Bioactivatable, Membrane-Permeant Analogs of Cyclic Nucleotides as Biological Tools for Growth Control of C6 Glioma Cells

2003 ◽  
Vol 384 (9) ◽  
pp. 1321-1326 ◽  
Author(s):  
M. Bartsch ◽  
M. Zorn-Kruppa ◽  
N. Kühl ◽  
H.-G. Genieser ◽  
F. Schwede ◽  
...  
Keyword(s):  
Cyclic Nucleotides ◽  
Growth Control ◽  
Glioma Cells ◽  
Glioma Cell Line ◽  
C6 Glioma ◽  
C6 Glioma Cells ◽  
C6 Cells ◽  
Dibutyryl Camp ◽  
Ester Prodrugs ◽  
Rat C6 Glioma

Abstract In the present study, the cAMP analogs 8-bromocAMP (8-Brc-AMP), N6-2'O-dibutyryl-cAMP (DBcAMP) and 8-parachlorophenylthio-cAMP (8-CPT-cAMP), as well as the corresponding cAMP-acetoxymethyl (AM)-ester-prodrugs were tested in a HPLC study for their membrane permeability, intracellular accumulation and biotransformation. Antiproliferative activities of these compounds were studied in the rat C6 glioma cell line. Chromatographic analysis revealed that the AM-ester analogs of the cyclic nucleotides penetrate quantitatively into rat C6 glioma cells and generate high amounts of their parent cyclic nucleotides intracellularly within 60 min; however, longterm growth inhibition tested in C6 cells is only slightly enhanced with the AM-ester prodrugs of 8-Br-cAMP or DBcAMP.

scholarly journals Binding, degradation and apoptotic activity of stearoylethanolamide in rat C6 glioma cells

2002 ◽  
Vol 366 (1) ◽  
pp. 137-144 ◽  
Author(s):  
Mauro MACCARRONE ◽  
Riccardo PAUSELLI ◽  
Marianna di RIENZO ◽  
Alessandro FINAZZI-AGRÒ
Keyword(s):  
Biological Activity ◽  
Acid Amide ◽  
Glioma Cells ◽  
C6 Glioma ◽  
C6 Glioma Cells ◽  
C6 Cells ◽  
Cannabinoid Type 1 Receptor ◽  
Apoptotic Activity ◽  
Rat C6 Glioma

Stearoylethanolamide (SEA) is present in human, rat and mouse brain in amounts comparable with those of the endocannabinoid anandamide (arachidonoylethanolamide; AEA). Yet, the biological activity of SEA has never been investigated. We synthesized unlabelled and radiolabelled SEA to investigate its binding, degradation and biological activity in rat C6 glioma cells. We report that SEA binds to a specific site distinct from known cannabinoid or vanilloid receptors, and that AEA and capsazepine partly (approx. 50%) antagonized this binding. Treatment of C6 cells with SEA inhibits cellular nitric oxide synthase and does not affect adenylate cyclase, whereas treatment with cannabinoid type 1 agonist 2-arachidonoylglycerol activates the former enzyme and inhibits the latter. C6 cells also have a specific SEA membrane transporter, which is inhibited by NO, and a fatty acid amide hydrolase capable of cleaving SEA. In these cells, SEA shows pro-apoptotic activity, due to elevation of intracellular calcium, activation of the arachidonate cascade and mitochondrial uncoupling. NO further enhances SEA-induced apoptosis. Moreover, the cannabinoid type 1 receptor-mediated decrease in cAMP induced by AEA in C6 cells is potentiated by SEA, suggesting that this compound also has an ‘entourage’ effect. Taken together, this study shows that SEA is an endocannabinoid-like compound which binds to and is transported by new components of the endocannabinoid system. It seems noteworthy that degradation and pro-apoptotic activity of SEA are regulated by NO in a way opposite to that reported for AEA.

scholarly journals Sensitivity of the Natriuretic Peptide/cGMP System to Hyperammonaemia in Rat C6 Glioma Cells and GPNT Brain Endothelial Cells

