Effect of temozolomide combined with curcumin on the apoptosis of the C6 glioma cells / 实用医学杂志

Objective To study the temozolomide combined with curcumin on the inhibitory effect and apoptosis of the C6 glioma cells. Methods The C6 glioma cells were treated with temozomide in combination with curcumin. The anti proliferation effect of liposomes on the C6 glioma cells was investigated by using the method of sulforhodamine B (SRB). Flow cytometry was used to detect apoptosis of the C6 glioma cells. Confocal laser scan-ning microscope was used to observe apoptosis and location in the C6 glioma cells. Results The results of SRB as-say showed that temozolomide in combination with curcumin inhibition rate were (91.22 ± 0.51)%in 48 h of the C6 glioma cells; Flow cytometry showed that the apoptosis rate were (33.15 ± 0.79)% with temozolomide (5 μmol/L) in combination with curcumin (10 μmol/L). Laser scanning confocal scanning microscope indicated that the apop-tosis of in the C6 glioma cells treated with temozolomide in combination with curcumin was more than that of free drug. Conclusion The temozolomide in combination of curcumin can inhibit the growth and induce apoptosis of the C6 glioma cells.

Expression of IL-12 family subunit genes in mice C6 glioma cells / 中国免疫学杂志

Objective:To observe the expression of IL-12 family subunit genes by real-time quantitative PCR in mice C6 glioma cells,construct the basis of the brain glioma research on IL-12 family in the future.Methods:Mice C6 glioma RNA was abstracted and reversed transcription cDNA.The mice C6 glioma cells mRNA expression influence of IL-12 family subunit genes was compared and analyzed by real-time quantitative PCR.Results: In mice C6 glioma cells, high expression abundances in IL-23a, IL-12a, midlde expression abundances in EBI3, IL-27, low expression abundance in IL-12b.Conclusion: IL-12 families are closely related to the occurrence and development of glioma,IL-12,IL-23 are regarded as the most potential anti-glioma cytokines among them,research de-velopments will bring a new way of brain glioma immune therapy.

The inhibitory effect of photodynamic therapy and of an anti-VCAM-1 monoclonal antibody on the in vivo growth of C6 glioma xenografts

We investigated the effect of photodynamic therapy (PDT) and of an anti-vascular cell adhesion molecule-1 (VCAM-1) monoclonal antibody on the in vivo growth of C6 glioma. Seven days after inoculation with C6 cells, adult male Wistar rats weighing 280-300 g with MRI-confirmed glioma were randomly assigned to 4 groups (N = 15 per group): PDT + VCAM-1 antibody group; PDT group; VCAM-1 antibody group; control group. Eight days after inoculation, hematoporphyrin monomethyl ether (HMME) was administered as a photosensitizer and PDT was performed at 630 nm (illumination intensity: 360 J/cm²) for 10 min. VCAM-1 antibody (50 µg/mL) was then administered (0.5 mL) through the tail vein every other day from day 8 to day 16. At day 21, 5 rats in each group were sacrificed and cancers were harvested for immunohistochemistry and Western blot assay for the detection of VCAM-1, and TUNEL assay was used to detect apoptosis. Survival and tumor volume were recorded in the remaining 10 rats in each group. In the PDT group, tumor growth was significantly suppressed (67.2 percent) and survival prolonged (89.3 percent), accompanied by an increase in apoptosis (369.5 percent), when compared to control. Furthermore, these changes were more pronounced in the PDT + VCAM-1 antibody group. After PDT, VCAM-1 expression was markedly increased (121.8 percent) and after VCAM-1 monoclonal antibody treatment, VCAM-1 expression was significantly reduced (58.2 percent). PDT in combination with VCAM-1 antibody can significantly inhibit the growth of C6 glioma and prolong survival. This approach may represent a promising strategy in the treatment of glioma.

Thrombin-induced Migration and Matrix Metalloproteinase-9 Expression Are Regulated by MAPK and PI3K Pathways in C6 Glioma Cells

Glioblastoma multiforme is one of the most common and aggressive tumors in central nervous system. It often possesses characteristic necrotic lesions with hemorrhages, which increase the chances of exposure to thrombin. Thrombin has been known as a regulator of MMP-9 expression and cancer cell migration. However, the effects of thrombin on glioma cells have not been clearly understood. In the present study, influences of thrombin on glioma cell migration were examined using Boyden chamber migration assay and thrombin-induced changes in MMP-9 expression were measured using zymography, semi-quantitative RT-PCR, and Western blotting. Furthermore, underlying signaling pathways by which thrombin induces MMP-9 expression were examined. Thrombin-induced migration and MMP-9 expression were significantly potentiated in the presence of wortmannin, a PI3K inhibitor, whereas MAPK inhibitors suppressed thrombin-induced migration and MMP-9 expression in C6 glioma cells. The present data strongly demonstrate that MAPK and PI3K pathways evidently regulate thrombin-induced migration and MMP-9 expression of C6 glioma cells. Therefore, the control of these pathways might be a beneficial therapeutic strategy for treatment of invasive glioblastoma multiforme.

