salicylates and Neuroblastoma

To date, the effect of resveratrol on tinnitus has not been reported. The attenuative effects of resveratrol (RSV) on a salicylate-induced tinnitus model were evaluated by in vitro and in vivo experiments. The gene expression of the activity-regulated cytoskeleton-associated protein (

Topics: Animals; Disease Models, Animal; Humans; Neuroblastoma; Rats; Rats, Sprague-Dawley; Resveratrol; Salicylates; Tinnitus; Tumor Necrosis Factor-alpha

Parkinson's disease (PD) and Amyotrophic lateral sclerosis (ALS), are neurodegenerative disorders characterized by loss of dopaminergic or motor neurons, respectively. Although understanding of the PD and ALS pathogenesis remains incomplete, increasing evidence from human and animal studies has suggested that aberrant GSK3β, oxidative stress and mitochondrial damage are involved in their pathogenesis. Using two different molecular models, treatment with L-BMAA for ALS and rotenone for PD the effect of isolecanoric acid, a natural product isolated from a fungal culture, was evaluated. Pre-treatment with this molecule caused inhibition of GSK3β and CK1, and a decrease in oxidative stress, mitochondrial damage, apoptosis and cell death. Taken together, these results indicated that isolecanoric acid might have a protective effect against the development of these neurodegenerative disorders.

Topics: Amino Acids, Diamino; Apoptosis; Cell Line, Transformed; Cell Survival; Cyanobacteria Toxins; Dose-Response Relationship, Drug; Excitatory Amino Acid Agonists; Flow Cytometry; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Humans; Membrane Potential, Mitochondrial; Neuroblastoma; Neuroprotective Agents; Reactive Oxygen Species; Salicylates

Several studies suggest that soluble Amyloid β (Aβ) oligomer-induced aberrant neuronal cell cycle re-entry is the initial trigger for a significant part of the neuronal degeneration and loss in Alzheimer's disease (AD). In this study, we investigated the role of Ras, which is a well-known protooncoprotein, in soluble Aβ oligomer-induced aberrant neuronal cell cycle activation and subsequent cell loss using retinoic acid differentiated human SH-SY5Y neuroblastoma cells as model system. In line with previous literature, we showed that in vitro preparations of soluble Aβ42 oligomers triggered cell cycle activation but not cell proliferation. As a new finding, we showed that Farnesylthiosalicylic acid (FTS), a specific chemical Ras inhibitor, prevented soluble Aβ42 oligomer preparation-induced cell cycle activation. Moreover, we showed that the expression of dominant negative mutant H-Ras (S17N) prevented soluble Aβ42 oligomer preparation-induced cell cycle activation, confirming the specific role of Ras in this pathway. As a possible better mimic of the situation in the AD brain, we prepared soluble oligomers from Aβ42 : Aβ40 (3:7) peptide mixture and showed that this oligomer preparation similarly induced cell cycle activation which was also inhibited by the Ras inhibitor. Finally, we showed that FTS prevented soluble Aβ42 oligomer preparationinduced cell death in our retinoic acid differentiated SH-SY5Y cells. Overall, our results strongly suggest that Ras activity is required for soluble Aβ oligomer-induced aberrant neuronal cell cycle reentry and subsequent neuronal loss, which are considered important mechanisms in AD pathogenesis.

Topics: Amyloid beta-Peptides; Cell Cycle; Cell Death; Cell Differentiation; Cell Line, Tumor; Dose-Response Relationship, Drug; Enzyme Inhibitors; Farnesol; Gene Expression Regulation; Humans; Microtubule-Associated Proteins; Neuroblastoma; Neurons; Peptide Fragments; ras Proteins; Salicylates; Time Factors

Aggregation of human islet amyloid polypeptide (IAPP) into pancreatic fibrillar deposits has been postulated to be one of the main contributors to impaired insulin secretion and pancreatic β-cell death in approximately 90% of type 2 diabetic patients. So, compounds that prevent cytotoxic protein/polypeptide self-assembly and amyloidogenesis are considered as novel therapeutic agents against this disease. In this study, using thioflavin-T (ThT) and Anilinonaphthalene-8-sulfonic acid (ANS) fluorescence assays, transmission electron microscopy (TEM) and docking studies, we investigated whether EUK-8 and EUK-134, two salen derivatives with proven antioxidants activities, could interfere with the conversion of synthetic human amylin to its insoluble amyloid form. Spectroscopy and electron microscopy data indicated that incubation of human amylin with either EUK-8 or EUK-134 significantly inhibited amyloid formation at two molar ratios of 1:1 and 5:1 (drugs to protein). In addition, [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) assay showed that treatment of SK-N-MC cells with the pre-formed fibrils in the presence of compounds at drug-to-protein molar ratios of 1:1 and 5:1, dramatically increased the viability of cells compared to the only fibrils formed-treated SK-N-MC cells. Docking results also demonstrated that the aromatic rings of EUK-8 and EUK-134 interact with the hydrophobic region (23-25) of IAPP via Van der Waals interactions. Based on these results and the proven antioxidant properties of these compounds, it could be concluded that these compounds might provide a novel approach to prevent islet amyloid deposition in β-cells and provide useful information for developing other novel compounds for the treatment of type 2 diabetes.