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 398
Author(s):  
Jacob T. Regan ◽  
Samantha M. Mirczuk ◽  
Christopher J. Scudder ◽  
Emily Stacey ◽  
Sabah Khan ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Natriuretic Peptide ◽  
Glioma Cells ◽  
C6 Glioma ◽  
Nitric Oxide Donor ◽  
C6 Glioma Cells ◽  
Brain Endothelial Cells ◽  
C6 Cells ◽  
Rat C6 Glioma

C-type natriuretic peptide (CNP) is the major natriuretic peptide of the central nervous system and acts via its selective guanylyl cyclase-B (GC-B) receptor to regulate cGMP production in neurons, astrocytes and endothelial cells. CNP is implicated in the regulation of neurogenesis, axonal bifurcation, as well as learning and memory. Several neurological disorders result in toxic concentrations of ammonia (hyperammonaemia), which can adversely affect astrocyte function. However, the relationship between CNP and hyperammonaemia is poorly understood. Here, we examine the molecular and pharmacological control of CNP in rat C6 glioma cells and rat GPNT brain endothelial cells, under conditions of hyperammonaemia. Concentration-dependent inhibition of C6 glioma cell proliferation by hyperammonaemia was unaffected by CNP co-treatment. Furthermore, hyperammonaemia pre-treatment (for 1 h and 24 h) caused a significant inhibition in subsequent CNP-stimulated cGMP accumulation in both C6 and GPNT cells, whereas nitric-oxide-dependent cGMP accumulation was not affected. CNP-stimulated cGMP efflux from C6 glioma cells was significantly reduced under conditions of hyperammonaemia, potentially via a mechanism involving changed in phosphodiesterase expression. Hyperammonaemia-stimulated ROS production was unaffected by CNP but enhanced by a nitric oxide donor in C6 cells. Extracellular vesicle production from C6 cells was enhanced by hyperammonaemia, and these vesicles caused impaired CNP-stimulated cGMP signalling in GPNT cells. Collectively, these data demonstrate functional interaction between CNP signalling and hyperammonaemia in C6 glioma and GPNT cells, but the exact mechanisms remain to be established.

Radiosensitivity of glioma to Gamma Knife treatment enhanced in vitro and in vivo by RNA interfering Ku70 that is mediated by a recombinant adenovirus

2010 ◽  
Vol 113 (Special_Supplement) ◽  
pp. 228-235 ◽  
Author(s):  
Qiang Jia ◽  
Yanhe Li ◽  
Desheng Xu ◽  
Zhenjiang Li ◽  
Zhiyuan Zhang ◽  
...  
Keyword(s):  
Western Blot ◽  
Gamma Knife ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Glioma Cells ◽  
C6 Glioma ◽  
C6 Glioma Cells ◽  
C6 Cells

Object The authors sought to evaluate modification of the radiation response of C6 glioma cells in vitro and in vivo by inhibiting the expression of Ku70. To do so they investigated the effect of gene transfer involving a recombinant replication-defective adenovirus containing Ku70 short hairpin RNA (Ad-Ku70shRNA) combined with Gamma Knife treatment (GKT). Methods First, Ad-Ku70shRNA was transfected into C6 glioma cells and the expression of Ku70 was measured using Western blot analysis. In vitro, phenotypical changes in C6 cells, including proliferation, cell cycle modification, invasion ability, and apoptosis were evaluated using the MTT (3′(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide) assay, Western blot analysis, and cell flow cytometry. In vivo, parental C6 cells transfected with Ad-Ku70shRNA were implanted stereotactically into the right caudate nucleus in Sprague-Dawley rats. After GKS, apoptosis was analyzed using the TUNEL (terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick-end labeling) method. The inhibitory effects on growth and invasion that were induced by expression of proliferating cell nuclear antigen and matrix metalloproteinase–9 were determined using immunohistochemical analyses. Results The expression of Ku70 was clearly inhibited in C6 cells after transfection with Ad-Ku70shRNA. In vitro following transfection, the C6 cells showed improved responses to GKT, including suppression of proliferation and invasion as well as an increased apoptosis index. In vivo following transfection of Ad-Ku70shRNA, the therapeutic efficacy of GKT in rats with C6 gliomas was greatly enhanced and survival times in these animals were prolonged. Conclusions Our data support the potential for downregulation of Ku70 expression in enhancing the radiosensitivity of gliomas. The findings of our study indicate that targeted gene therapy–mediated inactivation of Ku70 may represent a promising strategy in improving the radioresponsiveness of gliomas to GKT.

