The strict dependence of cancer cells on glucose metabolism is a fairly common feature among otherwise biologically diverse types of cancer. Therefore, inhibition of glycolysis or starvation of cancer cells through glucose deprivation via a high-fat low-carbohydrate diet may be a promising avenue for future adjuvant therapeutic strategies. PMID:26835356

  6. Structure and function of the visual arrestin oligomer

    PubMed Central

    Hanson, Susan M; Van Eps, Ned; Francis, Derek J; Altenbach, Christian; Vishnivetskiy, Sergey A; Arshavsky, Vadim Y; Klug, Candice S; Hubbell, Wayne L; Gurevich, Vsevolod V

    2007-01-01

    A distinguishing feature of rod arrestin is its ability to form oligomers at physiological concentrations. Using visible light scattering, we show that rod arrestin forms tetramers in a cooperative manner in solution. To investigate the structure of the tetramer, a nitroxide side chain (R1) was introduced at 18 different positions. The effects of R1 on oligomer formation, EPR spectra, and inter-spin distance measurements all show that the structures of the solution and crystal tetramers are different. Inter-subunit distance measurements revealed that only arrestin monomer binds to light-activated phosphorhodopsin, whereas both monomer and tetramer bind microtubules, which may serve as a default arrestin partner in dark-adapted photoreceptors. Thus, the tetramer likely serves as a ‘storage' form of arrestin, increasing the arrestin-binding capacity of microtubules while readily dissociating to supply active monomer when it is needed to quench rhodopsin signaling. PMID:17332750

  7. 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.

  8. Pigment oligomers as natural and artificial photosynthetic antennas

    SciTech Connect

    Blankenship, R.E.

    1996-12-31

    Green photosynthetic bacteria contain antenna complexes known as chlorosomes. These complexes are appressed to the cytoplasmic side of the inner cell membrane and function to absorb light and transfer the energy to the photochemical reaction center, where photochemical energy storage takes place. Chlorosomes differ from all other known photosynthetic antenna complexes in that the geometrical arrangement of pigments is determined primarily by pigment-pigment interactions instead of pigment-protein interactions. The bacteriochlorophyll c, d or e pigments found in chlorosomes form large oligomers with characteristic spectral properties significantly perturbed from those exhibited by monomeric pigments. Because of their close spatial interaction, the pigments are thought to be strongly coupled electronically, and many of the optical properties result from exciton interactions. This presentation will summarize existing knowledge on the chemical composition and properties of chlorosomes, the evidence for the oligomeric nature of chlorosome pigment organization and proposed structures for the oligomers, and the kinetics and mechanisms of energy transfer in chlorosomes.

  9. 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).

  10. 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.

  11. 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.

  12. 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

  13. NMR structural inference of symmetric homo-oligomers.

    PubMed

    Chandola, Himanshu; Yan, Anthony K; Potluri, Shobha; Donald, Bruce R; Bailey-Kellogg, Chris

    2011-12-01

    Symmetric homo-oligomers represent a majority of proteins, and determining their structures helps elucidate important biological processes, including ion transport, signal transduction, and transcriptional regulation. In order to account for the noise and sparsity in the distance restraints used in Nuclear Magnetic Resonance (NMR) structure determination of cyclic (C(n)) symmetric homo-oligomers, and the resulting uncertainty in the determined structures, we develop a Bayesian structural inference approach. In contrast to traditional NMR structure determination methods, which identify a small set of low-energy conformations, the inferential approach characterizes the entire posterior distribution of conformations. Unfortunately, traditional stochastic techniques for inference may under-sample the rugged landscape of the posterior, missing important contributions from high-quality individual conformations and not accounting for the possible aggregate effects on inferred quantities from numerous unsampled conformations. However, by exploiting the geometry of symmetric homo-oligomers, we develop an algorithm that provides provable guarantees for the posterior distribution and the inferred mean atomic coordinates. Using experimental restraints for three proteins, we demonstrate that our approach is able to objectively characterize the structural diversity supported by the data. By simulating spurious and missing restraints, we further demonstrate that our approach is robust, degrading smoothly with noise and sparsity. PMID:21718128

  14. Patterning polyethylene oligomers on carbon nanotubes using physical vapor deposition.

    PubMed

    Li, Lingyu; Yang, Yao; Yang, Guoliang; Chen, Xuming; Hsiao, Benjamin S; Chu, Benjamin; Spanier, Jonathan E; Li, Christopher Y

    2006-05-01

    Periodic patterning on one-dimensional (1D) carbon nanotubes (CNTs) is of great interest from both scientific and technological points of view. In this letter, we report using a facile physical vapor deposition method to achieve periodic polyethylene (PE) oligomer patterning on individual CNTs. Upon heating under vacuum, PE degraded into oligomers and crystallized into rod-shaped single crystals. These PE rods periodically decorate on CNTs with their long axes perpendicular to the CNT axes. The formation mechanism was attributed to "soft epitaxy" growth of PE oligomer crystals on CNTs. Both SWNTs and MWNTs were decorated successfully with PE rods. The intermediate state of this hybrid structure, MWNTs absorbed with a thin layer of PE, was captured successfully by depositing PE vapor on MWNTs detached from the solid substrate, and was observed using high-resolution transmission electron microscopy. Furthermore, this hybrid structure formation depends critically on CNT surface chemistry: alkane-modification of the MWNT surface prohibited the PE single-crystal growth on the CNTs. We anticipate that this work could open a gateway for creating complex CNT-based nanoarchitectures for nanodevice applications.

  15. 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.

  16. 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.

  17. 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.

  18. Molecularly guided therapy of neuroblastoma: a review of different approaches.

    PubMed

    Tonini, Gian Paolo; Pistoia, Vito

    2006-01-01

    Neuroblastoma (NB) is the most frequent extra-cranial solid tumor and the first cause of lethality in pre-school age children. NB accounts for 9-10% of pediatric tumors and affects more than ten thousand children a year. It originates from the sympathetic nervous system and is characterized by heterogeneous pathological and clinical presentation. Stage 4 NB represents approximately 50% of the cases and shows metastatic dissemination at onset; its prognosis is grim, with 20% of the patients surviving at 5 years from diagnosis in spite of aggressive chemotherapy with autologous hematopoietic stem cell support. Novel therapeutic strategies are urgently needed to improve the prognosis of stage 4 NB patients. Here we review the most promising approaches to NB treatment that have already reached clinical testing or have proved to be successful in preclinical models of the disease. All of these approaches are molecularly guided, since their rational development has benefited from the enormous amount of information on the biology of neuroblastoma gathered through molecular biology and genetics studies. The following topics are reviewed: MYCN oncogene amplification as parameter for therapeutic decision, minimal residual disease, immunotherapy, gene therapy, differentiation and apoptotic therapy, anti-angiogenic therapy, gene expression profiling as tool for generating novel therapeutic approaches. Although several efforts are still needed to reach a significant cure of patients with neuroblastoma, molecularly guided approaches have opened new ways to neuroblastoma treatment and can represent useful models for other cancers of either childhood or adulthood.

  19. 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.

  20. 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

  1. Mechanisms of prodigiosin cytotoxicity in human neuroblastoma cell lines.

    PubMed

    Francisco, Roser; Pérez-Tomás, Ricardo; Gimènez-Bonafé, Pepita; Soto-Cerrato, Vanessa; Giménez-Xavier, Pol; Ambrosio, Santiago

    2007-10-31

    Prodigiosin is a bacterial red pigment with cytotoxic properties and potential antitumor activity that has been tested against different cancerous cells. In this study we report the effect and mechanisms of action of prodigiosin against different human neuroblastoma cell lines: SH-SY5Y, LAN-1, IMR-32 (N-type) and SK-N-AS (S-type). We compare the anticancerous effect of prodigiosin with that of cisplatin at different concentrations during 24 h of exposure. Prodigiosin is more potent, with IC50 values lower than 1.5 microM in N-type neuroblastoma cells and around 7 microM in the S-type neuroblastoma cell line. We describe prodigiosin as a proton sequestering agent that destroys the intracellular pH gradient, and propose that its main cytotoxic effect could be related to its action on mitochondria, where it exerts an uncoupling effect on the electronic chain transport of protons to mitochondrial ATP synthase. As a result of this action, ATP production is reduced but without decreasing in oxygen consumption. This mechanism of action differs from those induced by conventional chemotherapeutic drugs, suggesting a possible role for prodigiosin to enhance the effect of antitumor agents in the treatment of neuroblastoma.

  2. 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

  3. 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

  4. 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

  5. Synthesis and Characterization of Unsymmetrical Perylene Derivatives and Perylene Oligomers

    NASA Astrophysics Data System (ADS)

    Sun, Runkun

    Since the discovery of high fluorescent property of perylene tetracarboxylic diimide (PDI) derivatives in 1959, more and more researchers' attention has been attracted to related fields. Ever since, many kinds of PDI derives has been synthesized and characterized. And many special properties of PDI derivatives also has been found, such as strong absorbance ability, special redox property and self assembly induced by pi-pi interaction etc. All these properties endow PDI derivatives wide applications in photovoltaic field and semi-conducting materials area. At the same time, those important applications also encourage researchers to do more exploration on the synthesis and characterization of PDI derivatives. As one of those researchers, my thesis also mainly focused on developing new synthetic methods and characterization of novel PDI derivatives. In Chapter 1, the history of perylene, PDI derivatives and PDI oligomers are introduced. Their corresponding properties and applications also are introduced. Furthermore, the synthetic methods for different kinds of PDI derivatives, both advantages and disadvantages, are discussed thoroughly. In Chapter 2, with the investigation of known reactions which were used to prepare the key intermediate, perylene monoimide monoanhydride, a new synthetic method was developed. The key intermediate could be prepared with high yield conveniently. With the key intermediate, several unsymmetric PDI derivatives were prepared with decent yield. The optical property of one unsymmetric PDI was studied. In Chapter 3, the synthesis of peryelene diester monoanhydride (PEA) and perylene monoimide monoanhydride (PIA) was discussed. We discovered a new way to prepare PEA and PEI. Several PEA and PEI with complex structure were prepared with decent yield. The first unsymmetric PEA was synthesized. In Chapter 4, the synthesis of several perylene oligomers was discussed. Base on our experience gained in the Chapter 3 and our investigation of Langhals

  6. Clusterin Binds to Aβ1-42 Oligomers with High Affinity and Interferes with Peptide Aggregation by Inhibiting Primary and Secondary Nucleation.

    PubMed

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

    2016-03-25

    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 Aβ1-42oligomers, 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 Aβ1-42oligomers, as evaluated in a recently developedin vivomodel inCaenorhabditis 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

  7. Lacking immunocytological GD2 expression in neuroblastoma: report of 3 cases.

    PubMed

    Schumacher-Kuckelkorn, Roswitha; Hero, Barbara; Ernestus, Karen; Berthold, Frank

    2005-08-01

    Immunocytological bone marrow assessment for contamination with neuroblastoma cells is based on their characteristic GD2 surface staining. Neuroblastoma without GD2 expression have been rarely and only after antibody therapy reported. Conventional cytology was performed using Pappenheim staining. For immunocytology, the APAAP method was utilized with the 14G2a anti-GD2 mouse monoclonal antibody. 7 x 10(5) cells on cytospin preparations were investigated. In 2003, 288 bone marrow samples from 191 neuroblastoma patients were investigated by cytology and immunocytology. Three cases demonstrated GD2 negativity on cytologically unambiguous neuroblastoma cells. Two female cases (94 and 37 months of age) with stage 4 neuroblastoma had GD2 expressing neuroblastoma cells in bone marrow at diagnosis. At 2nd relapse 25 and 23 months after diagnosis and 8 months and 12 months after anti-GD2 antibody treatment (ch14.18), the bone marrow infiltrating neuroblastoma cells lacked GD2 staining. The third patient, a 63-month-old girl with bone marrow replacement by neuroblastoma cells showed at diagnosis a mixture of GD2-unstained tumor clumps and very weakly stained neuroblastoma cells. Neuroblastoma cells may lack GD2 expression at diagnosis and at recurrence. This observation has diagnostic and therapeutic implications. PMID:15800908

  8. Targeting p53 Null Neuroblastomas through RLIP76**

    PubMed Central

    Singhal, Jyotsana; Yadav, Sushma; Nagaprashantha, Lokesh Dalasanur; Vatsyayan, Rit; Singhal, Sharad S; Awasthi, Sanjay

    2011-01-01

    The search for p53-independent mechanism of cancer cell killing is highly relevant to pediatric neuroblastomas, where successful therapy is limited by its transformation into p53 mutant and a highly drug-resistant neoplasm. Our studies on the drug-resistant p53 mutant as compared with drug-resistant p53 wild-type neuroblastoma revealed a novel mechanism for resistance to apoptosis: a direct role of p53 in regulating the cellular concentration of pro-apoptotic alkenals by functioning as a specific and saturable allosteric inhibitor of the alkenal-glutathione-conjugate transporter, RLIP76. The RLIP76-p53 complex was demonstrated both using immuno-precipitation analyses of purified proteins as well as by immuno-fluorescence analysis. Drug transport studies revealed that p53 inhibited both basal and PKCα stimulated transport of glutathione-conjugates of 4HNE (GS-HNE) and cisplatin. Drug resistance was significantly greater for p53 mutant as compared with p53 wild-type neuroblastoma cell lines, but both were susceptible to depletion of RLIP76 by antisense alone. In addition, inhibition of RLIP76 significantly enhanced the cytotoxicity of cisplatin. Taken together, these studies provide powerful evidence for a novel mechanism for drug and apoptosis resistance in p53 mutant neuroblastoma, based on a model of regulation of p53 induced apoptosis by RLIP76, where p53 is a saturable and specific allosteric inhibitor of RLIP76, and p53 loss results in over-expression of RLIP76; thus, in the absence of p53, the drug and glutathione-conjugate transport activities of RLIP76 are enhanced. Most importantly, our findings strongly indicate RLIP76 as a novel target for therapy of drug-resistant and p53 mutant neuroblastoma. PMID:21411502

  9. Intrinsic versus imposed curvature in cyclical oligomers: the portal protein of bacteriophage SPP1.

    PubMed Central

    van Heel, M; Orlova, E V; Dube, P; Tavares, P

    1996-01-01

    Large cyclical oligomers may be formed by (curvi-) linear polymerization of monomers until the n(th) monomer locks in with the first member of the chain. The subunits in incomplete structures exhibit a natural curvature with respect to each other which can be perturbed when the oligomer closes cyclically. Using cryo-electron microscopy and multivariate statistical image processing we report herein a direct structural observation of this effect. A sub-population (approximately 15%) of incomplete oligomers was found within a sample of SPP1 bacteriophage portal proteins embedded in vitreous ice. Whereas the curvature between adjacent subunits of the closed circular 13-fold symmetric oligomer is 27.7 degrees, in these incomplete oligomers the angle is only 25.8 degrees, a value which almost allows for a 14-subunit cyclical arrangement. A simple model for the association of large cyclical oligomers is suggested by our data. Images PMID:8890151

  10. Apoptosis induced by islet amyloid polypeptide soluble oligomers is neutralized by diabetes-associated specific antibodies

    PubMed Central

    Bram, Yaron; Frydman-Marom, Anat; Yanai, Inbal; Gilead, Sharon; Shaltiel-Karyo, Ronit; Amdursky, Nadav; Gazit, Ehud

    2014-01-01

    Soluble oligomeric assemblies of amyloidal proteins appear to act as major pathological agents in several degenerative disorders. Isolation and characterization of these oligomers is a pivotal step towards determination of their pathological relevance. Here we describe the isolation of Type 2 diabetes-associated islet amyloid polypeptide soluble cytotoxic oligomers; these oligomers induced apoptosis in cultured pancreatic cells, permeated model lipid vesicles and interacted with cell membranes following complete internalization. Moreover, antibodies which specifically recognized these assemblies, but not monomers or amyloid fibrils, were exclusively identified in diabetic patients and were shown to neutralize the apoptotic effect induced by these oligomers. Our findings support the notion that human IAPP peptide can form highly toxic oligomers. The presence of antibodies identified in the serum of diabetic patients confirms the pathological relevance of the oligomers. In addition, the newly identified structural epitopes may also provide new mechanistic insights and a molecular target for future therapy. PMID:24589570

  11. Chitosan polymer sizes effective in inducing phytoalexin accumulation and fungal suppression are verified with synthesized oligomers.

    PubMed

    Hadwiger, L A; Ogawa, T; Kuyama, H

    1994-01-01

    Biologically derived chitosan has been reported to induce pisatin and disease resistance response proteins in pea tissue and also to inhibit the germination and growth of some fungal pathogens. Stereo-controlled synthesis of chitosan tetramer, hexamer, and octamer allowed the precise verification of oligomer size required for biological activity. The octameric oligomer optimally induced pisatin accumulation and inhibited fungal growth, verifying previous results obtained with column-purified oligomers derived from crab shells.

  12. Case study on the evolution of hetero-oligomer interfaces based on the differences in paralogous proteins

    PubMed Central

    Aoto, Saki; Yura, Kei

    2015-01-01

    We addressed the evolutionary trace of hetero-oligomer interfaces by comparing the structures of paralogous proteins; one of them is a monomer or homo-oligomer and the other is a hetero-oligomer. We found different trends in amino acid conservation pattern and hydrophobicity between homo-oligomer and hetero-oligomer. The degree of amino acid conservation in the interface of homo-oligomer has no obvious difference from that in the surface, whereas the degree of conservation is much higher in the interface of hetero-oligomer. The interface of homo-oligomer has a few very conserved residue positions, whereas the residue conservation in the interface of hetero-oligomer tends to be higher. In addition, the interface of hetero-oligomer has a tendency of being more hydrophobic compared with the one in homo-oligomer. We conjecture that these differences are related to the inherent symmetry in homo-oligomers that cannot exist in hetero-oligomers. Paucity of the structural data precludes statistical tests of these tendencies, yet the trend can be applied to the prediction of the interface of hetero-oligomer. We obtained putative interfaces of the subunits in CPSF (cleavage and polyadenylation specificity factor), one of the human pre-mRNA 3′-processing complexes. The locations of predicted interface residues were consistent with the known experimental data. PMID:27493859

  13. 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

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. Cancer Stem Cells and Their Interaction with the Tumor Microenvironment in Neuroblastoma

    PubMed Central

    Garner, Evan F.; Beierle, Elizabeth A.

    2015-01-01

    Neuroblastoma, a solid tumor arising from neural crest cells, accounts for over 15% of all pediatric cancer deaths. The interaction of neuroblastoma cancer-initiating cells with their microenvironment likely plays an integral role in the maintenance of resistant disease and tumor relapse. In this review, we discuss the interaction between neuroblastoma cancer-initiating cells and the elements of the tumor microenvironment and how these interactions may provide novel therapeutic targets for this difficult to treat disease. PMID:26729169

  19. 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.

  20. Functional analysis of the putative tumor suppressor PTPRD in neuroblastoma cells.

    PubMed

    Clark, O; Schmidt, F; Coles, C H; Tchetchelnitski, V; Stoker, A W

    2012-06-01

    The gene encoding PTPδ is mutated or downregulated in human cancers including neuroblastoma. Here, we functionally tested the tumor-suppressive potential of PTPδ in neuroblastoma cell lines by reconstitution of both short and long PTPδ isoforms. We did not observe any significant difference in colony forming ability between cells expressing wild-type or catalytically inactive PTPδ. Although endogenous PTPδ expression was very low in neuroblastoma cells, it was also low in mouse embryo adrenal glands, suggesting that PTPδ may have little developmental function in early adrenal neuroblasts. This study, therefore, questions the significance of PTPδ as a tumor suppressor protein in neuroblastoma.

  1. Nordihydroguaiaretic Acid Inhibits Insulin-Like Growth Factor Signaling, Growth, and Survival in Human Neuroblastoma Cells

    PubMed Central

    Meyer, Gary E.; Chesler, Louis; Liu, Dandan; Gable, Karissa; Maddux, Betty A.; Goldenberg, David D.; Youngren, Jack F.; Goldfine, Ira D.; Weiss, William A.; Matthay, Katherine K.; Rosenthal, Stephen M.

    2010-01-01

    Neuroblastoma is a common pediatric malignancy that metastasizes to the liver, bone, and other organs. Children with metastatic disease have a less than 50% chance of survival with current treatments. Insulin-like growth factors (IGFs) stimulate neuroblastoma growth, survival, and motility, and are expressed by neuroblastoma cells and the tissues they invade. Thus, therapies that disrupt the effects of IGFs on neuroblastoma tumorigenesis may slow disease progression. We show that NVP-AEW541, a specific inhibitor of the IGF-I receptor (IGF-IR), potently inhibits neuroblastoma growth in vitro. Nordihydroguaiaretic acid (NDGA), a phenolic compound isolated from the creosote bush (Larrea divaricata), has anti-tumor properties against a number of malignancies, has been shown to inhibit the phosphorylation and activation of the IGF-IR in breast cancer cells, and is currently in Phase I trials for prostate cancer. In the present study in neuroblastoma, NDGA inhibits IGF-I-mediated activation of the IGF-IR and disrupts activation of ERK and Akt signaling pathways induced by IGF-I. NDGA inhibits growth of neuroblastoma cells and induces apoptosis at higher doses, causing IGF-I-resistant activation of caspase-3 and a large increase in the fraction of sub-G0 cells. In addition, NDGA inhibits the growth of xenografted human neuroblastoma tumors in nude mice. These results indicate that NDGA may be useful in the treatment of neuroblastoma and may function in part via disruption of IGF-IR signaling. PMID:17486636

  2. Premature physeal closure following 13-cis-retinoic acid and prolonged fenretinide administration in neuroblastoma.

    PubMed

    Steineck, Angela; MacKenzie, John D; Twist, Clare J

    2016-11-01

    Retinoid therapy has contributed to improved outcomes in neuroblastoma. Clinical trials of fenretinide report favorable toxicity and disease stabilization in patients with high risk (HR) neuroblastoma. Skeletal effects have been described with other retinoids, but not with fenretinide to date. Two patients with HR, metastatic, refractory neuroblastoma received protracted courses of oral fenretinide for more than 5 years' duration. Both developed premature long bone physeal closure, causing limb length discrepancies; their neuroblastoma remains in remission. The radiographic and clinical findings reported suggest these skeletal abnormalities may be a consequence of treatment with 13-cis-retinoic acid (13cisRA) followed by prolonged oral fenretinide exposure.

  3. Omega-3 fatty acid supplementation delays the progression of neuroblastoma in vivo.

    PubMed

    Gleissman, Helena; Segerström, Lova; Hamberg, Mats; Ponthan, Frida; Lindskog, Magnus; Johnsen, John Inge; Kogner, Per

    2011-04-01

    Epidemiological and preclinical studies have revealed that omega-3 fatty acids have anticancer properties. We have previously shown that the omega-3 fatty acid docosahexaenoic acid (DHA) induces apoptosis of neuroblastoma cells in vitro by mechanisms involving intracellular peroxidation of DHA by means of 15-lipoxygenase or autoxidation. In our study, the effects of DHA supplementation on neuroblastoma tumor growth in vivo were investigated using two complementary approaches. For the purpose of prevention, DHA as a dietary supplement was fed to athymic rats before the rats were xenografted with human neuroblastoma cells. For therapeutic purposes, athymic rats with established neuroblastoma xenografts were given DHA daily by gavage and tumor growth was monitored. DHA levels in plasma and tumor tissue were analyzed by gas liquid chromatography. DHA delayed neuroblastoma xenograft development and inhibited the growth of established neuroblastoma xenografts in athymic rats. A revised version of the Pediatric Preclinical Testing Program evaluation scheme used as a measurement of treatment response showed that untreated control animals developed progressive disease, whereas treatment with DHA resulted in stable disease or partial response, depending on the DHA concentration. In conclusion, prophylactic treatment with DHA delayed neuroblastoma development, suggesting that DHA could be a potential agent in the treatment of minimal residual disease and should be considered for prevention in selected cases. Treatment results on established aggressive neuroblastoma tumors suggest further studies aiming at a clinical application in children with high-risk neuroblastoma.

  4. Nordihydroguaiaretic acid inhibits insulin-like growth factor signaling, growth, and survival in human neuroblastoma cells.

    PubMed

    Meyer, Gary E; Chesler, Louis; Liu, Dandan; Gable, Karissa; Maddux, Betty A; Goldenberg, David D; Youngren, Jack F; Goldfine, Ira D; Weiss, William A; Matthay, Katherine K; Rosenthal, Stephen M

    2007-12-15

    Neuroblastoma is a common pediatric malignancy that metastasizes to the liver, bone, and other organs. Children with metastatic disease have a less than 50% chance of survival with current treatments. Insulin-like growth factors (IGFs) stimulate neuroblastoma growth, survival, and motility, and are expressed by neuroblastoma cells and the tissues they invade. Thus, therapies that disrupt the effects of IGFs on neuroblastoma tumorigenesis may slow disease progression. We show that NVP-AEW541, a specific inhibitor of the IGF-I receptor (IGF-IR), potently inhibits neuroblastoma growth in vitro. Nordihydroguaiaretic acid (NDGA), a phenolic compound isolated from the creosote bush (Larrea divaricata), has anti-tumor properties against a number of malignancies, has been shown to inhibit the phosphorylation and activation of the IGF-IR in breast cancer cells, and is currently in Phase I trials for prostate cancer. In the present study in neuroblastoma, NDGA inhibits IGF-I-mediated activation of the IGF-IR and disrupts activation of ERK and Akt signaling pathways induced by IGF-I. NDGA inhibits growth of neuroblastoma cells and induces apoptosis at higher doses, causing IGF-I-resistant activation of caspase-3 and a large increase in the fraction of sub-G0 cells. In addition, NDGA inhibits the growth of xenografted human neuroblastoma tumors in nude mice. These results indicate that NDGA may be useful in the treatment of neuroblastoma and may function in part via disruption of IGF-IR signaling.

  5. Smac mimetic LBW242 sensitizes XIAP-overexpressing neuroblastoma cells for TNF-α-independent apoptosis.

    PubMed

    Eschenburg, Georg; Eggert, Angelika; Schramm, Alexander; Lode, Holger N; Hundsdoerfer, Patrick

    2012-05-15

    Despite intensive treatment regimens, high-risk and late-stage neuroblastoma tends to have a poor survival outcome. Overexpression of the apoptotic regulator, X-linked inhibitor of apoptosis protein (XIAP), has been associated with chemotherapy resistance in several cancers including neuroblastoma. Here, we report preclinical evidence that XIAP offers an effective therapeutic target in neuroblastoma. Human and murine neuroblastoma cells were treated with the Smac mimetic LBW242 alone or in combination with cytotoxic drugs used clinically to treat neuroblastoma. Expression of XIAP protein, but not mRNA, was highly increased in neuroblastoma cells compared to healthy adrenal gland tissue, consistent with a posttranscriptional regulation of XIAP expression. Treatment with LBW242 sensitized human and murine neuroblastoma cells to chemotherapy-induced apoptosis, which was mediated by activation of both the intrinsic and extrinsic apoptosis pathways. Although Smac mimetics have been reported to stimulate TNF-α-induced apoptosis by degradation of cellular IAP (cIAP)-1/2, we found that LBW242-mediated sensitization in neuroblastoma cells occurred in a TNF-α-independent manner, despite induction of cIAP-1/2 degradation and TNF-α expression. Together, our findings show that XIAP targeting sensitizes neuroblastoma to chemotherapy-induced apoptosis, suggesting a novel therapeutic approach to treat this childhood malignancy.

  6. Of mice and men: olfactory neuroblastoma among animals and humans.

    PubMed

    Lubojemska, A; Borejko, M; Czapiewski, P; Dziadziuszko, R; Biernat, W

    2016-09-01

    Olfactory neuroblastoma (ONB) is a rare tumour of nasal cavity and paranasal sinuses that arises from the olfactory neuroepithelium and has unpredictable clinical course. As the sense of smell is phylogenetically one of the first senses and olfactory neuroepithelium is evolutionary conserved with striking similarities among different species, we performed an extensive analysis of the literature in order to evaluate the similarities and differences between animals and humans on the clinical, morphological, immunohistochemical, ultrastructural and molecular level. Our analysis revealed that ONB was reported mainly in mammals and showed striking similarities to human ONB. These observations provide rationale for introduction of therapy modalities used in humans into the veterinary medicine. Animal models of neuroblastoma should be considered for the preclinical studies evaluating novel therapies for ONB. PMID:25041470

  7. Cell-mediated immune reactions to clinical neuroblastoma.

    PubMed

    Okabe, I; Kurosu, Y; Morita, K

    1985-09-01

    Immunotherapy may be an effective treatment for neuroblastoma. It is of importance to delineate changes in various parameters of tumor immunity over an extended period, before and during the course of treatment, in any given case. In our patients with neuroblastoma, tumor-associated cell-mediated immune-reaction showed a good responsiveness before treatment. However, delayed cutaneous hypersensitivity reactions were shown to be negative in many cases, particularly in those with advanced tumor, and T gamma cells were enormously increased in some cases. During the course of therapy, the tumor-associated cellular immune responsiveness showed a tendency to become negative when the patient was tumor free or was in remission, but showed a tendency to become positive on regrowth, recurrence or metastasis of tumor. The T gamma cells showed much the same fluctuations as did the tumor-associated cellular immune responsiveness.

  8. 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. PMID:27397082

  9. 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.

  10. Tinospora cordifolia Induces Differentiation and Senescence Pathways in Neuroblastoma Cells.

    PubMed

    Mishra, Rachana; Kaur, Gurcharan

    2015-08-01

    Children diagnosed with neuroblastomas often suffer from severe side as well as late effects of conventional treatments like chemotherapy and radiotherapy. Recent advances in understanding of molecular pathways involved in cellular differentiation and apoptosis have helped in the development of new therapeutic approach based on differentiation-based therapy of malignant tumours. Natural medicines with their holistic therapeutic approach are known to selectively eliminate cancer cells thus provide a better substitute for the conventional treatment modes. The current study was aimed to investigate the anti-cancer potential of aqueous ethanolic extract of Tinospora cordifolia (TCE) using IMR-32 human neuroblastoma cell line as a model system. TCE is highly recommended in Ayurveda for its general body and metal health-promoting properties. TCE treatment was seen to arrest the majority of cells in G0/G1 phase and modulated the expression of DNA clamp sliding protein (PCNA) and cyclin D1. Further, TCE-treated cells showed differentiation as revealed by their morphology and the expression of neuronal cell specific differentiation markers NF200, MAP-2 and NeuN in neuroblastoma cells. The differentiated phenotype was associated with induction of senescence and pro-apoptosis pathways by enhancing expression of senescence marker mortalin and Rel A subunit of nuclear factor kappa beta (NFkB) along with decreased expression of anti-apoptotic marker, Bcl-xl. TCE exhibited anti-metastatic activity and significantly reduced cell migration in the scratched area along with downregulation of neural cell adhesion molecule (NCAM) polysialylation and secretion of matrix metalloproteinases (MMPs). Our data suggest that crude extract or active phytochemicals from this plant may be a potential candidate for differentiation-based therapy of malignant neuroblastoma cells. PMID:25280667

  11. Recent developments in cell-based immune therapy for neuroblastoma.

    PubMed

    Verneris, Michael R; Wagner, John E

    2007-06-01

    Neuroblastoma (NB) is a common and aggressive tumor of early childhood. To date, treatment with chemotherapy, surgery, and radiation therapy has resulted in suboptimal outcomes in those with advanced disease. Immune-based treatments hold promise for patients with recurrent or advanced NB. Here, recent preclinical studies and early stage (phase I) clinical trials using cellular therapeutic approaches for NB are reviewed, including studies of natural killer cells, gammadelta T cells, chimeric receptor expressing T cells, dendritic cells, and allogeneic hematopoietic cell transplant.

  12. Intrapleural therapy of malignant pleurisy in patients with neuroblastoma.

    PubMed

    Ha, K; Tawa, A; Ikeda, T; Tanaka, J; Okada, A; Yabuuchi, H

    1981-01-01

    Three children with advanced neuroblastoma developed pleural effusion in the course of their disease. This unusual complication was successfully treated with intrapleural administration of a nonspecific "immunostimulatory" agent; cell wall skeleton of Nocardia rubra (N-cws). The side effects of this procedure were mild and well tolerated even in infants in spite of their terminal stage. Intrapleural therapy in this study seemed to be useful for the treatment of pediatric malignant pleurisy.

  13. Contemporary therapeutic options for children with high risk neuroblastoma.

    PubMed

    Sterba, J

    2002-01-01

    Despite the use of aggressive chemotherapy, stage 4 high risk neuroblastoma still has a very poor prognosis, which is estimated at 25%. Therefore, novel treatment approaches are needed. Increasing number of reports has been concerned with the use of novel treatment modalities. Literature regarding intensive induction, local therapy, myeloablative therapy and immunotherapy and biotherapy was reviewed in order to draw conclusions and recommendations for the management of children with high risk neuroblastic tumors.

