Induced Apoptosis In Glioma Cells Research Articles

Nrf2-driven TERT regulates pentose phosphate pathway in glioblastoma.

Given the involvement of telomerase activation and dysregulated metabolism in glioma progression, the connection between these two critical players was investigated. Pharmacological inhibition of human Telomerase reverse transcriptase (hTERT) by Costunolide induced glioma cell apoptosis in a reactive oxygen species (ROS)-dependent manner. Costunolide induced an ROS-dependent increase in p53 abrogated telomerase activity. Costunolide decreased Nrf2 level; and ectopic Nrf2 expression decreased Costunolide-induced ROS generation. While TERT knock-down abrogated Nrf2 levels, overexpression of Nrf2 increased TERT expression. Inhibition of hTERT either by Costunolide, or by siRNA or dominant-negative hTERT (DN-hTERT) abrogated (i) expression of Glucose-6-phosphate dehydrogenase (G6PD) and Transketolase (TKT) – two major nodes in the pentose phosphate (PPP) pathway; and (ii) phosphorylation of glycogen synthase (GS). hTERT knock-down decreased TKT activity and increased glycogen accumulation. Interestingly, siRNA-mediated knock-down of TKT elevated glycogen accumulation. Coherent with the in vitro findings, Costunolide reduced tumor burden in heterotypic xenograft glioma mouse model. Costunolide-treated tumors exhibited diminished TKT activity, heightened glycogen accumulation, and increased senescence. Importantly, glioblastoma multiforme (GBM) patient tumors bearing TERT promoter mutations (C228T and C250T) known to be associated with increased telomerase activity; exhibited elevated Nrf2 and TKT expression and decreased glycogen accumulation. Taken together, our findings highlight the previously unknown (i) role of telomerase in the regulation of PPP and glycogen accumulation and (ii) the involvement of Nrf2-TERT loop in maintaining oxidative defense responses in glioma cells.

MicroRNA-132 cause apoptosis of glioma cells through blockade of the SREBP-1c metabolic pathway related to SIRT1.

The inhibition role of miRNA (microRNA or miR) on cancer signaling pathways has been used to prospective cancer treatment. SIRT1 might promote tumorigenesis in human glioma. Here, we investigated whether miR-132 regulate the expression of SIRT1 and its downstream SREBP (Sterol regulatory element-binding protein)-lipogenesis-cholesterogenesis metabolic pathway in human glioma cells. Furthermore, we studied the effect on biology function of glioma cell induced by miR-132. MiR-132 inhibited SIRT1 and SREBP-1c expression and downregulated their targeted genes, including HMGCR and FASN. MiR-132 suppressed the cell growth, tumorigenicity, the invasion of glioma cells and migration as well as promoted their apoptosis. The pathways associated with cancer progression and tumorigenicity, and induce glioma cell apoptosis has been inhibited by miR-132 involving in a caspase-dependent apoptotic mechanism. The recovery of miR-132 resulted in caspase-dependent apoptotic death in glioma cells. MiR-132 that was newly discovered represents a newly targeting mechanism in treatment for glioma.

Resveratrol Induces Glioma Cell Apoptosis through Activation of Tristetraprolin.

Tristetraprolin (TTP) is an AU-rich elements (AREs)-binding protein, which regulates the decay of AREs-containing mRNAs such as proto-oncogenes, anti-apoptotic genes and immune regulatory genes. Despite the low expression of TTP in various human cancers, the mechanism involving suppressed expression of TTP is not fully understood. Here, we demonstrate that Resveratrol (3,5,4′-trihydroxystilbene, Res), a naturally occurring compound, induces glioma cell apoptosis through activation of tristetraprolin (TTP). Res increased TTP expression in U87MG human glioma cells. Res-induced TTP destabilized the urokinase plasminogen activator and urokinase plasminogen activator receptor mRNAs by binding to the ARE regions containing the 3′ untranslated regions of their mRNAs. Furthermore, TTP induced by Res suppressed cell growth and induced apoptosis in the human glioma cells. Because of its regulation of TTP expression, these findings suggest that the bioactive dietary compound Res can be used as a novel anti-cancer agent for the treatment of human malignant gliomas.

GSK1904529A, an insulin-like growth factor-1 receptor inhibitor, inhibits glioma tumor growth, induces apoptosis and inhibits migration.

