Proliferation Of C6 Glioma Cells Research Articles

GDNF triggers proliferation of rat C6 glioma cells via the NF-κB/CXCL1 signaling pathway.

Glioblastoma multiforme (GBM) is the most common primary malignant brain tumor that is characterized by its high proliferative and migratory potential, leading to a high invasiveness of this tumor type. However, the underlying mechanism of GBM proliferation and migration has not been fully elucidated. In this study, at first, we used RNA-seq together with bioinformatics technology to screen for C-X-C motif ligand 1 (CXCL1) as a proliferation-related gene. And exogenous glial cell line-derived neurotrophic factor (GDNF) induced proliferation and up-regulated the level of CXCL1 in rat C6 glioma cells determined by sqPCR and ELISA. Then, we manipulated the CXCL1 expression by using a lentiviral vector (CXCL1-RNAi) approach. By this, the proliferation of C6 cells was decreased, suggesting that CXCL1 plays a key role in proliferation in these cells. We hypothesized that exogenous GDNF promoted NF-κB nuclear translocation and therefore, analyzed the interaction of CXCL1 with NF-κB by Western Blot and immunofluorescence. Additionally, we used BAY 11-7082, a phosphorylation inhibitor of NF-κB, to elucidate NF-κB mediated the effect of GDNF on CXCL1. These results demonstrated that GDNF enhanced the proliferation of rat C6 glioma cells through activating the NF-κB/CXCL1 signaling pathway. In summary, these studies not only revealed the mechanism of action of exogenous GDNF in promoting the proliferation of C6 glioma cells but may also provide a new biological target for the treatment of malignant glioma.

Influence of 3-acetyl-5-hydroxy-2-methylindole on glioma cell proliferation and metabolism

A 3-acetyl analogue of 5-hydroxyindole was synthesised and evaluated for its effects on rat C6 glioma cell functions. It was found that 3-acetyl-5-hydroxy-2-methylindole at 10 μmol/L led to a sharp reduction of mitochondrial membrane potential, induction of autophagy and decrease of proliferation of C6 glioma cells. The compound’s effect was comparable to that of rotenone, an inhibitor of cell respiration.

Chemical engineering methods in analyses of 3D cancer cell cultures: Hydrodinamic and mass transport considerations

A multidisciplinary approach based on experiments and mathematical modeling was used in biomimetic system development for three-dimensional (3D) cultures of cancer cells. Specifically, two cancer cell lines, human embryonic teratocarcinoma NT2/D1 and rat glioma C6, were immobilized in alginate microbeads and microfibers, respectively, and cultured under static and flow conditions in perfusion bioreactors. At the same time, chemical engineering methods were applied to explain the obtained results. The superficial medium velocity of 80 ?m s-1 induced lower viability of NT2/D1 cells in superficial microbead zones, implying adverse effects of fluid shear stresses estimated as ?67 mPa. On the contrary, similar velocity (100 ?m s-1) enhanced the proliferation of C6 glioma cells within microfibers compared to static controls. An additional study of silver release from nanocomposite Ag/honey/alginate microfibers under perfusion indicated that the medium partially flows through the hydrogel (interstitial velocity of ?10 nm s-1). Thus, a diffusion-advection-reaction model described the mass transport to immobilized cells within microfibers. Substances with diffusion coefficients of ?10-9-10-11 m2 s-1 are sufficiently supplied by diffusion only, while those with significantly lower diffusivities (?10-19 m2 s-1) require additional convective transport. The present study demonstrates the selection and contribution of chemical engineering methods in tumor model system development.