  14. Compartmental intrathecal radioimmunotherapy: results for treatment for metastatic CNS neuroblastoma.

    PubMed

    Kramer, Kim; Kushner, Brian H; Modak, Shakeel; Pandit-Taskar, Neeta; Smith-Jones, Peter; Zanzonico, Pat; Humm, John L; Xu, Hong; Wolden, Suzanne L; Souweidane, Mark M; Larson, Steven M; Cheung, Nai-Kong V

    2010-05-01

    Innovation in the management of brain metastases is needed. We evaluated the addition of compartmental intrathecal antibody-based radioimmunotherapy (cRIT) in patients with recurrent metastatic central nervous system (CNS) neuroblastoma following surgery, craniospinal irradiation, and chemotherapy. Twenty one patients treated for recurrent neuroblastoma metastatic to the CNS, received a cRIT-containing salvage regimen incorporating intrathecal (131)I-monoclonal antibodies (MoAbs) targeting GD2 or B7H3 following surgery and radiation. Most patients also received outpatient craniospinal irradiation, 3F8/GMCSF immunotherapy, 13-cis-retinoic acid and oral temozolomide for systemic control. Seventeen of 21 cRIT-salvage patients are alive 7-74 months (median 33 months) since CNS relapse, with all 17 remaining free of CNS neuroblastoma. One patient died of infection at 22 months with no evidence of disease at autopsy, and one of lung and bone marrow metastases at 15 months, and one of progressive bone marrow disease at 30 months. The cRIT-salvage regimen was well tolerated, notable for myelosuppression minimized by stem cell support (n = 5), and biochemical hypothyroidism (n = 5). One patient with a 7-year history of metastatic neuroblastoma is in remission from MLL-associated secondary leukemia. This is significantly improved to published results with non-cRIT based where relapsed CNS NB has a median time to death of approximately 6 months. The cRIT-salvage regimen for CNS metastases was well tolerated by young patients, despite their prior history of intensive cytotoxic therapies. It has the potential to increase survival with better than expected quality of life.

  15. Limited neuropeptide Y precursor processing in unfavourable metastatic neuroblastoma tumours.

    PubMed

    Bjellerup, P; Theodorsson, E; Jörnvall, H; Kogner, P

    2000-07-01

    Neuropeptide Y (NPY) is found at high concentrations in neural crest-derived tumours and has been implicated as a regulatory peptide in tumour growth and differentiation. Neuroblastomas, ganglioneuromas and phaeochromocytomas with significant concentrations of NPY-like immunoreactivity were investigated for different molecular forms of NPY and for significance of proNPY processing. Gel-permeation chromatography identified intact NPY (1-36) in all tumours, whereas proNPY (69 amino acids) was detected only in control adrenal tissue and malignant neuroblastomas. Purification of NPY-like immunoreactivity in tumour extracts and structural characterization revealed that both NPY (1-36) and the truncated form NPY (3-36) was present. The degree of processing of proNPY to NPY in tumour tissue was lower in advanced neuroblastomas with regional or metastatic spread (stage 3 and 4) (n = 6), (41%, 12-100%, median, range), compared to the less aggressive stage 1, 2 and 4S tumours (n = 12), (93%; 69-100%), (P= 0.012). ProNPY processing of less than 50% was correlated with poor clinical outcome (P = 0.004). MYCN oncogene amplification was also correlated to a low degree of proNPY processing (P = 0.025). In summary, a low degree of proNPY processing was correlated to clinical advanced stage and poor outcome in neuroblastomas. ProNPY/NPY processing generated molecular forms of NPY with known differences in NPY-receptor selectivity, implicating a potential for in vivo modulation of NPY-like effects in tumour tissue.

  16. Anti-tumor activity of safranal against neuroblastoma cells

    PubMed Central

    Samarghandian, Saeed; Shoshtari, Mohammad Ebrahim; Sargolzaei, Javad; Hossinimoghadam, Hosna; Farahzad, Jabbari Azad

    2014-01-01

    Objective: Safranal (2,6,6-trimethyl-1,3-cyclohexadiene-1-carboxaldehyde, C10H14O) is an active ingredient in the saffron, which is used in traditional medicine, and also, the biological activity of saffron in anti-cancer is in development. It has been reported to have anti-oxidant effects, but its anti-tumor effects remain uncertain. The aim of this study was to evaluate effects of safranal on anti-tumor on neuroblastoma cells. Materials and Methods: Neuroblastoma cells were cultured and exposed to safranal (0, 10, 15, 20, 50 μg/ml). Cell proliferation was examined using the 3-(4, 5-dimethyl thiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay. Apoptotic cells, cell cycle distribution, and sub-G1 fraction were analyzed using flow cytometric analysis after propidium iodide staining. Results: Safranal inhibited the growth of malignant cells in a dose-and time-dependent manner. The IC (50) values against the neuroblastoma cell line were determined as 11.1 and 23.3 μg/ml after 24 and 48 h, respectively. Safranal induced a sub-G1 peak in the flow cytometry histogram of treated cells compared to control cells indicating that apoptotic cell death is involved in safranal toxicity. Conclusions: Our pre-clinical study demonstrated a neuroblastoma cell line to be highly sensitive to safranal-mediated growth inhibition and apoptotic cell death. Although the molecular mechanisms of safranal action are not yet clearly understood, it appears to have potential as a therapeutic agent. PMID:24991121

  17. Organic heterostructures based on arylenevinylene oligomers deposited by MAPLE

    NASA Astrophysics Data System (ADS)

    Socol, M.; Preda, N.; Vacareanu, L.; Grigoras, M.; Socol, G.; Mihailescu, I. N.; Stanculescu, F.; Jelinek, M.; Stanculescu, A.; Stoicanescu, M.

    2014-05-01

    Organic heterostructures were fabricated by matrix assisted pulsed laser evaporation (MAPLE) method using arylenevinylene oligomers based on triphenylamine (P78)/carbazole (P13) group and tris(8-hydroxyquinolinato)aluminum salt (Alq3). Optical properties of the organic multilayer structures were characterized by spectroscopic techniques: FTIR, UV-vis and photoluminescence (PL). A good transparency (over 60%) was remarked for the structures with two organic layers in the 550-800 nm range. Photoluminescence (PL) spectra proved that the emission characteristics of the materials have been preserved. I-V characteristics of (ITO/oligomer/Alq3/Al and ITO/Alq3/Al) heterostructures were symmetrically while rectifying properties of these heterostructures have not been observed. A comparison between the heterostructures made of layers with different thickness reveals that the higher current (8 × 10-6 A at 1 V) was obtained for the ITO/P78/Alq3/Al heterostructure, which is characterized by a larger thickness of the double organic layer. AFM measurements revealed a similar topography while RMS values of the reported structures depend on the organic material.

  18. EGFP oligomers as natural fluorescence and hydrodynamic standards.

    PubMed

    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 μm(2)/s and 97.3…54.8 μm(2)/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

  19. A covalent homodimer probing early oligomers along amyloid aggregation

    PubMed Central

    Halabelian, Levon; Relini, Annalisa; Barbiroli, Alberto; Penco, Amanda; Bolognesi, Martino; Ricagno, Stefano

    2015-01-01

    Early oligomers are crucial in amyloid aggregation; however, due to their transient nature they are among the least structurally characterized species. We focused on the amyloidogenic protein beta2-microglobulin (β2m) whose early oligomers are still a matter of debate. An intermolecular interaction between D strands of facing β2m molecules was repeatedly observed, suggesting that such interface may be relevant for β2m dimerization. In this study, by mutating Ser33 to Cys, and assembling the disulphide-stabilized β2m homodimer (DimC33), such DD strand interface was locked. Although the isolated DimC33 display a stability similar to wt β2m under native conditions, it shows enhanced amyloid aggregation propensity. Three distinct crystal structures of DimC33 suggest that dimerization through the DD interface is instrumental for enhancing DimC33 aggregation propensity. Furthermore, the crystal structure of DimC33 in complex with the amyloid-specific dye Thioflavin-T pinpoints a second interface, which likely participates in the first steps of β2m aggregation. The present data provide new insight into β2m early steps of amyloid aggregation. PMID:26420657

  20. 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.

  1. 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.

  2. Polycaprolactone/oligomer compound scaffolds for cardiac tissue engineering.

    PubMed

    Reddy, Chaganti Srinivasa; Venugopal, Jayarama Reddy; Ramakrishna, Seeram; Zussman, Eyal

    2014-10-01

    Polycaprolactone (PCL), a synthetic biocompatible and biodegradable polymer generally used as a scaffold material for tissue engineering applications. The high stiffness and hydrophobicity of the PCL fiber mesh does not provide significant cell attachment and proliferation in cardiac tissue engineering. Towards this goal, the study focused on a compound of PCL and oligomer hydrogel [Bisphenol A ethoxylated dimethacrylate (BPAEDMA)] processed into electrospun nanofibrous scaffolds. The composition, morphology and mechanical properties of the compound scaffolds, composed of varying ratios of PCL and hydrogel were characterized by scanning electron microscopy, infrared spectroscopy and dynamic mechanical analyzer. The elastic modulus of PCL/BPAEDMA nanofibrous scaffolds was shown to be varying the BPAEDMA weight fraction and was decreased by increasing the BPAEDMA weight fraction. Compound fiber meshes containing 75 wt % BPAEDMA oligomer hydrogel exhibited lower modulus (3.55 MPa) and contact angle of 25(o) . Rabbit cardiac cells cultured for 10 days on these PCL/BPAEDMA compound nanofibrous scaffolds remained viable and expressed cardiac troponin and alpha-actinin proteins for the normal functioning of myocardium. Cell adhesion and proliferations were significantly increased on compound fiber meshes containing 75 wt % BPAEDMA, when compared with other nanofibrous scaffolds. The results observed that the produced PCL/BPAEDMA compound nanofibrous scaffolds promote cell adhesion, proliferation and normal functioning of cardiac cells to clinically beneficial levels, relevant for cardiac tissue engineering. PMID:24288184

  3. 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.

  4. [131I]metaiodobenzylguanidine therapy after conventional therapy for neuroblastoma.

    PubMed

    Hoefnagel, C A; Voûte, P A; De Kraker, J; Valdés Olmos, R A

    1991-01-01

    [131I]Metaiodobenzylguanidine (131I-MIBG) is used for diagnostic scintigraphy and targeted therapy in a range of neural crest tumors, which exhibit an active uptake-1 mechanism at the cell membrane and cytoplasmatic storage in neurosecretory granules. A good and selective concentration and a long retention in the tumor, as is generally the case in neuroblastoma, are the basis for successful 131I-MIBG treatment. At The Netherlands Cancer Institute a phase II study was carried out in 53 patients with progressive recurrent disease after conventional therapy had failed. Despite the unfavorable basis for treatment, 131I-MIBG therapy induced 7 complete remissions, 23 partial remissions and arrest of disease (no change) in 10. Nine patients had progressive disease and one patient was lost to follow-up. The palliative effect of the treatment under these conditions was impressive. The duration of remissions varied from 2 to 38 months. The best results were obtained in patients with voluminous soft tissue disease. In general the treatment was well tolerated by children and the toxicity was mild, provided the bone marrow was not invaded by the disease. It is concluded that 131I-MIBG therapy has a definitive place in the treatment of neuroblastoma after conventional treatment has failed. As the invasiveness and toxicity of this therapy compare favorably with that of chemotherapy, immunotherapy and external beam radiotherapy, 131I-MIBG therapy is the best palliative treatment for patients with advanced recurrent neuroblastoma.

  5. Acquired Multiple Cysts of the Kidney in Neuroblastoma Survivors.

    PubMed

    Moodalbail, Divya G; Apple, Leah Z; Meyers, Kevin E; Ginsberg, Jill P; Kaplan, Bernard S; Bellah, Richard

    2016-07-01

    Cystic kidney disease includes a wide range of hereditary, developmental, and acquired conditions of the kidneys. Some of the inherited causes of cystic kidney disease include autosomal dominant polycystic kidney diseases (caused by mutations in PKD1 or PKD2), autosomal recessive polycystic kidney disease, tuberous sclerosis complex, von Hippel-Lindau disease, oral-facial-digital syndrome type I, and Hadju-Cheney syndrome. Acquired cystic kidney disease has been reported in patients receiving long-term hemodialysis or peritoneal dialysis and in children after liver transplantation. Acute kidney injury can occur in patients with neuroblastoma, usually as a result of thrombotic microangiopathy associated with bone marrow transplantation. End-stage renal disease is described in long-term survivors. However, in this case report, we provide what is to our knowledge the first description of multiple kidney cysts in long-term survivors of stage IV neuroblastoma. None of the 7 patients we describe with neuroblastoma and multiple kidney cysts had a family history of autosomal dominant polycystic kidney disease. Also, all lacked stigmata of tuberous sclerosis complex, von Hippel-Lindau disease, or Hadju-Cheney syndrome. Two patients progressed to end-stage renal disease; in addition, one of them developed an oncocytoid renal cell carcinoma. PMID:27016049

  6. Therapeutic relationships between DNA synthesis and repair, membrane differentiation, and organ-specific immunotherapy in neuroblastoma.

    PubMed

    Byfield, J E

    1976-01-01

    The mouse neuroblastoma cell system (MNB) is of interest to both neurobiologists and cancer researchers because of its capacity to differentiate, with the consequent loss of some properties classically associated with malignancy. The effects of chemotherapeutic agents on MNB cells are variable; in general, cell cycle-specific agents will frequently induce differentiation, leaving viable surviving cells, while cell cycle nonspecific agents are toxic to both dividing and nondividing MNB cells. X-rays appear intermediate in that they are toxic to both cell populations, but survivors tend to resemble cells treated with cell cycle-specific drugs. Differentiated MNB cells apparently lose their capacity to repair some forms of DNA damage and this loss may be associated with their sensitivity to DNA damaging compounds. MNB cells are also susceptible to immunological lysis, particularly antibody-dependent cellular cytotoxicity. Integration of these diverse modes of MNB cell killing is of great interest because of the close resemblance of this murine tumor to human cancers in which cell differentiation is also partially membrane-mediated an indepth study of MNB cell surface receptors may have general relevance in the theoretical approach to cancer treatment.

  7. Induction of GADD45α protects M17 neuroblastoma cells against MPP*.

    PubMed

    Wang, Xiao-Feng; Zeng, Qing-Gan; Zeng, Yan; Man, Rong-Yong; Lu, Bing-Xun; Luo, Yi-Feng

    2014-11-01

    Growth arrest and DNA-damage-inducible protein 45α (GADD45α) is an important member of the family of growth arrest and DNA damage-inducible (GADD) proteins. The expression patterns and possible roles of GADD45α in Parkinson's disease (PD) are so far less understood. In this study, we found that 1-methyl-4-phenylpyridinium (MPP+) treatment up-regulates the expression of GADD45α in both a time-dependent manner and a dose-dependent manner in human dopamine neuroblastoma M17 cells. The up-regulation of GADD45α was abolished by pretreatment with the c-Jun N-terminal kinases (JNK) inhibitor SP600125 but not the p38 specific inhibitor SB203580. Further study revealed that c-Jun silencing abolished the effects of MPP+ on the expression of GADD45α. Important, ChIP studies verified the ability of c-Jun to bind to the GADD45 promoter. In addition, we found that inhibition of GADD45α by small RNA interference exacerbates the impaired cell viability, LDH release, and apoptosis induced by MPP+. Correspondingly, silence of GADD45 exacerbated Caspase-3 activation induced by MPP+. These data suggested a neuroprotective effect of GADD45α against MPP+ neurotoxicity. PMID:25469469

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

    PubMed Central

    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. PMID:26020775

  9. Linking gold nanoparticles with conductive 1,4-phenylene diisocyanide-gold oligomers.

    PubMed

    Kestell, John; Abuflaha, Rasha; Boscoboinik, J Anibal; Bai, Yun; Bennett, Dennis W; Tysoe, Wilfred T

    2013-02-18

    It is demonstrated that 1,4-phenylene diisocyanide (PDI)-gold oligomers can spontaneously bridge between gold nanoparticles on mica, thereby providing a strategy for electrically interconnecting nanoelectrodes. The barrier height of the bridging oligomer is 0.10 ± 0.02 eV, within the range of previous single-molecule measurements of PDI.

  10. 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.

  11. 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

  12. 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

  13. 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

  14. Electronic transport properties of linear nC20 (n ≤ 5) oligomers: Theoretical investigation

    NASA Astrophysics Data System (ADS)

    Javan, Masoud Bezi

    2015-03-01

    We have used extended Huckel tight binding (EHTB) method considering Landauer-Buttiker formalism for investigating the electronic transport properties in linear nC20 (n ≤ 5) oligomers sandwiched between two Au (111) electrodes. We have presented the I-V and conductance characteristics of the nC20 oligomers and also their dependences to the oligomer structural properties. It was found that the zero bias conductance of the energetically favorable nC20 oligomers increases with growth of their length and the I-V characteristic remains almost linear at low bias voltages (up to 0.2 V). Some quantities such as transmission spectrum and electronic structure of nC20 oligomers are discussed in the context. The results can be used for developing electronic nanodevices based on fullerenes.

  15. 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

  16. 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

  17. 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

    2016-01-01

    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.

  18. 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

    2016-01-01

    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

  19. 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

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

    PubMed

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

    2015-07-01

    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.

  1. Retroviral-mediated IL-2 gene transfer into murine neuroblastoma.

    PubMed

    Cho, H S; Song, J Y; Park, C Y; Lyu, C J; Kim, B S; Kim, K Y

    2000-02-01

    We used retroviral-mediated gene transfer of the human interleukin (IL)-2 gene into murine neuroblastoma cells to investigate whether locally-secreted IL-2 is able to influence the generation of anti-tumor immune responses. Supernatant obtained from cultures of approximately 1 x 10(6) IL-2 gene-transduced, G-418 selected neuro-2a cells was assayed for human IL-2 production by ELISA kit. First, to estimate whether the local secretion of IL-2 from the genetically-modified tumor cells would affect their tumorigenicity in vivo, IL-2-secreting neuro-2a cells were s.c. injected into A/J mice and tumor growth was measured weekly. And to estimate whether IL-2 transfected neuroblastoma cells protect mice from tumor development after wild-type tumor cell challenge, IL-2-secreting neuro-2a cells were s.c. injected into A/J mice. Seven days after IL-2 gene-transfected neuroblastoma cell injection, unmodified neuro-2a cells were s.c. injected into the contralateral site of A/J mice and tumor growth was measured weekly. Finally, to estimate IL-2 effect on pre-established large tumor burdens, IL-2-secreting neuro-2a cells were s.c. injected into A/J mice with established tumor and its growth was measured weekly. The IL-2 gene-transduced neuro-2a clones secreted 120.25-177.3 IU of IL-2 per ml per 10(6) cells during 24 hr. None of the mice injected with IL-2-secreting neuro-2a cells developed tumors within 6 weeks, while all of the mice injected with wild-type neuro-2a cells developed tumors. Immunization of mice with IL-2 gene-transfected, irradiated neuro-2a cells protected these animals against a subsequent challenge with wild-type tumor cells. Finally, the size of large neuroblastomas decreased after IL-2-secreting neuro-2a cell injection into mice. Local secretion of IL-2 gene-transduced tumor cells abrogates their tumorigenicity and induces protective immunity and may inhibit the growth of neuroblastoma.

  2. 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.

  3. 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

  4. 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.

  5. Toughening of Epoxies: Novel Self-Assembling Block Copolymers Versus Traditional Telechelic Oligomers

    NASA Astrophysics Data System (ADS)

    Bacigalupo, Lauren N.

    Epoxy resins are commonly utilized because of their adhesive capacity and high strength. However, epoxies are inherently brittle; so much research has been dedicated to improving their fracture toughness. This study will focus on a comparing a traditional telechelic oligomer, CTBN, and a novel self-assembling block copolymer, SBM, as it relates to improving the fracture toughness of a lightly crosslinked epoxy system. After characterizing the modified systems for fracture toughness, mechanical and thermal properties, namely yield stress and the glass transition, will be determined in order to discern the impact these modifiers have on the overall properties of the blend. TEM, SEM and TOM techniques will be utilized for characterizing morphology, fractography and subsurface damage, respectively. Once this was accomplished, it was deduced that the toughening mechanisms of CTBN and SBM-modified epoxies are very similar. The main difference between the two is that the inherent structure of SBM allows the SBM-modified epoxy to retain its compressive yield strength. This, consequently, makes SBM ideal for thin bondline applications in the industrial adhesive and/or electronics industry.

  6. Rates of Chemical Cleavage of DNA and RNA Oligomers Containing Guanine Oxidation Products

    PubMed Central

    2016-01-01

    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. PMID:25853314

  7. Targeting Gastrin-Releasing Peptide Suppresses Neuroblastoma Progression via Upregulation of PTEN Signaling

    PubMed Central

    Paul, Pritha; Qiao, Jingbo; Kim, Kwang Woon; Romain, Carmelle; Lee, Sora; Volny, Natasha; Mobley, Bret; Correa, Hernan; Chung, Dai H.

    2013-01-01

    We have previously demonstrated the role of gastrin-releasing peptide (GRP) as an autocrine growth factor for neuroblastoma. Here, we report that GRP silencing regulates cell signaling involved in the invasion-metastasis cascade. Using a doxycycline inducible system, we demonstrate that GRP silencing decreased anchorage-independent growth, inhibited migration and neuroblastoma cell-mediated angiogenesis in vitro, and suppressed metastasis in vivo. Targeted inhibition of GRP decreased the mRNA levels of oncogenes responsible for neuroblastoma progression. We also identified PTEN/AKT signaling as a key mediator of the tumorigenic properties of GRP in neuroblastoma cells. Interestingly, PTEN overexpression decreased GRP-mediated migration and angiogenesis; a novel role for this, otherwise, understated tumor suppressor in neuroblastoma. Furthermore, activation of AKT (pAKT) positively correlated with neuroblastoma progression in an in vivo tumor-metastasis model. PTEN expression was slightly decreased in metastatic lesions. A similar phenomenon was observed in human neuroblastoma sections, where, early-stage localized tumors had a higher PTEN expression relative to pAKT; however, an inverse expression pattern was observed in liver lesions. Taken together, our results argue for a dual purpose of targeting GRP in neuroblastoma –1) decreasing expression of critical oncogenes involved in tumor progression, and 2) enhancing activation of tumor suppressor genes to treat aggressive, advanced-stage disease. PMID:24039782

  8. 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.

  9. Adult Neuroblastoma Complicated by Increased Intracranial Pressure: A Case Report and Review of the Literature

    PubMed Central

    Stevens, Patrick L.; Johnson, Douglas B.; Thompson, Mary Ann; Keedy, Vicki L.; Frangoul, Haydar A.; Snyder, Kristen M.

    2014-01-01

    Neuroblastoma is the third most commonly occurring malignancy of the pediatric population, although it is extremely rare in the adult population. In adults, neuroblastoma is often metastatic and portends an extremely poor overall survival. Our case report documents metastatic neuroblastoma occurring in a healthy 29-year-old woman whose course was complicated by an unusual presentation of elevated intracranial pressures. The patient was treated with systemic chemotherapy, I131 metaiodobenzylguanidine (MIBG) radiotherapy, and autologous stem cell transplant (SCT). Unfortunately the patient's response to therapy was limited and she subsequently died. We aim to review neuroblastoma in the context of increased intracranial pressure and the limited data of neuroblastoma occurring in the adult population, along with proposed treatment options. PMID:25328733

  10. In vitro induction of lymphokine-activated killer (LAK) activity in patients with neuroblastoma.

    PubMed

    Handgretinger, R; Bruchelt, G; Kimmig, A; Dopfer, R; Niethammer, D; Treuner, J

    1989-01-01

    Therapy of disseminated neuroblastoma remains an unsolved problem in pediatric oncology. Therefore, new therapeutic approaches have to be developed for this malignancy. In this paper, we investigated the possibility of the in vitro generation and expansion of lymphokine-activated killer (LAK) cells in patients with disseminated neuroblastoma. Although the patients had very low Natural Killer (NK) activity, it was possible to induce LAK activity in peripheral mononuclear lymphocytes (PMNC) by incubation with Interleukin-2 (IL-2). Moreover, the PMNCs could be expanded up to 50-fold in the presence of Interleukin-2 while maintaining or even increasing their LAK activity. The target cells were neuroblastoma cell lines and, in one case, autologous neuroblastoma cells. Additionally, it was possible to induce LAK cell activity against autologous neuroblastoma cells in bone marrow-derived mononuclear cells.

  11. 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

  12. Mitigation of copper toxicity by DNA oligomers in green paramecia.

    PubMed

    Takaichi, Hiroshi; Comparini, Diego; Iwase, Junichiro; Bouteau, François; Mancuso, Stefano; Kawano, Tomonori

    2015-01-01

    Impact of transition metals which catalyze the generation of reactive oxygen species (ROS), on activation of cell death signaling in plant cells have been documented to date. Similarly in green paramecia (Paramecium bursaria), an aquatic protozoan species harboring symbiotic green algae in the cytoplasm, toxicities of various metallic ions have been documented. We have recently examined the effects of double-stranded GC-rich DNA fragments with copper-binding nature and ROS removal catalytic activity as novel plant cell-protecting agents, using the suspension-cultured tobacco cells. Here, we show that above DNA oligomers protect the cells of green paramecia from copper-induced cell death, suggesting that the phenomenon firstly observed in tobacco cells is not limited only within higher plants but it could be universally observable in wider range of organisms. PMID:26418558

  13. Thermodynamic and kinetic stabilities of CO2 oligomers.

    PubMed

    Dunlap, Brett I; Schweigert, Igor V; Purdy, Andrew P; Snow, Arthur W; Hu, Anguang

    2013-04-01

    Density-functional and coupled cluster calculations suggest that the stability, against unimolecular dissociation, of the cyclic D(3h) trimer of CO2, 1,3,5-trioxetanetrione, is greater than all but one other chemically bound oligomer of CO2. It requires far less energy to produce, on a per CO2 basis, than the low-symmetry cyclic 1,2 dioxetanedione dimer, but its kinetic stability against unimolecular dissociation is much lower. The extreme stability of the dimer, which makes it an excellent intermediate in chemiluminescence, is caused by an extreme range of geometric change to its transition state leading to a trapezoidal potential energy surface. The thermodynamically more stable trimer affords a low pressure pathway from molecular carbon dioxide to the extended covalent structure at high pressure. PMID:23574224

  14. Thermodynamic and kinetic stabilities of CO2 oligomers

    NASA Astrophysics Data System (ADS)

    Dunlap, Brett I.; Schweigert, Igor V.; Purdy, Andrew P.; Snow, Arthur W.; Hu, Anguang

    2013-04-01

    Density-functional and coupled cluster calculations suggest that the stability, against unimolecular dissociation, of the cyclic D3h trimer of CO2, 1,3,5-trioxetanetrione, is greater than all but one other chemically bound oligomer of CO2. It requires far less energy to produce, on a per CO2 basis, than the low-symmetry cyclic 1,2 dioxetanedione dimer, but its kinetic stability against unimolecular dissociation is much lower. The extreme stability of the dimer, which makes it an excellent intermediate in chemiluminescence, is caused by an extreme range of geometric change to its transition state leading to a trapezoidal potential energy surface. The thermodynamically more stable trimer affords a low pressure pathway from molecular carbon dioxide to the extended covalent structure at high pressure.

  15. 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.

  16. Mitigation of copper toxicity by DNA oligomers in green paramecia

    PubMed Central

    Takaichi, Hiroshi; Comparini, Diego; Iwase, Junichiro; Bouteau, François; Mancuso, Stefano; Kawano, Tomonori

    2015-01-01

    Impact of transition metals which catalyze the generation of reactive oxygen species (ROS), on activation of cell death signaling in plant cells have been documented to date. Similarly in green paramecia (Paramecium bursaria), an aquatic protozoan species harboring symbiotic green algae in the cytoplasm, toxicities of various metallic ions have been documented. We have recently examined the effects of double-stranded GC-rich DNA fragments with copper-binding nature and ROS removal catalytic activity as novel plant cell-protecting agents, using the suspension-cultured tobacco cells. Here, we show that above DNA oligomers protect the cells of green paramecia from copper-induced cell death, suggesting that the phenomenon firstly observed in tobacco cells is not limited only within higher plants but it could be universally observable in wider range of organisms. PMID:26418558

  17. 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

  18. Transthyretin as both Sensor and Scavenger of Aβ Oligomers

    PubMed Central

    Yang, Dennis T.; Joshi, Gururaj; Cho, Patricia Y.; Johnson, Jeffrey A.; Murphy, Regina M.

    2013-01-01

    Transthyretin (TTR) is a homotetrameric transport protein, assembled from monomers that each contains two four-stranded β-sheets and a short α-helix and loop. In the tetramer, the ‘inner’ β-sheet forms a hydrophobic pocket while the helix and loop are solvent-exposed. Beta-amyloid (Aβ) aggregates bind to TTR, and the binding is significantly reduced in mutants L82A (on the loop) and L110A (on the inner β-sheet). Protection against Aβ toxicity was demonstrated for wild-type TTR but not L82A or L110A, providing a direct link between TTR-Aβ binding, and TTR-mediated cytoprotection. Protection is afforded at substoichiometric (1:100) TTR:Aβ molar ratios, and binding of Aβ to TTR is highest for partially aggregated materials and decreased for freshly-prepared or heavily aggregated Aβ, suggesting that TTR binds selectively to soluble toxic Aβ aggregates. A novel technique, nanoparticle tracking, is used to show that TTR arrests Aβ aggregation by both preventing formation of new aggregates and inhibiting growth of existing aggregates. TTR tetramers are normally quite stable; tetrameric structure is necessary for the protein’s transport functions, and mutations that decrease tetramer stability have been linked to TTR amyloid diseases. However, TTR monomers bind more Aβ than do tetramers, presumably because the hydrophobic ‘inner’ sheet is solvent-exposed upon tetramer disassembly. Wild-type and L110A tetramers, but not L82A, were destabilized when co-incubated with Aβ, suggesting that Aβ binding to L82 triggers tetramer dissociation. Taken together, these results suggest a novel mechanism of action for TTR: the EF helix/loop ‘senses’ the presence of soluble toxic Aβ oligomers, triggering destabilization of TTR tetramers and exposure of the hydrophobic inner sheet, which then ‘scavenges’ these toxic oligomers and prevents them from causing cell death PMID:23570378

  19. Identification of beta-tubulin isoforms as tumor antigens in neuroblastoma.

    PubMed

    Prasannan, L; Misek, D E; Hinderer, R; Michon, J; Geiger, J D; Hanash, S M

    2000-10-01

    There is currently substantial interest in the identification of human tumor antigens for diagnosis and immunotherapy of cancer. We have implemented a proteomic approach for the identification of tumor proteins that elicit a humoral response in cancer patients, which we have applied to neuroblastoma. Proteins from neuroblastoma tumors and cell lines were separated by two-dimensional PAGE and transferred to poly(vinylidene difluoride) membranes. Sera from 23 newly diagnosed patients with neuroblastoma, from 12 newly diagnosed children with other solid tumors, and from 13 normal individuals were screened for IgG and IgM autoantibodies against neuroblastoma proteins by means of Western blot analysis. Sera from 11 patients with neuroblastoma and from 1 patient with a primitive neuroectodermal tumor, but none of the other controls exhibited IgG-based reactivity against a protein constellation with an estimated Mr 50,000. NH2-terminal sequence and mass spectrometric analysis identified the major constituents of this constellation as beta-tubulin isoforms I and III. The IgG antibodies were additionally characterized to be of the subclass IgG1. Neuroblastoma patient sera that contained anti-beta-tubulin IgG antibodies also contained IgM antibodies specific against the full-length beta-tubulin molecule and against COOH-terminal beta-tubulin cleavage products. Neuroblastoma patient sera that reacted with beta-tubulin I and III isoforms in neuroblastoma tissues did not react with beta-tubulin I and III isoforms found in normal brain tissue. Our findings indicate the occurrence of beta-tubulin peptides in neuroblastoma, which are immunogenic. The occurrence of immunogenic peptides in neuroblastoma may have utility in diagnosis and in immunotherapy of this aggressive childhood tumor.

  20. miR-542-3p exerts tumor suppressive functions in neuroblastoma by downregulating Survivin.

    PubMed

    Althoff, Kristina; Lindner, Sven; Odersky, Andrea; Mestdagh, Pieter; Beckers, Anneleen; Karczewski, Sarah; Molenaar, Jan J; Bohrer, Anna; Knauer, Shirley; Speleman, Frank; Epple, Matthias; Kozlova, Diana; Yoon, Sena; Baek, Kwanghee; Vandesompele, Jo; Eggert, Angelika; Schramm, Alexander; Schulte, Johannes H

    2015-03-15

    MicroRNAs (miRNAs) are deregulated in a variety of human cancers, including neuroblastoma, the most common extracranial tumor of childhood. We previously reported a signature of 42 miRNAs to be highly predictive of neuroblastoma outcome. One miRNA in this signature, miR-542, was downregulated in tumors from patients with adverse outcome. Reanalysis of quantitative PCR and next-generation sequencing transcript data revealed that miR-542-5p as well as miR-542-3p expression is inversely correlated with poor prognosis in neuroblastoma patients. We, therefore, analyzed the function of miR-542 in neuroblastoma tumor biology. Ectopic expression of miR-542-3p in neuroblastoma cell lines reduced cell viability and proliferation, induced apoptosis and downregulated Survivin. Survivin expression was also inversely correlated with miR-542-3p expression in primary neuroblastomas. Reporter assays confirmed that miR-542-3p directly targeted Survivin. Downregulating Survivin using siRNA copied the phenotype of miR-542-3p expression in neuroblastoma cell lines, while cDNA-mediated ectopic expression of Survivin partially rescued the phenotype induced by miR-542-3p expression. Treating nude mice bearing neuroblastoma xenografts with miR-542-3p-loaded nanoparticles repressed Survivin expression, decreased cell proliferation and induced apoptosis in the respective xenograft tumors. We conclude that miR-542-3p exerts its tumor suppressive function in neuroblastoma, at least in part, by targeting Survivin. Expression of miR-542-3p could be a promising therapeutic strategy for treating aggressive neuroblastoma.