Malignant gliomas are the most common type of primary malignancy of the central nervous system, with a poor prognosis. The therapeutic options for malignant gliomas are limited and far from satisfactory, and novel treatment strategies are urgently required to improve the outcome of the disease. Insulin-like growth factor (IGF)/IGF-1 receptor (IGF-1R) signaling pathway regulates cell proliferation, motility and survival. The dysregulation of this signaling pathway has been implicated in the development of malignant gliomas. In the present study, GSK1904529A, a small molecule inhibitor of IGF-1R, suppressed glioma cell viability, induced glioma cell apoptosis and inhibited glioma cell migration in vitro. In addition, GSK1904529A inhibited glioma tumor growth and induced tumor cell apoptosis in vivo. In conclusion, the results of the present study suggested GSK1904529A as a promising agent for the treatment of malignant glioma.

Inhibition of RNA transportation induces glioma cell apoptosis via downregulation of RanGAP1 expression

The prognosis of glioblastoma remains poor, even treatment with surgery, radiation, or chemotherapy. Therefore, it is still important to develop a new strategy for treatment of glioblastoma. Previous reports demonstrated that rRNA is produced at abnormally high levels in tumor cells. Nuclear export of all non-coding RNAs are known to depend on RanGTPase system. Hydrolyzation of RanGTP–RNA complex by RanGTPase activating protein 1 (RanGAP1) releases RNA from nucleus to cytoplasm. Therefore, inhibition of RNA transportation would be a useful strategy to affect cancer cell fate. In this study, 5–30μM of oridonin, a natural diterpenoid compound isolated from the traditional Chinese medicine, Rabdosia rubescens, induced U87MG glioma cell apoptosis and RNA accumulation in nucleus at 12h-time point. Before U87MG cell apoptosis, the RanGAP1 protein amount decreased and RanGTP accumulated in nucleus as respectively determined by immunoprecipitation and immunofluorescence, suggesting that decrease of RanGAP1 may result in nuclear entrapment of RanGTP and RNA, and then induce U87MG cell death. In contrast, over-expression of the RanGAP1 protein reversed oridonin-induced U87MG cell apoptosis. Hence, we demonstrated that downregulation of the RanGAP1 protein level by oridonin may result in RNA accumulation in nucleus via nuclear entrapment of RanGTP which eventually led to the apoptosis of glioma cells.

Antiproliferative and apoptosis-inducing activity of schisandrin B against human glioma cells.

BackgroundMalignant glioma is the most devastating and aggressive tumour in the brain and is characterised by high morbidity, high mortality and extremely poor prognosis. The main purpose of the present study was to investigate the effects of schisandrin B (Sch B) on glioma cells both in vitro and in vivo and to explore the possible anticancer mechanism underlying Sch B-induced apoptosis and cell cycle arrest.MethodsThe anti-proliferative ability of Sch B on glioma cells were assessed by MTT and clony formation assays. Flow cytometric analysis was used to detect cell cycle changes. Apoptosis was determined by Hoechst 33342 staining and annexin V/PI double-staining assays. The mitochondrial membrane potential was detected by Rhodamine 123 staining. The in vivo efficacy of Sch B was measured using a U87 xenograft model in nude mice. The expressions of the apoptosis-related and cell cycle-related proteins were analysed by western blot. Student’s t-test was used to compare differences between treated groups and their controls.ResultsWe found that Sch B inhibited growth in a dose- and time-dependent manner as assessed by MTT assay. In U87 and U251 cells, the number of clones was strongly suppressed by Sch B. Flow cytometric analysis revealed that Sch B induced cell cycle arrest in glioma cells at the G0/G1 phase. In addition, Sch B induced glioma cell apoptosis and reduced mitochondrial membrane potential (ΔΨm) in a dose-dependent manner. Mechanically, western blot analysis indicated that Sch B induced apoptosis by caspase-3, caspase-9, PARP, and Bcl-2 activation. Moreover, Sch B significantly inhibited tumour growth in vivo following the subcutaneous inoculation of U87 cells in athymic nude mice.CoclusionsIn summary, Sch B can reduce cell proliferation and induce apoptosis in glioma cells and has potential as a novel anti-tumour therapy to treat gliomas.

Tubeimoside-1 induces glioma apoptosis through regulation of Bax/Bcl-2 and the ROS/Cytochrome C/Caspase-3 pathway.