Bead‐free and tough electrospun PCL/gelatin/PGS ternary nanofibrous scaffolds for tissue engineering application

AbstractPoly(glycerol sebacate) (PGS) is a biodegradable and biocompatible polyester that is increasingly used in the biomedical field. Herein, a novel ternary poly(ε‐caprolactone)/gelatin/PGS (PCL/gelatin/PGS) blend nanofibers were designed and fabricated with a wide range of chemical compositions, mechanical properties, and modulated degradability levels. PGS blends with gelatin are commonly used for enhancing electrospinability but their low‐mechanical properties, lack of structural stability in an aqueous medium, and unmodulated degradation behavior limited their application. Blending PGS and gelatin with PCL could improve their properties in a ternary structure. In addition, considering ternary blends of PCL/gelatin/PGS, an enhancement of hydrophilicity due to the presence of gelatin in the system is expected, resulting in better biocompatibility and controlled biodegradation. By increasing the polymer concentration, voltage, and distance of the needle to the collector, the bead‐free electrospun nanofibers were obtained. The ternary blend nanofibers with an equal weight ratio of polymers, T33 (containing 33 wt% PGS, 33 wt% gelatin, and 33 wt% PCL), possess more than a 4‐fold increase in tensile strength (7 MPa) and 89‐fold increase in elongation at break (1760.6%) compared to gelatin/PGS binary nanofibers. In vitro studies on glioma cells showed well attachment and proliferation of C6 glioma cells. The obtained results demonstrated the potential of these scaffolds for nerve tissue engineering applications.

Inhibitory effects of miRNAs in astrocytes on C6 glioma progression via connexin 43

In many types of tumor cells, cell communication via gap junction is decreased or missing. Therefore, cancer cells acquire unique cytosolic environments that differ from those of normal cells. This study assessed the differences in microRNA (miRNA) expression between cancer and normal cells. MicroRNA microarray analysis revealed five miRNAs that were highly expressed in normal astrocytes compared with that in C6 gliomas. To determine whether these miRNAs could pass through gap junctions, connexin 43 was expressed in C6 glioma cells and co-cultured with normal astrocytes. The co-culture experiment showed the possibility that miR-152-3p and miR-143-3p propagate from normal astrocytes to C6 glioma in connexin 43-dependent and -independent manners, respectively. Moreover, we established C6 glioma cells that expressed miR-152-3p or miR-143-3p. Although the proliferation of these miRNA-expressing C6 glioma cells did not differ from that of empty vectors introduced in C6 glioma cells, cell migration and invasion were significantly decreased in C6 glioma cells expressing miR-152-3p or miR-143-3p. These results suggest the possibility that miRNA produced by normal cells attenuates tumor progression through connexin 43-dependent and -independent mechanisms.

Bacopaside II nanoparticles inhibit proliferation of C6 glioma cells

BackgroundBacopaside II is one of the four triterpenoid saponin components of bacoside A, the major bioactive constituent in the medicinal herb, Bacopa monnieri. PurposeThe present study is aimed to investigate the effect of PLGA-PEG encapsulated bacopaside II nanoparticles (BM1NPs) on C6 glioma cells. MethodsBacopaside II was isolated from B. monnieri using sequential extraction followed by fractionation, column chromatography and characterized by FTIR and NMR. BM1NPs were prepared by nanoprecipitation and their physicochemical characterization was carried out by DLS, XRD, TEM and zeta potential analyses. ResultsThe spherical nanoparticles showed optimum size range, negative zeta potential and slow but significant in vitro release profile. BM1NPs (100–300 µg/mL) on MTT assay displayed 30–90% cell cytotoxicity against C6 glioma cells. In 2′,7′-dichlorodihydrofluorescein diacetate (H2DCFDA) assay, BM1NP-treated cells showed more intracellular reactive oxygen species (ROS). The apoptosis-inducing property was evaluated by annexin V Alexa fluor 488 staining. EdU (5-ethynyl-2’-deoxyuridine) assay on C6 glioma cells confirmed the antiproliferative potential of BM1NPs. Cell cycle analysis by quantitation of DNA content showed the appearance of sub-G1 peak and confirmed the occurrence of apoptosis. ConclusionOur results indicate that BM1NPs significantly inhibited C6 glioma cell proliferation and promoted cell apoptosis.

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

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.

Development of curcumin-loaded zein nanoparticles for transport across the blood-brain barrier and inhibition of glioblastoma cell growth.