  1. Dynamical stability and assembly cooperativity of β-sheet amyloid oligomers--effect of polarization.

    PubMed

    Li, Yang; Ji, Changge; Xu, Weixin; Zhang, John Z H

    2012-11-15

    The soluble intermediate oligomers of amyloidogenic proteins are suspected to be more cytotoxic than the mature fibrils in neurodegenerative disorders. Here, the dynamic stability and assembly cooperativity of a model oligomer of human islet amyloid polypeptide (hIAPP) segments were explored by means of all-atom molecular dynamics (MD) simulations under different force fields including AMBER99SB, OPLS, and polarized protein-specific charge (PPC) model. Simulation results show that the dynamic stability of β-sheet oligomers is seriously impacted by electrostatic polarization. Without inclusion of polarization (simulation under standard AMBER and OPLS force field), the β-sheet oligomers are dynamically unstable during MD simulation. For comparison, simulation results under PPC give significantly more stable dynamical structures of the oligomers. Furthermore, calculation of electrostatic interaction energy between the neighboring β strands with an approximate polarizable method produces energetic evidence for cooperative assembly of β-strand oligomers. This result supports a picture of downhill-like cooperative assembly of β strands during fibrillation process. The present study demonstrates the critical role of polarization in dynamic stability and assembly cooperativity of β-sheet-rich amyloid oligomers.

  2. 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.

  3. Characteristics of Amyloid-Related Oligomers Revealed by Crystal Structures of Macrocyclic [beta]-Sheet Mimics

    SciTech Connect

    Liu, Cong; Sawaya, Michael R.; Cheng, Pin-Nan; Zheng, Jing; Nowick, James S.; Eisenberg, David

    2011-09-20

    Protein amyloid oligomers have been strongly linked to amyloid diseases and can be intermediates to amyloid fibers. {beta}-Sheets have been identified in amyloid oligomers. However, because of their transient and highly polymorphic properties, the details of their self-association remain elusive. Here we explore oligomer structure using a model system: macrocyclic peptides. Key amyloidogenic sequences from A{beta} and tau were incorporated into macrocycles, thereby restraining them to {beta}-strands, but limiting the growth of the oligomers so they may crystallize and cannot fibrillate. We determined the atomic structures for four such oligomers, and all four reveal tetrameric interfaces in which {beta}-sheet dimers pair together by highly complementary, dry interfaces, analogous to steric zippers found in fibers, suggesting a common structure for amyloid oligomers and fibers. In amyloid fibers, the axes of the paired sheets are either parallel or antiparallel, whereas the oligomeric interfaces display a variety of sheet-to-sheet pairing angles, offering a structural explanation for the heterogeneity of amyloid oligomers.

  4. Rescue from tau-induced neuronal dysfunction produces insoluble tau oligomers

    PubMed Central

    Cowan, Catherine M.; Quraishe, Shmma; Hands, Sarah; Sealey, Megan; Mahajan, Sumeet; Allan, Douglas W.; Mudher, Amritpal

    2015-01-01

    Aggregation of highly phosphorylated tau is a hallmark of Alzheimer’s disease and other tauopathies. Nevertheless, animal models demonstrate that tau-mediated dysfunction/toxicity may not require large tau aggregates but instead may be caused by soluble hyper-phosphorylated tau or by small tau oligomers. Challenging this widely held view, we use multiple techniques to show that insoluble tau oligomers form in conditions where tau-mediated dysfunction is rescued in vivo. This shows that tau oligomers are not necessarily always toxic. Furthermore, their formation correlates with increased tau levels, caused intriguingly, by either pharmacological or genetic inhibition of tau kinase glycogen-synthase-kinase-3beta (GSK-3β). Moreover, contrary to common belief, these tau oligomers were neither highly phosphorylated, and nor did they contain beta-pleated sheet structure. This may explain their lack of toxicity. Our study makes the novel observation that tau also forms non-toxic insoluble oligomers in vivo in addition to toxic oligomers, which have been reported by others. Whether these are inert or actively protective remains to be established. Nevertheless, this has wide implications for emerging therapeutic strategies such as those that target dissolution of tau oligomers as they may be ineffective or even counterproductive unless they act on the relevant toxic oligomeric tau species. PMID:26608845

  5. Ataxin-1 oligomers induce local spread of pathology and decreasing them by passive immunization slows Spinocerebellar ataxia type 1 phenotypes.

    PubMed

    Lasagna-Reeves, Cristian A; Rousseaux, Maxime Wc; Guerrero-Munoz, Marcos J; Vilanova-Velez, Luis; Park, Jeehye; See, Lauren; Jafar-Nejad, Paymaan; Richman, Ronald; Orr, Harry T; Kayed, Rakez; Zoghbi, Huda Y

    2015-12-17

    Previously, we reported that ATXN1 oligomers are the primary drivers of toxicity in Spinocerebellar ataxia type 1 (SCA1; Lasagna-Reeves et al., 2015). Here we report that polyQ ATXN1 oligomers can propagate locally in vivo in mice predisposed to SCA1 following intracerebral oligomeric tissue inoculation. Our data also show that targeting these oligomers with passive immunotherapy leads to some improvement in motor coordination in SCA1 mice and to a modest increase in their life span. These findings provide evidence that oligomer propagation is regionally limited in SCA1 and that immunotherapy targeting extracellular oligomers can mildly modify disease phenotypes.

  6. Conformational stability of fibrillar amyloid-beta oligomers via protofilament pair formation - a systematic computational study.

    PubMed

    Kahler, Anna; Sticht, Heinrich; Horn, Anselm H C

    2013-01-01

    Amyloid-[Formula: see text] (A[Formula: see text]) oligomers play a crucial role in Alzheimer's disease due to their neurotoxic aggregation properties. Fibrillar A[Formula: see text] oligomerization can lead to protofilaments and protofilament pairs via oligomer elongation and oligomer association, respectively. Small fibrillar oligomers adopt the protofilament topology, whereas fibrils contain at least protofilament pairs. To date, the underlying growth mechanism from oligomers to the mature fibril still remains to be elucidated. Here, we performed all-atom molecular dynamics simulations in explicit solvent on single layer-like protofilaments and fibril-like protofilament pairs of different size ranging from the tetramer to the 48-mer. We found that the initial U-shaped topology per monomer is maintained over time in all oligomers. The observed deviations of protofilaments from the starting structure increase significantly with size due to the twisting of the in-register parallel [Formula: see text]-sheets. This twist causes long protofilaments to be unstable and leads to a breakage. Protofilament pairs, which are stabilized by a hydrophobic interface, exhibit more fibril-like properties such as the overall structure and the twist angle. Thus, they can act as stable conformational templates for further fibril growth. Key properties like the twist angle, shape complementarity, and energetics show a size-dependent behavior so that small oligomers favor the protofilament topology, whereas large oligomers favor the protofilament pair topology. The region for this conformational transition is at the size of approximately twelve A[Formula: see text] monomers. From that, we propose the following growth mechanism from A[Formula: see text] oligomers to fibrils: (1) elongation of short protofilaments; (2) breakage of large protofilaments; (3) formation of short protofilament pairs; and (4) elongation of protofilament pairs.

  7. 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.

  8. Synthesis and Optoelectronic Properties of Thiophene Donor and Thiazole Acceptor Based Blue Fluorescent Conjugated Oligomers.

    PubMed

    Mahesh, K; Karpagam, S

    2016-07-01

    We report on the synthesis and characterization of low band gap, blue light emitting and thermal stable conjugated oligomer by Wittig condensation. Thiophene and thiazole type of donor-acceptor based series of conjugated oligomers, Oligo-4,5-bis-[2-[5-[2-thiophene-2-yl-vinyl]thiophene-2-yl]-vinyl]-thiazole (OBTV-TZ) and Oligo-2,4,5-Tris-[2-[5-[2-thiophene-2-yl-vinyl]thiophene-2-yl]-vinyl]-thiazole (OTTV-TZ) were synthesized. These oligomers were confirmed by FT-IR and (1)H-NMR and LC/MS analysis. The effect of the number of thiophene rings on the optical, electrochemical, thermal and morphological properties of the oligomers were systematically investigated. Both oligomers were exhibited almost same absorption wavelength in methanol solution (λmax = 365 nm and 369 nm) which indicates both oligomers illustrate similar intra molecular charge transfer (ICT). In solid state, the oligomers were exhibited broadening peaks with higher onset absorptions (λmax = 600 nm and 580 nm). The photoluminescence absorption spectrum of the oligomers was observed at 433 nm and 434 nm respectively in methanol solution with blue emission. The electrochemical band gap ([Formula: see text]) of the OBTV-TZ was 1.55 eV (low band gap) and OTTV-TZ was exhibited greater highest occupied molecular orbital (HOMO) value (E HOMO = -6.6 eV). Moreover morphological parameters of both oligomer film of 2D and 3D diagrams were observed by using AFM studies. PMID:27256285

  9. Neuroblastoma cell lines showing smooth muscle cell phenotypes.

    PubMed

    Sugimoto, T; Mine, H; Horii, Y; Takahashi, K; Nagai, R; Morishita, R; Komada, M; Asada, Y; Sawada, T

    2000-12-01

    Neuroblastoma is a tumor that is derived from the neural crest. Recent studies demonstrated that several human neuroblastoma cell lines exhibit at least three morphologic types: neuroblastic (N)-type, substrate-adhesive (S)-type and intermediate (I)-type cells. However, the origin of the S-type cells has not been clearly identified. In this study, the expressions of smooth muscle-specific proteins (desmin, alpha-smooth muscle actin, basic calponin and the smooth muscle myosin heavy-chain isoforms of SM1 and SM2) in three parent and four cloned neuroblastoma cell lines, composed of S-type cells, were examined by indirect immunofluorescence, Western blot and/or by reverse transcription-polymerase chain reaction (RT-PCR). Desmin was found in two of the seven cell lines, and alpha-smooth muscle actin and basic calponin were detected in all of seven of the cell lines. In three parent cell lines and one cloned cell line composed of N-type cells, none of three smooth muscle-specific proteins were detected. In smooth muscle myosin heavy-chain isoforms, SM1 was detected in two parent cell lines composed of S-type cells (MP-N-MS and KP-N-YS) by immunofluorescence, Western blot and/or by RT-PCR, whereas the SM2 isoform was detected in one parent cell line (MP-N-MS) by RT-PCR. These findings indicate that S-type cells have either the immature or mature smooth muscle cell phenotype, and neural crest cells very likely have the ability of to differentiate into smooth muscle cells in the human system.

  10. 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.

  11. A highly electron-deficient analogue of aniline, soluble oligomers, and their redox properties.

    PubMed

    Djukic, Brandon; Lough, Alan J; Seferos, Dwight S

    2013-09-20

    The synthesis and electrochemical oxidative coupling of a highly electron-deficient analogue of aniline results in the formation of soluble electron-deficient oligomers. Oligomers undergo related oxidation and reduction processes that are separated by a wide potential range. The mechanism behind this behavior is examined by cyclic voltammetry, optical absorption spectroscopy, (1)H NMR spectroscopy, and density functional theory calculations. Mesomeric isomerization of the oxidized oligomers leads to a very stable oxidized state that requires a large (2.8 V) overpotential to return to the neutral form. PMID:23971787

  12. Interleukin-24 induces neuroblastoma SH-SY5Y cell differentiation, growth inhibition, and apoptosis by promoting ROS production.

    PubMed

    Li, Yuan; Zhang, Hongwei; Zhu, Xiaoyu; Feng, Dongchuan; Gong, Jinchao; Han, Tao

    2013-11-01

    Neuroblastoma is among the most aggressive tumors that occur in childhood and infancy. The clinical prognosis of children with advanced-stage neuroblastoma is still poor. Interleukin-24 (IL-24) is emerging as a new cytokine involved in tumor cellular proliferation, differentiation, and apoptosis and has been widely studied as a tumor inhibitor. However, little is known about this cytokine's role in neuroblastoma. In this study, we investigated the possible effects of IL-24 on inducing neuroblastoma cell differentiation, growth inhibition, and apoptosis in vitro. Our data show that IL-24 promotes neuroblastoma SH-SY5Y cell differentiation, growth inhibition, and apoptosis. Furthermore, we found that the differentiation- and apoptosis-inducing action of IL-24 depends on the accumulation of reactive oxygen species (ROS). These results suggest that IL-24 can induce neuroblastoma cell differentiation and apoptosis and may be a potential therapeutic agent for neuroblastoma.

  13. Image analysis for neuroblastoma classification: segmentation of cell nuclei.

    PubMed

    Gurcan, Metin N; Pan, Tony; Shimada, Hiro; Saltz, Joel

    2006-01-01

    Neuroblastoma is a childhood cancer of the nervous system. Current prognostic classification of this disease partly relies on morphological characteristics of the cells from H&E-stained images. In this work, an automated cell nuclei segmentation method is developed. This method employs morphological top-hat by reconstruction algorithm coupled with hysteresis thresholding to both detect and segment the cell nuclei. Accuracy of the automated cell nuclei segmentation algorithm is measured by comparing its outputs to manual segmentation. The average segmentation accuracy is 90.24+/-5.14% PMID:17947119

  14. Revealed: The spy who regulates neuroblastoma stem cells.

    PubMed

    Vora, Parvez; Venugopal, Chitra; Singh, Sheila K

    2014-11-30

    Neuroblastoma (NB), an embryonal tumour of the sympathetic nervous system, is thought to originate from undifferentiated neural crest cells and is known to exhibit extremely heterogeneous biological and clinical behaviors. Occurring in very young children, the median age at diagnosis is 17 months and it accounts for 10% of all pediatric cancer mortalities. The standard treatment regimen for patients with high-risk NB includes induction and surgery followed by isotretinoin or Accutane (13-cis retinoic acid) treatment, which is shown to induce terminal differentiation of NB cells. However, molecular regulators that maintain an undifferentiated phenotype in NB cells are still poorly understood. PMID:25483101

  15. Metastatic mandibular neuroblastoma: a rare cause of tooth mobility.

    PubMed

    Kürklü, Esma; Emiroğlu, Halil Haldun; Kebudi, Rejin; Ozdaş, Didem Oner; Ayan, Inci; Görgün, Omer; Zülfikar, Bülent; Yekeler, Ensar; Gülsüm, A K

    2011-01-01

    Neuroblastoma (NBL), a malignant embryonic tumor derived from neural crest cells, is the most common tumor worldwide among children less than 1 year of age. Metastasis to the mandible is uncommon. This article reports the case of a 15-month-old male diagnosed with NBL with bone metastasis including the mandible which resulted in severe tooth mobility. Dentists or pediatricians should consider the primary or metastatic tumors of the maxillofacial region in the differential diagnosis in children presenting with premature loss of teeth related to tooth mobility.

  16. The p53 codon 72 Pro/Pro genotype identifies poor-prognosis neuroblastoma patients: correlation with reduced apoptosis and enhanced senescence by the p53-72P isoform.

    PubMed

    Cattelani, Sara; Ferrari-Amorotti, Giovanna; Galavotti, Sara; Defferrari, Raffaella; Tanno, Barbara; Cialfi, Samantha; Vergalli, Jenny; Fragliasso, Valentina; Guerzoni, Clara; Manzotti, Gloria; Soliera, Angela Rachele; Menin, Chiara; Bertorelle, Roberta; McDowell, Heather P; Inserra, Alessandro; Belli, Maria Luisa; Varesio, Luigi; Tweddle, Deborah; Tonini, Gian Paolo; Altavista, Pierluigi; Dominici, Carlo; Raschellà, Giuseppe; Calabretta, Bruno

    2012-07-01

    The p53 gene is rarely mutated in neuroblastoma, but codon 72 polymorphism that modulates its proapoptotic activity might influence cancer risk and clinical outcome. We investigated whether this polymorphism affects neuroblastoma risk and disease outcome and assessed the biologic effects of the p53-72R and p53-72P isoforms in p53-null cells. Comparison of 288 healthy subjects and 286 neuroblastoma patients revealed that the p53-72 polymorphism had no significant impact on the risk of developing neuroblastoma; however, patients with the Pro/Pro genotype had a shorter survival than those with the Arg/Arg or the Arg/Pro genotypes even in the stage 3 and 4 subgroup without MYCN amplification. By Cox regression analysis, the p53 Pro/Pro genotype seems to be an independent marker of poor prognosis (hazard ratio = 2.74; 95% confidence interval = 1.14-6.55, P = .014) together with clinical stage, MYCN status, and age at diagnosis. In vitro, p53-72P was less effective than p53-72R in inducing apoptosis and inhibiting survival of p53-null LAN-1 cells treated with etoposide, topotecan, or ionizing radiation but not taxol. By contrast, p53-72P was more effective in promoting p21-dependent accelerated senescence, alone or in the presence of etoposide. Thus, the p53-72 Pro/Pro genotype might be a marker of poor outcome independent of MYCN amplification, possibly improving risk stratification. Moreover, the lower apoptosis and the enhanced accelerated senescence by the p53-72P isoform in response to DNA damage suggest that patients with neuroblastoma with the p53-72 Pro/Pro genotype may benefit from therapeutic protocols that do not rely only on cytotoxic drugs that function, in part, through p53 activation.

  17. Clinical and Biologic Features Predictive of Survival After Relapse of Neuroblastoma: A Report From the International Neuroblastoma Risk Group Project

    PubMed Central

    London, Wendy B.; Castel, Victoria; Monclair, Tom; Ambros, Peter F.; Pearson, Andrew D.J.; Cohn, Susan L.; Berthold, Frank; Nakagawara, Akira; Ladenstein, Ruth L.; Iehara, Tomoko; Matthay, Katherine K.

    2011-01-01

    Purpose Survival after neuroblastoma relapse is poor. Understanding the relationship between clinical and biologic features and outcome after relapse may help in selection of optimal therapy. Our aim was to determine which factors were significantly predictive of postrelapse overall survival (OS) in patients with recurrent neuroblastoma—particularly whether time from diagnosis to first relapse (TTFR) was a significant predictor of OS. Patients and Methods Patients with first relapse/progression were identified in the International Neuroblastoma Risk Group (INRG) database. Time from study enrollment until first event and OS time starting from first event were calculated. Cox regression models were used to calculate the hazard ratio of increased death risk and perform survival tree regression. TTFR was tested in a multivariable Cox model with other factors. Results In the INRG database (N = 8,800), 2,266 patients experienced first progression/relapse. Median time to relapse was 13.2 months (range, 1 day to 11.4 years). Five-year OS from time of first event was 20% (SE, ± 1%). TTFR was statistically significantly associated with OS time in a nonlinear relationship; patients with TTFR of 36 months or longer had the lowest risk of death, followed by patients who relapsed in the period of 0 to less than 6 months or 18 to 36 months. Patients who relapsed between 6 and 18 months after diagnosis had the highest risk of death. TTFR, age, International Neuroblastoma Staging System stage, and MYCN copy number status were independently predictive of postrelapse OS in multivariable analysis. Conclusion Age, stage, MYCN status, and TTFR are significant prognostic factors for postrelapse survival and may help in the design of clinical trials evaluating novel agents. PMID:21768459

  18. 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.

  19. 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. PMID:27235336

  20. Antibody targeting of anaplastic lymphoma kinase induces cytotoxicity of human neuroblastoma.

    PubMed

    Carpenter, E L; Haglund, E A; Mace, E M; Deng, D; Martinez, D; Wood, A C; Chow, A K; Weiser, D A; Belcastro, L T; Winter, C; Bresler, S C; Vigny, M; Mazot, P; Asgharzadeh, S; Seeger, R C; Zhao, H; Guo, R; Christensen, J G; Orange, J S; Pawel, B R; Lemmon, M A; Mossé, Y P

    2012-11-15

    Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase aberrantly expressed in neuroblastoma, a devastating pediatric cancer of the sympathetic nervous system. Germline and somatically acquired ALK aberrations induce increased autophosphorylation, constitutive ALK activation and increased downstream signaling. Thus, ALK is a tractable therapeutic target in neuroblastoma, likely to be susceptible to both small-molecule tyrosine kinase inhibitors and therapeutic antibodies-as has been shown for other receptor tyrosine kinases in malignancies such as breast and lung cancer. Small-molecule inhibitors of ALK are currently being studied in the clinic, but common ALK mutations in neuroblastoma appear to show de novo insensitivity, arguing that complementary therapeutic approaches must be developed. We therefore hypothesized that antibody targeting of ALK may be a relevant strategy for the majority of neuroblastoma patients likely to have ALK-positive tumors. We show here that an antagonistic ALK antibody inhibits cell growth and induces in vitro antibody-dependent cellular cytotoxicity of human neuroblastoma-derived cell lines. Cytotoxicity was induced in cell lines harboring either wild type or mutated forms of ALK. Treatment of neuroblastoma cells with the dual Met/ALK inhibitor crizotinib sensitized cells to antibody-induced growth inhibition by promoting cell surface accumulation of ALK and thus increasing the accessibility of antigen for antibody binding. These data support the concept of ALK-targeted immunotherapy as a highly promising therapeutic strategy for neuroblastomas with mutated or wild-type ALK.

  1. Ex vivo activation of CD56(+) immune cells that eradicate neuroblastoma.

    PubMed

    Rujkijyanont, Piya; Chan, Wing Keung; Eldridge, Paul W; Lockey, Timothy; Holladay, Martha; Rooney, Barbara; Davidoff, Andrew M; Leung, Wing; Vong, Queenie

    2013-04-15

    Despite the use of intensive contemporary multimodal therapy, the overall survival of patients with high-risk neuroblastoma is still less than 50%. Therefore, immunotherapy without cross-resistance and overlapping toxicity has been proposed. In this study, we report the development of a novel strategy to specifically activate and expand human CD56(+) (NCAM1) natural killer (NK) immune cells from normal donors and patients with neuroblastoma. Enriched CD56(+) cells from peripheral blood were mixed with CD56(-) fraction at 1:1 ratio and cultured in the presence of OKT3, interleukin (IL)-2, and -15 for five days and then without OKT3 for 16 more days. The final products contained more than 90% CD56(+) cells and could kill neuroblastoma cells effectively that were originally highly resistant to nonprocessed NK cells. Mechanistically, cytolysis of neuroblastoma was mediated through natural cytotoxicity receptor (NCR), DNAX accessory molecule-1 (DNAM-1; CD226), perforin, and granzyme B. Successful clinical scale-up in a good manufacturing practices (GMP)-compliant bioreactor yielded effector cells that in a neuroblastoma xenograft model slowed tumor growth and extended survival without GVHD. Investigation of CD56(+) cells from patients with neuroblastoma revealed a similar postactivation phenotype and lytic activity. Our findings establish a novel and clinically expedient strategy to generate allogeneic or autologous CD56(+) cells that are highly cytotoxic against neuroblastoma with minimal risk of GVHD.

  2. Botulinum neurotoxin type C protease induces apoptosis in differentiated human neuroblastoma cells.

    PubMed

    Rust, Aleksander; Leese, Charlotte; Binz, Thomas; Davletov, Bazbek

    2016-05-31

    Neuroblastomas constitute a major cause of cancer-related deaths in young children. In recent years, a number of translation-inhibiting enzymes have been evaluated for killing neuroblastoma cells. Here we investigated the potential vulnerability of human neuroblastoma cells to protease activity derived from botulinum neurotoxin type C. We show that following retinoic acid treatment, human neuroblastoma cells, SiMa and SH-SY5Y, acquire a neuronal phenotype evidenced by axonal growth and expression of neuronal markers. Botulinum neurotoxin type C which cleaves neuron-specific SNAP25 and syntaxin1 caused apoptotic death only in differentiated neuroblastoma cells. Direct comparison of translation-inhibiting enzymes and the type C botulinum protease revealed one order higher cytotoxic potency of the latter suggesting a novel neuroblastoma-targeting pathway. Our mechanistic insights revealed that loss of ubiquitous SNAP23 due to differentiation coupled to SNAP25 cleavage due to botulinum activity may underlie the apoptotic death of human neuroblastoma cells. PMID:27121208

  3. Botulinum neurotoxin type C protease induces apoptosis in differentiated human neuroblastoma cells

    PubMed Central

    Rust, Aleksander; Leese, Charlotte; Binz, Thomas; Davletov, Bazbek

    2016-01-01

    Neuroblastomas constitute a major cause of cancer-related deaths in young children. In recent years, a number of translation-inhibiting enzymes have been evaluated for killing neuroblastoma cells. Here we investigated the potential vulnerability of human neuroblastoma cells to protease activity derived from botulinum neurotoxin type C. We show that following retinoic acid treatment, human neuroblastoma cells, SiMa and SH-SY5Y, acquire a neuronal phenotype evidenced by axonal growth and expression of neuronal markers. Botulinum neurotoxin type C which cleaves neuron-specific SNAP25 and syntaxin1 caused apoptotic death only in differentiated neuroblastoma cells. Direct comparison of translation-inhibiting enzymes and the type C botulinum protease revealed one order higher cytotoxic potency of the latter suggesting a novel neuroblastoma-targeting pathway. Our mechanistic insights revealed that loss of ubiquitous SNAP23 due to differentiation coupled to SNAP25 cleavage due to botulinum activity may underlie the apoptotic death of human neuroblastoma cells. PMID:27121208

  4. Ex vivo activation of CD56(+) immune cells that eradicate neuroblastoma.

    PubMed

    Rujkijyanont, Piya; Chan, Wing Keung; Eldridge, Paul W; Lockey, Timothy; Holladay, Martha; Rooney, Barbara; Davidoff, Andrew M; Leung, Wing; Vong, Queenie

    2013-04-15

    Despite the use of intensive contemporary multimodal therapy, the overall survival of patients with high-risk neuroblastoma is still less than 50%. Therefore, immunotherapy without cross-resistance and overlapping toxicity has been proposed. In this study, we report the development of a novel strategy to specifically activate and expand human CD56(+) (NCAM1) natural killer (NK) immune cells from normal donors and patients with neuroblastoma. Enriched CD56(+) cells from peripheral blood were mixed with CD56(-) fraction at 1:1 ratio and cultured in the presence of OKT3, interleukin (IL)-2, and -15 for five days and then without OKT3 for 16 more days. The final products contained more than 90% CD56(+) cells and could kill neuroblastoma cells effectively that were originally highly resistant to nonprocessed NK cells. Mechanistically, cytolysis of neuroblastoma was mediated through natural cytotoxicity receptor (NCR), DNAX accessory molecule-1 (DNAM-1; CD226), perforin, and granzyme B. Successful clinical scale-up in a good manufacturing practices (GMP)-compliant bioreactor yielded effector cells that in a neuroblastoma xenograft model slowed tumor growth and extended survival without GVHD. Investigation of CD56(+) cells from patients with neuroblastoma revealed a similar postactivation phenotype and lytic activity. Our findings establish a novel and clinically expedient strategy to generate allogeneic or autologous CD56(+) cells that are highly cytotoxic against neuroblastoma with minimal risk of GVHD. PMID:23440424

  5. 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.

  6. 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.

  7. Common genetic variants in NEFL influence gene expression and neuroblastoma risk

    PubMed Central

    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

    2014-01-01

    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 LINC00340, 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 8 additional genes selected as candidates for further study based on proven involvement in neuroblastoma differentiation. SNP at these candidate genes were tested for association with disease susceptibility in 2101 cases and 4202 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 SNP associated with neuroblastoma (rs11994014; Pcombined=0.0050; OR=0.88, rs2979704; Pcombined=0.0072; OR=0.87, rs105911; Pcombined=0.0049; OR=0.86). The protective allele of rs1059111 correlated with increased NEFL expression. Biological 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 was 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 progression. PMID:25312269

  8. The Anti-Prion Antibody 15B3 Detects Toxic Amyloid-β Oligomers.

    PubMed

    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

    2016-07-01

    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

  9. Abiotic ligation of DNA oligomers templated by their liquid crystal ordering

    NASA Astrophysics Data System (ADS)

    Fraccia, Tommaso P.; Smith, Gregory P.; Zanchetta, Giuliano; Paraboschi, Elvezia; Yi, Yougwooo; Walba, David M.; Dieci, Giorgio; Clark, Noel A.; Bellini, Tommaso

    2015-03-01

    It has been observed that concentrated solutions of short DNA oligomers develop liquid crystal ordering as the result of a hierarchically structured supramolecular self-assembly. In mixtures of oligomers with various degree of complementarity, liquid crystal microdomains are formed via the selective aggregation of those oligomers that have a sufficient degree of duplexing and propensity for physical polymerization. Here we show that such domains act as fluid and permeable microreactors in which the order-stabilized molecular contacts between duplex terminals serve as physical templates for their chemical ligation. In the presence of abiotic condensing agents, liquid crystal ordering markedly enhances ligation efficacy, thereby enhancing its own phase stability. The coupling between order-templated ligation and selectivity provided by supramolecular ordering enables an autocatalytic cycle favouring the growth of DNA chains, up to biologically relevant lengths, from few-base long oligomers. This finding suggests a novel scenario for the abiotic origin of nucleic acids.

  10. 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

  11. Adenosine A2a receptors form distinct oligomers in protein detergent complexes.

    PubMed

    Schonenbach, Nicole S; Rieth, Monica D; Han, Songi; O'Malley, Michelle A

    2016-09-01

    The human adenosine A2a receptor (A2aR) tunes its function by forming homo-oligomers and hetero-oligomers with other G protein-coupled receptors, but the biophysical characterization of these oligomeric species is limited. Here, we show that upon reconstitution into an optimized mixed micelle system, and purification via an antagonist affinity column, full-length A2aR exists as a distribution of oligomers. We isolated the dimer population from the other oligomers via size exclusion chromatography and showed that it is stable upon dilution, thus supporting the hypotheses that the A2aR dimer has a defined structure and function. This study presents a crucial enabling step to a detailed biophysical characterization of A2aR homodimers. PMID:27543907

  12. Mass screening for neuroblastoma and estimation of costs.

    PubMed

    Nishi, M; Miyake, H; Takeda, T; Takasugi, N; Hanai, J; Kawai, T

    1991-01-01

    On the basis of epidemiological data and medical costs for patients with neuroblastoma, we have calculated the cost of mass screening for neuroblastoma with high performance liquid chromatography (HPLC) compared to the cost when it is not performed. If the sensitivity of the mass screening is 80% and 22,000 infants are screened annually the cost will be 27,809,000 yen ($191,800). If mass is not performed, the cost will be 28,446,000 yen ($196,200). The difference in cost (637,000 yen or $4,400) is fairly small. If the sensitivity is 75% and 16,500 infants are screened, the difference is also small (174,000 yen or $1,200). Therefore, mass screening with the HPLC method will not be an undue financial burden. But re-screening at an older age will be done with less financially favorable results, considering that the sensitivity may not be as high as that of the first screening and that mothers are somewhat reluctant about re-screening. The balance of the cost of mass screening by qualitative methods may also be less favorable, since the detection rate is low. PMID:1957600

  13. New strategies in neuroblastoma: Therapeutic targeting of MYCN and ALK.

    PubMed

    Barone, Giuseppe; Anderson, John; Pearson, Andrew D J; Petrie, Kevin; Chesler, Louis

    2013-11-01

    Clinical outcome remains poor in patients with high-risk neuroblastoma, in which chemoresistant relapse is common following high-intensity conventional multimodal therapy. Novel treatment approaches are required. Although recent genomic profiling initiatives have not revealed a high frequency of mutations in any significant number of therapeutically targeted genes, two exceptions, amplification of the MYCN oncogene and somatically acquired tyrosine kinase domain point mutations in anaplastic lymphoma kinase (ALK), present exciting possibilities for targeted therapy. In contrast with the situation with ALK, in which a robust pipeline of pharmacologic agents is available from early clinical use in adult malignancy, therapeutic targeting of MYCN (and MYC oncoproteins in general) represents a significant medicinal chemistry challenge that has remained unsolved for two decades. We review the latest approaches envisioned for blockade of ALK activity in neuroblastoma, present a classification of potential approaches for therapeutic targeting of MYCN, and discuss how recent developments in targeting of MYC proteins seem to make therapeutic inhibition of MYCN a reality in the clinic.

  14. CpG oligonucleotides for immunotherapeutic treatment of neuroblastoma.

    PubMed

    Miles, Suzanne A; Sandler, Anthony D

    2009-03-28

    Neuroblastoma is the most common extracranial solid tumor malignancy of childhood. Although it is generally responsive to treatment, high risk cases of neuroblastoma frequently recur. The prognosis for relapsed cases is extremely poor despite aggressive therapy. The frequency of relapse and subsequent failure of further treatment has spurred the need to develop non toxic and more effective treatments for targeting residual tumor cells during the phase of minimal residual disease. Traditional cancer therapies are non-specific, leading to the destruction of normal, healthy tissues. Failure to induce specific tumor immunity may be due to several immunosuppressive factors. Primary amongst these factors are: lack of co-stimulatory molecules on the surface of tumor cells, the ability of the tumor to modulate immunity in a suppressive manner and the presence of an immunosuppressive microenvironment at the location of the tumor. Unfortunately, tumor tolerance impedes the ability to establish immunity to tumor antigens and overcoming this tolerance is essential to developing effective tumor immunity. Vaccine strategies that target host immune effector cells with synthetic oligodeoxynucleotides (ODNs) that contain unmethylated CpG motifs (CpG-ODNs) represent a novel approach to overcoming tolerance in cancer therapy. This approach enables biasing of host immunity toward a proinflammatory Th1 and thus anti-tumor response. The addition of immunogenic tumor specific antigen to the CpG-ODN vaccine may allow for specific targeting and killing of established tumors.