BackgroundTubeimoside-1 (TBMS1) is a natural compound isolated from tubeimoside, which has been widely used as a traditional Chinese herbal medicine. The purpose of the present study is to investigate the anti-tumor effect and the underling mechanism of TBMS1 on glioma cancer cells.MethodsThe MTT assay was performed to evaluate the effect of TBMS1 on glioma cell proliferation. The fluorescent microscopy and flow cytometry analysis were performed to evaluate the effect of TBMS1 on glioma cell apoptosis. The Western blot analysis was used to evaluate the protein change.ResultsTBMS1 inhibited glioma cancer cell proliferation in a dose- and time-dependent manner. Fluorescent microscopy and flow cytometry analysis demonstrated that TBMS1 induced glioma cell apoptosis in a concentration-dependent manner. Western blotting showed that TBMS1 induced apoptosis by increasing the expression of Bax and downregulating the level of Bcl-2. Furthermore, we found that TBMS1 induced apoptosis by increasing the concentration of reactive oxygen species through the release of Cytochrome C and activation of Caspase-3.ConclusionThese findings indicate that TBMS1 may be developed as a possible therapeutic agent for the management of glioma.

TGF-β-induced hCG-β regulates redox homeostasis in glioma cells.

Transforming growth factor (TGF-β) is associated with the progression of glioblastoma multiforme (GBM)-the most malignant of brain tumors. Since there is a structural homology between TGF-β and human chorionic gonadotropin (hCG) and as both TGF-β and hCG-β are known regulators of oxidative stress and survival responses in a variety of tumors, the role of TGF-β in the regulation of hCG-β and its consequences on redox modulation of glioblastoma cells was investigated. A heightened hCG-β level was observed in GBM tumors. TGF-β treatment increased hCG-β expression in glioma cell lines, and this heightened hCG-β was found to regulate redox homeostasis in TGF-β-treated glioma cells, as siRNA-mediated knockdown of hCG-β (i) elevated reactive oxygen species (ROS) generation, (ii) decreased thioredoxin Trx1 expression and thioredoxin reductase (TrxR) activity, and (iii) abrogated expression of TP53-induced glycolysis and apoptosis regulator (TIGAR). Silencing of hCG-β abrogated Smad2/3 levels, suggesting the existence of TGF-β-hCG-β cross-talk in glioma cells. siRNA-mediated inhibition of elevated TIGAR levels in TGF-β-treated glioma cells was accompanied by an increase in ROS levels. As a farnesyltransferase inhibitor, Manumycin is known to induce glioma cell apoptosis in a ROS-dependent manner, and we investigated whether Manumycin could induce apoptosis in TGF-β-treated cells with elevated hCG-β exhibiting ROS-scavenging property. Manumycin-induced apoptosis in TGF-β-treated cells was accompanied by elevated ROS levels and decreased expression of hCG-β, Trx1, Smad2/3, and TIGAR. These findings indicate the existence of a previously unknown TGF-β-hCG-β link that regulates redox homeostasis in glioma cells.

Pregnenolone, a cholesterol metabolite, induces glioma cell apoptosis via activating extrinsic and intrinsic apoptotic pathways.

Gliomas are one of the most common types of malignant tumors worldwide, however, an effective therapeutic strategy not yet been fully determined. The present study aimed to investigate the anti-glioma activity and underlying mechanisms of pregnenolone, which originates from cholesterol and is metabolized into important steroid hormones in the body. The results demonstrated that 100 μM pregnenolone induced a significant loss of cell viability in various malignant glioma cell lines. In the U-87 MG, LN-18 and C6 cell lines, the loss of cell viability resulted from cell apoptosis, which was evidenced by apoptotic nuclear morphology changes and caspase 3 activation. Moreover, the increased activities of caspase 8 and 9 strongly indicated that pregnenolone activated the extrinsic and intrinsic pathways of apoptosis. Additionally, glioma cell apoptosis was prevented by the general caspase inhibitor, Z-VAD-FMK. In the C6 cells, upregulation of Fas and Fas ligand triggered the activation of the extrinsic pathway, whereas knockdown of Fas significantly abrogated the cell apoptosis that was induced by pregnenolone. Furthermore, downregulation of the anti-apoptotic protein, B-cell lymphoma 2 and upregulation of pro-apoptotic proteins, such as Bax and Bak, activated the intrinsic pathway. In conclusion, pregnenolone induced glioma cell apoptosis in a caspase-dependent manner, which was mediated by activation of the extrinsic and intrinsic apoptotic pathways.

Chaetocin-induced ROS-mediated apoptosis involves ATM-YAP1 axis and JNK-dependent inhibition of glucose metabolism.