Topics: Amyloid; Anilino Naphthalenesulfonates; Antioxidants; Benzothiazoles; Cell Line, Tumor; Cell Survival; Diabetes Mellitus, Type 2; Ethylenediamines; Fluorescent Dyes; Humans; Islet Amyloid Polypeptide; Microscopy, Electron, Transmission; Molecular Docking Simulation; Neuroblastoma; Organometallic Compounds; Salicylates; Thiazoles

Alzheimer's disease is a neurodegenerative disorder that is characterized by the accumulation of senile plaques containing amyloid β (Aβ) and neurofibrillary tangles composed of hyperphosphorylated tau protein in the brain. Oxidative stress has been proposed to mediate Aβ-induced neurotoxicity. In that regard, we evaluated the ability of EUK134, a superoxide dismutase and catalase mimics, to protect human neuroblastoma cell line SK-N-MC against H(2)O(2) -induced oxidative stress. Our data clearly indicated that cell death induced by H(2)O(2) was reversed by EUK134. Likewise, lipid peroxidation, caspase-3 activation and intracellular reactive oxygen species formation all returned to control levels following pre-treatments with EUK134. Elevated phosphorylation of mitogen-activated protein kinases (MAPK) induced by H(2)O(2) in SK-N-MC cells was lowered by EUK134 in a dose-dependent manner. In addition, EUK134 decreased expression of pro-apoptotic genes p53 and Bax and enhanced expression of anti-apoptotic Bcl-2 gene. Taken together, these results suggest that EUK134 protects neuronal cells against H(2)O(2) toxicity by attenuating oxidative stress through inhibition of MAPK phosphorylation cascade.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Antineoplastic Agents; Antioxidants; Apoptosis; Caspase 3; Catalase; Cell Death; Cell Line, Tumor; Dose-Response Relationship, Drug; Free Radical Scavengers; Genes, bcl-2; Humans; Hydrogen Peroxide; Lipid Peroxidation; Mitogen-Activated Protein Kinases; Neuroblastoma; Neuroprotective Agents; Organometallic Compounds; Reactive Oxygen Species; Salicylates; Superoxide Dismutase

In neuroblastoma LAN-1 cells harboring an amplified MycN gene, disruption of cooperation between Ras and MycN proteins by the Ras inhibitor farnesylthiosalicylic acid (FTS, Salirasib) reportedly arrests cell growth. Our aim was to establish whether this is a general phenomenon. We examined the effects of FTS on gene-expression profiles, growth and death of NCIH929 myeloma cells and K562 leukemia cells, which-like LAN-1 cells-exhibit Myc gene amplification and harbor active Ras. Under specified conditions, FTS reduced Ras and Myc and induced cell growth arrest and death in all Myc-amplified cell lines but not in SHEP, a neuroblastoma cell line without Myc gene amplification. Gene-expression analysis revealed a common pattern of FTS-induced endoplasmic reticulum (ER) stress, known as the unfolded protein response (UPR), in Myc-amplified cells, but not in SHEP. Thus, Ras negatively regulates ER stress in cells with amplified Myc. ER stress was also inducible by dominant-negative (DN)-Ras or shRNA to Ras isoforms, all of which induced an increase in BIP (the master regulator of ER stress) and its downstream targets Nrf2 and eIF2alpha, both regulated by active p-PERK. FTS also induced an increase in p-PERK, while small interfering RNA to PERK reduced Nrf2 and ATF4 and rescued cells from FTS-induced death. BIP and its downstream targets were also increased by inhibitors of MAPK p38 and MEK. Ras, acting through MAPK p38 and MEK, negatively regulates the ER stress cascades BIP/PERK/Nrf2 and eIF2alpha/ATF4/ATF3. These findings can explain the Ras-dependent protection of Myc-amplified cells from ER stress-associated death.