  15. Neuropsychological resiliency after treatment for advanced stage neuroblastoma.

    PubMed

    Carpentieri, S C; Diller, L R

    2005-06-01

    The purpose of this study was to describe the neuropsychological functioning of survivors of advanced stage neuroblastoma. In all, 16 survivors, diagnosed at a median of 2.8 years, who had received intensive chemotherapy and surgical treatments, were identified; 11 had received myeloablative consolidation therapy, eight with total body irradiation (TBI). All patients were evaluated with a neuropsychological assessment battery at a median age of 8.8 years. Analyses included comparison of the performances of the TBI group vs the no-TBI group; determination of whether the proportion of individuals with impaired or superior performance on each measure exceeded normative expectations; and performance indexes reflecting patterns of performance. Results indicate no significant deleterious impact of TBI and/or presence or absence of myeloablative therapy on neurocognitive and neurobehavioral functioning. For this cohort, resilience to neuropsychological vulnerability was observed, which included the emergence of a profile of full-scale IQ, verbal IQ, and mathematical achievement well above average expectations. We concluded that the results document a lack of neuropsychological morbidity among this cohort of survivors of advanced stage neuroblastoma, regardless of the inclusion of TBI. Moreover, a striking pattern of excellent neurocognitive functioning with intact neurobehavioral functioning was observed.

  16. Molecular analysis of chromosome arm 17q gain in neuroblastoma.

    PubMed

    Janoueix-Lerosey, I; Penther, D; Thioux, M; de Crémoux, P; Derré, J; Ambros, P; Vielh, P; Bénard, J; Aurias, A; Delattre, O

    2000-07-01

    Complete or partial gain of the long arm of chromosome 17 (17q) has been shown recently by molecular cytogenetic techniques to be the most frequent chromosomal change in neuroblastoma and to be associated with adverse prognosis. Few reports, however, have focused on the precise mapping of the commonly overrepresented region. We have investigated 17q gain by the analysis of allelic imbalances at microsatellite loci dispersed along chromosome 17 in a series of 69 neuroblastomas. Allelic imbalances for at least two consecutive loci were observed in 39/59 informative cases, that is in agreement with previously reported frequencies of 17q gain. In a subset of the cases, comparative genomic hybridization analysis established the relationship between these allelic imbalances and the gain of 17q material. A partial 17q gain was observed in 9 cases, delineating a common region of 17q gain between the marker D17S787 (75 cM, 360 cR) and the telomere. In most cases, molecular results were suggestive of partial tri- or tetrasomy, whereas in 4 cases a higher copy number was documented. Our results also confirm that the presence of additional 17q material is closely associated with 1p36 deletion, MYCN amplification, and diploid or tetraploid chromosomal content. Genes Chromosomes Cancer 28:276-284, 2000. PMID:10862033

  17. MYCN repression of Lifeguard/FAIM2 enhances neuroblastoma aggressiveness.

    PubMed

    Planells-Ferrer, L; Urresti, J; Soriano, A; Reix, S; Murphy, D M; Ferreres, J C; Borràs, F; Gallego, S; Stallings, R L; Moubarak, R S; Segura, M F; Comella, J X

    2014-09-04

    Neuroblastoma (NBL) is the most common solid tumor in infants and accounts for 15% of all pediatric cancer deaths. Several risk factors predict NBL outcome: age at the time of diagnosis, stage, chromosome alterations and MYCN (V-Myc Avian Myelocytomatosis Viral Oncogene Neuroblastoma-Derived Homolog) amplification, which characterizes the subset of the most aggressive NBLs with an overall survival below 30%. MYCN-amplified tumors develop exceptional chemoresistance and metastatic capacity. These properties have been linked to defects in the apoptotic machinery, either by silencing components of the extrinsic apoptotic pathway (e.g. caspase-8) or by overexpression of antiapoptotic regulators (e.g. Bcl-2, Mcl-1 or FLIP). Very little is known on the implication of death receptors and their antagonists in NBL. In this work, the expression levels of several death receptor antagonists were analyzed in multiple human NBL data sets. We report that Lifeguard (LFG/FAIM2 (Fas apoptosis inhibitory molecule 2)/NMP35) is downregulated in the most aggressive and undifferentiated tumors. Intringuingly, although LFG has been initially characterized as an antiapoptotic protein, we have found a new association with NBL differentiation. Moreover, LFG repression resulted in reduced cell adhesion, increased sphere growth and enhanced migration, thus conferring a higher metastatic capacity to NBL cells. Furthermore, LFG expression was found to be directly repressed by MYCN at the transcriptional level. Our data, which support a new functional role for a hitherto undiscovered MYCN target, provide a new link between MYCN overexpression and increased NBL metastatic properties.

  18. Etoposide sensitizes neuroblastoma cells expressing caspase 8 to TRAIL.

    PubMed

    Kim, Hye Ryung; Lee, Myoung Woo; Kim, Dae Seong; Jo, Ha Yeong; Lee, Soo Hyun; Chueh, Hee Won; Jung, Hye Lim; Yoo, Keon Hee; Sung, Ki Woong; Koo, Hong Hoe

    2012-01-01

    TRAIL [TNF (tumour necrosis factor)-related apoptosis-inducing ligand] is a promising agent for clinical use since it kills a wide range of tumour cells without affecting normal cells. We provide evidence that pretreatment with etoposide significantly enhanced TRAIL-mediated apoptosis via up-regulation of DR5 (death receptor 5 or TRAIL-R2) expression in the caspase 8 expressing neuroblastoma cell line, SK-N-MC. In addition, sequential treatment with etoposide and TRAIL increased caspases 8, 9 and 3 activation, Mcl-1 cleavage and Bid truncation, which suggests that the ability of etoposide and TRAIL to induce apoptosis is mediated through activation of an intrinsic signalling pathway. Although TRAIL-R2 expression increased in IMR-32 cells in response to etoposide treatment, cell death was not increased by concurrent treatment with TRAIL compared with etoposide alone, because the cells lacked caspase 8 expression. Restoration of caspase 8 expression by exposure to IFNγ (interferon γ) sensitizes IMR-32 cells to TRAIL. Moreover, pretreatment with etoposide increased TRAIL-induced apoptosis in caspase 8 restored IMR-32 cells through activation of a caspase cascade that included caspases 8, 9 and 3. These results indicate that the etoposide-mediated sensitization of neuroblastoma cells to TRAIL is associated with an increase in TRAIL-R2 expression and requires caspase 8 expression. These observations support the potential use of a combination of etoposide and TRAIL in future clinical trials. PMID:23124518

  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. 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.

  1. Iodine-131-metaiodobenzylguanidine therapy with reduced-intensity allogeneic stem cell transplantation in recurrent neuroblastoma.

    PubMed

    Takahashi, Hiroka; Manabe, Atsushi; Aoyama, Chiaki; Kamiya, Takahiro; Kato, Itaru; Takusagawa, Ayako; Ogawa, Chitose; Ozawa, Miwa; Hosoya, Ryota; Yokoyama, Kunihiko

    2008-03-01

    Neuroblastoma is the most common extracranial solid tumor of childhood, and iodine-131-metaiodobenzylguanidine (MIBG) therapy is a new approach for grade IV neuroblastoma. We describe the case history of a 3-year-old girl with recurrent neuroblastoma who received MIBG therapy with reduced-intensity allogeneic stem cell transplantation (RIST) because of an extensive bone marrow involvement. The post-transplant course was uneventful and complete chimerism was obtained. Neither acute nor chronic graft-versus-host disease (GVHD) was observed. The patient remained in remission for 3 months after RIST until the second relapse. MIBG therapy combined with RIST warrants further trials.

  2. 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.

  3. 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.

  4. Ultrarobust Thin-Film Devices from Self-Assembled Metal-Terpyridine Oligomers.

    PubMed

    Karipidou, Zoi; Branchi, Barbara; Sarpasan, Mustafa; Knorr, Nikolaus; Rodin, Vadim; Friederich, Pascal; Neumann, Tobias; Meded, Velimir; Rosselli, Silvia; Nelles, Gabriele; Wenzel, Wolfgang; Rampi, Maria Anita; von Wrochem, Florian

    2016-05-01

    Ultrathin molecular layers of Fe(II) -terpyridine oligomers allow the fabrication of large-area crossbar junctions by conventional electrode vapor deposition. The junctions are electrically stable for over 2.5 years and operate over a wide range of temperatures (150-360 K) and voltages (±3 V) due to the high cohesive energy and packing density of the oligomer layer. Electrical measurements reveal ideal Richardson-Shottky emission in surprising agreement with electrochemical, optical, and photoemission data.

  5. Biofunctionalized Silica Nanoparticles: Standards in Amyloid-β Oligomer-Based Diagnosis of Alzheimer's Disease.

    PubMed

    Hülsemann, Maren; Zafiu, Christian; Kühbach, Katja; Lühmann, Nicole; Herrmann, Yvonne; Peters, Luriano; Linnartz, Christina; Willbold, Johannes; Kravchenko, Kateryna; Kulawik, Andreas; Willbold, Sabine; Bannach, Oliver; Willbold, Dieter

    2016-07-27

    Amyloid-β (Aβ) oligomers represent a promising biomarker for the early diagnosis of Alzheimer's disease (AD). However, state-of-the-art methods for immunodetection of Aβ oligomers in body fluids show a large variability and lack a reliable and stable standard that enables the reproducible quantitation of Aβ oligomers. At present, the only available standard applied in these assays is based on a random aggregation process of synthetic Aβ and has neither a defined size nor a known number of epitopes. In this report, we generated a highly stable standard in the size range of native Aβ oligomers that exposes a defined number of epitopes. The standard consists of a silica nanoparticle (SiNaP), which is functionalized with Aβ peptides on its surface (Aβ-SiNaP). The different steps of Aβ-SiNaP synthesis were followed by microscopic, spectroscopic and biochemical analyses. To investigate the performance of Aβ-SiNaPs as an appropriate standard in Aβ oligomer immunodetection, Aβ-SiNaPs were diluted in cerebrospinal fluid and quantified down to a concentration of 10 fM in the sFIDA (surface-based fluorescence intensity distribution analysis) assay. This detection limit corresponds to an Aβ concentration of 1.9 ng l-1 and lies in the sensitivity range of currently applied diagnostic tools based on Aβ oligomer quantitation. Thus, we developed a highly stable and well-characterized standard for the application in Aβ oligomer immunodetection assays that finally allows the reproducible quantitation of Aβ oligomers down to single molecule level and provides a fundamental improvement for the worldwide standardization process of diagnostic methods in AD research. PMID:27472876

  6. 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. PMID:26466138

  7. Structure and properties of binary polystyrene-epoxy acrylate oligomer mixtures irradiated by electron beams

    SciTech Connect

    Lomonosova, N.V.

    1995-03-01

    The change in the structure of oriented polymer-oligomer systems based on polystyrene (PS) with M > 10{sup 6} and epoxy acrylate oligomers (aliphatic and aromatic) under irradiation by accelerated electrons was studied using birefringence, isometric heating, IR dichroism, and thermooptical analysis. Mechanical properties of these systems were investigated. It was found that, by adding aliphatic epoxy acrylate to PS and further irradiating this mixture, one can obtain both isotropic and oriented composites with higher strengths, elasticity moduli, and glass transition temperatures.

  8. Formation of High-Order Oligomers by a Hyperthemostable Fe-Superoxide Dismutase (tcSOD)

    PubMed Central

    Wang, Sha; Dong, Zhi-Yang; Yan, Yong-Bin

    2014-01-01

    Hyperthermostable proteins are highly resistant to various extreme conditions. Many factors have been proposed to contribute to their ultrahigh structural stability. Some thermostable proteins have larger oligomeric size when compared to their mesophilic homologues. The formation of compact oligomers can minimize the solvent accessible surface area and increase the changes of Gibbs free energy for unfolding. Similar to mesophilic proteins, hyperthermostable proteins also face the problem of unproductive aggregation. In this research, we investigated the role of high-order oligomerization in the fight against aggregation by a hyperthermostable superoxide dismutase identified from Tengchong, China (tcSOD). Besides the predominant tetramers, tcSOD could also form active high-order oligomers containing at least eight subunits. The dynamic equilibrium between tetramers and high-order oligomers was not significantly affected by pH, salt concentration or moderate temperature. The secondary and tertiary structures of tcSOD remained unchanged during heating, while cross-linking experiments showed that there were conformational changes or structural fluctuations at high temperatures. Mutational analysis indicated that the last helix at the C-terminus was involved in the formation of high-order oligomers, probably via domain swapping. Based on these results, we proposed that the reversible conversion between the active tetramers and high-order oligomers might provide a buffering system for tcSOD to fight against the irreversible protein aggregation pathway. The formation of active high-order oligomers not only increases the energy barrier between the native state and unfolded/aggregated state, but also provides the enzyme the ability to reproduce the predominant oligomers from the active high-order oligomers. PMID:25313557

  9. 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.

  10. Causative factors for formation of toxic islet amyloid polypeptide oligomer in type 2 diabetes mellitus

    PubMed Central

    Jeong, Hye Rin; An, Seong Soo A

    2015-01-01

    Human islet amyloid polypeptide (h-IAPP) is a peptide hormone that is synthesized and cosecreted with insulin from insulin-secreting pancreatic β-cells. Recently, h-IAPP was proposed to be the main component responsible for the cytotoxic pancreatic amyloid deposits in patients with type 2 diabetes mellitus (T2DM). Since the causative factors of IAPP (or amylin) oligomer aggregation are not fully understood, this review will discuss the various forms of h-IAPP aggregation. Not all forms of IAPP aggregates trigger the destruction of β-cell function and loss of β-cell mass; however, toxic oligomers do trigger these events. Once these toxic oligomers form under abnormal metabolic conditions in T2DM, they can lead to cell disruption by inducing cell membrane destabilization. In this review, the various factors that have been shown to induce toxic IAPP oligomer formation will be presented, as well as the potential mechanism of oligomer and fibril formation from pro-IAPPs. Initially, pro-IAPPs undergo enzymatic reactions to produce the IAPP monomers, which can then develop into oligomers and fibrils. By this mechanism, toxic oligomers could be generated by diverse pathway components. Thus, the interconnections between factors that influence amyloid aggregation (eg, absence of PC2 enzyme, deamidation, reduction of disulfide bonds, environmental factors in the cell, genetic mutations, copper metal ions, and heparin) will be presented. Hence, this review will aid in understanding the fundamental causative factors contributing to IAPP oligomer formation and support studies for investigating novel T2DM therapeutic approaches, such as the development of inhibitory agents for preventing oligomerization at the early stages of diabetic pathology. PMID:26604727

  11. Causative factors for formation of toxic islet amyloid polypeptide oligomer in type 2 diabetes mellitus.

    PubMed

    Jeong, Hye Rin; An, Seong Soo A

    2015-01-01

    Human islet amyloid polypeptide (h-IAPP) is a peptide hormone that is synthesized and cosecreted with insulin from insulin-secreting pancreatic β-cells. Recently, h-IAPP was proposed to be the main component responsible for the cytotoxic pancreatic amyloid deposits in patients with type 2 diabetes mellitus (T2DM). Since the causative factors of IAPP (or amylin) oligomer aggregation are not fully understood, this review will discuss the various forms of h-IAPP aggregation. Not all forms of IAPP aggregates trigger the destruction of β-cell function and loss of β-cell mass; however, toxic oligomers do trigger these events. Once these toxic oligomers form under abnormal metabolic conditions in T2DM, they can lead to cell disruption by inducing cell membrane destabilization. In this review, the various factors that have been shown to induce toxic IAPP oligomer formation will be presented, as well as the potential mechanism of oligomer and fibril formation from pro-IAPPs. Initially, pro-IAPPs undergo enzymatic reactions to produce the IAPP monomers, which can then develop into oligomers and fibrils. By this mechanism, toxic oligomers could be generated by diverse pathway components. Thus, the interconnections between factors that influence amyloid aggregation (eg, absence of PC2 enzyme, deamidation, reduction of disulfide bonds, environmental factors in the cell, genetic mutations, copper metal ions, and heparin) will be presented. Hence, this review will aid in understanding the fundamental causative factors contributing to IAPP oligomer formation and support studies for investigating novel T2DM therapeutic approaches, such as the development of inhibitory agents for preventing oligomerization at the early stages of diabetic pathology. PMID:26604727

  12. Carnosic acid attenuates apoptosis induced by amyloid-β 1-42 or 1-43 in SH-SY5Y human neuroblastoma cells.

    PubMed

    Meng, Pengfei; Yoshida, Hidemi; Tanji, Kunikazu; Matsumiya, Tomoh; Xing, Fei; Hayakari, Ryo; Wang, Liang; Tsuruga, Kazushi; Tanaka, Hiroshi; Mimura, Junsei; Kosaka, Kunio; Itoh, Ken; Takahashi, Ippei; Kawaguchi, Shogo; Imaizumi, Tadaatsu

    2015-05-01

    Amyloid-beta (Aβ) peptides, Aβ 1-42 (Aβ42) and Aβ43 in particular, cause neurotoxicity and cell death in the brain of Alzheimer's disease (AD) at higher concentrations. Carnosic acid (CA), a phenolic diterpene compound in the labiate herbs rosemary and sage, serves as an activator for neuroprotective and neurotrophic functions in brain cells. We investigated the effect of CA on apoptosis induced by Aβ42 or Aβ43 in cultured SH-SY5Y human neuroblastoma cells. Treatment of the cells with Aβ42 or Aβ43 (monomer, 10 μM each) induced apoptosis, which was confirmed by the cleavage of poly-(ADP-ribose) polymerase (PARP) and apoptosis-inducing factor (AIF). Concurrently, the Aβ treatment induced the activation of caspase (Casp) cascades including an effector Casp (Casp3) and initiator Casps (Casp4, Casp8 and Casp9). Pretreatment of the cells with CA (10 μM) partially attenuated the apoptosis induced by Aβ42 or Aβ43. CA pretreatment also reduced the cellular oligomers of Aβ42 and Aβ43. These results suggest that CA suppressed the activation of Casp cascades by reducing the intracellular oligomerization of exogenous Aβ42/43 monomer. The ingestion of an adequate amount of CA may have a potential in the prevention of Aβ-mediated diseases, particularly AD. PMID:25510380

  13. Carnosic acid attenuates apoptosis induced by amyloid-β 1-42 or 1-43 in SH-SY5Y human neuroblastoma cells.

    PubMed

    Meng, Pengfei; Yoshida, Hidemi; Tanji, Kunikazu; Matsumiya, Tomoh; Xing, Fei; Hayakari, Ryo; Wang, Liang; Tsuruga, Kazushi; Tanaka, Hiroshi; Mimura, Junsei; Kosaka, Kunio; Itoh, Ken; Takahashi, Ippei; Kawaguchi, Shogo; Imaizumi, Tadaatsu

    2015-05-01

    Amyloid-beta (Aβ) peptides, Aβ 1-42 (Aβ42) and Aβ43 in particular, cause neurotoxicity and cell death in the brain of Alzheimer's disease (AD) at higher concentrations. Carnosic acid (CA), a phenolic diterpene compound in the labiate herbs rosemary and sage, serves as an activator for neuroprotective and neurotrophic functions in brain cells. We investigated the effect of CA on apoptosis induced by Aβ42 or Aβ43 in cultured SH-SY5Y human neuroblastoma cells. Treatment of the cells with Aβ42 or Aβ43 (monomer, 10 μM each) induced apoptosis, which was confirmed by the cleavage of poly-(ADP-ribose) polymerase (PARP) and apoptosis-inducing factor (AIF). Concurrently, the Aβ treatment induced the activation of caspase (Casp) cascades including an effector Casp (Casp3) and initiator Casps (Casp4, Casp8 and Casp9). Pretreatment of the cells with CA (10 μM) partially attenuated the apoptosis induced by Aβ42 or Aβ43. CA pretreatment also reduced the cellular oligomers of Aβ42 and Aβ43. These results suggest that CA suppressed the activation of Casp cascades by reducing the intracellular oligomerization of exogenous Aβ42/43 monomer. The ingestion of an adequate amount of CA may have a potential in the prevention of Aβ-mediated diseases, particularly AD.

  14. 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.

  15. A native interactor scaffolds and stabilizes toxic ATAXIN-1 oligomers in SCA1

    PubMed Central

    Lasagna-Reeves, Cristian A; Rousseaux, Maxime WC; Guerrero-Muñoz, Marcos J; Park, Jeehye; Jafar-Nejad, Paymaan; Richman, Ronald; Lu, Nan; Sengupta, Urmi; Litvinchuk, Alexandra; Orr, Harry T; Kayed, Rakez; Zoghbi, Huda Y

    2015-01-01

    Recent studies indicate that soluble oligomers drive pathogenesis in several neurodegenerative proteinopathies, including Alzheimer and Parkinson disease. Curiously, the same conformational antibody recognizes different disease-related oligomers, despite the variations in clinical presentation and brain regions affected, suggesting that the oligomer structure might be responsible for toxicity. We investigated whether polyglutamine-expanded ATAXIN-1, the protein that underlies spinocerebellar ataxia type 1, forms toxic oligomers and, if so, what underlies their toxicity. We found that mutant ATXN1 does form oligomers and that oligomer levels correlate with disease progression in the Atxn1154Q/+ mice. Moreover, oligomeric toxicity, stabilization and seeding require interaction with Capicua, which is expressed at greater ratios with respect to ATXN1 in the cerebellum than in less vulnerable brain regions. Thus, specific interactors, not merely oligomeric structure, drive pathogenesis and contribute to regional vulnerability. Identifying interactors that stabilize toxic oligomeric complexes could answer longstanding questions about the pathogenesis of other proteinopathies. DOI: http://dx.doi.org/10.7554/eLife.07558.001 PMID:25988806

  16. Application of an Amyloid Beta Oligomer Standard in the sFIDA Assay

    PubMed Central

    Kühbach, Katja; Hülsemann, Maren; Herrmann, Yvonne; Kravchenko, Kateryna; Kulawik, Andreas; Linnartz, Christina; Peters, Luriano; Wang, Kun; Willbold, Johannes; Willbold, Dieter; Bannach, Oliver

    2016-01-01

    Still, there is need for significant improvements in reliable and accurate diagnosis for Alzheimer's disease (AD) at early stages. It is widely accepted that changes in the concentration and conformation of amyloid-β (Aβ) appear several years before the onset of first symptoms of cognitive impairment in AD patients. Because Aβ oligomers are possibly the major toxic species in AD, they are a promising biomarker candidate for the early diagnosis of the disease. To date, a variety of oligomer-specific assays have been developed, many of them ELISAs. Here, we demonstrate the sFIDA assay, a technology highly specific for Aβ oligomers developed toward single particle sensitivity. By spiking stabilized Aβ oligomers to buffer and to body fluids from control donors, we show that the sFIDA readout correlates with the applied concentration of stabilized oligomers diluted in buffer, cerebrospinal fluid (CSF), and blood plasma over several orders of magnitude. The lower limit of detection was calculated to be 22 fM of stabilized oligomers diluted in PBS, 18 fM in CSF, and 14 fM in blood plasma. PMID:26858588

  17. 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.

  18. Cellulose oligomers production and separation for the synthesis of new fully bio-based amphiphilic compounds.

    PubMed

    Billès, Elise; Onwukamike, Kelechukwu N; Coma, Véronique; Grelier, Stéphane; Peruch, Frédéric

    2016-12-10

    Cellulose oligomers are water-soluble, on the contrary to cellulose, which greatly increase their application range. In this study, cellulose oligomers were obtained from the acidic hydrolysis of cellulose with phosphoric acid. The global yield in water-soluble oligomers was around 23% with polymerization degree (DP) ranging from 1 to 12. The cellulose oligomers DP distribution was successfully reduced by differential solubilisation in methanol as one of the goals of this work was to avoid the use of a time-consuming full chromatographic separation. The methanol-soluble oligomers were mainly low DP (≤3). The oligomers of higher molar mass, composed of 42% of cellotetraose and 36% of cellopentaose, were then functionalized and coupled with stearic acid through azide-alkyne click chemistry to obtain amphiphilic compounds. The self-assembly of these new bio-based compounds was finally investigated by dynamic light scattering (DLS) and transmission electron microscopy (TEM) and their critical micellar concentration (CMC) was found to be in the same range as alkylmaltosides and alkylglucosides. PMID:27577903

  19. Simulation of Force Spectroscopy Experiments on Galacturonic Acid Oligomers

    PubMed Central

    Cybulska, Justyna; Brzyska, Agnieszka; Zdunek, Artur; Woliński, Krzysztof

    2014-01-01

    Pectins, forming a matrix for cellulose and hemicellulose, determine the mechanics of plant cell walls. They undergo salient structural changes during their development. In the presence of divalent cations, usually calcium, pectins can form gel-like structures. Because of their importance they have been the subject of many force spectroscopy experiments, which have examined the conformational changes and molecular tensions due to external forces. The most abundant unit present in the pectin backbone is polygalacturonic acid. Unfortunately, experimental force spectroscopy on polygalacturonic acid molecules is still not a trivial task. The mechanism of the single-molecule response to external forces can be inferred by theoretical methods. Therefore, in this work we simulated such force spectroscopy experiments using the Enforced Geometry Optimization (EGO) method. We examined the oligomeric (up to hexamer) structures of α-D-galacturonic acid exposed to external stretching forces. The EGO simulation of the force spectroscopy appropriately reproduced the experimental course of the enforced conformational transition: chair →inverted chair via the twisted boat conformation(s) in the pyranose ring of α-D-galacturonic acid. Additionally, our theoretical approach also allowed to determine the minimum oligomer size adequate for the description of nano-mechanical properties of (poly)-α-D-galacturonic acid. PMID:25229407

  20. 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.

  1. GeneGenie: optimized oligomer design for directed evolution.

    PubMed

    Swainston, Neil; Currin, Andrew; Day, Philip J; Kell, Douglas B

    2014-07-01

    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.

  2. Supercritical fluid assisted production of chitosan oligomers micrometric powders.

    PubMed

    Du, Zhe; Shen, Yu-Bin; Tang, Chuan; Guan, Yi-Xin; Yao, Shan-Jing; Zhu, Zi-Qiang

    2014-02-15

    Chitosan oligomers (O-chitosan) micrometric particles were produced from aqueous solution using a novel process, i.e. supercritical fluid assisted atomization introduced by hydrodynamic cavitation mixer (SAA-HCM). Hydrodynamic cavitation was introduced to enhance mass transfer and facilitate the mixing between SC-CO2 and liquid solution for fine particles formation. Well defined, separated and spherical microparticles were obtained, and the particles size could be well controlled with narrow distribution ranging from 0.5 μm to 3 μm. XRD patterns showed amorphous structure of O-chitosan microparticles. FTIR, TGA and DSC analyses confirmed that no change in molecular structure and thermal stability after SAA-HCM processing, while the water content was between 5.8% and 8.4%. Finally, tap densities were determined to be below 0.45 g/cm(3) indicating hollow or porous structures of microparticles. By tuning process parameters, theoretical mass median aerodynamic sizes lied inside respirable range of 1-2 μm, which presented the potential of the O-chitosan microparticles in application as inhaled dry powders. SAA-HCM was demonstrated to be very useful in particle size engineering. PMID:24507297

  3. 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.

  4. 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

  5. Treatment of neuroblastoma patients with antiganglioside GD2 antibody plus interleukin-2 induces antibody-dependent cellular cytotoxicity against neuroblastoma detected in vitro.

    PubMed

    Hank, J A; Surfus, J; Gan, J; Chew, T L; Hong, R; Tans, K; Reisfeld, R; Seeger, R C; Reynolds, C P; Bauer, M

    1994-01-01

    Therapy of neuroblastoma patients with interleukin (IL)-2 activates effector cells capable of lysing tumor cells in vitro. When tumor cells are pretreated with certain monoclonal antibodies (MoAb), these in vivo activated effectors show augmented tumor lysis via antibody-dependent cellular cytotoxicity (ADCC). This study presents immunological analyses of serial blood samples from two refractory neuroblastoma patients who received combined in vivo therapy with murine anti-ganglioside GD2 monoclonal antibody 14.G2a and IL-2. These studies were designed to determine whether conditions that induce ADCC in vitro can be generated in vivo by combined therapy with IL-2 and MoAb. As shown previously, administration of IL-2 dramatically augments the ability of peripheral blood mononuclear cells (PBMC) to mediate ADCC. In addition, we demonstrate here that sera, obtained 1 h after infusion of 14.G2a, provides an effective source of functional antibody for ADCC mediated by PBMC from healthy donors. Finally, effective ADCC-mediated killing of neuroblastoma target cells was also achieved in vitro following IL-2 plus 14.G2a treatment when patients' effector cells were combined with patients' serum, as the source of 14.G2a antibody. These results indicate that this combination of IL-2 and 14.G2a generates conditions within the peripheral blood of pediatric neuroblastoma patients that enable their own lymphocytes to mediate antibody-dependent cellular cytotoxicity sufficient to effectively kill neuroblastoma cells in vitro.

  6. 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

  7. 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

  8. Immunoglobulin GM and FcγRIIIa genotypes influence cytotoxicity of neuroblastoma cells.

    PubMed

    Pandey, Janardan P; Namboodiri, Aryan M

    2014-05-15

    Immunoglobulin GM (γ marker) allotypes are strongly associated with neuroblastoma, but the mechanism is not known. One mechanism could involve antibody-dependent cell-mediated cytotoxicity (ADCC) of neuroblastoma cells. Using an ADCC inhibition assay, we show that IgG1 expressing GM 3+,1-,2- allotypes blocked all phenylalanine-expressing FcγRIIIa present on NK cells, resulting in total inhibition of anti-GD2 antibody-mediated ADCC of GD2-overexpressing neuroblastoma cells. In contrast, the inhibitory effect of this protein was significantly lower when the NK cells were homozygous for the valine allele of FcγRIIIa (100 vs. 21%; p=0.00004). These and other findings presented here could lead to a more effective immunotherapy of neuroblastoma.

  9. The role of genetic and epigenetic alterations in neuroblastoma disease pathogenesis

    PubMed Central

    Domingo-Fernandez, Raquel; Watters, Karen; Piskareva, Olga; Bray, Isabella

    2013-01-01

    Neuroblastoma is a highly heterogeneous tumor accounting for 15 % of all pediatric cancer deaths. Clinical behavior ranges from the spontaneous regression of localized, asymptomatic tumors, as well as metastasized tumors in infants, to rapid progression and resistance to therapy. Genomic amplification of the MYCN oncogene has been used to predict outcome in neuroblastoma for over 30 years, however, recent methodological advances including miR-NA and mRNA profiling, comparative genomic hybridization (array-CGH), and whole-genome sequencing have enabled the detailed analysis of the neuroblastoma genome, leading to the identification of new prognostic markers and better patient stratification. In this review, we will describe the main genetic factors responsible for these diverse clinical phenotypes in neuroblastoma, the chronology of their discovery, and the impact on patient prognosis. PMID:23274701

  10. Tideglusib induces apoptosis in human neuroblastoma IMR32 cells, provoking sub-G0/G1 accumulation and ROS generation.

    PubMed

    Mathuram, Theodore Lemuel; Ravikumar, Vilwanathan; Reece, Lisa M; Karthik, Selvaraju; Sasikumar, Changam Sheela; Cherian, Kotturathu Mammen

    2016-09-01

    Neuroblastoma is the most common tumor amongst children amounting to nearly 15% of cancer deaths. This cancer is peculiar in its characteristics, exhibiting differentiation, maturation and metastatic transformation leading to poor prognosis and low survival rates among children. Chemotherapy, though toxic to normal cells, has shown to improve the survival of the patient with emphasis given more towards targeting angiogenesis. Recently, Tideglusib was designed as an 'Orphan Drug' to target the neurodegenerative Alzheimer's disease and gained significant momentum in its function during clinical trials. Duffy et al. recently reported a reduction in cell viability of human IMR32 neuroblastoma cells when treated with Tideglusib at varying concentrations. We investigated the effects of Tideglusib, at various concentrations, compared to Lithium chloride at various concentrations, on IMR32 cells. Lithium, a known GSK-3 inhibitor, was used as a standard to compare the efficiency of Tideglusib in a dose-dependent manner. Cell viability was assessed by MTT assay. The stages of apoptosis were evaluated by AO/EB staining and nuclear damage was determined by Hoechst 33258 staining. Reactive oxygen species (ROS) and mitochondrial membrane potential (ΔΨm) were assessed by DCFDA dye and Rhodamine-123 dye, respectively. Tideglusib reported a significant dose-dependent increase in pro-apoptotic proteins (PARP, Caspase-9, Caspase-7, Caspase-3) and tumor-related genes (FasL, TNF-α, Cox-2, IL-8, Caspase-3). Anti-GSK3 β, pGSK3 β, Bcl-2, Akt-1, p-Akt1 protein levels were observed with cells exposed to Tideglusib and Lithium chloride. No significant dose-dependent changes were observed for the mRNA expression of collagenase MMP-2, the tumor suppressor p53, or the cell cycle protein p21. Our study also reports Tideglusib reducing colony formation and increasing the level of sub-G0/G1 population in IMR32 cells. Our investigations report the significance of Tideglusib as a promising

  11. Tideglusib induces apoptosis in human neuroblastoma IMR32 cells, provoking sub-G0/G1 accumulation and ROS generation.