scholarly journals α-Conotoxins and α-Cobratoxin Promote, while Lipoxygenase and Cyclooxygenase Inhibitors Suppress the Proliferation of Glioma C6 Cells

Marine Drugs ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. 118
Author(s):  
Tatiana I. Terpinskaya ◽  
Alexey V. Osipov ◽  
Elena V. Kryukova ◽  
Denis S. Kudryavtsev ◽  
Nina V. Kopylova ◽  
...  
Keyword(s):  
Nicotinic Acetylcholine Receptors ◽  
Acetylcholine Receptors ◽  
Glioma Cells ◽  
Nordihydroguaiaretic Acid ◽  
C6 Glioma ◽  
Cyclooxygenase Inhibitors ◽  
C6 Glioma Cells ◽  
C6 Cells ◽  
Lipoxygenase Inhibitor ◽  
Glioma C6

Among the brain tumors, glioma is the most common. In general, different biochemical mechanisms, involving nicotinic acetylcholine receptors (nAChRs) and the arachidonic acid cascade are involved in oncogenesis. Although the engagement of the latter in survival and proliferation of rat C6 glioma has been shown, there are practically no data about the presence and the role of nAChRs in C6 cells. In this work we studied the effects of nAChR antagonists, marine snail α-conotoxins and snake α-cobratoxin, on the survival and proliferation of C6 glioma cells. The effects of the lipoxygenase and cyclooxygenase inhibitors either alone or together with α-conotoxins and α-cobratoxin were studied in parallel. It was found that α-conotoxins and α-cobratoxin promoted the proliferation of C6 glioma cells, while nicotine had practically no effect at concentrations below 1 µL/mL. Nordihydroguaiaretic acid, a nonspecific lipoxygenase inhibitor, and baicalein, a 12-lipoxygenase inhibitor, exerted antiproliferative and cytotoxic effects on C6 cells. nAChR inhibitors weaken this effect after 24 h cultivation but produced no effects at longer times. Quantitative real-time polymerase chain reaction showed that mRNA for α4, α7, β2 and β4 subunits of nAChR were expressed in C6 glioma cells. This is the first indication for involvement of nAChRs in mechanisms of glioma cell proliferation.

scholarly journals Impact of calcitriol and an AKT inhibitor, AT7867, on survival of rat C6 glioma cells

2021 ◽  
Vol 35 (1) ◽  
pp. 730-738
Author(s):  
Ozlem Kucukhuseyin ◽  
Aris Cakiris ◽  
Mehmet Tolgahan Hakan ◽  
Cem Horozoglu ◽  
Erdem Tuzun ◽  
...  
Keyword(s):  
Glioma Cells ◽  
C6 Glioma ◽  
C6 Glioma Cells ◽  
Akt Inhibitor ◽  
Rat C6 Glioma

Increased expression and secretion of r-Gsp protein, rat counterpart of complement C1s precursor, during cyclic AMP-induced differentiation in rat C6 glioma cells

2002 ◽  
Vol 106 (1-2) ◽  
pp. 12-21 ◽  
Author(s):  
Masanori Nakagawa ◽  
Shigeru Nakashima ◽  
Yoshiko Banno ◽  
Jun Yamada ◽  
Motoshi Sawada ◽  
...  
Keyword(s):  
Cyclic Amp ◽  
Glioma Cells ◽  
C6 Glioma ◽  
C6 Glioma Cells ◽  
Induced Differentiation ◽  
Rat C6 Glioma
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