Oxidative stress serves as an important regulator of both apoptosis and metabolic reprogramming in tumor cells. Chaetocin, a histone methyltransferase inhibitor, is known to induce ROS generation. As elevating basal ROS level sensitizes glioma cells to apoptosis, the ability of Chaetocin in regulating apoptotic and metabolic adaptive responses in glioma was investigated. Chaetocin induced glioma cell apoptosis in a ROS-dependent manner. Increased intracellular ROS induced (i) Yes-associated protein 1 (YAP1) expression independent of the canonical Hippo pathway as well as (ii) ATM and JNK activation. Increased interaction of YAP1 with p73 and p300 induced apoptosis in an ATM-dependent manner. Chaetocin induced JNK modulated several metabolic parameters like glucose uptake, lactate production, ATP generation, and activity of glycolytic enzymes hexokinase and pyruvate kinase. However, JNK had no effect on ATM or YAP1 expression. Coherent with the in vitro findings, Chaetocin reduced tumor burden in heterotypic xenograft glioma mouse model. Chaetocin-treated tumors exhibited heightened ROS, pATM, YAP1 and pJNK levels. Our study highlights the coordinated control of glioma cell proliferation and metabolism by ROS through (i) ATM-YAP1-driven apoptotic pathway and (ii) JNK-regulated metabolic adaptation. The elucidation of these newfound connections and the roles played by ROS to simultaneously shift metabolic program and induce apoptosis could provide insights toward the development of new anti-glioma strategies.

Cytochalasin B inhibits the proliferation of human glioma U251 cells through cell cycle arrest and apoptosis.

Cytochalasin B (CB) is known to inhibit a number of cancer types, but its effects on gliomas are unknown. We examined the in vitro effects of CB on the proliferation of human glioma U251 cells, as well as determined its mechanism of action. Cell proliferation was determined using CCK-8. The effect of CB on U251 cell morphology was observed under a transmission electron microscope. Cell cycle distribution was assessed using propidium iodine and Giemsa staining, and cell apoptosis was determined by annexin V-fluorescein isothiocyanate/propidium iodide. Cell cycle-related proteins were determined by Western blot. CB effectively inhibited U251 cell proliferation in a dose- and time-dependent manner. The 24, 48, 72, and 96 h IC50 values were 6.41 x 10(-2), 9.76 x 10(-4), 2.57 x 10(-5), and 2.08 x 10(-5) M, respectively. CB increased the proportion of cells in the G2/M phase in a dose-dependent manner, thus increasing the mitotic index and decreasing cdc2 and cyclin B1 protein levels. CB induced morphological changes in the cytoskeleton. Additionally, 10(-5) M CB induced apoptosis in 23.4 ± 0.5% of U251 cells (P < 0.05 vs control group). Caspase-3, -8, and -9 activities were increased after CB treatment. CB inhibited U251 glioma cell proliferation by damaging the microfilament structure. CB also induced glioma cell apoptosis, suggesting that it may be an effective therapeutic agent against gliomas.

ATM-NFκB axis-driven TIGAR regulates sensitivity of glioma cells to radiomimetics in the presence of TNFα

Gliomas are resistant to radiation therapy, as well as to TNFα induced killing. Radiation-induced TNFα triggers Nuclear factor κB (NFκB)-mediated radioresistance. As inhibition of NFκB activation sensitizes glioma cells to TNFα-induced apoptosis, we investigated whether TNFα modulates the responsiveness of glioma cells to ionizing radiation-mimetic Neocarzinostatin (NCS). TNFα enhanced the ability of NCS to induce glioma cell apoptosis. NCS-mediated death involved caspase-9 activation, reduction of mitochondrial copy number and lactate production. Death was concurrent with NFκB, Akt and Erk activation. Abrogation of Akt and NFκB activation further potentiated the death inducing ability of NCS in TNFα cotreated cells. NCS-induced p53 expression was accompanied by increase in TP53-induced glycolysis and apoptosis regulator (TIGAR) levels and ATM phosphorylation. siRNA-mediated knockdown of TIGAR abrogated NCS-induced apoptosis. While DN-IκB abrogated NCS-induced TIGAR both in the presence and absence of TNFα, TIGAR had no effect on NFκB activation. Transfection with TIGAR mutant (i) decreased apoptosis and γH2AX foci formation (ii) decreased p53 (iii) elevated ROS and (iv) increased Akt/Erk activation in cells cotreated with NCS and TNFα. Heightened TIGAR expression was observed in GBM tumors. While NCS induced ATM phosphorylation in a NFκB independent manner, ATM inhibition abrogated TIGAR and NFκB activation. Metabolic gene profiling indicated that TNFα affects NCS-mediated regulation of several genes associated with glycolysis. The existence of ATM-NFκB axis that regulate metabolic modeler TIGAR to overcome prosurvival response in NCS and TNFα cotreated cells, suggests mechanisms through which inflammation could affect resistance and adaptation to radiomimetics despite concurrent induction of death.