    PubMed

    Mathuram, Theodore Lemuel; Ravikumar, Vilwanathan; Reece, Lisa M; Karthik, Selvaraju; Sasikumar, Changam Sheela; Cherian, Kotturathu Mammen

    2016-09-01

    Neuroblastoma is the most common tumor amongst children amounting to nearly 15% of cancer deaths. This cancer is peculiar in its characteristics, exhibiting differentiation, maturation and metastatic transformation leading to poor prognosis and low survival rates among children. Chemotherapy, though toxic to normal cells, has shown to improve the survival of the patient with emphasis given more towards targeting angiogenesis. Recently, Tideglusib was designed as an 'Orphan Drug' to target the neurodegenerative Alzheimer's disease and gained significant momentum in its function during clinical trials. Duffy et al. recently reported a reduction in cell viability of human IMR32 neuroblastoma cells when treated with Tideglusib at varying concentrations. We investigated the effects of Tideglusib, at various concentrations, compared to Lithium chloride at various concentrations, on IMR32 cells. Lithium, a known GSK-3 inhibitor, was used as a standard to compare the efficiency of Tideglusib in a dose-dependent manner. Cell viability was assessed by MTT assay. The stages of apoptosis were evaluated by AO/EB staining and nuclear damage was determined by Hoechst 33258 staining. Reactive oxygen species (ROS) and mitochondrial membrane potential (ΔΨm) were assessed by DCFDA dye and Rhodamine-123 dye, respectively. Tideglusib reported a significant dose-dependent increase in pro-apoptotic proteins (PARP, Caspase-9, Caspase-7, Caspase-3) and tumor-related genes (FasL, TNF-α, Cox-2, IL-8, Caspase-3). Anti-GSK3 β, pGSK3 β, Bcl-2, Akt-1, p-Akt1 protein levels were observed with cells exposed to Tideglusib and Lithium chloride. No significant dose-dependent changes were observed for the mRNA expression of collagenase MMP-2, the tumor suppressor p53, or the cell cycle protein p21. Our study also reports Tideglusib reducing colony formation and increasing the level of sub-G0/G1 population in IMR32 cells. Our investigations report the significance of Tideglusib as a promising

  12. 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

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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. PMID:26598443

  18. 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.

  19. Cytopathogenicity of Naegleria fowleri for rat neuroblastoma cell cultures: scanning electron microscopy study.

    PubMed

    Marciano-Cabral, F; John, D T

    1983-06-01

    Neuroblastoma cells were inoculated with Naegleria fowleri Lee and examined for cytopathology at various periods post-inoculation by scanning electron microscopy. By 18 h post-inoculation, approximately 50% of neuroblastoma cells were nonviable, as evidenced by trypan blue exclusion and light microscopic examination. This cytopathology resulted from piecemeal consumption of target cells mediated by a sucker apparatus extending from the surface of N. fowleri.

  20. The risk-associated long noncoding RNA NBAT-1 controls neuroblastoma progression by regulating cell proliferation and neuronal differentiation.

    PubMed

    Pandey, Gaurav Kumar; Mitra, Sanhita; Subhash, Santhilal; Hertwig, Falk; Kanduri, Meena; Mishra, Kankadeb; Fransson, Susanne; Ganeshram, Abiarchana; Mondal, Tanmoy; Bandaru, Sashidhar; Ostensson, Malin; Akyürek, Levent M; Abrahamsson, Jonas; Pfeifer, Susan; Larsson, Erik; Shi, Leming; Peng, Zhiyu; Fischer, Matthias; Martinsson, Tommy; Hedborg, Fredrik; Kogner, Per; Kanduri, Chandrasekhar

    2014-11-10

    Neuroblastoma is an embryonal tumor of the sympathetic nervous system and the most common extracranial tumor of childhood. By sequencing transcriptomes of low- and high-risk neuroblastomas, we detected differentially expressed annotated and nonannotated long noncoding RNAs (lncRNAs). We identified a lncRNA neuroblastoma associated transcript-1 (NBAT-1) as a biomarker significantly predicting clinical outcome of neuroblastoma. CpG methylation and a high-risk neuroblastoma associated SNP on chromosome 6p22 functionally contribute to NBAT-1 differential expression. Loss of NBAT-1 increases cellular proliferation and invasion. It controls these processes via epigenetic silencing of target genes. NBAT-1 loss affects neuronal differentiation through activation of the neuronal-specific transcription factor NRSF/REST. Thus, loss of NBAT-1 contributes to aggressive neuroblastoma by increasing proliferation and impairing differentiation of neuronal precursors. PMID:25517750

  1. Thiophene-based oligomers, polymers and dendrimers for organic photovoltaics

    NASA Astrophysics Data System (ADS)

    Zhang, Yong

    Demand for inexpensive renewable energy sources has stimulated new approaches for the production of efficient, low cost photovoltaic (PV) solar cell devices. This thesis research has focused on developing thiophene-based oligomers, polymers and dendrimers for this purpose. The key results are summarized as follows: First, three fully characterized polynorbornenes with electronically active pendant oligothiophene side chains have been synthesized and incorporated as active electronic components into single-layer photovoltaic cells. The device tests along with the electrochemical experiments demonstrate that incorporating chemically stable end-groups on the oligothiophene unit is responsible for the improvement of operation stability under ambient conditions. Second, in-situ surface-initiated polymerization of thiophene inside nanoporous networks has been realized. The resulting organic-inorganic hybrids with polythiophene covalently bound inside nanopores can achieve better interface contact, larger surface coverage and more complete filling of the pores. These result in more efficient photoinjection of electrons into the conduction band of nanocrystalline TiO2 than an analogous nanoporous structure infiltrated by polymer synthesized outside the network. The last part of this thesis covers the synthesis and characterization of a new series of semi-flexible oligothiophene-based dendrimers, which show pronounced solvatochromic and thermochromic properties. Microscopic fluorescence investigation of such surface adhered dendrimers provides the evidence that the intramolecular interactions inside these dendritic structures mainly account for the origin of the morphology-related chromism properties. This architecture is promising to make processable light harvesting structures having scaffolded donors covalently integrated with acceptors such as fullerenes in order to fabricate photovoltaics where phase segregation is suppressed.

  2. Self-assembly of conjugated oligomers and polymers at the interface: structure and properties.

    PubMed

    Xu, Lirong; Yang, Liu; Lei, Shengbin

    2012-08-01

    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

  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. 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.

  5. 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.

  6. New immunotherapeutic strategies for the treatment of neuroblastoma.

    PubMed

    Croce, Michela; Corrias, Maria Valeria; Rigo, Valentina; Ferrini, Silvano

    2015-01-01

    The prognosis of high-risk neuroblastoma (NB) is still poor, in spite of aggressive multimodal treatment. Recently, adjuvant immunotherapy with anti-GD2 antibodies combined with IL-2 or GM-CSF has been shown to improve survival. Several other immunotherapy strategies proved efficacy in preclinical models of NB, including different types of vaccines, adoptive cell therapies and combined approaches. The remarkable differences in the immunobiology of syngeneic models and human NB may, at least in part, limit the translation of preclinical therapies to a clinical setting. Nonetheless, several preliminary evidences suggest that new antibodies, cancer vaccines and adoptive transfer of lymphocytes, genetically engineered to acquire NB specificity, may result in clinical benefit, and clinical studies are currently ongoing.

  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. 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. PMID:27383785

  9. Liposome-Encapsulated Curcumin Suppresses Neuroblastoma Growth Through Nuclear Factor-κB Inhibition

    PubMed Central

    Orr, W. Shannon; Denbo, Jason W.; Saab, Karim R.; Myers, Adrianne L.; Ng, Catherine Y.; Zhou, Junfang; Morton, Christopher L.; Pfeffer, Lawrence M.; Davidoff, Andrew M.

    2012-01-01

    Background Nuclear factor-κB (NF-κB) has been implicated in tumor cell proliferation and survival, and tumor angiogenesis. We sought to evaluate the effects of curcumin, an inhibitor of NF-κB, on a xenograft model on disseminated neuroblastoma. Methods For in vitro studies, neuroblastoma cell lines, NB1691, CHLA-20, and SK-N-AS, were treated with varying doses of liposomal curcumin. Disseminated neuroblastoma was established in vivo by tail vein injection of NB1691-luc cells into SCID mice which were then treated with 50mg/kg/day of liposomal curcumin 5 days/week intraperitoneal. Results Curcumin suppressed NF-κB activation and proliferation of all neuroblastoma cell lines in vitro. In vivo, curcumin treatment resulted in a significant decrease in disseminated tumor burden. Curcumin treated tumors had decreased NF-κB activity and an associated significant decrease in tumor cell proliferation and an increase in tumor cell apoptosis, as well as a decrease in tumor VEGF levels and microvessel density. Conclusions Liposomal curcumin suppressed neuroblastoma growth, with treated tumors showing a decrease in NF-kB activity. Our results suggest that liposomal curcumin maybe a viable option for the treatment of neuroblastoma that works via inhibiting the NF-κB pathway. PMID:22284765

  10. 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. PMID:26821351

  11. Breakpoint Features of Genomic Rearrangements in Neuroblastoma with Unbalanced Translocations and Chromothripsis

    PubMed Central

    Daveau, Romain; Combaret, Valérie; Pierre-Eugène, Cécile; Cazes, Alex; Louis-Brennetot, Caroline; Schleiermacher, Gudrun; Ferrand, Sandrine; Pierron, Gaëlle; Lermine, Alban; Frio, Thomas Rio; Raynal, Virginie; Vassal, Gilles; Barillot, Emmanuel; Delattre, Olivier; Janoueix-Lerosey, Isabelle

    2013-01-01

    Neuroblastoma is a pediatric cancer of the peripheral nervous system in which structural chromosome aberrations are emblematic of aggressive tumors. In this study, we performed an in-depth analysis of somatic rearrangements in two neuroblastoma cell lines and two primary tumors using paired-end sequencing of mate-pair libraries and RNA-seq. The cell lines presented with typical genetic alterations of neuroblastoma and the two tumors belong to the group of neuroblastoma exhibiting a profile of chromothripsis. Inter and intra-chromosomal rearrangements were identified in the four samples, allowing in particular characterization of unbalanced translocations at high resolution. Using complementary experiments, we further characterized 51 rearrangements at the base pair resolution that revealed 59 DNA junctions. In a subset of cases, complex rearrangements were observed with templated insertion of fragments of nearby sequences. Although we did not identify known particular motifs in the local environment of the breakpoints, we documented frequent microhomologies at the junctions in both chromothripsis and non-chromothripsis associated breakpoints. RNA-seq experiments confirmed expression of several predicted chimeric genes and genes with disrupted exon structure including ALK, NBAS, FHIT, PTPRD and ODZ4. Our study therefore indicates that both non-homologous end joining-mediated repair and replicative processes may account for genomic rearrangements in neuroblastoma. RNA-seq analysis allows the identification of the subset of abnormal transcripts expressed from genomic rearrangements that may be involved in neuroblastoma oncogenesis. PMID:23991058

  12. 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. PMID:27080224

  13. MicroRNA-184-Mediated Inhibition of Tumour Growth in an Orthotopic Murine Model of Neuroblastoma

    PubMed Central

    TIVNAN, AMANDA; FOLEY, NIAMH H.; TRACEY, LORRAINE; DAVIDOFF, ANDREW M.; STALLINGS, RAYMOND L.

    2016-01-01

    Background Neuroblastoma is a paediatric cancer which originates from precursor cells of the sympathetic nervous system. Previous studies have shown that miR-184 expression has anti-proliferative effects in neuroblastoma cells grown in culture. Therefore, it was of interest to evaluate this effect in vivo. Materials and Methods Neuroblastoma cells overexpressing miR-184 were injected retroperitoneally into CB17-SCID mice and tumour burden was assessed by measuring bioluminescence. Overall survival was also evaluated. Results Ectopic overexpression of miR-184 in neuroblastoma cell lines is anti-proliferative. In addition, overexpression of miR-184 led to a significant reduction in tumour growth relative to negative control-treated cohorts in a xenograft model of neuroblastoma. Conclusion This study demonstrated for the first time that miR-184 significantly reduces tumour growth and increases overall survival in an orthotopic murine model of neuroblastoma through assessment of tumour growth and moribundity relative to control miRNA-treated cohorts. PMID:21115884

  14. Breakpoint features of genomic rearrangements in neuroblastoma with unbalanced translocations and chromothripsis.

    PubMed

    Boeva, Valentina; Jouannet, Stéphanie; Daveau, Romain; Combaret, Valérie; Pierre-Eugène, Cécile; Cazes, Alex; Louis-Brennetot, Caroline; Schleiermacher, Gudrun; Ferrand, Sandrine; Pierron, Gaëlle; Lermine, Alban; Rio Frio, Thomas; Raynal, Virginie; Vassal, Gilles; Barillot, Emmanuel; Delattre, Olivier; Janoueix-Lerosey, Isabelle

    2013-01-01

    Neuroblastoma is a pediatric cancer of the peripheral nervous system in which structural chromosome aberrations are emblematic of aggressive tumors. In this study, we performed an in-depth analysis of somatic rearrangements in two neuroblastoma cell lines and two primary tumors using paired-end sequencing of mate-pair libraries and RNA-seq. The cell lines presented with typical genetic alterations of neuroblastoma and the two tumors belong to the group of neuroblastoma exhibiting a profile of chromothripsis. Inter and intra-chromosomal rearrangements were identified in the four samples, allowing in particular characterization of unbalanced translocations at high resolution. Using complementary experiments, we further characterized 51 rearrangements at the base pair resolution that revealed 59 DNA junctions. In a subset of cases, complex rearrangements were observed with templated insertion of fragments of nearby sequences. Although we did not identify known particular motifs in the local environment of the breakpoints, we documented frequent microhomologies at the junctions in both chromothripsis and non-chromothripsis associated breakpoints. RNA-seq experiments confirmed expression of several predicted chimeric genes and genes with disrupted exon structure including ALK, NBAS, FHIT, PTPRD and ODZ4. Our study therefore indicates that both non-homologous end joining-mediated repair and replicative processes may account for genomic rearrangements in neuroblastoma. RNA-seq analysis allows the identification of the subset of abnormal transcripts expressed from genomic rearrangements that may be involved in neuroblastoma oncogenesis.

  15. T cells targeting NY-ESO-1 demonstrate efficacy against disseminated neuroblastoma

    PubMed Central

    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.

    2016-01-01

    abstract 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. PMID:26942053

  16. Targeting the mTOR Complex by Everolimus in NRAS Mutant Neuroblastoma

    PubMed Central

    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. PMID:26821351

  17. 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

  18. Mutation-Independent Activation of the Anaplastic Lymphoma Kinase in Neuroblastoma.

    PubMed

    Regairaz, Marie; Munier, Fabienne; Sartelet, Hervé; Castaing, Marine; Marty, Virginie; Renauleaud, Céline; Doux, Camille; Delbé, Jean; Courty, José; Fabre, Monique; Ohta, Shigeru; Viehl, Philippe; Michiels, Stefan; Valteau-Couanet, Dominique; Vassal, Gilles

    2016-02-01

    Activating mutations of anaplastic lymphoma kinase (ALK) have been identified as important players in neuroblastoma development. Our goal was to evaluate the significance of overall ALK activation in neuroblastoma. Expression of phosphorylated ALK, ALK, and its putative ligands, pleiotrophin and midkine, was screened in 289 neuroblastomas and 56 paired normal tissues. ALK was expressed in 99% of tumors and phosphorylated in 48% of cases. Pleiotrophin and midkine were expressed in 58% and 79% of tumors, respectively. ALK activation was significantly higher in tumors than in paired normal tissues, together with ALK and midkine expression. ALK activation was largely independent of mutations and correlated with midkine expression in tumors. ALK activation in tumors was associated with favorable features, including a younger age at diagnosis, hyperdiploidy, and detection by mass screening. Antitumor activity of the ALK inhibitor TAE684 was evaluated in wild-type or mutated ALK neuroblastoma cell lines and xenografts. TAE684 was cytotoxic in vitro in all cell lines, especially those harboring an ALK mutation. TAE684 efficiently inhibited ALK phosphorylation in vivo in both F1174I and R1275Q xenografts but demonstrated antitumor activity only against the R1275Q xenograft. In conclusion, ALK activation occurs frequently during neuroblastoma oncogenesis, mainly through mutation-independent mechanisms. However, ALK activation is not associated with a poor outcome and is not always a driver of cell proliferation and/or survival in neuroblastoma. PMID:26687816

  19. Preclinical Evaluation of a Novel RXR Agonist for the Treatment of Neuroblastoma.

    PubMed

    Waters, Alicia M; Stewart, Jerry E; Atigadda, Venkatram R; Mroczek-Musulman, Elizabeth; Muccio, Donald D; Grubbs, Clinton J; Beierle, Elizabeth A

    2015-07-01

    Neuroblastoma remains a common cause of pediatric cancer deaths, especially for children who present with advanced stage or recurrent disease. Currently, retinoic acid therapy is used as maintenance treatment to induce differentiation and reduce tumor recurrence following induction therapy for neuroblastoma, but unavoidable side effects are seen. A novel retinoid, UAB30, has been shown to generate negligible toxicities. In the current study, we hypothesized that UAB30 would have a significant impact on multiple neuroblastoma cell lines in vitro and in vivo. Cellular survival, cell-cycle analysis, migration, and invasion were studied using AlamarBlue assays, FACS, and Transwell assays, respectively, in multiple cell lines following treatment with UAB30. In addition, an in vivo murine model of human neuroblastoma was utilized to study the effects of UAB30 upon tumor xenograft growth and animal survival. We successfully demonstrated decreased cellular survival, invasion, and migration, cell-cycle arrest, and increased apoptosis after treatment with UAB30. Furthermore, inhibition of tumor growth and increased survival was observed in a murine neuroblastoma xenograft model. The results of these in vitro and in vivo studies suggest a potential therapeutic role for the low toxicity synthetic retinoid X receptor selective agonist, UAB30, in neuroblastoma treatment.

  20. Human neuroblastoma (SH-SY5Y) cells are highly sensitive to the lysosomotropic aldehyde 3-aminopropanal.

    PubMed

    Yu, Zhengquan; Li, Wei; Hillman, Jan; Brunk, Ulf T

    2004-08-01

    3-Aminopropanal (3-AP), a degradation product of polyamines such as spermine, spermidine and putrescine, is a lysosomotropic small aldehyde that causes apoptosis or necrosis of most cells in culture, apparently by inducing moderate or extensive lysosomal rupture, respectively, and secondary mitochondrial changes. Here, using the human neuroblastoma SH-SY5Y cell line, we found simultaneous occurrence of apoptotic and necrotic cell death when cultures were exposed to 3-AP in concentrations that usually are either nontoxic, or only cause apoptosis. At 30 mM, but not at 10 mM, the lysosomotropic base and proton acceptor NH3 completely blocked the toxic effect of 3-AP, proving that 3-AP is lysosomotropic and suggesting that the lysosomal membrane proton pump of neuroblastoma cells is highly effective, creating a lower than normal lysosomal pH and, thus, extensive intralysosomal accumulation of lysosomotropic drugs. A wave of internal oxidative stress, secondary to changes in mitochondrial membrane potential, followed and gave rise to further lysosomal rupture. The preincubation of cells for 24 h with a chain-breaking free radical-scavenger, alpha-tocopherol, before exposure to 3-AP, significantly delayed both the wave of oxidative stress and the secondary lysosomal rupture, while it did not interfere with the early 3-AP-mediated phase of lysosomal break. Obviously, the reported oxidative stress and apoptosis/necrosis are consequences of lysosomal rupture with ensuing release of lysosomal enzymes resulting in direct/indirect effects on mitochondrial permeability, membrane potential, and electron transport. The induced oxidative stress seems to act as an amplifying loop causing further lysosomal break that can be partially prevented by alpha-tocopherol. Perhaps secondary brain damage during a critical post injury period can be prevented by the use of drugs that temporarily raise lysosomal pH, inactivate intralysosomal 3-AP, or stabilize lysosomal membranes against

  1. Radiofrequency currents exert cytotoxic effects in NB69 human neuroblastoma cells but not in peripheral blood mononuclear cells

    PubMed Central

    HERNÁNDEZ-BULE, MARÍA LUISA; ROLDÁN, ERNESTO; MATILLA, JOAQUÍN; TRILLO, MARÍA ÁNGELES; ÚBEDA, ALEJANDRO

    2012-01-01

    Recently, a number of electric and electrothermal therapies have been applied to the treatment of specific cancer types. However, the cellular and molecular mechanisms involved in the response to such therapies have not been well characterized yet. Capacitive-resistive electric transfer (CRET) therapy uses electric currents at frequencies within the 0.45–0.6 MHz range to induce hyperthermia in target tissues. Preliminary trials in cancer patients have shown consistent signs that CRET could slow down growth of tumor tissues in brain gliomas, without inducing detectable damage in the surrounding healthy tissue. Previous studies by our group have shown that subthermal treatment with 0.57-MHz electric currents can induce a cytostatic, not cytotoxic response in HepG2 human hepatocarcinoma cells; such effect being mediated by cell cycle alterations. In contrast, the study of the response of NB69 human neuroblastoma cells to the same electric treatment revealed consistent indications of cytotoxic effects. The present study extends the knowledge on the response of NB69 cells to the subthermal stimulus, comparing it to that of primary cultures of human peripheral blood mononuclear cells (PBMC) exposed to the same treatment. The results showed no sensitivity of PBMC to the 0.57 MHz subthermal currents and confirmed that the treatment exerts a cytotoxic action in NB69 cells. The data also revealed a previously undetected cytostatic response of the neuroblastoma cell line. CRET currents affected NB69 cell proliferation by significantly reducing the fraction of cells in the phase G2/M of the cell cycle at 12 h of exposure. These data provide new information on the mechanisms of response to CRET therapy, and are consistent with a cytotoxic and/or cytostatic action of the electric treatment, which would affect human cells of tumor origin but not normal cells with a low proliferation rate. PMID:22843038

  2. Aluminum Activates PERK-EIF2α Signaling and Inflammatory Proteins in Human Neuroblastoma SH-SY5Y Cells.

    PubMed

    Rizvi, Syed Husain Mustafa; Parveen, Arshiya; Ahmad, Israr; Ahmad, Iqbal; Verma, Anoop K; Arshad, Md; Mahdi, Abbas Ali

    2016-07-01

    Aluminum is the third most abundant element present in the earth's crust and human exposure to it is possible due to industrialization, utensils, medicines, antiperspirants, etc. Evidences suggest involvement of aluminum in a variety of neurodegenerative disorders including Alzheimer's disease. Endoplasmic reticulum (ER) stress has been implicated in various neurological disorders. ER stress may be a result of impaired calcium homeostasis due to perturbed redox balance and is known to elicit inflammation through the activation of unfolded protein response (UPR). In the present study, we aimed to investigate the role of aluminum in ER stress-mediated activation of inflammatory responses in neuroblastoma cells. Lactate dehydrogenase (LDH) release assay revealed that aluminum compromised the membrane integrity of neuroblastoma cells, probably due to membrane damage, as indicated by enhanced levels of lipid peroxidation (LPO). Besides this, our results clearly demonstrated elevated reactive oxygen species (ROS) levels and a weakened antioxidant defence system manifested by decrease in catalase (CAT) activity and cellular glutathione (GSH). Moreover, we studied the expression of key apoptosis-related proteins, ER stress-mediated activation of UPR, and its downstream inflammatory pathway. It was observed that aluminum potentially enhanced protein levels of PERK, EIF2α, caspase 9, caspase 3, and inflammatory markers like NF-κB, NLRP3, HMGB1, and nitric oxide (NO). Furthermore, aluminum altered TNFα, IL1β, IL6, and IL10 mRNA levels as well. The overall findings indicated that aluminum mediates UPR activation through ER stress, which results in induction of inflammatory pathway and apoptotic proteins in neuronal cells. PMID:26546554

  3. DCA promotes progression of neuroblastoma tumors in nude mice.

    PubMed

    Feuerecker, Benedikt; Seidl, Christof; Pirsig, Sabine; Bruchelt, Gernot; Senekowitsch-Schmidtke, Reingard

    2015-01-01

    Even in the presence of oxygen most cancer cells convert glucose to lactate via pyruvate instead of performing oxidative phosphorylation (aerobic glycolysis-Warburg effect). Thus, it has been considered to shift pyruvate - the metabolite of aerobic glycolysis - to acetylCoA by activation of pyruvate dehydrogenase (PDH). AcetylCoA will then be metabolized by oxidative phosphorylation. Therefore, the purpose of this study was to shift tumor cells from aerobic glycolysis to oxidative phosphorylation using dichloroacetate (DCA), an inhibitor of PDH-kinase. The effects of DCA were assayed in vitro in Neuro-2a (murine neuroblastoma), Kelly and SK-N-SH (human neuroblastoma) as well as SkBr3 (human breast carcinoma) cell lines. The effects of DCA on tumor development were investigated in vivo using NMRI nu/nu mice bearing subcutaneous Neuro-2a xenografts. For that purpose animals were treated continuously with DCA in the drinking water. Tumor volumes were monitored using caliper measurements and via [18F]-FDG-positron emission tomography. DCA treatment increased viability/proliferation in Neuro-2a and SkBr3 cells, but did not cause significant alterations of PDH activity. However, no significant effects of DCA could be observed in Kelly and SK-N-SH cells. Accordingly, in mice bearing Neuro-2a xenografts, DCA significantly increased tumor proliferation compared to mock-treated mice. Thus, we could demonstrate that DCA - an indicated inhibitor of tumor growth - efficiently promotes tumor growth in Neuro-2a cells in vitro and in vivo. PMID:25973318

  4. Advances in chimeric antigen receptor immunotherapy for neuroblastoma.

    PubMed

    Heczey, Andras; Louis, Chrystal U

    2013-12-01

    Neuroblastoma (NBL) is the most common extracranial pediatric solid tumor and has heterogeneous biology and behavior. Patients with high-risk disease have poor prognosis despite complex multimodal therapy; therefore, novel curative approaches are needed. Immunotherapy is a novel therapeutic approach that harnesses the inherent activity of the immune system to control and eliminate malignant cells. One form of immunotherapy uses chimeric antigen receptors (CAR) to target tumor-associated antigens. CARs are derived from the antigen-binding domain of a monoclonal antibody (MAb) coupled with the intracellular signaling portion of the T cell receptor. CARs can combine the specificity and effectiveness of MAbs with the active bio-distribution, direct cytotoxicity, and long-term persistence of T cells. NBL provides an attractive target for CAR immunotherapy as many of its tumor-associated antigens are not expressed at significant levels on normal tissues, thus decreasing potential treatment related toxicity. Two previous clinical trials utilizing L1-cell adhesion molecule (L1-CAM) and disialoganglioside (GD2) specific CARs (GD2-CAR) have demonstrated safety and anti-tumor efficacy in heavily pretreated relapsed/refractory neuroblastoma patients. Based on these promising results and on improved techniques that can further potentiate CAR therapies, two clinical trials are currently investigating the use of GD2-CARs in children with NBL. Several approaches may further enhance anti-tumor activity and persistence of CAR modified cells, and if these can be safely translated into the clinic, CAR-based immunotherapy could become a viable adjunct or potential alternative to conventional treatment options for patients with NBL.

  5. Contemporary approach to diagnosis and treatment of neuroblastoma.

    PubMed

    Charron, M

    2013-03-01

    The diagnostic value of Metaiodobenzylguanidine (MIBG) scintigraphy in the management of neuroblastoma is well established. The specificity of MIBG is virtually 100% and remains the most specific imaging modality. Numerous semi-quantitative scores and guidelines have emerged in the last decade that illustrate standardization of the procedure. Other pharmaceuticals such as norcholesterol derivatives, [111In]pentetreotide and [68Ga]somatostatin analogs, [18F]fluorodeoxyglucose, [18F]fluorodopa, [18F]fluorodopamine, [11C]meta hydroxyephedrine, and [11C] /[18F] /[123I]Metomidate (MTO) have been or are being evaluated currently (including development of new analogues labeled with positron emitting radionuclides such as [124I], [18F], and [76Br]. Radiopharmaceutical therapy of neuroblastoma, initiated over 30 years ago, demonstrates that a significant fraction of patients enter partial remission but complete remission is rare and relapse is frequent. With the combination of chemotherapy, radiosensitizers, and autologous stem cell support, some centers have seen overall response rates of up to 30% in refractory or recurrent diseases. Topoisomerase I inhibitor topotecan may improve upon existing [131I]MIBG therapy. Areas of future development may be in vitro cultures and animal models, proper instrumentation to acquire sub-centimeter resolution and human clinical trials to evaluate treatment at earlier times or stages of disease, evaluation with concomitant immunotherapy with monoclonal antibodies targeting the GD2 ganglioside or inhibitors of anaplastic lymphoma kinase. Because of the complexity of those trials, progress remains extremely slow as well designed multicenter studies are required. Nonetheless, the future has never been so hopeful.

  6. MYCN repression of Lifeguard/FAIM2 enhances neuroblastoma aggressiveness

    PubMed Central

    Planells-Ferrer, L; Urresti, J; Soriano, A; Reix, S; Murphy, D M; Ferreres, J C; Borràs, F; Gallego, S; Stallings, R L; Moubarak, R S; Segura, M F; Comella, J X

    2014-01-01

    Neuroblastoma (NBL) is the most common solid tumor in infants and accounts for 15% of all pediatric cancer deaths. Several risk factors predict NBL outcome: age at the time of diagnosis, stage, chromosome alterations and MYCN (V-Myc Avian Myelocytomatosis Viral Oncogene Neuroblastoma-Derived Homolog) amplification, which characterizes the subset of the most aggressive NBLs with an overall survival below 30%. MYCN-amplified tumors develop exceptional chemoresistance and metastatic capacity. These properties have been linked to defects in the apoptotic machinery, either by silencing components of the extrinsic apoptotic pathway (e.g. caspase-8) or by overexpression of antiapoptotic regulators (e.g. Bcl-2, Mcl-1 or FLIP). Very little is known on the implication of death receptors and their antagonists in NBL. In this work, the expression levels of several death receptor antagonists were analyzed in multiple human NBL data sets. We report that Lifeguard (LFG/FAIM2 (Fas apoptosis inhibitory molecule 2)/NMP35) is downregulated in the most aggressive and undifferentiated tumors. Intringuingly, although LFG has been initially characterized as an antiapoptotic protein, we have found a new association with NBL differentiation. Moreover, LFG repression resulted in reduced cell adhesion, increased sphere growth and enhanced migration, thus conferring a higher metastatic capacity to NBL cells. Furthermore, LFG expression was found to be directly repressed by MYCN at the transcriptional level. Our data, which support a new functional role for a hitherto undiscovered MYCN target, provide a new link between MYCN overexpression and increased NBL metastatic properties. PMID:25188511

  7. Advances in Chimeric Antigen Receptor Immunotherapy for Neuroblastoma

    PubMed Central

    Heczey, Andras; Louis, Chrystal U.

