Synergistic Apoptotic Effect of Naringenin on enhancing the Anti-Glioma Efficacy of Temozolomide in an in vitro Experimental Model

Glioma is one of the most devastating and difficult-totreat brain tumors with a very poor prognosis. Despite the current treatment modalities, the overall survival rate is only 5% contributing to a high mortality rate. Nevertheless, of emerging treatment strategies, there is still a rising need for novel mitigation strategies to counteract glioma aggressiveness. One attempt towards this long-term goal was made in this study to reveal the combined efficacy of naringenin, a bioactive flavonoid on enhancing the anti-glioma potency of temozolomide in C6 glioma cells. The cytotoxic effect of temozolomide and naringenin, both individually and in combination was assessed by employing MTT assay. The synergistic effect of the drugs temozolomide and naringenin was determined by calculating the combination index. To confirm the presence of apoptotic changes in the cells at morphological level, acridine orange/ethidium bromide staining was performed. Further, the modulatory effects of the drugs on apoptotic genes, caspase-3 and BCL-2 were evaluated using quantitative real time-PCR. Interestingly, we found that the combinatorial drug treatment was in consensus and effectively inhibited the growth of C6 glioma cells in a dose-dependent manner. Furthermore, this combinatorial drug treatment significantly up-regulated the expression of the proapoptotic gene, caspase-3 and down-regulated the anti-apoptotic gene BCL-2 suggesting a shift of equilibrium towards apoptosis. Our findings suggest that naringenin can be employed as a potent drug to enhance the anti-glioma efficacy of temozolomide and could be therapeutically exploited for the management of glioma.

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

Journal of Neurosurgery ◽

10.3171/2010.7.gks10972 ◽

2010 ◽

Vol 113 (Special_Supplement) ◽

pp. 228-235 ◽

Cited By ~ 4

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.

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Rodent and primate adrenal medullary cells in vitro: phenotypic plasticity in response to coculture with C6 glioma cells or NGF

Experimental Brain Research ◽

10.1007/bf00253621 ◽

1989 ◽

Vol 76 (1) ◽

Cited By ~ 8

Author(s):

M.F.D. Notter ◽

J.T. Hansen ◽

S. Okawara ◽

D.M. Gash

Keyword(s):

Phenotypic Plasticity ◽

Glioma Cells ◽

C6 Glioma ◽

C6 Glioma Cells ◽

Adrenal Medullary Cells ◽

Medullary Cells

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Significant correlations between atmospheric spectra according to Baumer and the in vitro incorporation of [3 H]thymidine into the nuclear DNA of C6-glioma cells

FEBS Letters ◽

10.1016/0014-5793(91)81045-a ◽

1991 ◽

Vol 288 (1-2) ◽

pp. 244-246 ◽

Cited By ~ 4

Author(s):

Siegfried Vogl ◽

Georg Hoffmann ◽

Barbara Stöpfel ◽

Hans Baumer ◽

Oliver Kempski ◽

...

Keyword(s):

Nuclear Dna ◽

Glioma Cells ◽

C6 Glioma ◽

C6 Glioma Cells

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Binding of bovine, ovine, porcine, canine, and rat plasminogen to rat hepatocytes and rat C6 glioma cells in vitro

Biochemical and Biophysical Research Communications ◽

10.1016/0006-291x(89)91809-3 ◽

1989 ◽

Vol 164 (3) ◽

pp. 1288-1294 ◽

Cited By ~ 5

Author(s):

Scott W. Hall ◽

Lela L. Braud ◽

Steven L. Gonias

Keyword(s):

Glioma Cells ◽

Rat Hepatocytes ◽

C6 Glioma ◽

C6 Glioma Cells ◽

Rat C6 Glioma

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Characterization of angiotensin receptors mediating prostaglandin synthesis in C6 glioma cells

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1991.260.5.r1000 ◽

1991 ◽

Vol 260 (5) ◽

pp. R1000-R1006 ◽

Cited By ~ 4

Author(s):