Glioblastoma (GBM) is a devastating primary brain tumor resistant to conventional therapies. A major obstacle to GBM treatment is the blood-brain barrier (BBB), or blood-glioma barrier, which prevents the transport of systemically administered (chemotherapeutic) drugs into the tumor. This study reports the design of dodecamer peptide (G23)-functionalized polydopamine (pD)-coated curcumin-loaded zein nanoparticles (CUR-ZpD-G23 NPs) that efficiently traversed the BBB, and delivered curcumin to glioblastoma cells. The NPs enhanced the cellular uptake of curcumin by C6 glioma cells compared to free curcumin, and showed high penetration into 3D tumor spheroids. Functionalization of the NPs with G23 stimulated BBB crossing and tumor spheroid penetration. Moreover, the NPs markedly inhibited proliferation and migration and induced cell death in liquid and soft agar models of C6 glioma cell growth. Fluorescence microscopy and flow cytometry studies showed that the CUR-ZpD-G23 NPs increased cellular ROS production and induced apoptosis of C6 glioma cells. Following in vivo intravenous injection in zebrafish, ZpD-G23 NPs demonstrated the ability to circulate, which is a first prerequisite for their use in targeted drug delivery. In conclusion, zein-polydopamine-G23 NPs show potential as a drug delivery platform for therapy of GBM, which requires further validation in in vivo glioblastoma models.

Synthetic Betulin Derivatives Inhibit Growth of Glioma Cells In Vitro.

Glioma is the most malignant tumour of the human brain still lacking effective treatment modalities. Betulin, a pentacyclic triterpene abundantly found in the birch bark, has been shown to demonstrate interesting anti-cancer activity towards many cancer cells. We determined the effects of acetylenic synthetic betulin derivatives (ASBDs) as anti-tumour agents on glioma cells in vitro. T98G and C6 glioma cell viability and proliferation were determined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay and BrdU (bromo deoxyuridine) test, respectively. Cell-cycle progression and induction of apoptosis were investigated with flow cytometry. ASBDs significantly decreased glioma cell viability/survival and inhibited proliferation in a dose-dependent manner in vitro. Moreover, ASBDs were more cytotoxic than clinically used chemotherapeutics - temozolomide and cisplatin. ASBDs may be considered for further study as potent anti-tumour agents in glioma treatment.

New 3β-hydroxysteroid-indolamine conjugates: Design, synthesis and inhibition of C6 glioma cell proliferation

Four novel indole steroids based on dehydroepiandrosterone (IS-1), estrone (IS-2) and pregnenolone (IS-3) were obtained and studied for their ability to inhibit C6 glioma proliferation. A reduction in cell proliferation by 52 ± 13% was observed for IS-1 at 10 μM, whereas IS-3 and abiraterone acetate at 10 μM caused a 36 ± 8% decrease. Surprisingly, the cellular effects reported for abiraterone, namely, cytochrome P450 CYP17A1 inhibition and endoplasmic reticulum stress were not detected for IS-1. However, both abiraterone and IS-1 significantly increased glutathione levels. Docking studies predicted good affinity of IS-1 to liver X receptors and regulatory protein Keap1, which are proposed to be involved in the compounds’ antiproliferative activity.

Chlorogenic acid in Viscum album callus is a potential anticancer agent against C6 glioma cells

Background: Chlorogenic acid (CA), a polyphenolic component of fruits, vegetables, coffee, wine, and olive oil, has beneficial effects on human heath, including antioxidant and anticancer effects. However, its precise effects on glioma have not been examined. Objective: Our study aimed to explore the anticancer effects of CA obtained from Viscum album callus on C6 glioma cell migration and proliferation. Materials and Methods: Anticancer potency was analyzed by the 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide salt assay to assess the ability to inhibit cell growth and proliferation. Cell mobility was investigated based on the Boyden chamber and the scratch wound healing assay. Factors involved in cell cycle progression were evaluated by mRNA and protein expression. Cell death was determined by staining with specific dyes and fluorescence microscopy. Results: CA significantly reduced C6 glioma cell proliferation and migration. Furthermore, it induced reactive oxygen species generation and apoptotic cell death. Treatment with CA also suppressed extracellular signal-regulated kinase ½ (ERK½) phosphorylation and the gene expression of cyclins E and A. Conclusion: Our results show that CA may regulate glioma cell migration and proliferation via modulation of ERK½ phosphorylation and cell cycle regulation. Thus, it might be a potent anticancer agent in preventing progression of glioma.