    2014-01-01

    Neuroblastoma (NBL) is the most common extracranial pediatric solid tumor and has heterogeneous biology and behavior. Patients with high-risk disease have poor prognosis despite complex multimodal therapy; therefore, novel curative approaches are needed. Immunotherapy is a novel therapeutic approach that harnesses the inherent activity of the immune system to control and eliminate malignant cells. One form of immunotherapy uses chimeric antigen receptors (CAR) to target tumor-associated antigens. CARs are derived from the antigen-binding domain of a monoclonal antibody (MAb) coupled with the intracellular signaling portion of the T cell receptor. CARs can combine the specificity and effectiveness of MAbs with the active bio-distribution, direct cytotoxicity, and long-term persistence of T cells. NBL provides an attractive target for CAR immunotherapy as many of its tumor-associated antigens are not expressed at significant levels on normal tissues, thus decreasing potential treatment related toxicity. Two previous clinical trials utilizing L1-cell adhesion molecule (L1-CAM) and disialoganglioside (GD2) specific CARs (GD2-CAR) have demonstrated safety and anti-tumor efficacy in heavily pretreated relapsed/refractory neuroblastoma patients. Based on these promising results and on improved techniques that can further potentiate CAR therapies, two clinical trials are currently investigating the use of GD2-CARs in children with NBL. Several approaches may further enhance anti-tumor activity and persistence of CAR modified cells, and if these can be safely translated into the clinic, CAR-based immunotherapy could become a viable adjunct or potential alternative to conventional treatment options for patients with NBL. PMID:24333408

  8. Folding Landscape of Mutant Huntingtin Exon1: Diffusible Multimers, Oligomers and Fibrils, and No Detectable Monomer.

    PubMed

    Sahoo, Bankanidhi; Arduini, Irene; Drombosky, Kenneth W; Kodali, Ravindra; Sanders, Laurie H; Greenamyre, J Timothy; Wetzel, Ronald

    2016-01-01

    Expansion of the polyglutamine (polyQ) track of the Huntingtin (HTT) protein above 36 is associated with a sharply enhanced risk of Huntington's disease (HD). Although there is general agreement that HTT toxicity resides primarily in N-terminal fragments such as the HTT exon1 protein, there is no consensus on the nature of the physical states of HTT exon1 that are induced by polyQ expansion, nor on which of these states might be responsible for toxicity. One hypothesis is that polyQ expansion induces an alternative, toxic conformation in the HTT exon1 monomer. Alternative hypotheses posit that the toxic species is one of several possible aggregated states. Defining the nature of the toxic species is particularly challenging because of facile interconversion between physical states as well as challenges to identifying these states, especially in vivo. Here we describe the use of fluorescence correlation spectroscopy (FCS) to characterize the detailed time and repeat length dependent self-association of HTT exon1-like fragments both with chemically synthesized peptides in vitro and with cell-produced proteins in extracts and in living cells. We find that, in vitro, mutant HTT exon1 peptides engage in polyQ repeat length dependent dimer and tetramer formation, followed by time dependent formation of diffusible spherical and fibrillar oligomers and finally by larger, sedimentable amyloid fibrils. For expanded polyQ HTT exon1 expressed in PC12 cells, monomers are absent, with tetramers being the smallest molecular form detected, followed in the incubation time course by small, diffusible aggregates at 6-9 hours and larger, sedimentable aggregates that begin to build up at 12 hrs. In these cell cultures, significant nuclear DNA damage appears by 6 hours, followed at later times by caspase 3 induction, mitochondrial dysfunction, and cell death. Our data thus defines limits on the sizes and concentrations of different physical states of HTT exon1 along the reaction profile

  9. Folding Landscape of Mutant Huntingtin Exon1: Diffusible Multimers, Oligomers and Fibrils, and No Detectable Monomer

    PubMed Central

    Sahoo, Bankanidhi; Arduini, Irene; Drombosky, Kenneth W.; Kodali, Ravindra; Sanders, Laurie H.; Greenamyre, J. Timothy; Wetzel, Ronald

    2016-01-01

    Expansion of the polyglutamine (polyQ) track of the Huntingtin (HTT) protein above 36 is associated with a sharply enhanced risk of Huntington’s disease (HD). Although there is general agreement that HTT toxicity resides primarily in N-terminal fragments such as the HTT exon1 protein, there is no consensus on the nature of the physical states of HTT exon1 that are induced by polyQ expansion, nor on which of these states might be responsible for toxicity. One hypothesis is that polyQ expansion induces an alternative, toxic conformation in the HTT exon1 monomer. Alternative hypotheses posit that the toxic species is one of several possible aggregated states. Defining the nature of the toxic species is particularly challenging because of facile interconversion between physical states as well as challenges to identifying these states, especially in vivo. Here we describe the use of fluorescence correlation spectroscopy (FCS) to characterize the detailed time and repeat length dependent self-association of HTT exon1-like fragments both with chemically synthesized peptides in vitro and with cell-produced proteins in extracts and in living cells. We find that, in vitro, mutant HTT exon1 peptides engage in polyQ repeat length dependent dimer and tetramer formation, followed by time dependent formation of diffusible spherical and fibrillar oligomers and finally by larger, sedimentable amyloid fibrils. For expanded polyQ HTT exon1 expressed in PC12 cells, monomers are absent, with tetramers being the smallest molecular form detected, followed in the incubation time course by small, diffusible aggregates at 6–9 hours and larger, sedimentable aggregates that begin to build up at 12 hrs. In these cell cultures, significant nuclear DNA damage appears by 6 hours, followed at later times by caspase 3 induction, mitochondrial dysfunction, and cell death. Our data thus defines limits on the sizes and concentrations of different physical states of HTT exon1 along the reaction

  10. 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.

  11. Insolubility of disrupted-in-schizophrenia 1 disrupts oligomer-dependent interactions with nuclear distribution element 1 and is associated with sporadic mental disease.

    PubMed

    Leliveld, S Rutger; Bader, Verian; Hendriks, Philipp; Prikulis, Ingrid; Sajnani, Gustavo; Requena, Jesús R; Korth, Carsten

    2008-04-01

    Disrupted-in-schizophrenia 1 (DISC1) and other genes have been identified recently as potential molecular players in chronic psychiatric diseases such as affective disorders and schizophrenia. A molecular mechanism of how these genes may be linked to the majority of sporadic cases of these diseases remains unclear. The chronic nature and irreversibility of clinical symptoms in a subgroup of these diseases prompted us to investigate whether proteins corresponding to candidate genes displayed subtle features of protein aggregation. Here, we show that in postmortem brain samples of a distinct group of patients with phenotypes of affective disorders or schizophrenia, but not healthy controls, significant fractions of DISC1 could be identified as cold Sarkosyl-insoluble protein aggregates. A loss-of-function phenotype could be demonstrated for insoluble DISC1 through abolished binding to a key DISC1 ligand, nuclear distribution element 1 (NDEL1): in human neuroblastoma cells, DISC1 formed expression-dependent, detergent-resistant aggregates that failed to interact with endogenous NDEL1. Recombinant (r) NDEL1 expressed in Escherichia coli selectively bound an octamer of an rDISC1 fragment but not dimers or high molecular weight multimers, suggesting an oligomerization optimum for molecular interactions of DISC1 with NDEL1. For DISC1-related sporadic psychiatric disease, we propose a mechanism whereby impaired cellular control over self-association of DISC1 leads to excessive multimerization and subsequent formation of detergent-resistant aggregates, culminating in loss of ligand binding, here exemplified by NDEL1. We conclude that the absence of oligomer-dependent ligand interactions of DISC1 can be associated with sporadic mental disease of mixed phenotypes.

  12. 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.

  13. Protection of mice against syngeneic C1300 neuroblastoma challenge by immunization with membranes of C1300 neuroblastoma cells.

    PubMed

    Lauro, G; Businaro, R; Butler, R H; Revoltella, R

    1980-05-01

    Male A/J mice 2-3 months old were inoculated sc with membranes from syngeneic C1300 neuroblastoma cells (clone NB6R) in complete Freund's adjuvant. Significant immunoprophylaxis was noted in the sensitized mice upon sc challenge with viable NB6R cells. During the experiment (60 days from viable cell challenge), each control mouse developed a palpable tumor and died within 50 days. Complete protection was obtained with a program of 4 inoculations of NB6R cell membranes. Each mouse given only 1 inoculation of NB6R cell membranes developed a palpable tumor, but afer 60 days only 1 mouse in 7 had died, which indicated a significant degree of protection. With in vitro tests of lymphocyte proliferation, rosette formation, and complement fixation, it was shown that these mice had mounted both cellular and humoral immune response against the tumor cells.

  14. Solvent Free Low-Melt Viscosity Imide Oligomers And Thermosetting Polyimide Composites

    NASA Technical Reports Server (NTRS)

    Chuang, CHun-Hua (Inventor)

    2006-01-01

    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" C. When the imide oligomer melt is cured at about 371 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 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 C. (450-535 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 288-343C (550-650 F) high temperature performance capability.

  15. Effect of pathogenic mutations on the structure and dynamics of Alzheimer's A beta 42-amyloid oligomers.

    PubMed

    Kassler, Kristin; Horn, Anselm H C; Sticht, Heinrich

    2010-05-01

    Converging lines of evidence suggest that soluble A beta-amyloid oligomers play a pivotal role in the pathogenesis of Alzheimer's disease, and present direct effectors of synaptic and cognitive dysfunction. Three pathological E22-A beta-amyloid point mutants (E22G, E22K, E22Q) and the deletion mutant E22 Delta exhibit an enhanced tendency to form prefibrillar aggregates. The present study assessed the effect of these four mutations using molecular dynamics simulations and subsequent structural and energetic analyses. Our data shows that E22 plays a unique role in wild type A beta, since it has a destabilising effect on the oligomer structure due to electrostatic repulsion between adjacent E22 side chains. Mutations in which E22 is replaced by an uncharged residue result in higher oligomer stability. This effect is also observed to a lesser extent for the E22K mutation and is consistent with its lower pathogenicity compared to other mutants. Interestingly, deletion of E22 does not destroy the amyloid fold but is compensated by local changes in the backbone geometry that allow the preservation of a structurally important salt bridge. The finding that all mutant oligomers investigated exhibit higher internal stability than the wild type offers an explanation for the experimentally observed enhanced oligomer formation and stability.

  16. Collagen oligomers modulate physical and biological properties of three-dimensional self-assembled matrices.

    PubMed

    Bailey, J L; Critser, P J; Whittington, C; Kuske, J L; Yoder, M C; Voytik-Harbin, S L

    2011-02-01

    Elucidation of mechanisms underlying collagen fibril assembly and matrix-induced guidance of cell fate will contribute to the design and expanded use of this biopolymer for research and clinical applications. Here, we define how Type I collagen oligomers affect in-vitro polymerization kinetics as well as fibril microstructure and mechanical properties of formed matrices. Monomers and oligomers were fractionated from acid-solubilized pig skin collagen and used to generate formulations varying in monomer/oligomer content or average polymer molecular weight (AMW). Polymerization half-times decreased with increasing collagen AMW and closely paralleled lag times, indicating that oligomers effectively served as nucleation sites. Furthermore, increasing AMW yielded matrices with increased interfibril branching and had no correlative effect on fibril density or diameter. These microstructure changes increased the stiffness of matrices as evidenced by increases in both shear storage and compressive moduli. Finally, the biological relevance of modulating collagen AMW was evidenced by the ability of cultured endothelial colony forming cells to sense associated changes in matrix physical properties and alter vacuole and capillary-like network formation. This work documents the importance of oligomers as another physiologically-relevant design parameter for development and standardization of polymerizable collagen formulations to be used for cell culture, regenerative medicine, and engineered tissue applications. PMID:20740490

  17. Parametrization of the Gay-Berne potential for conjugated oligomer with a high aspect ratio

    NASA Astrophysics Data System (ADS)

    Lee, Cheng K.; Hua, Chi C.; Chen, Show A.

    2010-08-01

    The Gay-Berne (GB) potential has been a popular semiempirical model for describing the short-range intermolecular forces for a wide variety of aspherical molecules, including liquid crystals and anisotropic colloids, with generally small molecular dimensions and low aspect ratios (<5). This study evaluates the parametrization of the GB potential for a high-aspect-ratio (=10) oligomer belonging to a model conjugated polymer. We elaborate that the semiflexibility associated with a large oligomer species demands a variant umbrella-sampling scheme in establishing the potentials of mean force (PMFs) for four pair ellipsoid arrangements typically utilized to parametrize the GB potential. The model ellipsoid so constructed is shown to capture the PMFs of essential intermediate arrangements as well, and, according to the results of simplex optimizations, recommendations are given for the minimum set of parameters to be included in the optimization of a large oligomer or particulate species. To further attest the parametrized GB potential, the coarse-grained (CG) Monte Carlo simulations employing the GB potential and the back-mapped, full-atom atomistic molecular dynamics (AMD) simulations were performed for a dense oligomer system at two representative system temperatures. The results indicated that the CG simulations can capture, with exceptional computational efficiency, the AMD predictions with good thermal transferability. In future perspectives, we remark on potential applications to construct efficient, parameter-free CG models for capturing fundamental material properties of large oligomer/particulate species as well as long-chain conjugated polymers.

  18. Methods for the Specific Detection and Quantitation of Amyloid-β Oligomers in Cerebrospinal Fluid.

    PubMed

    Schuster, Judith; Funke, Susanne Aileen

    2016-05-01

    Protein misfolding and aggregation are fundamental features of the majority of neurodegenerative diseases, like Alzheimer's disease (AD), Parkinson's disease, frontotemporal dementia, and prion diseases. Proteinaceous deposits in the brain of the patient, e.g., amyloid plaques consisting of the amyloid-β (Aβ) peptide and tangles composed of tau protein, are the hallmarks of AD. Soluble oligomers of Aβ and tau play a fundamental role in disease progression, and specific detection and quantification of the respective oligomeric proteins in cerebrospinal fluid may provide presymptomatically detectable biomarkers, paving the way for early diagnosis or even prognosis. Several studies on the development of techniques for the specific detection of Aβ oligomers were published, but some of the existing tools do not yet seem to be satisfactory, and the study results are contradicting. The detection of oligomers is challenging due to their polymorphous and unstable nature, their low concentration, and the presence of competing proteins and Aβ monomers in body fluids. Here, we present an overview of the current state of the development of methods for Aβ oligomer specific detection and quantitation. The methods are divided in the three subgroups: (i) enzyme linked immunosorbent assays (ELISA), (ii) methods for single oligomer detection, and (iii) others, which are mainly biosensor based methods. PMID:27163804

  19. Mitochondrial Ca2+ Overload Underlies Aβ Oligomers Neurotoxicity Providing an Unexpected Mechanism of Neuroprotection by NSAIDs

    PubMed Central

    Sanz-Blasco, Sara; Valero, Ruth A.; Rodríguez-Crespo, Ignacio; Villalobos, Carlos; Núñez, Lucía

    2008-01-01

    Dysregulation of intracellular Ca2+ homeostasis may underlie amyloid β peptide (Aβ) toxicity in Alzheimer's Disease (AD) but the mechanism is unknown. In search for this mechanism we found that Aβ1–42 oligomers, the assembly state correlating best with cognitive decline in AD, but not Aβ fibrils, induce a massive entry of Ca2+ in neurons and promote mitochondrial Ca2+ overload as shown by bioluminescence imaging of targeted aequorin in individual neurons. Aβ oligomers induce also mitochondrial permeability transition, cytochrome c release, apoptosis and cell death. Mitochondrial depolarization prevents mitochondrial Ca2+ overload, cytochrome c release and cell death. In addition, we found that a series of non-steroidal anti-inflammatory drugs (NSAIDs) including salicylate, sulindac sulfide, indomethacin, ibuprofen and R-flurbiprofen depolarize mitochondria and inhibit mitochondrial Ca2+ overload, cytochrome c release and cell death induced by Aβ oligomers. Our results indicate that i) mitochondrial Ca2+ overload underlies the neurotoxicity induced by Aβ oligomers and ii) inhibition of mitochondrial Ca2+ overload provides a novel mechanism of neuroprotection by NSAIDs against Aβ oligomers and AD. PMID:18648507

  20. Nature of the Amyloid-β Monomer and the Monomer-Oligomer Equilibrium

    PubMed Central

    Nag, Suman; Sarkar, Bidyut; Bandyopadhyay, Arkarup; Sahoo, Bankanidhi; Sreenivasan, Varun K. A.; Kombrabail, Mamata; Muralidharan, Chandrakesan; Maiti, Sudipta

    2011-01-01

    The monomer to oligomer transition initiates the aggregation and pathogenic transformation of Alzheimer amyloid-β (Aβ) peptide. However, the monomeric state of this aggregation-prone peptide has remained beyond the reach of most experimental techniques, and a quantitative understanding of this transition is yet to emerge. Here, we employ single-molecule level fluorescence tools to characterize the monomeric state and the monomer-oligomer transition at physiological concentrations in buffers mimicking the cerebrospinal fluid (CSF). Our measurements show that the monomer has a hydrodynamic radius of 0.9 ± 0.1 nm, which confirms the prediction made by some of the in silico studies. Surprisingly, at equilibrium, both Aβ40 and Aβ42 remain predominantly monomeric up to 3 μm, above which it forms large aggregates. This concentration is much higher than the estimated concentrations in the CSF of either normal or diseased brains. If Aβ oligomers are present in the CSF and are the key agents in Alzheimer pathology, as is generally believed, then these must be released in the CSF as preformed entities. Although the oligomers are thermodynamically unstable, we find that a large kinetic barrier, which is mostly entropic in origin, strongly impedes their dissociation. Thermodynamic principles therefore allow the development of a pharmacological agent that can catalytically convert metastable oligomers into nontoxic monomers. PMID:21349839

  1. Chain-length and mode-delocalization dependent amide-I anharmonicity in peptide oligomers

    NASA Astrophysics Data System (ADS)

    Zhao, Juan; Wang, Jianping

    2012-06-01

    The diagonal anharmonicities of the amide-I mode in the alanine oligomers are examined in the normal-mode basis by ab initio calculations. The selected oligomers range from dimer to heptamer, in either the α-helical or β-sheet conformations. It is found that the anharmonicity varies from mode to mode within the same oligomer. For a given amide-I mode, the anharmonicity is closely related to the delocalization extent of the mode: the less it delocalizes, the larger the anharmonicity it has. Thus, the single-mode potential energy distribution (PEDmax) can be used as an indicator of the magnitude of the anharmonicity. It is found that as the peptide chain length increases, the averaged diagonal anharmonicity generally decreases; however, the sum of the averaged diagonal and off-diagonal anharmonicities within a peptide roughly remains a constant for all the oligomers examined, indicating the excitonic characteristics of the amide-I modes. Excitonic coupling tends to decrease the diagonal anharmonicities in a coupled system with multiple chromophores, which explains the observed behavior of the anharmonicities. The excitonic nature of the amide-I band in peptide oligomers is thus verified by the anharmonic computations. Isotopic substitution effect on the anharmonicities and mode localizations of the amide-I modes in peptides is also discussed.

  2. Amyloid Oligomers and Mature Fibrils Prepared from an Innocuous Protein Cause Diverging Cellular Death Mechanisms.

    PubMed

    Harte, Níal P; Klyubin, Igor; McCarthy, Eoin K; Min, Soyoung; Garrahy, Sarah Ann; Xie, Yongjing; Davey, Gavin P; Boland, John J; Rowan, Michael J; Mok, K Hun

    2015-11-20

    Despite significant advances, the molecular identity of the cytotoxic species populated during in vivo amyloid formation crucial for the understanding of neurodegenerative disorders is yet to be revealed. In this study lysozyme prefibrillar oligomers and fibrils in both mature and sonicated states have been isolated through an optimized ultrafiltration/ultracentrifugation method and characterized with various optical spectroscopic techniques, atomic force microscopy, and transmission electron microscopy. We examined their level and mode of toxicity on rat pheochromocytoma (PC12) cells in both differentiated and undifferentiated states. We find that oligomers and fibrils display cytotoxic capabilities toward cultured cells in vitro, with oligomers producing elevated levels of cellular injury toward undifferentiated PC12 cells (PC12(undiff)). Furthermore, dual flow cytometry staining experiments demonstrate that the oligomers and mature fibrils induce divergent cellular death pathways (apoptosis and secondary necrosis, respectively) in these PC12 cells. We have also shown that oligomers but not sonicated mature fibrils inhibit hippocampal long term potentiation, a form of synaptic plasticity implicated in learning and memory, in vivo. We conclude that our in vitro and in vivo findings confer a level of resistance toward amyloid fibrils, and that the PC 12-based comparative cytotoxicity assay can provide insights into toxicity differences between differently aggregated protein species.

  3. Nitrogen Containing Organic Compounds and Oligomers in Secondary Organic Aerosol Formed by Photooxidation of Isoprene

    SciTech Connect

    Nguyen, Tran B.; Laskin, Julia; Laskin, Alexander; Nizkorodov, Serguei

    2011-07-06

    Electrospray ionization high-resolution mass spectrometry (ESI HR-MS) was used to probe molecular structures of oligomers in secondary organic aerosol (SOA) generated in laboratory experiments on isoprene photooxidation at low- and high-NOx conditions. Up to 80-90% of the observed products are oligomers and up to 33% are nitrogen-containing organic compounds (NOC). We observe oligomers with up to 8 monomer units in length. Tandem mass spectrometry (MSn) confirms NOC compounds are organic nitrates and elucidates plausible chemical building blocks contributing to oligomer formation. Most organic nitrates are comprised of methylglyceric acid units. Other important multifunctional C2-C5 monomer units are identified including methylglyoxal, hydroxyacetone, hydroxyacetic acid, glycolaldehyde, and 2-methyltetrols. The majority of the NOC oligomers contain only one nitrate moiety resulting in a low average N:C ratio of 0.019. Average O:C ratios of the detected SOA compounds are 0.54 under the low-NOx conditions and 0.83 under the high-NOx conditions. Our results underscore the importance of isoprene photooxidation as a source of NOC in organic particulate matter.

  4. Structural polymorphism of amyloid oligomers and fibrils underlies different fibrillization pathways: immunogenicity and cytotoxicity.

    PubMed

    Stefani, Massimo

    2010-08-01

    The past fifteen years have led to a profound re-consideration of the molecular and cellular basis of amyloid diseases. Since the formulation of the amyloid hypothesis in 1991-1992, increasing interest was initially focused at amyloid fibrils and, subsequently, at their precursors, oligomers and pre-fibrillar aggregates as main culprits of cell impairment and demise, particularly in neurodegenerative diseases with amyloid deposition. In 2002, this concept was generalized by the demonstration that pre-fibrillar aggregates were toxic even when they were grown from proteins not associated with amyloid disease. Presently, the general structural features and polymorphism of amyloid fibrils grown from a range of different peptides and proteins are rather well known; however, in spite of the growing interest in amyloid oligomers as the main source of amyloid toxicity, a better definition of their structural features remains elusive due to their transient nature, remarkable instability, high flexibility and structural heterogeneity possibly resulting in the appearance of polymorphic assemblies. Nevertheless, recent studies have started to unravel this key topic by providing significant insights into some general structural features and conformational polymorphism of amyloid oligomers and the higher order structures they generate. Important clues into the structure-toxicity relation of amyloids, the role performed by natural surfaces in oligomer growth and the molecular basis of oligomer-membrane interaction are also emerging. PMID:20423295

  5. The Aβ oligomer hypothesis for synapse failure and memory loss in Alzheimer's diseas

    PubMed Central

    Ferreira, Sergio T; Klein, William L

    2015-01-01

    Alzheimer's disease is the 3rd most costly disease and is estimated to be the 6th leading cause of death. Alzheimer's disease (AD) is fatal and affected individuals can sometimes linger many years. Current treatments are palliative and transient, not disease modifying. This article reviews progress in the search to identify the primary AD-causing toxins. We summarize the shift from an initial focus on amyloid plaques to the contemporary concept that AD memory failure is caused by small soluble oligomers of the Aβ peptide, toxins that target and disrupt particular synapses. Evidence is presented that links Aβ oligomers to pathogenesis in animal models and humans, with reference to seminal discoveries from cell biology and new ideas concerning pathogenic mechanisms. These findings have established the oligomer hypothesis as a new molecular basis for the cause, diagnosis, and treatment of AD. PMID:21914486

  6. Soluble androgen receptor oligomers underlie pathology in a mouse model of spinobulbar muscular atrophy.

    PubMed

    Li, Mei; Chevalier-Larsen, Erica S; Merry, Diane E; Diamond, Marc I

    2007-02-01

    In polyglutamine diseases such as X-linked spinobulbar muscular atrophy (SBMA), it is unknown whether the toxic form of the protein is an insoluble or soluble aggregate or a monomer. We have addressed this question by studying a full-length androgen receptor (AR) mouse model of SBMA. We used biochemistry and atomic force microscopy to immunopurify oligomers soluble after ultracentrifugation that are comprised of a single approximately 50-kDa N-terminal polyglutamine-containing AR fragment. AR oligomers appeared several weeks prior to symptom onset, were distinct and temporally dissociated from intranuclear inclusions, and disappeared rapidly after castration, which halts disease. This is the first demonstration of soluble AR oligomers in vivo and suggests that they underlie neurodegeneration in SBMA. PMID:17121819

  7. Exploring the assembly mechanism of tetrapeptide oligomers using the Activation-Relaxation Technique

    NASA Astrophysics Data System (ADS)

    Wei, Guanghong; Mousseau, Normand; Derreumaux, Philippe

    2004-03-01

    Alzheimer's disease and Parkinson's disease are associated with formation of amyloid fibrils. All amyloid fibrils seem to share a common cross β-sheet structure. Experimental studies have shown that peptides as short as 4 amino acids can form amyloid fibrils. It has also been shown that the oligomers that form early in the aggregation process of even non-disease-related proteins may be cytotoxic. We report a detailed study of the assembly mechanisms of the tetrapeptides into different size oligomers: trimers, hexamers and more. The assembly of the oligomers, in which the peptides form β-sheets through interpeptide interactions, are studied using the activation-relaxation technique (ART) in combination with a reduced off-lattice energy model (OPEP). We also describe the multiple pathways of oligomerization as well as categorize the various oligomeric intermediates, providing information of the early events of β-sheet formation.

  8. Properties of pertussis toxin B oligomer assembled in vitro from recombinant polypeptides produced by Escherichia coli.

    PubMed Central

    Burnette, W N; Arciniega, J L; Mar, V L; Burns, D L

    1992-01-01

    The subunits that make up the pentameric B oligomer of pertussis toxin (S2, S3, S4, and S5) were individually synthesized as recombinant polypeptides in Escherichia coli, isolated as insoluble inclusion bodies, and assembled into a multimeric form in vitro by spontaneous association following treatment with a chaotropic agent, reduction, and reoxidation. The recombinant B multimer, purified by fetuin-Sepharose affinity chromatography, contained all four of the individual subunits and possessed the mitogenic and hemagglutinating activities characteristic of the native B oligomer. Immunization of mice with the recombinant B oligomer elicited antibodies that neutralized pertussis toxin in vitro and, moreover, provided protection in vivo against the leukocytosis-promoting activity of the toxin. These results demonstrate the potential for assembly of complex multimeric proteins from recombinant DNA-derived polypeptides and provide a novel means for production of an acellular pertussis vaccine component. Images PMID:1587592

  9. Detection of misfolded Aβ oligomers for sensitive biochemical diagnosis of Alzheimer's disease.

    PubMed

    Salvadores, Natalia; Shahnawaz, Mohammad; Scarpini, Elio; Tagliavini, Fabrizio; Soto, Claudio

    2014-04-10

    Alzheimer's disease (AD) diagnosis is hampered by the lack of early, sensitive, and objective laboratory tests. We describe a sensitive method for biochemical diagnosis of AD based on specific detection of misfolded Aβ oligomers, which play a central role in AD pathogenesis. The protein misfolding cyclic amplification assay (Aβ-PMCA), exploits the functional property of Aβ oligomers to seed the polymerization of monomeric Aβ. Aβ-PMCA allowed detection of as little as 3 fmol of Aβ oligomers. Most importantly, using cerebrospinal fluid, we were able to distinguish AD patients from control individuals affected by a variety of other neurodegenerative disorders or nondegenerative neurological diseases with overall sensitivity of 90% and specificity of 92%. These findings provide the proof-of-principle basis for developing a highly sensitive and specific biochemical test for AD diagnosis. PMID:24656814

  10. Simple extrapolation method to predict the electronic structure of conjugated polymers from calculations on oligomers

    DOE PAGES

    Larsen, Ross E.

    2016-04-12

    In this study, we introduce two simple tight-binding models, which we call fragment frontier orbital extrapolations (FFOE), to extrapolate important electronic properties to the polymer limit using electronic structure calculations on only a few small oligomers. In particular, we demonstrate by comparison to explicit density functional theory calculations that for long oligomers the energies of the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO), and of the first electronic excited state are accurately described as a function of number of repeat units by a simple effective Hamiltonian parameterized from electronic structure calculations on monomers, dimers and, optionally,more » tetramers. For the alternating copolymer materials that currently comprise some of the most efficient polymer organic photovoltaic devices one can use these simple but rigorous models to extrapolate computed properties to the polymer limit based on calculations on a small number of low-molecular-weight oligomers.« less

  11. Formation of nitrogen-containing oligomers by methylglyoxal and amines in simulated evaporating cloud droplets.

    PubMed

    De Haan, David O; Hawkins, Lelia N; Kononenko, Julia A; Turley, Jacob J; Corrigan, Ashley L; Tolbert, Margaret A; Jimenez, Jose L

    2011-02-01

    Reactions of methylglyoxal with amino acids, methylamine, and ammonium sulfate can take place in aqueous aerosol and evaporating cloud droplets. These processes are simulated by drying droplets and bulk solutions of these compounds (at low millimolar and 1 M concentrations, respectively) and analyzing the residuals by scanning mobility particle sizing, nuclear magnetic resonance, aerosol mass spectrometry (AMS), and electrospray ionization MS. The results are consistent with imine (but not diimine) formation on a time scale of seconds, followed by the formation of nitrogen-containing oligomers, methylimidazole, and dimethylimidazole products on a time scale of minutes to hours. Measured elemental ratios are consistent with imidazoles and oligomers being major reaction products, while effective aerosol densities suggest extensive reactions take place within minutes. These reactions may be a source of the light-absorbing, nitrogen-containing oligomers observed in urban and biomass-burning aerosol particles.

  12. Mitochondrial oligomers boost glycolysis in cancer stem cells to facilitate blebbishield-mediated transformation after apoptosis.

    PubMed

    Jinesh, G G; Molina, J R; Huang, L; Laing, N M; Mills, G B; Bar-Eli, M; Kamat, A M

    2016-01-01

    Apoptosis culminates in secondary necrosis due to lack of ATP. Cancer stem cells form spheres after apoptosis by evoking the blebbishield emergency program. Hence, determining how blebbishields avoid secondary necrosis is crucial. Here we demonstrate that N-Myc and VEGFR2 control transformation from blebbishields, during which oligomers of K-Ras, p27, BAD, Bax, and Bak boost glycolysis to avoid secondary necrosis. Non-apoptotic cancer cells also utilize oligomers to boost glycolysis, which differentiates the glycolytic function of oligomers from their apoptotic action. Smac mimetic in combination with TNF-α or TRAIL but not in combination with FasL abrogates transformation from blebbishields by inducing secondary necrosis. Thus blebbishield-mediated transformation is dependent on glycolysis, and Smac mimetics represent potential candidates to abrogate the blebbishield emergency program. PMID:27551498

  13. New insight into the dynamical system of αB-crystallin oligomers

    PubMed Central

    Inoue, Rintaro; Takata, Takumi; Fujii, Norihiko; Ishii, Kentaro; Uchiyama, Susumu; Sato, Nobuhiro; Oba, Yojiro; Wood, Kathleen; Kato, Koichi; Fujii, Noriko; Sugiyama, Masaaki

    2016-01-01

    α-Crystallin possesses a dynamic quaternary structure mediated by its subunit dynamics. Elucidation of a mechanism of subunit dynamics in homo-oligomers of αB-crystallin was tackled through deuteration-assisted small-angle neutron scattering (DA-SANS) and electrospray ionization (ESI) native mass spectrometry (nMS). The existence of subunit exchange was confirmed with DA-SANS, and monomers liberated from the oligomers were observed with nMS. With increasing temperature, an increase in both the exchange rate and monomer population was observed despite the absence of oligomer collapse. It is proposed that transiently liberated subunits, namely, “traveling subunits,” play a role in subunit exchange. Moreover, we propose that protein function is regulated by these traveling subunits. PMID:27381175

  14. A mechanistic model of tau amyloid aggregation based on direct observation of oligomers

    NASA Astrophysics Data System (ADS)

    Shammas, Sarah L.; Garcia, Gonzalo A.; Kumar, Satish; Kjaergaard, Magnus; Horrocks, Mathew H.; Shivji, Nadia; Mandelkow, Eva; Knowles, Tuomas P. J.; Mandelkow, Eckhard; Klenerman, David

    2015-04-01

    Protein aggregation plays a key role in neurodegenerative disease, giving rise to small oligomers that may become cytotoxic to cells. The fundamental microscopic reactions taking place during aggregation, and their rate constants, have been difficult to determine due to lack of suitable methods to identify and follow the low concentration of oligomers over time. Here we use single-molecule fluorescence to study the aggregation of the repeat domain of tau (K18), and two mutant forms linked with familial frontotemporal dementia, the deletion mutant ΔK280 and the point mutant P301L. Our kinetic analysis reveals that aggregation proceeds via monomeric assembly into small oligomers, and a subsequent slow structural conversion step before fibril formation. Using this approach, we have been able to quantitatively determine how these mutations alter the aggregation energy landscape.

  15. Biodegradable polyester-based eco-composites containing hemp fibers modified with macrocyclic oligomers

    NASA Astrophysics Data System (ADS)

    Conzatti, Lucia; Utzeri, Roberto; Hodge, Philip; Stagnaro, Paola

    2016-05-01

    An original compatibilizing pathway for hemp fibers/poly(1,4-butylene adipate-co-terephtalate) (PBAT) eco-composites was explored exploiting the capability of macrocyclic oligomers (MCOs), obtained by cyclodepolymerization (CDP) of PBAT at high dilution, of being re-converted into linear chains by entropically-driven ring-opening polymerization (ED-ROP) that occurs simply heating the MCOS in the bulk. CDP reaction of PBAT was carried out varying solvent, catalyst and reaction time. Selected MCOs were used to adjust the conditions of the ED-ROP reaction. The best experimental conditions were then adopted to modify hemp fibers. Eco-composites based on PBAT and hemp fibers as obtained or modified with PBAT macrocyclics or oligomers were prepared by different process strategies. The best fiber-PBAT compatibility was observed when the fibers were modified with PBAT oligomers before incorporation in the polyester matrix.