N. Jaiswal ◽

D. I. Diz ◽

E. A. Tallant ◽

M. C. Khosla ◽

C. M. Ferrario

Keyword(s):

Glioma Cells ◽

C6 Glioma ◽

C6 Glioma Cells ◽

Angiotensin Receptors ◽

Receptor Subtype ◽

Receptor Subtypes ◽

Dependent Manner ◽

Ang Ii ◽

Selective Antagonist ◽

Pge2 Release

The heptapeptide angiotensin (ANG)-(1-7) mimics some but not all the central actions of ANG II, suggesting that receptor subtypes may exist. The effects of ANG-(1-7), ANG II, and ANG I on prostaglandin (PG) E2 and prostacyclin (PGI2) synthesis were investigated in neurally derived rat C6 glioma cells. All three ANG peptides stimulated PG release in a dose-dependent manner with the order of potency ANG-(1-7) greater than ANG I greater than ANG II. PGE2 release induced by ANG-(1-7) (10(-7) M) was partially blocked by [Sar1,Ile8]ANG II (10(-6) M), [Sar1,Thr8]ANG II (10(-6) M), or the subtype 1 selective antagonist Du Pont 753 (10(-5) M) but not by the subtype 2 selective antagonist CGP 42112A (10(-7)-10(-5) M). PGI2 release was inhibited only by [Sar1,Thr8]ANG II. ANG II-induced PGE2 release was blocked by [Sar1,Thr8]ANG II (10(-6) M), [Sar1,Ile8]ANG II (10(-6) M), or Du Pont 753 (10(-7) M) but not by CGP 42112A (10(-7)-10(-5) M). In contrast, ANG II-induced PGI2 release was blocked by Du Pont 753 (10(-7) M) as well as [Sar1,Ile8]ANG II (10(-6) M) but not by [Sar1,Thr8]ANG II or CGP 42112A. Thus ANG II-stimulated PGE2 and PGI2 syntheses in C6 glioma cells are mediated via receptor subtype 1. ANG-(1-7)-induced PGE2 synthesis is also mediated via subtype 1 receptors; however, PGI2 release was blocked by [Sar1,Thr8]ANG II only.(ABSTRACT TRUNCATED AT 250 WORDS)

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Membrane-type 1 Matrix Metalloprotease (MT1-MMP) Enables Invasive Migration of Glioma Cells in Central Nervous System White Matter

The Journal of Cell Biology ◽

10.1083/jcb.144.2.373 ◽

1999 ◽

Vol 144 (2) ◽

pp. 373-384 ◽

Cited By ~ 166

Author(s):

Ann T.J. Beliën ◽

Paolo A. Paganetti ◽

Martin E. Schwab

Keyword(s):

Central Nervous System ◽

Nervous System ◽

White Matter ◽

Plasma Membranes ◽

Malignant Gliomas ◽

Glioma Cells ◽

C6 Glioma ◽

C6 Glioma Cells ◽

Glioblastoma Cells

Invasive glioma cells migrate preferentially along central nervous system (CNS) white matter fiber tracts irrespective of the fact that CNS myelin contains proteins that inhibit cell migration and neurite outgrowth. Previous work has demonstrated that to migrate on a myelin substrate and to overcome its inhibitory effect, rat C6 and human glioblastoma cells require a membrane-bound metalloproteolytic activity (C6-MP) which shares several biochemical and pharmacological characteristics with MT1-MMP. We show now that MT1-MMP is expressed on the surface of rat C6 glioblastoma cells and is coenriched with C6-MP activity. Immunodepletion of C6-MP activity is achieved with an anti–MT1-MMP antibody. These data suggest that MT1-MMP and the C6-MP are closely related or identical. When mouse 3T3 fibroblasts were transfected with MT1-MMP they acquired the ability to spread and migrate on the nonpermissive myelin substrate and to infiltrate into adult rat optic nerve explants. MT1-MMP–transfected fibroblasts and C6 glioma cells were able to digest bNI-220, one of the most potent CNS myelin inhibitory proteins. Plasma membranes of both MT1-MMP–transfected fibroblasts and C6 glioma cells inactivated inhibitory myelin extracts, and this activity was sensitive to the same protease inhibitors. Interestingly, pretreatment of CNS myelin with gelatinase A/MMP-2 could not inactivate its inhibitory property. These data imply an important role of MT1-MMP in spreading and migration of glioma cells on white matter constituents in vitro and point to a function of MT1-MMP in the invasive behavior of malignant gliomas in the CNS in vivo.