Proliferation of C6 glioma cells requires the phospholipid remodeling enzyme tafazzin independent of cardiolipin composition

The mitochondrial phospholipid (CL) has been linked to mitochondrial and cellular functions. It has been postulated that the composition of CL is of impact for mitochondrial energy metabolism and cell proliferation. Although a correlation between CL composition and proliferation could be demonstrated for several cell types, evidence for a causal relationship remains obscure. Here, we applied two independent approaches, i) supplementation of fatty acids and ii) knock-out of the phospholipid remodeling enzyme tafazzin, to manipulate CL composition and analyzed the response on proliferation of C6 glioma cells. Both strategies caused substantial changes in the distribution of cellular fatty acids as well as in the distribution of fatty acids incorporated in CL that were accompanied by changes of the composition of molecular CL species. These changes did not correlate with cell proliferation. However, knock-out of tafazzin caused dramatic reduction in proliferation of C6 glioma cells independent of CL composition. The mechanism of tafazzin-dependent restriction of proliferation remains unclear. Among the various fatty acids administered only palmitic acid restricted cell proliferation by induction of cell death.

Preparation and characterization of angiopep-2 functionalized Ginsenoside-Rg3 loaded nanoparticles and the effect on C6 Glioma cells

The purpose of this work was to prepare and characterize Angiopep-2 functionalized ginsenoside-Rg3 loaded nanoparticles (ANG-Rg3-NP) and evaluate the therapeutic effect on C6 glioma cells. Nanoparticles were prepared by the emulsion solvent evaporation method. Angiopep-2 was functionalized to nanoparticles via a maleimide-thiol covalent binding reaction to obtain ANG-Rg3-NP. The prepared nanoparticles were evaluated for size, zeta potential, morphology, stability, encapsulation efficiency, loading capacity, and release properties. The cytotoxicity study and targeting effect of ANG-Rg3-NP were evaluated by MTT assay. The study of cellular uptake in C6 glioma cells was performed by fluorescence microscopy and by using a microplate reader. The prepared ANG-Rg3-NP was observed to be uniformly spherical in shape with a particle size at 147.1 ± 2.7 nm. The encapsulation efficiency and loading capacity reached 80.6 ± 3.0% and 27.2 ± 1.4%, respectively. Additionally, ANG-Rg3-NP exhibited a desirable sustained release behavior. In vitro cytotoxicity study indicated that ANG-Rg3-NP could inhibit the proliferation of C6 glioma cells in a concentration-dependent manner. Also, the functionalization of Angiopep-2 made nanoparticles cross the blood-brain barrier more easily and accelerated the cellular uptake of nanoparticles. The ANG-Rg3-NP was a promising brain drug delivery carrier for the treatment of glioma.

Inhibition of the Proliferation and Invasion of C6 Glioma Cells by Tricin via the Upregulation of Focal-Adhesion-Kinase-Targeting MicroRNA-7.

Tricin, a natural flavonoid present in large amounts in rice bran, was investigated for the mechanisms by which it exhibited antiproliferation and anti-invasion in C6 glioma cells. The results indicated that treatment with 5, 10, 25, and 50 μM tricin for 48 h significantly ( p < 0.05) inhibited cell numbers and colony numbers with values of 134.3 ± 5.5, 114.6 ± 2.5, 106.3 ± 3.2, and 57.3 ± 10.2, respectively. Tricin also inhibited C6-cell motility, migration, and invasion. Tricin changed the cytoskeletal organization, reduced matrix-metalloproteinase (MMP) expression, and upregulated E-cadherin. Tricin decreased FAK protein levels and suppressed focal-adhesion-kinase (FAK)-downstream-signal activation. Most importantly, tricin dose-dependently upregulated microRNA-7 (miR-7). Transfection with an miR-7 inhibitor suppressed miR-7 expression, increased FAK expression, and promoted the proliferation and invasion in C6 cells. The data support a novel anticancer mechanism of tricin that involves upregulation of FAK-targeting miR-7 in C6 glioma cells.