  16. Osteochondroma in Long-Term Survivors of High-Risk Neuroblastoma

    PubMed Central

    Kushner, Brian H.; Roberts, Stephen S.; Friedman, Danielle N.; Kuk, Deborah; Ostrovnaya, Irina; Modak, Shakeel; Kramer, Kim; Basu, Ellen M.; Cheung, Nai-Kong V.

    2016-01-01

    Background Osteochondromas are benign bony protrusions that can be spontaneous or associated with radiation therapy (RT). Current treatment of high-risk neuroblastoma includes dose-intensive chemotherapy, local RT, anti-GD2 monoclonal antibody (MAb), and isotretinoin. Late effects are emerging. Methods We studied osteochondromas in 362 patients who were <10 years old when diagnosed with neuroblastoma; received MAb+isotretinoin since 2000; and survived ≥24 months from the first dose of MAb. The incidence rate of osteochondromas was determined using the competing risks approach where the primary event was osteochondroma calculated from the date of neuroblastoma diagnosis and the competing event was death without osteochondroma. Results Twenty-one osteochondromas were found in 14 patients who were 5.7-15.3 (median 10.4) years of age and 3.1-11.2 (median 8.2) years from neuroblastoma diagnosis. The cumulative incidence rate was 0.6% at five years and 4.9% at 10 years from neuroblastoma diagnosis. Nine osteochondromas were revealed incidentally during assessments of neuroblastoma disease status or bone age. Thirteen osteochondromas were outside RT portals and had characteristics of spontaneous forms. Complications were limited to pain necessitating resection in three patients, but follow-up is short at 0.3-7.7 (median 3.5) years. Conclusions Osteochondromas in long-term survivors of neuroblastoma should be expected because these benign growths can be RT-related and these patients undergo radiologic studies over years, are monitored for late toxicities through and beyond adolescence, and receive special attention (because of concern about relapse) if they develop a bony protuberance. A pathogenic role for chemotherapy, anti-GD2 MAb, or isotretinoin remains speculative. PMID:25728463

  17. Improved therapy for neuroblastoma using a combination approach: superior efficacy with vismodegib and topotecan

    PubMed Central

    Chaturvedi, Nagendra K.; McGuire, Timothy R.; Coulter, Don W.; Shukla, Ashima; McIntyre, Erin M.; Sharp, John Graham; Joshi, Shantaram S.

    2016-01-01

    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. PMID:26934655

  18. 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

  19. Oncolytic poliovirus therapy and immunization with poliovirus-infected cell lysate induces potent antitumor immunity against neuroblastoma in vivo.

    PubMed

    Toyoda, Hidemi; Wimmer, Eckard; Cello, Jeronimo

    2011-01-01

    In a previous study, we demonstrated that neuroblastoma subcutaneously implanted in immuno-competent mice is eliminated by intratumoral administration of neuroattenuated poliovirus (PV). Our results also suggested that the in vivo destruction of neuroblastoma cells by virotherapy lead to a robust antitumor immune response. In this work, splenocytes harvested from neuroblastoma-bearing animals treated with neuroattenuated PV exhibited significantly higher lytic activity against tumor target cells than did those from splenocytes derived from control mice. In vitro T-cell depletion experiments indicated that CD8(+) T cells were essential for the cytotoxic antitumor activity of splenocytes. Moreover, adoptive transfer of splenocytes obtained from mice cured of neuroblastoma by PV virotherapy markedly delayed the tumor growth of previously established neuroblastomas in recipient naïve mice. These results confirmed that treatment with a neuroattenuated oncolytic PV strain induces antitumor immunity against neuroblastoma that is mainly mediated by cytotoxic CD8(+) T cells. Immunocompetent mice, on the other hand, were immunized with PV-infected neuroblastoma cell lysate prior intravenous challenge with neuroblastoma cells. As a control, mice were vaccinated with either non-infected neuroblastoma cell lysate alone or mixed with PV, or with PBS prior tumor cell injection. Results showed that survival is significantly prolonged only in mice immunized with PV-infected tumor lysate. This finding clearly suggested that in vitro poliovirus infection of neuroblastoma cells turns these cells into a potent tumor immunogen. Further studies in oncolytic treatment of neuroblastoma using attenuated PV alone or in combination with immunotherapy with PV oncolysate should improve the probability for successful translation in the clinic.

  20. microRNA-449a functions as a tumor suppressor in neuroblastoma through inducing cell differentiation and cell cycle arrest

    PubMed Central

    Zhao, Zhenze; Ma, Xiuye; Sung, Derek; Li, Monica; Kosti, Adam; Lin, Gregory; Chen, Yidong; Pertsemlidis, Alexander; Hsiao, Tzu-Hung; Du, Liqin

    2015-01-01

    microRNA-449a (miR-449a) has been identified to function as a tumor suppressor in several types of cancers. However, the role of miR-449a in neuroblastoma has not been intensively investigated. We recently found that the overexpression of miR-449a significantly induces neuroblastoma cell differentiation, suggesting its potential tumor suppressor function in neuroblastoma. In this study, we further investigated the mechanisms underlying the tumor suppressive function of miR-449a in neuroblastoma. We observed that miR-449a inhibits neuroblastoma cell survival and growth through 2 mechanisms—inducing cell differentiation and cell cycle arrest. Our comprehensive investigations on the dissection of the target genes of miR-449a revealed that 3 novel targets- MFAP4, PKP4 and TSEN15 -play important roles in mediating its differentiation-inducing function. In addition, we further found that its function in inducing cell cycle arrest involves down-regulating its direct targets CDK6 and LEF1. To determine the clinical significance of the miR-449a-mediated tumor suppressive mechanism, we examined the correlation between the expression of these 5 target genes in neuroblastoma tumor specimens and the survival of neuroblastoma patients. Remarkably, we noted that high tumor expression levels of all the 3 miR-449a target genes involved in regulating cell differentiation, but not the target genes involved in regulating cell cycle, are significantly correlated with poor survival of neuroblastoma patients. These results suggest the critical role of the differentiation-inducing function of miR-449a in determining neuroblastoma progression. Overall, our study provides the first comprehensive characterization of the tumor-suppressive function of miR-449a in neuroblastoma, and reveals the potential clinical significance of the miR-449a-mediated tumor suppressive pathway in neuroblastoma prognosis. PMID:25760387

  1. Exendin-4 protects Aβ(1-42) oligomer-induced PC12 cell apoptosis

    PubMed Central

    Qiu, Chen; Wang, Yan-Ping; Pan, Xiao-Dong; Liu, Xiao-Ying; Chen, Zhou; Liu, Li-Bin

    2016-01-01

    Background: Type 2 diabetes mellitus (T2DM) increases the risk of developing Alzheimer’s disease. Most recently, GLP-1 analogs have been shown to have a significant neuroprotective role in several neurodegenerative diseases. However, few are known on its potential mechanism. Objective: In this study, we report the effect of exendin-4 (Ex-4), a GLP-1 receptor agonist, on amyloid-β(1-42) peptide oligomer-induced apoptosis in a PC12 neuronal cell model. Methods: MTT, DAPI and Annexin-V/PI assays revealed that the viability of PC12 cells decreased in a dose- and time-dependent manner after exposure to amyloid-β(1-42) oligomers. This apoptotic effect could be attenuated by Ex-4 (100-300 nM) pre-treatment, compared with the PC12 cells treated with amyloid-β(1-42) oligomers alone. Moreover, treatment with amyloid-β(1-42) oligomers (10 μM) resulted in a decrease in active- and pro-caspase-3 expression, as well as in Bcl-2 protein expression; suggesting that amyloid-β(1-42) oligomers impaired neuronal cells via the apoptosis signaling pathway. A further study of this mechanism revealed that amyloid-β oligomers (AβOs) decreased the phosphorylation of Akt and CREB. As expected, pre-treatment with Ex-4 (300 nM) increased the expression of anti-apoptotic protein Bcl-2 and reduced active caspase-3 expression levels. In addition, Ex-4 upregulated the phosphorylation levels of Akt and CREB. Conclusions: These findings indicate that GLP-1 analogue Ex-4 has a neuroprotective effect against AβO-induced PC12 cell apoptosis through reversing the impairment of the neuronal survival signaling pathway. This strongly suggests that Ex-4 is a potential therapeutic option for ameliorating AβO-induced neurotoxicity in the clinical application of Ex-4 for AD treatment, particularly when associated with diabetes. PMID:27648144

  2. Exendin-4 protects Aβ(1-42) oligomer-induced PC12 cell apoptosis

    PubMed Central

    Qiu, Chen; Wang, Yan-Ping; Pan, Xiao-Dong; Liu, Xiao-Ying; Chen, Zhou; Liu, Li-Bin

    2016-01-01

    Background: Type 2 diabetes mellitus (T2DM) increases the risk of developing Alzheimer’s disease. Most recently, GLP-1 analogs have been shown to have a significant neuroprotective role in several neurodegenerative diseases. However, few are known on its potential mechanism. Objective: In this study, we report the effect of exendin-4 (Ex-4), a GLP-1 receptor agonist, on amyloid-β(1-42) peptide oligomer-induced apoptosis in a PC12 neuronal cell model. Methods: MTT, DAPI and Annexin-V/PI assays revealed that the viability of PC12 cells decreased in a dose- and time-dependent manner after exposure to amyloid-β(1-42) oligomers. This apoptotic effect could be attenuated by Ex-4 (100-300 nM) pre-treatment, compared with the PC12 cells treated with amyloid-β(1-42) oligomers alone. Moreover, treatment with amyloid-β(1-42) oligomers (10 μM) resulted in a decrease in active- and pro-caspase-3 expression, as well as in Bcl-2 protein expression; suggesting that amyloid-β(1-42) oligomers impaired neuronal cells via the apoptosis signaling pathway. A further study of this mechanism revealed that amyloid-β oligomers (AβOs) decreased the phosphorylation of Akt and CREB. As expected, pre-treatment with Ex-4 (300 nM) increased the expression of anti-apoptotic protein Bcl-2 and reduced active caspase-3 expression levels. In addition, Ex-4 upregulated the phosphorylation levels of Akt and CREB. Conclusions: These findings indicate that GLP-1 analogue Ex-4 has a neuroprotective effect against AβO-induced PC12 cell apoptosis through reversing the impairment of the neuronal survival signaling pathway. This strongly suggests that Ex-4 is a potential therapeutic option for ameliorating AβO-induced neurotoxicity in the clinical application of Ex-4 for AD treatment, particularly when associated with diabetes.

  3. Detection of TDP-43 Oligomers in Frontotemporal Lobar Degeneration–TDP

    PubMed Central

    Kao, Patricia F.; Chen, Yun-Ru; Liu, Xiao-Bo; DeCarli, Charles; Seeley, William W.; Jin, Lee-Way

    2016-01-01

    Objective The proteinaceous inclusions in TDP-43 proteinopathies such as frontotemporal lobar degeneration (FTLD)-TDP are made of high–molecular-weight aggregates of TDP-43. These aggregates have not been classified as amyloids, as prior amyloid staining results were not conclusive. Here we used a specific TDP-43 amyloid oligomer antibody called TDP-O to determine the presence and abundance of TDP-43 oligomers among different subtypes of FTLD-TDP as well as in hippocampal sclerosis (HS), which represents a non-FTLD pathology with TDP-43 inclusions. Methods Postmortem tissue from the hippocampus and anterior orbital gyrus from 54 prospectively assessed and diagnosed subjects was used for immunostaining with TDP-O. Electron microscopy was used to assess the subcellular locations of TDP-O–decorated structures. Results TDP-43 inclusions staining with TDP-O were present in FTLD-TDP and were most conspicuous for FTLD-TDP type C, the subtype seen in most patients with semantic variant primary progressive aphasia. TDP-O immunoreactivity was absent in the hippocampus of HS patients despite abundant TDP-43 inclusions. Ultrastructurally, TDP-43 oligomers resided in granular or tubular structures, frequently in close proximity to, but not within, neuronal lysosomes. Interpretation TDP-43 forms amyloid oligomers in the human brain, which may cause neurotoxicity in a manner similar to other amyloid oligomers. Oligomer formation may contribute to the conformational heterogeneity of TDP-43 aggregates and mark the different properties of TDP-43 inclusions between FTLD-TDP and HS. PMID:25921485

  4. Conformational Switching and Nanoscale Assembly of Human Prion Protein into Polymorphic Amyloids via Structurally Labile Oligomers.

    PubMed

    Dalal, Vijit; Arya, Shruti; Bhattacharya, Mily; Mukhopadhyay, Samrat

    2015-12-29

    Conformational switching of the prion protein (PrP) from an α-helical normal cellular form (PrP(C)) to an aggregation-prone and self-propagating β-rich scrapie form (PrP(Sc)) underlies the molecular basis of pathogenesis in prion diseases. Anionic lipids play a critical role in the misfolding and conformational conversion of the membrane-anchored PrP into the amyloidogenic pathological form. In this work, we have used a diverse array of techniques to interrogate the early intermediates during amyloid formation from recombinant human PrP in the presence of a membrane mimetic anionic detergent such as sodium dodecyl sulfate. We have been able to detect and characterize two distinct types of interconvertible oligomers. Our results demonstrate that highly ordered large β-oligomers represent benign off-pathway intermediates that lack the ability to mature into amyloid fibrils. On the contrary, structurally labile small oligomers are capable of switching to an ordered amyloid-state that exhibits profound toxicity to mammalian cells. Our fluorescence resonance energy transfer measurements revealed that the partially disordered PrP serves as precursors to small amyloid-competent oligomers. These on-pathway oligomers are eventually sequestered into higher order supramolecular assemblies that conformationally mature into polymorphic amyloids possessing varied nanoscale morphology as evident by the atomic force microscopy imaging. The nanoscale diversity of fibril architecture is attributed to the heterogeneous ensemble of early obligatory oligomers and offers a plausible explanation for the existence of multiple prion strains in vivo. PMID:26645611

  5. Thio-urethane oligomers improve the properties of light-cured resin cements

    PubMed Central

    Bacchi, Ataís; Consani, Rafael L.; Martim, Gedalias C.; Pfeifer, Carmem S.

    2015-01-01

    Thio-urethanes were synthesized by combining 1,6-Hexanediol-diissocyante (aliphatic) with pentaerythritol tetra-3-mercaptopropionate (PETMP) or 1,3-bis(1-isocyanato-1-methylethyl)benzene (aromatic) with trimethylol-tris-3-mercaptopropionate (TMP), at 1:2 isocyanate:thiol, leaving pendant thiols. Oligomers were added at 10–30 phr to BisGMA-UDMA-TEGDMA (5:3:2, BUT). 25wt% silanated inorganic fillers were added. Commercial cement (Relyx Veneer, 3M-ESPE) was also evaluated with 10–20 phr of aromatic oligomer. Near-IR was used to follow methacrylate conversion (DC) and rate of polymerization (Rpmax). Mechanical properties were evaluated in three-point bending (ISO 4049) for flexural strength/modulus (FS/FM, and toughness), and notched specimens (ASTM Standard E399-90) for fracture toughness (KIC). Polymerization stress (PS) was measured on the Bioman. Volumetric shrinkage (VS, %) was measured with the bonded disk technique. Results were analyzed with ANOVA/Tukey’s test (α=5%). In general terms, for BUT cements, conversion and mechanical properties in flexure increased for selected groups with the addition of thio-urethane oligomers. The aromatic versions resulted in greater FS/FM than aliphatic. Fracture toughness increased by twofold in the experimental groups (from 1.17±0.36 to around 3.23±0.22 MPa.m1/2). Rpmax decreased with the addition of thio-urethanes, though the vitrification point was not statistically different from the control. VS and PS decreased with both oligomers. For the commercial cement, 20 phr of oligomer increased DC, vitrification, reduced Rpmax and also significantly increased KIC, and reduced PS and FM. Thio-urethane oligomers were shown to favorably modify conventional dimethacrylate networks. Significant reductions in polymerization stress were achieved at the same time conversion and fracture toughness increased. PMID:25740124

  6. Thio-urethane oligomers improve the properties of light-cured resin cements.

    PubMed

    Bacchi, Ataís; Consani, Rafael L; Martim, Gedalias C; Pfeifer, Carmem S

    2015-05-01

    Thio-urethanes were synthesized by combining 1,6-hexanediol-diissocyante (aliphatic) with pentaerythritol tetra-3-mercaptopropionate (PETMP) or 1,3-bis(1-isocyanato-1-methylethyl)benzene (aromatic) with trimethylol-tris-3-mercaptopropionate (TMP), at 1:2 isocyanate:thiol, leaving pendant thiols. Oligomers were added at 10-30 phr to BisGMA-UDMA-TEGDMA (5:3:2, BUT). 25 wt% silanated inorganic fillers were added. Commercial cement (Relyx Veneer, 3M-ESPE) was also evaluated with 10-20 phr of aromatic oligomer. Near-IR was used to follow methacrylate conversion (DC) and rate of polymerization (Rpmax). Mechanical properties were evaluated in three-point bending (ISO 4049) for flexural strength/modulus (FS/FM, and toughness), and notched specimens (ASTM Standard E399-90) for fracture toughness (KIC). Polymerization stress (PS) was measured on the Bioman. Volumetric shrinkage (VS, %) was measured with the bonded disk technique. Results were analyzed with ANOVA/Tukey's test (α=5%). In general terms, for BUT cements, conversion and mechanical properties in flexure increased for selected groups with the addition of thio-urethane oligomers. The aromatic versions resulted in greater FS/FM than aliphatic. Fracture toughness increased by two-fold in the experimental groups (from 1.17 ± 0.36 MPam(1/2) to around 3.23 ± 0.22 MPam(1/2)). Rpmax decreased with the addition of thio-urethanes, though the vitrification point was not statistically different from the control. VS and PS decreased with both oligomers. For the commercial cement, 20 phr of oligomer increased DC, vitrification, reduced Rpmax and also significantly increased KIC, and reduced PS and FM. Thio-urethane oligomers were shown to favorably modify conventional dimethacrylate networks. Significant reductions in polymerization stress were achieved at the same time conversion and fracture toughness increased.

  7. 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.

  8. Synthesis and Properties of Phenylethynyl-Terminated, Star-Branched, Phenylquinoxaline Oligomers

    NASA Technical Reports Server (NTRS)

    Ooi, I. H.; Hergenrother, P. M.; Harris, F. W.

    2000-01-01

    The primary objective of this work was to prepare readily melt and solution processable phenylquinoxaline (PQ) oligomers that could be thermally crosslinked to solvent-resistant resins. Thus, a mixture of 2-(4-hydroxyphenyl)-3-phenyl-6-fluoroquinoxaline and 3-(4-hydroxyphenyl)-2-phenyl-6-fluoroquinoxaline (HPFQ) was used to prepare star-branched PQ oligomers end-capped with 4-fluoro-4-phenylethynylbenzophenone (FPEB). 1,1,1-Tris(4-hydroxyphenyl)ethane (THPE) was used as the branching unit. The oligomer number-average molecular weights (M (bar) (sub n) S) as determined by size exclusion chromatography (SEC) were close to the calculated values of 2922, 4698, 6474, and 13,578 g/mol, and their intrinsic viscosities ranged from 0.16 to 0.57 dl/g (m-cresol at 30 C). The oligomers, which were quite soluble in common organic solvents, had glass transition temperatures (T (sub g) S) that ranged from 181 to 233 C (DSC, DELTA T = 20 C/min). They also underwent an exothermic cure with maxima from 377 to 443 C. The T (sub g) S of the cured oligomers ranged from 259 to 284 C depending on the oligomer M (bar) (sub n) and the curing conditions. The oligomers had low melt viscosities, e.g. an oligomer (SPQ-46) with an M (bar) (sub n) of 4816 g/mol (SEC) had a melt viscosity of 150 Pa s at 348 C. A cured thin film of SPQ-46, which was insoluble in common organic solvents, had a room temperature (RT) tensile strength of 100 MPa, a RT modulus of 2358 MPa, and a RT elongation of 5.9%. A cured sample of SPQ-46 displayed a RT titanium-titanium lap shear tensile strength of 35.2 MPa. SPQ-46/carbon fiber(IM-7) composites, were prepared that displayed a RT flexural strength of 1902 MPa, a RT modulus of 1.38 GPa and a RT open hole compressive strength of 433 MPa.

  9. Age dependence of tumor genetics in unfavorable neuroblastoma: arrayCGH profiles of 34 consecutive cases, using a Swedish 25-year neuroblastoma cohort for validation

    PubMed Central

    2013-01-01

    Background Aggressive neuroblastoma remains a significant cause of childhood cancer death despite current intensive multimodal treatment protocols. The purpose of the present work was to characterize the genetic and clinical diversity of such tumors by high resolution arrayCGH profiling. Methods Based on a 32K BAC whole-genome tiling path array and using 50-250K Affymetrix SNP array platforms for verification, DNA copy number profiles were generated for 34 consecutive high-risk or lethal outcome neuroblastomas. In addition, age and MYCN amplification (MNA) status were retrieved for 112 unfavorable neuroblastomas of the Swedish Childhood Cancer Registry, representing a 25-year neuroblastoma cohort of Sweden, here used for validation of the findings. Statistical tests used were: Fisher’s exact test, Bayes moderated t-test, independent samples t-test, and correlation analysis. Results MNA or segmental 11q loss (11q-) was found in 28/34 tumors. With two exceptions, these aberrations were mutually exclusive. Children with MNA tumors were diagnosed at significantly younger ages than those with 11q- tumors (mean: 27.4 vs. 69.5 months; p=0.008; n=14/12), and MNA tumors had significantly fewer segmental chromosomal aberrations (mean: 5.5 vs. 12.0; p<0.001). Furthermore, in the 11q- tumor group a positive correlation was seen between the number of segmental aberrations and the age at diagnosis (Pearson Correlation 0.606; p=0.037). Among nonMNA/non11q- tumors (n=6), one tumor displayed amplicons on 11q and 12q and three others bore evidence of progression from low-risk tumors due to retrospective evidence of disease six years before diagnosis, or due to tumor profiles with high proportions of numerical chromosomal aberrations. An early age at diagnosis of MNA neuroblastomas was verified by registry data, with an average of 29.2 months for 43 cases that were not included in the present study. Conclusion MNA and segmental 11q loss define two major genetic variants of

  10. Enzymatic production of defined chitosan oligomers with a specific pattern of acetylation using a combination of chitin oligosaccharide deacetylases

    PubMed Central

    Hamer, Stefanie Nicole; Cord-Landwehr, Stefan; Biarnés, Xevi; Planas, Antoni; Waegeman, Hendrik; Moerschbacher, Bruno Maria; Kolkenbrock, Stephan

    2015-01-01

    Chitin and chitosan oligomers have diverse biological activities with potentially valuable applications in fields like medicine, cosmetics, or agriculture. These properties may depend not only on the degrees of polymerization and acetylation, but also on a specific pattern of acetylation (PA) that cannot be controlled when the oligomers are produced by chemical hydrolysis. To determine the influence of the PA on the biological activities, defined chitosan oligomers in sufficient amounts are needed. Chitosan oligomers with specific PA can be produced by enzymatic deacetylation of chitin oligomers, but the diversity is limited by the low number of chitin deacetylases available. We have produced specific chitosan oligomers which are deacetylated at the first two units starting from the non-reducing end by the combined use of two different chitin deacetylases, namely NodB from Rhizobium sp. GRH2 that deacetylates the first unit and COD from Vibrio cholerae that deacetylates the second unit starting from the non-reducing end. Both chitin deacetylases accept the product of each other resulting in production of chitosan oligomers with a novel and defined PA. When extended to further chitin deacetylases, this approach has the potential to yield a large range of novel chitosan oligomers with a fully defined architecture. PMID:25732514

  11. Cyclic oligomers in polyamide for food contact material: quantification by HPLC-CLND and single-substance calibration.

    PubMed

    Heimrich, M; Bönsch, M; Nickl, H; Simat, T J

    2012-01-01

    Cyclic oligomers are the major substances migrating from polyamide (PA) food contact materials. However, no commercial standards are available for the quantification of these substances. For the first time the quantification of cyclic oligomers was carried out by HPLC coupled with a chemiluminescence nitrogen detector (CLND) and single-substance calibration. Cyclic monomer (MW = 226 Da) and dimer (MW = 452 Da) of PA66 were synthesised and equimolar N detection of CLND to synthesised oligomers, caprolactam, 6-aminohexanoic acid (monomers of PA6) and caffeine (a typical nitrogen calibrant) was proven. Relative response factors (UVD at 210 nm) referring to caprolactam were determined for cyclic PA6 oligomers from dimer to nonamer, using HPLC-CLND in combination with a UVD. A method for quantification of cyclic oligomer content in PA materials was introduced using HPLC-CLND analysis and caffeine as a single nitrogen calibrant. The method was applied to the quantification of cyclic PA oligomers in several PA granulates. For two PA6 granulates from different manufacturers markedly different oligomer contents were analysed (19.5 versus 13.4 g kg⁻¹). The elution pattern of cyclic oligomers offers the possibility of identifying the PA type and differentiating between PA copolymers and blends.

  12. Permeability and partitioning of ferrocene ethylene oxide and propylene oxide oligomers into electropolymerized films from acetonitrile and polyether solutions

    SciTech Connect

    Pyati, R.; Murray, R.W. )

    1994-10-27

    We report the first electrochemically-based measurements of the rates of small polymer permeation into another polymer. The small polymer permeants are ferrocene ethylene oxide oligomers containing 2, 7, and 16 units and a propylene oxide oligomer containing 3 units. Their permeation into ultrathin microelectrode-supported films of the metal complex polymer poly[Ru(vbpy)[sub 3

  13. Structural study of metastable amyloidogenic protein oligomers by photo-induced cross-linking of unmodified proteins.

    PubMed

    Bitan, Gal

    2006-01-01

    Oligomers of amyloidogenic proteins are believed to be key effectors of cytotoxicity and cause a variety of amyloid-related diseases. Dissociation or inhibition of formation of the toxic oligomers is thus an attractive strategy for the prevention and treatment of these diseases. In order to develop reagents capable of inhibiting protein oligomerization, the structures and mechanisms of oligomer formation must be understood. However, structural studies of oligomers are difficult because of the metastable nature of the oligomers and their existence in mixtures with monomers and other assemblies. A useful method for characterization of oligomer size distributions in vitro is photo-induced cross-linking of unmodified proteins (PICUP) (Fancy and Kodadek, 1999). By providing "snapshots" of dynamic oligomer mixtures, PICUP enables quantitative analysis of the relations between primary and quaternary structures, offering insights into the molecular organization of the oligomers. This chapter discusses the photochemical mechanism; reviews the scope, usefulness, and limitations of PICUP for characterizing metastable protein assemblies; and provides detailed experimental instructions for performing PICUP experiments.

  14. Enzymatic production of defined chitosan oligomers with a specific pattern of acetylation using a combination of chitin oligosaccharide deacetylases

    NASA Astrophysics Data System (ADS)

    Hamer, Stefanie Nicole; Cord-Landwehr, Stefan; Biarnés, Xevi; Planas, Antoni; Waegeman, Hendrik; Moerschbacher, Bruno Maria; Kolkenbrock, Stephan

    2015-03-01

    Chitin and chitosan oligomers have diverse biological activities with potentially valuable applications in fields like medicine, cosmetics, or agriculture. These properties may depend not only on the degrees of polymerization and acetylation, but also on a specific pattern of acetylation (PA) that cannot be controlled when the oligomers are produced by chemical hydrolysis. To determine the influence of the PA on the biological activities, defined chitosan oligomers in sufficient amounts are needed. Chitosan oligomers with specific PA can be produced by enzymatic deacetylation of chitin oligomers, but the diversity is limited by the low number of chitin deacetylases available. We have produced specific chitosan oligomers which are deacetylated at the first two units starting from the non-reducing end by the combined use of two different chitin deacetylases, namely NodB from Rhizobium sp. GRH2 that deacetylates the first unit and COD from Vibrio cholerae that deacetylates the second unit starting from the non-reducing end. Both chitin deacetylases accept the product of each other resulting in production of chitosan oligomers with a novel and defined PA. When extended to further chitin deacetylases, this approach has the potential to yield a large range of novel chitosan oligomers with a fully defined architecture.

  15. Interleukin-2 in neuroblastoma: clinical perspectives based on biological studies.

    PubMed

    Rueda, F; Martí, F; Pardo, N; Badell, I; Peiró, M; Bertran, E; Villén, E; García, J; Cubells, J

    1996-10-01

    Stage IV neuroblastoma (NB) is a disease with a poor prognosis. Chemotherapeutical intensification and hematological rescue with autologous bone marrow transplantation (ABMT) achieve some complete remissions (CR), but most patients relapse during the first year. Immunotherapy could be an alternative in this situation of high risk of relapse due to residual disease and ABMT-related immunodepression. Ten stage IV NB patients in CR or very good partial remission have been treated with recurrent 5-day cycles of high doses of Interleukin-2 (IL2) after ABMT throughout one year (usually 5-6 cycles). Natural killer (NK) and lymphokine-activated killer (LAK) cytotoxic activities, as well as phenotype and number of circulating NK cells were determined, before and after each course of IL2 treatment. The effects promoted by IL2 varied during treatment: early cycles of IL2 induced a great extent of cell expansion, mainly on CD3-/CD16-/CD56+bright and CD8+dim cell phenotypes; conversely, late courses of IL2 promoted higher NK cytotoxic activity but a lesser increase on circulating NK cells. The induction of LAK activity did not significantly differ from early and late IL2 treatments. Clinical results are still inconclusive due to the small number of patients. The median follow-up of patients treated with IL2 is 24 months and the disease free survival (DFS) probability is 0.80 +/- 0.12 vs 0.16 +/- 0.15 from a historical control with identical treatment, but in the absence of IL2 treatment (p < 0.005). IL2 treatment-related toxicity was mild and no interruption of the treatment was required. Extremely accurate hydric control was carried out to avoid, as much as possible, the consequences of vascular leak syndrome, one of the most important toxic effects of IL2 treatment. The results presented here suggest an evolution of NK activity during IL2 treatment after ABMT, which should be taken into account for the designing of new immunotherapeutical protocols and opens a promising

  16. Human gammadelta T lymphocytes exert natural and IL-2-induced cytotoxicity to neuroblastoma cells.

    PubMed

    Schilbach, K E; Geiselhart, A; Wessels, J T; Niethammer, D; Handgretinger, R

    2000-01-01

    Human gammadelta T lymphocytes play an important role in nonadaptive reactions to infection and early tumor defense. This is the first report that freshly isolated, native gammadelta T cells of some healthy donors can kill human neuroblastoma cells to varying degrees. Their killing ability was increased and maintained during expansion and cultivation with interleukin-2 (IL-2; 400 IU/mL) for as long as 30 days (100% specific lysis at an effector-to-target cell (E:T) ratio of 20:1). gammadelta T lymphocytes without this spontaneous killing ability gained a specific cytolytic activity of 81% +/- 10.4% SD after stimulation with IL-2 for 24 hours. gammadelta cells were isolated from peripheral blood by positive enrichment (using a magnetic cell sorting system; purity, 95.2% +/- 3.2% SD, n = 21). High natural cytotoxic activity against human neuroblastoma cell lines (>50% specific lysis at an E:T ratio of 20:1) was exhibited by one of 11 donors, whereas two of 11 showed medium cytotoxicity (30% to 50% specific lysis). Eight of 11 donors showed very slight or no lytic activity against human neuroblastoma cells (<30% specific lysis). gammadelta T cells were also cytotoxic against Daudi (32.7% specific lysis at an E:T ratio of 20:1), Raji (10.3%), Colo 205 (23.1%), A 204 (54%), K 562 (100%), and SK-N-MC (100%) cells. Isolated gammadelta T cells were grown in Iscove modified Dulbecco medium with IL-2 (400 IU/mL). Increased cell proliferation (38.5% to 182%) was induced with phytohemagglutinin, IL-15, Clodronat, OKT3, or various combinations of these. Results of cold target inhibition assays suggest a natural killer-like activity of the gammadelta T-cell killing mechanism. Peptidase or papain render neuroblastoma cells unsusceptible to gammadelta T-cell killing, suggesting the involvement of antigen peptide(s) in the process of neuroblastoma cell killing. Treatment with acid phosphatase reduced specific lysis by 66.5% +/- 34.1% SD, which suggests a binding to phosphorylated

  17. Isobavachalcone, a chalcone constituent of Angelica keiskei, induces apoptosis in neuroblastoma.

    PubMed

    Nishimura, Reiko; Tabata, Keiichi; Arakawa, Motoki; Ito, Yoshihisa; Kimura, Yumiko; Akihisa, Toshihiro; Nagai, Hisashi; Sakuma, Atsuko; Kohno, Hideki; Suzuki, Takashi

    2007-10-01

    Six chalcones from Angelica keiskei KOIDZUMI (Ashitaba in Japanese) and two chalcones from Humulus lupulus L. (hop) were examined for their cytotoxicity in two human neuroblastoma cell lines (IMR-32 and NB-39) and normal cells (primary culture of rat cerebellar granule cells) by [3-(4,5)-dimethyl-2-thiazolyl]-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. All chalcones exhibited cytotoxicity against neuroblastoma cells, and two of them (isobavachalcone and xanthoangelol H) had no effect on normal cells even at high concentration (10(-4) M) exposure. Typical morphologic features of apoptosis, including cell shrinkage, chromatin condensation, nuclear fragmentation and formation of apoptotic bodies, were observed in isobavachalcone-treated cells by Hoechst 33342 staining. Western blot analysis showed that isobavachalcone significantly reduced pro-caspase-3 and pro-caspase-9, and subsequently increased the level of cleaved caspase-3 and cleaved caspase-9 in both neuroblastoma cell lines. Moreover, Bax was markedly induced by isobavachalcone application. These results suggest that isobavachalcone induces apoptotic cell death in neuroblastoma via the mitochondrial pathway and has no cytotoxicity against normal cells. Therefore, isobavachalcone may be applicable as an efficacious and safe drug for the treatment of neuroblastoma.