MiR-218 sensitizes glioma cells to apoptosis and inhibits tumorigenicity by regulating ECOP-mediated suppression of NF-κB activity

Malignant gliomas are the most common and deadly primary brain tumors in adults. Increasing evidence has indicated that microRNAs (miRNAs) have an influence on the regulation of apoptotic cell signaling. Downregulation of miRNA 218 (miR-218) has been indicated in human glioma specimens. Here, we investigate the function of miR-218 in apoptosis and tumor growth of glioma cells. The expression of miR-218 was detected by real-time quantitative reverse transcriptase PCR. The effects of miR-218 on glioma cell proliferation and tumorigenicity were investigated by in vitro clonogenicity and in vivo xenograft assay. Apoptosis was evaluated by flow cytometric analysis and assay by terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling. The downstream targets of miR-218 were identified by bioinformatics analysis and further validated by Western blot and luciferase reporter assay. Overexpression of miR-218 induces glioma cell apoptosis and inhibits glioma cell viability, proliferation, and tumorigenicity. Epidermal growth factor receptor-coamplified and overexpressed protein (ECOP) was identified as a functional downstream target of miR-218, which can regulate transcriptional activity of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and associated with apoptotic response. Ectopic expression of ECOP rescued the glioma cells from miR-218-induced apoptosis and increased NF-κB activity. These results suggest that miR-218 sensitizes glioma cells to apoptosis by regulating ECOP-mediated suppression of NF-κB activity, which may provide novel opportunities for glioma therapy.

β-elemene induces glioma cell apoptosis by downregulating survivin and its interaction with hepatitis B X-interacting protein.

β-elemene, extracted from the ginger plant, possesses antitumor activity against a broad range of cancers clinically. However, the mechanism underlying β-elemene-induced cytotoxicity remains incompletely understood. Here, we show that β-elemene promoted apoptotic cell death in human glioma cells, downregulated survivin gene expression, and induced caspase-9, -3 and -7 activities. Induction of apoptosis was associated with inhibition of survivin gene expression, and restoration of survivin levels remarkably attenuated β-elemene-induced glioma cell death. Moreover, we found that the interaction between surviving and HBXIP, a critical regulator of caspase-9 activity, was impaired by β-elemene treatment. The results, therefore, reveal a caspase-mediated apoptotic pathway induced by β-elemene in human glioma cells, which is associated with downregulation of survivin itself and the interaction between survivin and HBXP.

The repressive effect of microRNA-25 inhibitor on human glioma cell growth

Objective To observe the effect of microRNA (miR-25) inhibitor on glioma cell growth.Methods The miR-25 inhibitor was transfected by liposome. Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect miR-25 expression after transfection.The cell cycle kinetics and cell proliferation rate were examined by using flow cytometry and methyl thiazol tetrazolium (MTT) assay,the anchorage-independent cell proliferation was evaluated by soft agar assay,the apoptosis rate was tested by Annexin V staining,and the invasive ability was measured by Transwell.Results The antisense oligonucleotide effectively down-regulated the miR-25 expression in glioma cells.Meanwhile,the proportion of cells in S phase was decreased by about 6％-10％,and the proliferation activity was significantly suppressed (P＜0.05 ).Also,the down-regulation of miR-25 promoted glioma cell apoptosis ( P ＜0.05).However,no significant changes were observed in the number of cells getting through matrigel.Conclusion Suppression of miR-25 expression could inhibit the proliferative ability and induce apoptosis of glioma cells,but had no effect on the invasive ability in glioma cells.This preliminary finding suggests that miR-25 may play an oncogenic role in glioma cell growth,but not invasion. Key words: Glioma; MicroRNA-25; Cell growth; Invasion

Induction of Apoptosis in Glioma Cells and Upregulation of Fas Expression Using the Human Interferon-β Gene