Antiproliferative Effect of Vine Stem Extract from Spatholobus Suberectus Dunn on Rat C6 Glioma Cells Through Regulation of ROS, Mitochondrial Depolarization, and P21 Protein Expression

ABSTRACTThe vine stem of Spatholobus suberectus Dunn (SS) is used as a traditional herbal medicine in China. Chinese herbal medicines are well known as natural bioactive compounds that can be used as new medicines, and their antioxidant and anticancer effects have also been reported. This study aimed to examine the anticancer effect of a high-pressure hot-water SS extract on rat C6 glioma cells. The SS extract effectively suppressed the viability and proliferation of C6 glioma cells through an antioxidant effect. Reactive oxygen species (ROS) levels in cancer cells are higher than that in normal cells. If the ROS level falls below that required for the growth of cancer cells, their rapid proliferation and growth can be suppressed. We also measured the induction of mitochondrial membrane depolarization and cell cycle arrest effect caused by the SS extract in C6 glioma cells through a FACS analysis. In addition, we observed an increase in STAT3, p53, E2F1, and p21 mRNA expression and a decrease in Bcl-2 mRNA expression by quantitative PCR. An increase in p21 protein expression of over 83% was observed through western blot analysis. All these data support the fact that the high-pressure hot-water SS extract has the potential to be used for glioma treatment.

Anti-proliferative effect of Zea mays L. cob extract on rat C6 glioma cells through regulation of glycolysis, mitochondrial ROS, and apoptosis

Gliomas are one of the most common types of primary brain tumors, characterized by rapid proliferation and infiltration into normal brain tissue. Corncob is the most plentiful byproducts of Zea mays L., of which anti-cancer effect has not been reported. Therefore, we aimed to examine the anti-proliferative effect of a high-pressure hot-water extract of corncob on glioma cells and elucidated the underlying mechanism. The high-pressure hot-water corncob extract contained approximately 94.8 mg/g and 1.82 μg/g of total phenol and catechin, respectively. Glioma cell treated with different concentrations of high-pressure hot-water corncob extract was shown to be suppressed in growth during three days of culture. In parallel, corncob extract reduced the glioma cell viability and induced cell cycle arrest in G0/G1 phase by upregulating the expression level of cyclin-dependent kinase inhibitor p21. Decreased proliferation and viability in glioma cells treated with corncob extract can be attributed to reduced reactive oxygen species (ROS), antiapoptotic Bcl-2 protein, and a lactate transporter monocarboxylate transporter 1 of which levels are higher than those in normal cells. Based on its inhibitory effects on proliferation and viability of C6 glioma cells, a high-pressure hot-water corncob extract has the potential to be used for glioma treatment.

Ketamine suppresses the proliferation of rat C6 glioma cells.

The present study investigated the effects of N-methyl-D-aspartate receptor (NMDAR) antagonist ketamine, on the growth of gliomas. To analyze the effects of ketamine treatment, rat C6 glioma cells arising from astrocytes, and RNB cells representing non-malignant astrocytes, were examined. In ketamine-treated C6 cells, the gene expression changes associated with cell proliferation following ketamine treatment were evaluated using a cDNA microarray. A cell proliferation assay was performed to analyze the dose-dependent proliferation of C6 glioma and RNB cells following culture (72 h) with ketamine treatment (0-100 µM). Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays were performed following cell incubation with/without ketamine, to confirm if the ketamine-induced cell death of C6 glioma and RNB cells were due to apoptosis. In addition, cell proliferation and TUNEL assays were performed following cell incubations with a selective NMDAR antagonist, D-2-amino-5-phosphonovaleric acid (D-AP5). Analysis of the cDNA microarray indicated that the growth of C6 glioma cells were suppressed by the effects of ketamine. Furthermore, results of the proliferation assay confirmed that ketamine treatment inhibited C6 cell proliferation, most notably at a dose of 30 µM (n=7, 66.4%; P<0.001). The TUNEL assay results revealed that ketamine induced an apoptotic effect on C6 glioma cells, with a significant effect on the rate of death observed at all tested concentrations (3, 10, 30 and 100 µM). Results of the aforementioned proliferation and TUNEL assay experiments were reproduced when ketamine was replaced with a selective NMDAR antagonist, D-AP5. However, the NMDARantagonist-induced effects were not observed in RNB cell cultures. Although it would be premature to apply the results from the present study to human cases, these results indicated that ketamine is an anesthetic candidate providing potential benefit for glioma resection.