  18. New anti-GD2 monoclonal antibodies produced from gamma-interferon-treated neuroblastoma cells.

    PubMed

    Gross, N; Beck, D; Portoukalian, J; Favre, S; Carrel, S

    1989-04-15

    Three monoclonal antibodies (IgG2) have been produced from hybridomas obtained by fusion of murine myeloma cells and spleen cells of mice hyperimmunized with gamma-interferon-treated neuroblastoma cells. The 3 MAbs, 7A4, 2A6 and IG8, detected an antigen present on neuroblastoma tumors and cell lines, but also on some neuro-ectoderm-derived tissues and cells. All 3 clones were shown to react with an epitope of the di-sialo-ganglioside GD2 molecules highly expressed by some neuro-ectoderm-derived tumors, mainly neuroblastoma. Whereas MAb IG8 specificity was restricted to GD2 and its o-acylated form, MAb 2A6 and 7A4 were also able to detect GD3 at high concentration of antibody as shown by TLC analysis and immunodetection. The 3 MAbs were able to lyse 100% neuroblastoma cells in the presence of rabbit or human complement. Direct binding assays with 125I-labelled MAbs showed that MAb 7A4 might be a good candidate for in vivo immunolocalization experiments. The high proportion of anti-GD2 MAbs obtained by our fusion and the increased binding of anti-GD2 MAbs on gamma-IFN-treated neuroblastoma cells suggests a modulation of the exposure and an increase in the immunogenicity of GD2 induced by gamma-IFN.

  19. Immunomodulatory effects of human neuroblastoma cells transduced with a retroviral vector encoding interleukin-2.

    PubMed

    Leimig, T; Foreman, N; Rill, D; Coze, C; Holladay, M; Brenner, M

    1994-12-01

    We have investigated whether retroviral mediated transfer of the IL-2 gene renders human neuroblastoma cells immunogenic, justifying their use in a clinical tumor immunization study. Fourteen neuroblastoma cell lines were established from patients with disseminated neuroblastoma and transduced with the vector G1Ncvl2, which contains the neomycin phosphotransferase gene and the cDNA of the human interleukin-2 gene. Clones secreting > 150 pg/10(6) cells/24 h of IL-2 were selected for further study. Secretion of IL-2 was maintained for at least 3 weeks in nonselective media, implying that production of the cytokine would continue under in vivo conditions. Co-culture of IL-2 transduced cell lines with patient lymphocytes induced potent cytotoxic activity against both transduced and parental neuroblastoma cell lines. This activity was HLA unrestricted, and predominantly mediated by CD16+ or CD56+ and CD8- lymphocytes. These data form the preclinical justification for our current immunization protocol for patients with relapsed or resistant neuroblastoma.

  20. Autologous tumor-specific cytotoxic T-lymphocytes in a child with neuroblastoma.

    PubMed

    Azuma, E; Hanada, M; Masuda, S I; Komada, Y; Sakurai, M

    1990-01-01

    Activation of peripheral blood lymphocytes from a neuroblastoma patient by co-cultivation with autologous neuroblastoma cells in a mixed lymphocyte-tumor cell culture (A-MLTC) resulted in the generation of cytotoxic activity against the autologous neuroblastoma cell line HNB-MS. A-MLTC was set up in the presence of recombinant human interleukin-2 (IL-2). HNB-MS stimulator was treated with recombinant human interferon-gamma (IFN-gamma) prior to A-MLTC. CTL generated in short-term culture effectively lysed HNB-MS, while they had no effect on an Epstein-Barr virus transformed autologous B-cell line EB-MS. Moreover, CTL lysed 3 different allogeneic neuroblastoma cell lines, but not a rhabdomyosarcoma cell line RBB. Recombinant human tumor necrosis factor-alpha (TNF-alpha) and interleukin-4 (IL-4) enhanced and suppressed CTL generation, respectively, when added to the A-MLTC from the beginning of culture. CD3+ CD4- CD8+ T cells were the major anti-tumor effectors. Furthermore, 111indium-labeled CTL clearly accumulated in metastatic sites. These results indicate that CTL can be used for adoptive immunotherapy in neuroblastoma.

  1. New strategies in refractory and recurrent neuroblastoma: translational opportunities to impact patient outcome.

    PubMed

    Cole, Kristina A; Maris, John M

    2012-05-01

    Neuroblastoma remains responsible for a disproportionate amount of childhood cancer morbidity and mortality despite recent significant advances in understanding the genetic basis of tumor initiation and progression. About half of newly diagnosed patients can be reliably identified as having tumors of low malignant potential, and these children have cure rates of greater than 95% with little or no cytotoxic therapy. On the other hand, the other half of neuroblastomas typically present in an explosive fashion with widely metastatic disease, and reliable tumor-specific biomarkers have been defined for this phenotype as well. Empiric approaches to high-risk neuroblastoma therapy have relied on dramatic escalation of chemotherapy dose intensity and, recently, the incorporation of targeted immunotherapy, but nearly 50% of children with high-risk disease will be refractory to therapy or suffer a relapse, both of which are invariably fatal. Future improvements in high-risk neuroblastoma outcomes will require the identification of disease and patient-specific oncogenic vulnerabilities that can be leveraged therapeutically. Rational development of novel approaches to neuroblastoma therapy requires forward-thinking strategies to unequivocally prove activity in the relapse setting and, ultimately, efficacy in curing patients when integrated into frontline treatment plans.

  2. Improved antitumour immunity in murine neuroblastoma using a combination of IL-2 and IL-12.

    PubMed

    Siapati, K E; Barker, S; Kinnon, C; Michalski, A; Anderson, R; Brickell, P; Thrasher, A J; Hart, S L

    2003-05-19

    Neuroblastoma immunotherapy using cytokine-modified tumour cells has been tested in clinical trials. However, because of the complex nature of antitumour immune responses, a number of therapies may be required for complete tumour eradication and generation of systemic immunity. We report here the improved antitumour effect of two cytokines, interleukin-2 (IL-2) and interleukin-12 (IL-12), when coexpressed by neuroblastoma cell lines. Initially, transfection of human and mouse neuroblastoma cell lines resulted in high expression levels of biologically active IL-2 and IL-12 in vitro. These cytokines when expressed by transfected Neuro-2A cells completely abolished their in vivo tumorigenicity in a syngeneic neuroblastoma model. Vaccination of established tumours with IL-12-producing cells exhibited a clear effect with reduced tumour growth in the presence of IL-2. In vivo depletion studies showed that CD4(+) and CD8(+) T cells mediate the response against cytokine-producing cells. These results suggest that IL-2 and IL-12, when cotransfected in tumour cells, are effective against established disease and provide a promising immunotherapeutic approach for the treatment of neuroblastoma.

  3. Parental occupational exposures to chemicals and incidence of neuroblastoma in offspring.

    PubMed

    De Roos, A J; Olshan, A F; Teschke, K; Poole, C; Savitz, D A; Blatt, J; Bondy, M L; Pollock, B H

    2001-07-15

    To evaluate the effects of parental occupational chemical exposures on incidence of neuroblastoma in offspring, the authors conducted a multicenter case-control study, using detailed exposure information that allowed examination of specific chemicals. Cases were 538 children aged 19 years who were newly diagnosed with confirmed neuroblastoma in 1992-1994 and were registered at any of 139 participating hospitals in the United States and Canada. One age-matched control for each of 504 cases was selected through random digit dialing. Self-reported exposures were reviewed by an industrial hygienist, and improbable exposures were reclassified. Effect estimates were calculated using unconditional logistic regression, adjusting for child's age and maternal demographic factors. Maternal exposures to most chemicals were not associated with neuroblastoma. Paternal exposures to hydrocarbons such as diesel fuel (odds ratio (OR) = 1.5; 95% confidence interval (CI): 0.8, 2.6), lacquer thinner (OR = 3.5; 95% CI: 1.6, 7.8), and turpentine (OR = 10.4; 95% CI: 2.4, 44.8) were associated with an increased incidence of neuroblastoma, as were exposures to wood dust (OR = 1.5; 95% CI: 0.8, 2.8) and solders (OR = 2.6; 95% CI: 0.9, 7.1). The detailed exposure information available in this study has provided additional clues about the role of parental occupation as a risk factor for neuroblastoma. PMID:11447042

  4. Occurrence of Neuroblastoma among TP53 p.R337H Carriers

    PubMed Central

    Mastellaro, Maria José; Cardinalli, Izilda Aparecida; Zambaldi, Lilian Girotto; Aguiar, Simone Santos; Yunes, José Andrés

    2015-01-01

    The high incidence of adrenocortical tumors and choroid plexus carcinoma in children from South and Southeastern regions of Brazil is associated with the germline p.R337H mutation of TP53 gene. The concomitant occurrence of neuroblastoma and adrenocortical tumors in pediatric patients harboring the p.R337H mutation at our institution prompted us to investigate the putative association between p.R337H and pediatric neuroblastoma. Genomic DNA samples from 83 neuroblastoma patients referred to a single institution during the period of 2000–2014 were screened for the p.R337H mutation. Available samples from carriers were investigated for both nuclear p53 accumulation and loss of heterozigosity in tumor. Clinical data were obtained from medical records in order to assess the impact of 337H allele on manifestation of the disease. Seven out 83 neuroblastoma patients (8.4%) were carriers of the TP53 p.R337H mutation in our cohort. Immunohistochemical analysis of p.R337H-positive tumors revealed nuclear p53 accumulation. Loss of heterozigosity was not found among available samples. The presence of 337H allele was associated with increased proportion of stage I tumors. Our data indicate that in addition to adrenocortical tumors, choroid plexus carcinoma, breast cancer and osteosarcoma, genetic counseling and clinical surveillance should consider neuroblastoma as a potential neoplasia affecting p.R337H carriers. PMID:26452166

  5. Gene expression profiling of 1p35-36 genes in neuroblastoma.

    PubMed

    Janoueix-Lerosey, Isabelle; Novikov, Eugene; Monteiro, Marta; Gruel, Nadège; Schleiermacher, Gudrun; Loriod, Béatrice; Nguyen, Catherine; Delattre, Olivier

    2004-08-01

    Deletion of the chromosome 1p36 region is a frequent abnormality in neuroblastoma. To gain further insights into the role of this alteration in oncogenesis, we have constructed a specific cDNA microarray representing most known genes and ESTs from the 1p35-36 region and analysed the expression profiles of 15 neuroblastoma cell lines and 28 neuroblastoma tumours. Hierarchical clustering using expression levels of 320 cDNAs from 1p35-36 separated localized or 4S cases without 1p deletion from advanced stages and cell lines. Supervised learning classification enabled to predict reliably the status of chromosome 1p according to its expression profile. Around 15% of the genes or ESTs presented a significantly decreased expression in samples with 1p deletion as compared to 1p-normal samples suggesting that 1p deletion results in a gene dosage effect on a subset of genes critical for the development of 1p-deleted neuroblastoma. Several genes presumed to have functions in neural differentiation (CDC42, VAMP3, CLSTN1), signal transduction in neural cells (GNB1) and cell cycle regulation (STMN1, RPA2, RBAF600, FBXO6, MAD2L2) exhibited a decreased expression in samples presenting 1p deletion. The identification of such genes provides baseline information for further studies to elucidate how these genes could individually or collectively play a critical role in neuroblastoma tumorigenesis. PMID:15195138

  6. Knockdown of survivin (BIRC5) causes apoptosis in neuroblastoma via mitotic catastrophe.

    PubMed

    Lamers, Fieke; van der Ploeg, Ida; Schild, Linda; Ebus, Marli E; Koster, Jan; Hansen, Bo R; Koch, Troels; Versteeg, Rogier; Caron, Huib N; Molenaar, Jan J

    2011-10-01

    BIRC5 (survivin) is one of the genes located on chromosome arm 17q in the region that is often gained in neuroblastoma. BIRC5 is a protein in the intrinsic apoptotic pathway that interacts with XIAP and DIABLO leading to caspase-3 and caspase-9 inactivation. BIRC5 is also involved in stabilizing the microtubule-kinetochore dynamics. Based on the Affymetrix mRNA expression data, we here show that BIRC5 expression is strongly upregulated in neuroblastoma compared with normal tissues, adult malignancies, and non-malignant fetal adrenal neuroblasts. The over-expression of BIRC5 correlates with an unfavorable prognosis independent of the presence of 17q gain. Silencing of BIRC5 in neuroblastoma cell lines by various antisense molecules resulted in massive apoptosis as measured by PARP cleavage and FACS analysis. As both the intrinsic apoptotic pathway and the chromosomal passenger complex can be therapeutically targeted, we investigated in which of them BIRC5 exerted its essential anti-apoptotic role. Immunofluorescence analysis of neuroblastoma cells after BIRC5 silencing showed formation of multinucleated cells indicating mitotic catastrophe, which leads to apoptosis via P53 and CASP2. We show that BIRC5 silencing indeed resulted in activation of P53 and we could rescue apoptosis by CASP2 inhibition. We conclude that BIRC5 stabilizes the microtubules in the chromosomal passenger complex in neuroblastoma and that the apoptotic response results from mitotic catastrophe, which makes BIRC5 an interesting target for therapy.

  7. CAMTA1, a 1p36 tumor suppressor candidate, inhibits growth and activates differentiation programs in neuroblastoma cells.

    PubMed

    Henrich, Kai-Oliver; Bauer, Tobias; Schulte, Johannes; Ehemann, Volker; Deubzer, Hedwig; Gogolin, Sina; Muth, Daniel; Fischer, Matthias; Benner, Axel; König, Rainer; Schwab, Manfred; Westermann, Frank

    2011-04-15

    A distal portion of human chromosome 1p is often deleted in neuroblastomas and other cancers and it is generally assumed that this region harbors one or more tumor suppressor genes. In neuroblastoma, a 261 kb region at 1p36.3 that encompasses the smallest region of consistent deletion pinpoints the locus for calmodulin binding transcription activator 1 (CAMTA1). Low CAMTA1 expression is an independent predictor of poor outcome in multivariate survival analysis, but its potential functionality in neuroblastoma has not been explored. In this study, we used inducible cell models to analyze the impact of CAMTA1 on neuroblastoma biology. In neuroblastoma cells that expressed little endogenous CAMTA1, its ectopic expression slowed cell proliferation, increasing the relative proportion of cells in G(1)/G(0) phases of the cell cycle, inhibited anchorage-independent colony formation, and suppressed the growth of tumor xenografts. CAMTA1 also induced neurite-like processes and markers of neuronal differentiation in neuroblastoma cells. Further, retinoic acid and other differentiation- inducing stimuli upregulated CAMTA1 expression in neuroblastoma cells. Transciptome analysis revealed 683 genes regulated on CAMTA1 induction and gene ontology analysis identified genes consistent with CAMTA1-induced phenotypes, with a significant enrichment for genes involved in neuronal function and differentiation. Our findings define properties of CAMTA1 in growth suppression and neuronal differentiation that support its assignment as a 1p36 tumor suppressor gene in neuroblastoma.

  8. Phosphatidylinositol 3-kinase regulation of gastrin-releasing peptide-induced cell cycle progression in neuroblastoma cells.

    PubMed

    Ishola, Titilope A; Kang, JungHee; Qiao, Jingbo; Evers, B Mark; Chung, Dai H

    2007-06-01

    Gastrin-releasing peptide (GRP), the mammalian equivalent of bombesin (BBS), is an autocrine growth factor for neuroblastoma; its receptor is up-regulated in undifferentiated neuroblastomas. Phosphatidylinositol 3-kinase (PI3K) is a critical cell survival pathway; it is negatively regulated by the PTEN tumor suppressor gene. We have recently found that poorly differentiated neuroblastomas express decreased PTEN protein levels. Moreover, overexpression of the GRP receptor, a member of the G-protein coupled receptor family, down-regulates PTEN expression, resulting in increased neuroblastoma cell growth. Therefore, we sought to determine whether GRP or BBS activates PI3K in neuroblastoma cells (BE(2)-C, LAN-1, SK-N-SH). GRP or BBS treatment rapidly increased phosphorylation of Akt and GSK-3beta in neuroblastoma cells. Inhibition of GRP receptor, with antagonist GRP-H2756 or siRNA, attenuated BBS-induced phosphorylation of Akt. LY294002, a PI3K inhibitor, also abrogated BBS-stimulated phospho-Akt as well as its cell cycle targets. GRP increased G1/S phase progression in SK-N-SH cells. BBS-mediated BrdU incorporation was blocked by LY294002. Our findings identify PI3K as an important signaling pathway for GRP-mediated neuroblastoma cell growth. A novel therapy targeted at GRP/GRP receptor may prove to be an effective treatment option to inhibit PI3K in neuroblastomas.

  9. Galectin-3 impairment of MYCN-dependent apoptosis-sensitive phenotype is antagonized by nutlin-3 in neuroblastoma cells.

    PubMed

    Veschi, Veronica; Petroni, Marialaura; Cardinali, Beatrice; Dominici, Carlo; Screpanti, Isabella; Frati, Luigi; Bartolazzi, Armando; Gulino, Alberto; Giannini, Giuseppe

    2012-01-01

    MYCN amplification occurs in about 20-25% of human neuroblastomas and characterizes the majority of the high-risk cases, which display less than 50% prolonged survival rate despite intense multimodal treatment. Somehow paradoxically, MYCN also sensitizes neuroblastoma cells to apoptosis, understanding the molecular mechanisms of which might be relevant for the therapy of MYCN amplified neuroblastoma. We recently reported that the apoptosis-sensitive phenotype induced by MYCN is linked to stabilization of p53 and its proapoptotic kinase HIPK2. In MYCN primed neuroblastoma cells, further activation of both HIPK2 and p53 by Nutlin-3 leads to massive apoptosis in vitro and to tumor shrinkage and impairment of metastasis in xenograft models. Here we report that Galectin-3 impairs MYCN-primed and HIPK2-p53-dependent apoptosis in neuroblastoma cells. Galectin-3 is broadly expressed in human neuroblastoma cell lines and tumors and is repressed by MYCN to induce the apoptosis-sensitive phenotype. Despite its reduced levels, Galectin-3 can still exert residual antiapoptotic effects in MYCN amplified neuroblastoma cells, possibly due to its specific subcellular localization. Importantly, Nutlin-3 represses Galectin-3 expression, and this is required for its potent cell killing effect on MYCN amplified cell lines. Our data further characterize the apoptosis-sensitive phenotype induced by MYCN, expand our understanding of the activity of MDM2-p53 antagonists and highlight Galectin-3 as a potential biomarker for the tailored p53 reactivation therapy in patients with high-risk neuroblastomas.

  10. PPAR Gamma in Neuroblastoma: The Translational Perspectives of Hypoglycemic Drugs

    PubMed Central

    Conaldi, Pier Giulio

    2016-01-01

    Neuroblastoma (NB) is the most common and aggressive pediatric cancer, characterized by a remarkable phenotypic diversity and high malignancy. The heterogeneous clinical behavior, ranging from spontaneous remission to fatal metastatic disease, is attributable to NB biology and genetics. Despite major advances in therapies, NB is still associated with a high morbidity and mortality. Thus, novel diagnostic, prognostic, and therapeutic approaches are required, mainly to improve treatment outcomes of high-risk NB patients. Among neuroepithelial cancers, NB is the most studied tumor as far as PPAR ligands are concerned. PPAR ligands are endowed with antitumoral effects, mainly acting on cancer stem cells, and constitute a possible add-on therapy to antiblastic drugs, in particular for NB with unfavourable prognosis. While discussing clinical background, this review will provide a synopsis of the major studies about PPAR expression in NB, focusing on the potential beneficial effects of hypoglycemic drugs, thiazolidinediones and metformin, to reduce the occurrence of relapses as well as tumor regrowth in NB patients. PMID:27799938

  11. Molecular mechanism of action of opioids in human neuroblastoma cells

    SciTech Connect

    Yu, V.C.K.

    1987-01-01

    A series of human neuroblastoma cell lines was screened for the presence of opioid receptor sites. Of these cell lines, SK-N-SH was found to express approximately 50,000 ..mu.. and 10,000 delta opioid receptor sites/cell. In vitro characterization revealed that the binding properties of these receptor sites closely resembled those of human and rodent brain. Phosphatidylinositol turnover as a potential second messenger system for the ..mu.. receptor was examined in SK-N-SH cells. Neurotransmitter receptor systems were determined in the three sub-clones of SK-N-SH cells. Cells of the SH-SY5Y line, a phenotypically stable subclone of SK-N-SH cells, were induced to differentiate by treatment with various inducing agents, and changes of several neurotransmitter receptor systems were determined. Nerve growth factor (NGF) and retinoic acid (RA) up-regulated, while dBcAMP down-regulated opioid receptor sites. (/sup 3/H)Dopamine uptake was slightly enhanced only in RA-treated cells. Strikingly, the efficacy of PGE/sub 1/-stimulated accumulation of cAMP was enhanced by 15- to 30-fold upon RA treatment.

  12. Trace metals and cancer: The case of neuroblastoma

    NASA Astrophysics Data System (ADS)

    Gouget, B.; Sergeant, C.; Llabador, Y.; Devès, G.; Vesvres, M. H.; Simonoff, M.; Bénard, J.

    2001-07-01

    N- myc oncogene amplification is one of the most established prognostic factors in neuroblastoma (NB), a young children solid tumor. Amounts of ferritin, an iron storage protein, are abnormally increased in serum of patients with advanced stage disease. N- myc amplified NB cells can synthesize zinc metalloenzymes allowing tumor invasion and metastases formation. The aim of this study was to find a relationship between N- myc amplification and trace metals in human neuroblasts. Coupling PIXE and RBS techniques, nuclear microprobe allowed to analyze elemental distributions and to determine trace metal concentrations within cultured neuroblasts characterized by various degrees of N- myc amplification. They were compared to trace metal distributions and concentrations in tumor xenograft models of human NB, after injection of cells from the same lines in athymic nude mice. Our data allowed to establish a relation between trace metal contents and mechanisms of NB oncogenesis, amplified cell lines representing more aggressive phenotypes of the disease. They should be confirmed by analysis of cultured neuroblasts and tumors issued from a non-amplified cell line transfected with the N- myc oncogene.

  13. The influence of natural killer cells in neuroblastoma.

    PubMed

    Reynolds, J V; Shou, J; Choi, H; Sigal, R; Ziegler, M M; Daly, J M

    1989-02-01

    Human neuroblastoma (NRB) cell lines are markedly sensitive to natural killer (NK) cell lysis in vitro, but patients with NRBs have low or absent NK activity. This study evaluated the NK sensitivity of murine NRBs (C1300 and TBJ) in the regulation of NRB growth and determined the effects of recombinant (r) interferon gamma and recombinant interleukin 2 (rIL-2). Both basal (8% +/- 3% specific cytotoxicity) and induced (20% +/- 3%) NK lyses of C1300-NRB were observed. In vivo depletion of NK cells with anti-asialo GM-1 significantly enhanced growth of C1300-NRB and decreased survival. Treatment with r-interferon gamma or rIL-2 on days 1 through 3 after C1300-NRB inoculation significantly prolonged the mean tumor latency period, decreased the tumor growth rate, and enhanced in vitro NK killing of C1300-NRB and YAC-1. The effects of r-interferon gamma and IL-2 were abrogated by pretreatment with anti-asialo GM-1. These results demonstrated that NK cells form one important component of regulation of a murine NRB, but immunomodulation with potent lymphokines requires cooperation of more than one cell type.

  14. Combination therapies improve the anticancer activities of retinoids in neuroblastoma

    PubMed Central

    Cheung, Belamy B

    2015-01-01

    Most therapeutic protocols for child cancers use cytotoxic agents which have a narrow therapeutic index, and resulting in severe acute and chronic toxicities to normal tissues. Despite the fact that most child cancer patients achieve complete remission after chemotherapy, death still occurs due to relapse of persistent minimal residual disease (MRD) which remaining after initial cytotoxic chemotherapy. Advanced neuroblastoma (NB) is a leading cause of cancer deaths in young children. Retinoids are an important component of advanced NB therapy at the stage of MRD, yet half of all patients treated with 13-cis-retinoic acid still relapse and die. More effective combination therapies, with a lower side-effect profile, are required to improve outcomes for NB. Fenretinide or N-4-hydroxyphenyl retinamide is a synthetic derivative of retinoic acid which works on cancer cells through nuclear receptor-dependent and -independent signalling mechanisms. Moreover, several histone deacetylase inhibitors have entered early phase trials, and, suberoylanilide hydroxamic acid has been approved for use in adult cutaneous T cell lymphoma. A number of studies suggest that retinoid signal activation is necessary for histone deacetylase inhibitor activity. A better understanding of their mechanism of actions will lead to more evidence-based retinoid combination therapies. PMID:26677433

  15. Neuroblastoma: oncogenic mechanisms and therapeutic exploitation of necroptosis

    PubMed Central

    Nicolai, S; Pieraccioli, M; Peschiaroli, A; Melino, G; Raschellà, G

    2015-01-01

    Neuroblastoma (NB) is the most common extracranial childhood tumor classified in five stages (1, 2, 3, 4 and 4S), two of which (3 and 4) identify chemotherapy-resistant, highly aggressive disease. High-risk NB frequently displays MYCN amplification, mutations in ALK and ATRX, and genomic rearrangements in TERT genes. These NB subtypes are also characterized by reduced susceptibility to programmed cell death induced by chemotherapeutic drugs. The latter feature is a major cause of failure in the treatment of advanced NB patients. Thus, proper reactivation of apoptosis or of other types of programmed cell death pathways in response to treatment is relevant for the clinical management of aggressive forms of NB. In this short review, we will discuss the most relevant genomic rearrangements that define high-risk NB and the role that destabilization of p53 and p73 can have in NB aggressiveness. In addition, we will propose a strategy to stabilize p53 and p73 by using specific inhibitors of their ubiquitin-dependent degradation. Finally, we will introduce necroptosis as an alternative strategy to kill NB cells and increase tumor immunogenicity. PMID:26633716

  16. A single center clinical analysis of children with neuroblastoma

    PubMed Central

    SHAO, JING-BO; LU, ZHENG-HUA; HUANG, WEN-YAN; LV, ZHI-BAO; JIANG, HUI

    2015-01-01

    In the present study, the cases of 59 children diagnosed with neuroblastoma (NB) were retrospectively analyzed to assess the association between the short-term efficacy of treatment and prognostic factors. In total, 59 patients with NB that were diagnosed between July 1, 2008 and June 30, 2013 at Shanghai Children's Hospital were enrolled in the present study. The follow-up was performed until December 31, 2013, and the data revealed that 43 patients (72.9%) achieved complete remission (CR) or partial remission (PR). The 3-year overall survival (OS) rate of patients with stage I, II, III, IV and IVs disease was 100, 100, 65.6, 34.8 and 85.7%, respectively (P=0.02). The 3-year OS and event-free survival rates were evidently increased in patients with favorable histology compared with the rates in the patients with unfavorable histology (P=0.046 and 0.030, respectively). Univariate statistical analysis revealed that the factors significantly associated with prognosis were patient age, tumor stage and risk group (P=0.004, 0.02 and 0.001, respectively). The present study identified that tumor stage, risk group and patient age are important prognostic factors for NB. An age of 18 months was also hypothesized to be the cut-off for the prognosis of patients. PMID:26622841

  17. Neuroblastoma: oncogenic mechanisms and therapeutic exploitation of necroptosis.

    PubMed

    Nicolai, S; Pieraccioli, M; Peschiaroli, A; Melino, G; Raschellà, G

    2015-01-01

    Neuroblastoma (NB) is the most common extracranial childhood tumor classified in five stages (1, 2, 3, 4 and 4S), two of which (3 and 4) identify chemotherapy-resistant, highly aggressive disease. High-risk NB frequently displays MYCN amplification, mutations in ALK and ATRX, and genomic rearrangements in TERT genes. These NB subtypes are also characterized by reduced susceptibility to programmed cell death induced by chemotherapeutic drugs. The latter feature is a major cause of failure in the treatment of advanced NB patients. Thus, proper reactivation of apoptosis or of other types of programmed cell death pathways in response to treatment is relevant for the clinical management of aggressive forms of NB. In this short review, we will discuss the most relevant genomic rearrangements that define high-risk NB and the role that destabilization of p53 and p73 can have in NB aggressiveness. In addition, we will propose a strategy to stabilize p53 and p73 by using specific inhibitors of their ubiquitin-dependent degradation. Finally, we will introduce necroptosis as an alternative strategy to kill NB cells and increase tumor immunogenicity. PMID:26633716

  18. Recurrent Olfactory Neuroblastoma Treated With Cetuximab and Sunitinib

    PubMed Central

    Wang, Lizhi; Ding, Yan; Wei, Lai; Zhao, Dewei; Wang, Ruoyu; Zhang, Yuewei; Gu, Xuesong; Wang, Zhiqiang

    2016-01-01

    Abstract Olfactory neuroblastoma (ONB) is a rare cancer originating in the olfactory epithelium of the nasal vault. The recurrence rate of ONB is high, as the standard treatment of surgery followed by radiotherapy and/or chemotherapy is usually unsuccessful. The use of targeted therapy based on individual genomic variations after cancer relapse has not been reported. Here, we present the case of a 44-year-old man who was diagnosed with recurrent ONB and treated with a regimen developed using whole exome sequencing. Potential targets were first identified and then matched to appropriate drugs. Gene mutations in the genes encoding EGFR, FGFR2, KDR, and RET were discovered in the patient's tumor tissue by whole exome sequencing and the patient was treated with a combination of the targeted drugs cetuximab and sunitinib. Five days after treatment, enhancement magnetic resonance imaging showed a 65% reduction in tumor size, and the Visual analog scale headache scores went down to 2/10 from 10/10. Repeat imaging at 1 month showed a complete response. This study represents the first demonstration of an effective personalized treatment of ONB by targeted drugs, and sheds light on how precision medicine can be used to treat recurrent ONB that fails to respond to routine tumor resection, radiotherapy, and/or chemotherapy. PMID:27149458

  19. Novel proteasome inhibitor ixazomib sensitizes neuroblastoma cells to doxorubicin treatment

    PubMed Central

    Li, Haoyu; Chen, Zhenghu; Hu, Ting; Wang, Long; Yu, Yang; Zhao, Yanling; Sun, Wenijing; Guan, Shan; Pang, Jonathan C.; Woodfield, Sarah E.; Liu, Qing; Yang, Jianhua

    2016-01-01

    Neuroblastoma (NB) is the most common extracranial malignant solid tumor seen in children and continues to lead to the death of many pediatric cancer patients. The poor outcome in high risk NB is largely attributed to the development of chemoresistant tumor cells. Doxorubicin (dox) has been widely employed as a potent anti-cancer agent in chemotherapeutic regimens; however, it also leads to chemoresistance in many cancer types including NB. Thus, developing novel small molecules that can overcome dox-induced chemoresistance is a promising strategy in cancer therapy. Here we show that the second generation proteasome inhibitor ixazomib (MLN9708) not only inhibits NB cell proliferation and induces apoptosis in vitro but also enhances dox-induced cytotoxicity in NB cells. Ixazomib inhibits dox-induced NF-κB activity and sensitizes NB cells to dox-induced apoptosis. More importantly, ixazomib demonstrated potent anti-tumor efficacy in vivo by enhancing dox-induced apoptosis in an orthotopic xenograft NB mouse model. Collectively, our study illustrates the anti-tumor efficacy of ixazomib in NB both alone and in combination with dox, suggesting that combination therapy including ixazomib with traditional therapeutic agents such as dox is a viable strategy that may achieve better outcomes for NB patients. PMID:27687684

  20. Synchronous Hepatoblastoma, Neuroblastoma, and Cutaneous Capillary Hemangiomas: A Case Report.

    PubMed

    Ozawa, Michael G; Cooney, Tabitha; Rangaswami, Arun; Hazard, Florette K

    2016-01-01

    Multiple synchronous tumors presenting in infancy raise concern for inherited or sporadic cancer predisposition syndromes, which include Beckwith-Wiedemann syndrome, familial adenomatous polyposis syndrome, and Li-Fraumeni syndrome. We report a case of a 7-month-old previously healthy male born following an in vitro fertilization-assisted twin pregnancy who presented with new-onset refractory shock, severe acidosis, and rapid decline over several hours. An autopsy revealed a ruptured liver involved by hepatoblastoma, an adrenal gland involved by neuroblastoma, and multiple cutaneous capillary hemangiomas. Standard genetic testing demonstrated that both twins were Gaucher disease (GD) carriers without evidence of other known cancer predisposition syndromes. This report describes a unique association of multiple synchronous tumors, which underscores the utility and importance of the pediatric autopsy. Moreover, given that the reported child was a GD carrier, the possibility the tumors were the result of a GD-mediated cancer-associated phenotype or an unrecognized sporadic clinical syndrome remains an unanswered, but intriguing, question worthy of further investigation. PMID:26368548