Induction of Inducible Nitric Oxide Synthase Expression by Manganese in C6 Glioma Cells / 대한산업의학회지

OBJECTIVE: It is well established that manganese neurotoxicity is associated with clinical symptoms similar to those of idiopathic Parkinson's disease. Recent research has shown that the exposure to manganese (MnCl2) leads to induction of iNOS in BV2 microglial cells via iNOS transcriptional up-regulation and activation of both MAPKs and PI3K/Akt signaling pathways. Here, we further investigated the effect and the action mechanism of MnCl2 on iNOS expression in C6 glioma cells. METHODS: Western blot analyses demonstrated that treatment with MnCl2 at 250 micronmeter was sufficient to induce iNOS at both the protein and mRNA levels in C6 cells. RESULTS: These studies demonstrated that the induction of iNOS protein and mRNA was visible after 4h- and 2 h-treatment with MnCl2, respectively. MnCl2 treatment led to strong phosphorylation of JNKs and ERKs, members of MAP kinases (MAPKs), and Akt, a PI3-kinase (PI3K) downstream effector, in C6 cells. MnCl2 treatment had no effect on I kappa B-alpha in C6 cells. Notably, pretreatment with LY294002 (a PI3K inhibitor), which inhibited phosphorylation of Akt by MnCl2, caused strong suppression of MnCl2- induced iNOS protein and mRNA expression in C6 cells. Moreover, pretreatment with SP600125 (an inhibitor of JNKs) and PD98050 (an inhibitor of ERKs), which respectively interfered with MnCl2-mediated phosphorylation of JNKs and ERKs, led to the partial suppression of MnCl2-induced iNOS protein. Interestingly, pretreatment with LY294002 inhibited phosphorylation of not only Akt, but also ERKs and JNKs, in response to MnCl2. Moreover, there was an effective suppression of MnCl2-mediated phosphorylation of AKT by SP600125. CONCLUSION: These results collectively suggest that MnCl2 induces iNOS expression in C6 glioma cells via activation of PI3K/Akt and JNK-ERK MAPK signaling proteins, whose activations seem to be mutually interconnected in response to MnCl2.

Group Ⅱ and Ⅲ metabotropic glutamate receptors agonists reverse 1-methyl-4-phenylpyridinium-induced glutamate uptake inhibition in C6 glioma cells / 中国临床药理学与治疗学

AIM: To study the effect of group Ⅱ and Ⅲ metabotropic glutamate receptors (mGluRs) agonists on 1-methyl-4-phenylpyridinium (MPP~+)-induced glutamate uptake inhibition in C6 glioma cells. METHODS: The glutamate uptake into astrocytes was measured by using radio-ligand binding assay method. RESULTS: It was shown that Group Ⅱ mGluRs agonist (2' S, 2' R, 3 ' R) -2- (2', 3 ' -dicarboxycyclopropyl) glycine (DCG-Ⅳ) (100 ?mol?L~(-1)) and Group Ⅲ mGluRs agonist L(+)-2-amino-4-phosphonobutyric acid (L-AP4) (100 ?mol?L~(-1)) significantly reversed MPP~+-induced glutamate uptake inhibition. Furthermore, the enhancement effects of DCG-Ⅳ and L-AP4 were blocked by their respective antagonists, (RS)-1 -Amino-5-phosphonoinan-1-carboxylic acid (APICA) and (RS)-?-methylserine-O-phosphate (MSOP). CONCLUSION: Group Ⅱ and Ⅲ mGluRs agonists produce neuroprotective effects by enhancing the activity of glutamate transporters.

Study of the rdiosensitivity of DL-BSO on rats C_6 glioma cells / 中国药理学通报

Aim To observe the effect of DL-buthionine s ulfoximine(DL-BSO) on the radiosensitivity of rat C 6 glioma cells under the a erobic and the hypoxic condition. Methods The source of radiati on was 60Co ?-rays. The rats C 6 glioma cells were treated by radia tion alone or DL-BSO+radiation under the aerobic and the hypoxic condition. Col ony forming assay was used to measure effects of DL-BSO on the radiosensitivity . Results Radiosensitive effect of DL-BSO was time-depedent u nder the aerobic condition. After treatment with 0.1 mmol?L -1 DL-BSO fo r 2, 6, 12 hours, the radiosensitive effect was not observed, whereas an enhance ment of radiosensitivity was seen at 24 and 48 hours. An enhancement of radiosen sitivity was seen at 2～48 hours after treatment with 0.1 mmol?L -1 DL-B SO under the hypoxic condition. The radiosensitive effects related to DL-BSO co ncentration under the aerobic and the hypoxic condition. Conclusion Both under the aerobic and the hypoxic conditions DL-BSO can increase the radio sensitivity of rat C 6 glioma cells. DL-BSO increased the rat C 6 gliom a cells radiosensitivity especially under the hypoxic condition, and radiosensit ive effect of DL-BSO is time and concentration-dependent.