MicroRNA-124 inhibits the proliferation of C6 glioma cells by targeting Smad4.

MicroRNA-124 (miR-124) has been shown to be downregulated in glioma; however, its biological functions in glioma are not yet fully understood. The aim of this study was to examine the Smad4‑dependent effects of miR‑124 on C6glioma cell proliferation. In this study, the level of miR‑124 was found to be enhanced in C6cells upon transfection with miR‑124 mimics, and the mechanisms of action of miR‑124 in C6cells were investigated by reverse transcriptase-quantitative polymerase chain reaction, MTT assay, western blot analysis and luciferase reporter assays invitro. The results revealed that miR‑124 expression was significantly lower in the C6cells than in either normal rat brain tissue or astrocytes. Upon the overexpression of miR‑124, the proliferation of the C6cells decreased and Smad4 expression was significantly suppressed. Smad4 was identified as a direct target of miR‑124 through luciferase reporter assays. Furthermore, miR‑124 was found to modulate signal transducer and activator of transcription3(Stat3) by downregulating Smad4 expression. Using small interfering RNA targeting Smad4 mRNA, we also confirmed that miR‑124 downregulated c‑Myc by modulating Smad4 expression. In addition, caspase‑3 expression was induced by miR‑124 overexpression, but not via Smad4 downregulation. On the whole, our results demonstrate that miR‑124 upregulation inhibits the growth of C6glioma cells by targeting Smad4 directly. These findings may be clinically useful for the development of therapeutic strategies directed toward miR‑124 function in patients with glioma.

Experimental study of a novel tumstatin on C6 brain glioma in vitro.

To investigate the effect of a novel tumstatin on C6 brain glioma cells, the MTT method was used to detect C6 glioma cell proliferation activity at different time periods (12, 48 and 72 h). Cell cycle distribution and apoptosis rate were detected by flow cytometry, and the acridine orange/ethidium bromide staining method was used to detect apoptosis and mitochondrial membrane potential by fluorescence microscopy. Novel tumstatin had an evident inhibitory effect on C6 glioma cells, and the most notable impact emerged after 48 h. The following were observed under the fluorescence microscope: Characteristic morphological changes of cell apoptosis were typically observed in the novel tumstatin (2,000 µg/ml) group; mitochondrial membrane potential decreased significantly (P<0.05); the cells in the G0/G1 phase significantly increased (P<0.05); and the number of cells in the S phase was reduced. There was an increase in cell apoptosis rate in the novel tumstatin (2,000 µg/ml) group compared with the novel tumstatin (1,000 µg/ml) group and the Mock group, and the data were statistically significant (P<0.05). Novel tumstatin may reduce the mitochondrial membrane potential, inducing cell apoptosis, and thereby exerting antitumor activity.

Propofol inhibits invasion and proliferation of C6 glioma cells by regulating the Ca2+ permeable AMPA receptor-system xc− pathway

Anesthetics are documented to affect tumors; therefore, we studied the antiglioma effect of propofol on proliferation and invasiveness of glioma cells and explored the underlying mechanism. C6 glioma cells were cultured and treated with propofol, and cell viability, invasiveness, and migration were measured. Glutamate release was measured using an enzyme-catalyzed kinetic reaction. xCT protein and α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor GluR2 subunit protein expression was assessed with Western blot analysis and immunofluorescent staining. We observed that propofol significantly inhibited C6 glioma cell viability, invasiveness, and migration and decreased glutamate release. An agonist of the cystine/glutamate antiporter system (system xc−), N-acetylcysteine (NAC), reversed propofol's effects, and propofol could inhibit C6 glioma cell proliferation by adding excess exogenous glutamate (100μM). Finally, propofol increased the surface expression of GluR2, but decreased surface expression of xCT. The effects of propofol on surface expression of GluR2 and xCT could be rescued by (R, S)-AMPA, an agonist of Ca2+ permeable AMPA receptor (CPAR). Thus, propofol can inhibit cell viability, invasiveness, and migration of C6 glioma cells, and the CPAR-system xc− pathway contributes to these events.