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Effect of Rat C6 Glioma Cells in Varying Concentrations of Cultured in Isorhamnetin

Journal of Clinical and Nursing Research ◽

10.26689/jcnr.v1i1.98 ◽

1970 ◽

Vol 1 (1) ◽

Author(s):

TIAN Rui-rui

Keyword(s):

High Performance ◽

Colorimetric Assay ◽

Glioma Cells ◽

C6 Glioma ◽

C6 Glioma Cells ◽

Control Group ◽

Blank Control Group ◽

Rat Glioma ◽

Solvent Control

Objective:Â To investigate the effects of different concentrationsÂ of isorhamnetin on C6 rat glioma cells in vitro from JanuaryÂ 2015 to June 2015. Methods: The blank control group, blankÂ solvent control group and four concentration groups were usedÂ to observe the cell growth status under a microscope. MTTÂ colorimetric assay was used to detect the effect of isorhamnetin on C6 glioma cells in vitro and the cell inhibition rate AndÂ survival rate were measured. The apoptotic and apoptotic ratesÂ were measured by flow cytometry in the treatment group andÂ the control group. The relationship between the different concentrations of isorhamnetin and C6 glioma cell apoptosis wasÂ analyzed the total protein was extracted and the total AKT protein and Ser473 AKT protein content were detected by WesternÂ blotting. The rat model of glioma was constructed by SD rats.Five days of isorhamnetin was continuously fed and the plasma was detected by high-performance liquid chromatography,liver, brain tissue isorhamnetin content.Â

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Domains of tenascin involved in glioma migration

Journal of Cell Science ◽

10.1242/jcs.111.8.1095 ◽

1998 ◽

Vol 111 (8) ◽

pp. 1095-1104

Author(s):

G.R. Phillips ◽

L.A. Krushel ◽

K.L. Crossin

Keyword(s):

Cell Migration ◽

Matrix Protein ◽

Glioma Cells ◽

C6 Glioma ◽

Extracellular Matrix Protein ◽

C6 Glioma Cells ◽

Dependent Manner ◽

Type Iii ◽

Fibronectin Type Iii ◽

Fibronectin Type

Tenascin (TN) is an extracellular matrix protein found in areas of cell migration during development and expressed at high levels in migratory tumor cells. TN was previously shown to support the attachment and migration of glioma cells in culture. To determine the domains responsible for glioma migration and attachment, we produced recombinant fusion proteins that collectively span the majority of the molecule including its epidermal growth factor-like repeats, fibronectin type III repeats and fibrinogen domain. These domains were tested for their ability to support migration of C6 glioma cells in an aggregate migration assay. A recombinant fusion protein including fibronectin type III (FNIII) repeats 2–6 (TNfn2-6) was the only fragment found to promote migration of C6 glioma cells at levels similar to that promoted by intact TN. Evaluation of smaller segments and individual FNIII repeats revealed that TNfn3 promoted migration and attachment of glioma cells and TNfn6 promoted migration but not attachment. While TNfn3 and TNfn6 promoted migration individually, the presence of both TNfn3 and TNfn6 was required for migration on segments of the FNIII region that included TNfn5. TNfn5 inhibited migration in a dose dependent manner when mixed with TNfn3 and also promoted strong attachment and spreading of C6 glioma cells. TNfn3 and TNfn6 promote cell migration and may function cooperatively to overcome the inhibitory activity of TNfn5. Additional cell attachment studies suggested that both beta1 integrins and heparin may differentially influence the attachment of glioma cells to TN fragments. Together, these findings show that C6 glioma cells integrate their response upon binding to at least three domains within TN.

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