Rat spleen-derived endothelial progenitor cells promote proliferation of C6 glioma cells under co-culture system in vitro / 第三军医大学学报

Objective To investigate the effect of endothelial progenitor cells (EPCs) on the growth of C6 glioma cells in vitro.Methods EPCs were obtained from the spleen of healthy SD rats with density gradient centrifugation and adherence screening.The obtained EPCs were identified through morphologic characteristics,specificity to DiI-acLDL uptaking and Lectin binding,and positive expressions of CD34 and CD31 by immunofluorescence assay.The EPCs-conditional medium was added into the convention medium of C6 glioma cells to assess its effect on the proliferation of glioma cells.After cultured for 36 or 48 h with the EPCs-conditional medium or conventional medium (control),MTT assay was employed to measure the cell proliferation and flow cytometry was used to detect the cell cycle.Results In 10 d after culture,the attached cells presented a "line-like" structure,and the adherent cells were double positive to DiI-acLDL uptaking and FITC-UEA-1 binding by direct flourescence staining under a laser scanning confocal microscope.Those cells were differentiated EPCs,and expressed wholly expressed CD34 and CD31.MTT assay showed that the OD value of each group at both the 2 time points were increased with the increasing of EPCs content in conditioned medium.The OD value of the group containing 50% of EPCs conditional medium of 36 h(2.018?0.220) and 48 h (2.388?0.448) was markedly higher than those of the control group (1.163?0.103,1.106?0.174) with significant difference (P

Agonists of group II and III metabotropic glutamate receptors reverse LPS-induced glutamate uptake inhibition in C6 glioma cells / 中国临床药理学与治疗学

AIM: To study whether agonists of group II and III metabotropic glutamate receptors (mGluRs) exert effects on LPS-induced glutamate uptake inhibition in C6 glioma cells. METHODS: The glutamate uptake into C6 glioma cells was measured by uptake of [3H]-D,L-glutamate; and the apoptosis and the viability of C6 glioma cells were investigated by Hoechst33342 and MTT methods, respectively. RESULTS: LPS (4, 6 ?g/mL) inhibited glutamate uptake significantly compared with that in the control group without effect on the apoptosis and viability of C6 glioma cells. Pretreatment of C6 glioma cells with group II and III mGluRs agonists DCG-IV(100 ?mol/L) and L-AP4(100 ?mol/L) reversed LPS-induced glutamate uptake inhibition. These recovery effects were abolished by their respective antagonists APICA and MSOP. CONCLUSION: Activation of group II and III mGluRs recovers LPS-induced glutamate uptake inhibition in C6 glioma cells, suggesting the enhancement of glutamate uptake is involved in neuroprotective roles exerted by group II and III mGluRs agonists.

Cholera toxin mediated regulation of the expression of Gq alpha and G11 alpha GTP binding proteins

Previously it has been shown that persistent activation of the stimulatory adenylyl cyclase pathway with cholera toxin (CT) downregulates the Gs alpha polypeptide (80%) in a cAMP-independent manner in C6 glioma cells (Shah, 1997). This study was conducted to examine the short and long term effects of CT on the regulation of pertussis toxin-sensitive and -insensitive G proteins and their transcripts in C6 glioma cells. Treatment of C6 cells with CT (100 ng/ml) up to 16 h had no effect on either Gi or Gq/11 alpha proteins. However, prolonged exposure (24-48 h) caused increased expression of Gi (20-30%) and Gq/11 alpha proteins (40%). Urea gradient gels, which can separate Gq alpha and G11 alpha proteins, revealed that prolonged CT treatment increased the expression of both of these G proteins. The CT-mediated enhanced expression of Gq alpha and G11 alpha proteins was accompanied by increased mRNA levels of these proteins as determined by RT/PCR. Cyclic-AMP elevating agents like forskolin (10 microM) and db-cAMP (1 mM) mimicked the effect of CT on Gi but not Gq/11 alpha proteins. These studies show long term cAMP-dependent regulation of Gi and cAMP-independent expression of Gq/11 alpha proteins in C6 glioma cells.