Topics: Antineoplastic Agents; Cell Line, Tumor; Cell Proliferation; eIF-2 Kinase; Endoplasmic Reticulum; Enzyme Inhibitors; Farnesol; Gene Amplification; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Humans; K562 Cells; Mitogen-Activated Protein Kinase Kinases; N-Myc Proto-Oncogene Protein; Neuroblastoma; NF-E2-Related Factor 2; Nuclear Proteins; Oncogene Proteins; ras Proteins; RNA, Small Interfering; Salicylates; Transcription Factors; Unfolded Protein Response

Topics: Cell Line, Tumor; Cell Proliferation; Farnesol; Gene Expression Regulation, Neoplastic; Humans; Models, Biological; Neuroblastoma; Proto-Oncogene Proteins c-myc; ras Proteins; Salicylates; Signal Transduction

Our aim was to examine whether active Ras and MycN cooperation contributes to the malignant phenotype of human neuroblastoma with amplified MycN gene, an aggressive incurable tumor.. Human neuroblastoma LAN-1 cells, in which the MycN gene is amplified, were used to examine the impact of the Ras inhibitor farnesylthiosalicylic acid on cell growth, on the levels Ras and MycN proteins, and on profiles of gene expression.. We show that LAN-1 cells express relatively large amounts of MycN and active Ras-GTP. Inhibition of active Ras by farnesylthiosalicylic acid led to attenuation of the Raf-MEK-ERK and phosphoinositide 3-kinase-Akt-glycogen synthase-3 (GSK-3) pathways, to reduction in cyclin D1, phospho-retinoblastoma, and E2F, and to increase in the cyclin-dependent kinase inhibitor p27 and in retinoblastoma-binding protein-1, an inhibitor of E2F transcriptional activity. Ras inhibition by farnesylthiosalicylic acid or by a dominant-negative Ras also led to complete disappearance of MycN protein from the nuclei of LAN-1 cells. This was a result of blocking of Akt inactivation of GSK-3, leading to GSK-3-dependent phosphorylation with consequent proteosomal degradation of MycN. Loss of active Ras and of MycN in LAN-1 cells was manifested in profiles of gene expression that could be expected from the loss of MycN transcriptional activity and of Ras signaling. These changes explain the farnesylthiosalicylic acid-induced inhibition of LAN-1 cell growth.. Active Ras is needed to block MycN degradation, promoting cooperative Ras- and MycN-dependent cell cycle progression in LAN-1 cells. Ras inhibitors are therefore likely candidates for the treatment of advanced neuroblastoma characterized by high expression of MycN.

Topics: Carrier Proteins; Cell Cycle Proteins; Cell Line, Tumor; Cell Nucleus; Cell Proliferation; Cell Survival; Cyclin-Dependent Kinase Inhibitor p27; Down-Regulation; Farnesol; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Glycogen Synthase Kinase 3; Green Fluorescent Proteins; Humans; Immunoblotting; In Situ Hybridization, Fluorescence; Microscopy, Confocal; Mitogen-Activated Protein Kinases; Neuroblastoma; Oligonucleotide Array Sequence Analysis; Phosphatidylinositol 3-Kinases; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-myc; raf Kinases; ras Proteins; Retinoblastoma-Binding Protein 1; Salicylates; Signal Transduction; Transfection; Tumor Suppressor Proteins

A lipophilic farnesyl moiety attached to the carboxyl terminal cysteine of ras proteins structurally supports their membrane anchorage, required for ras-dependent growth-factor signaling and for transforming activity of ras oncoproteins. It has been shown that inhibition of ras farnesylation can block tumor growth in nude mice but that some ras-dependent tumors escape such blockage as a result of prenylation of ras. S-trans-transfarnesylthiosalicylic acid (FTS) is a potent ras-dislodging antagonist that does not affect ras prenylation but rather acts on the mature, membrane-bound ras and facilitates its degradation. Here we demonstrate that FTS induces reappearance of stress fibers in H-ras-transformed rat-1 cells (EJ cells) in vitro, inhibits their anchorage-independent growth in vitro, and blocks EJ-tumor growth in nude mice. The anchorage-independent growth of cells expressing ErbB2 (B104), but not that of v-raf-transformed cells, is also inhibited by FTS, suggesting specificity towards activated ras. FTS treatment (5 mg/kg i.p. daily) caused inhibition (75-80%) of tumor growth in nude mice implanted with EJ, but not in mice implanted with v-raf-transformed cells, with no evidence of systemic toxicity. Moreover, FTS treatment increased the survival rate of EJ-tumor-bearing mice from 48 to 68 days. Here we demonstrate anti-tumor potency in a synthetic, non-toxic, ras-dislodging antagonist acting independently of farnesyltransferases.

Topics: 3T3 Cells; Actins; Animals; Antineoplastic Agents; Cell Division; Cell Transformation, Neoplastic; Cytoskeleton; Farnesol; Genes, erbB-2; Genes, ras; Male; Mice; Mice, Nude; Neoplasm Proteins; Neoplasm Transplantation; Neoplasms, Experimental; Neuroblastoma; Oncogene Proteins v-raf; Protein Prenylation; Protein Processing, Post-Translational; Proto-Oncogene Proteins p21(ras); Rats; Receptor, ErbB-2; Retroviridae Proteins, Oncogenic; Salicylates; Substrate Specificity; Tumor Cells, Cultured