We investigated whether IFN-β inhibits the growth of human malignant glioma and induces glioma cell apoptosis using the human IFN-β gene transfected into glioma cells. A eukaryonic expression vector (pSV2IFNβ) for IFN-β was transfected into the glioma cell line SHG44 using liposome transfection. Stable transfection and IFN-β expression were confirmed using an enzyme-linked immunosorbent assay (ELISA). Cell apoptosis was also assessed by Hoechst staining and electron microscopy. In vivo experiments were used to establish a SHG44 glioma model in nude mice. Liposomes containing the human IFN-β gene were injected into the SHG44 glioma of nude mice to observe glioma growth and calculate tumor size. Fas expression was evaluated using immunohistochemistry. The IFN-β gene was successfully transfected and expressed in the SHG44 glioma cells in vitro. A significant difference in the number of apoptotic cells was observed between transfected and non- transfected cells. Glioma growth in nude mice was inhibited in vivo, with significant induction of apoptosis. Fas expression was also elevated. The IFN-β gene induces apoptosis in glioma cells, possibly through upregulation of Fas. The IFN-β gene modulation in the Fas pathway and apoptosis in glioma cells may be important for the treatment of gliomas.

The effects of celastrol on the apoptosis and cell cycle arrest of C6 glioma cells and its mechanism

Objective To investigate the effects of celastrol on the apoptosis and cell cycle arrest of C6 glioma cells and its mechanism.Methods C6 glioma cells were cultured in vitro.MTT was used to assay cellular proliferation.Fluorescence microscope and transmission electron microscope were used to evaluate the morphological alterations of C5 glioma cells after being incubated with 2.56 μmol/L celastrol.Flow cytometry was used to analyze the alterations of apoptosis rate and cell cycle.Results The inhibitory effects of celastrol on C6 glioma cells were dependent on celastrol concentration and incubation time.Typical morphological alterations of apoptosis were observed under photo-microscope,fluorescence microscope and transmission electron microscope respectively.Flow cytometry showed that the apoptosis rate increased from 1.32％ in control group to 19.34％ in celastrol group,and cellular quantity decreased from 76.42％ to 54.52％ at G0/G1 phase but increased from 9.29％ to 30.50％ at G2/M.Western blotting analysis showed that the expression of apoptosis -related proteins Bc1-2 and XIAP were down-regulated,but Bax,Caspase-3 and cleaved PARP were up -regulated.Moreover,the expression of cell cycle regulator p21,p2 and cyclin B1 were increased,but cdk2 was decreased.Conclusion Celastrol could induce C6 glioma cell apoptosis and cell cycle arrest via influencing the expression of apoptosis related proteins and cell cycle regulators. Key words: Celastrol; C6 glioma cell; Apoptosis; Cell cycle arrest

Dendritic cells pulsed with heat-treated U251 cells induce antitumor immunity against malignant glioma

Objective To investigate the ability and mechanism of dendritic cells (DCs) inducing specific cytotoxicity T cells to kill giloma cells.Methods DCs were induced and cultured from the murine bone marrow cells by using modified Inaba method in vitro.The biological characteristics of DCs were detected by an electron microscope and flow cytometry.The DCs vaccine was obtained by mixing DCs with apoptotic glioma cells induced by heating treatment.The capacity of DCs vaccine promoting proliferation and killing glioma cells was tested by the method of cell counting kit-8 (CCK-8).DCs vaccine was injected into the tumor-bearing mice via the tail vein to examine the tumor growth inhibition in vivo.Results The flow cytometry confirmed that DCs vaccine highly expressed the typical surface markers CD11C,CD80,CD86 and MHC Ⅱ,and that the optimal thermal condition for inducing apoptosis of glioma cells was 44 ℃for 3 h with the maximum apoptosis rate being (40.10 ± 1.08)％.DCs loaded with apoptotic glioma cells antigen could effectively promote T cell proliferation,and increase the interferon-γ (IFN-γ) secretion.And increased effector/target ratio enhanced the cytotoxity activity.Four weeks after vaccine treatment,tumor size was (301.704 ±21.659) mm3 in treatment group,and (487.116 ±65.975) mm3 in blank control group (P ＜0.01 ).Conclusion DCs,sensitized by heating treatment apoptotic glioma cells,can effectively promote T cell proliferation and induce specific cytotoxic T cells to kill glioma cellsin vitro,and inhibit tumor growth in vivo. Key words: Glioma; Dendritic cells; Tumor vaccine; Immunotherapy

BMS-345541 induces apoptosis of glioma cells through inhibition of IKB kinase/nuclear factor-KB pathway

Objective To investigate the effect of BMS-345541, a novel compound with a highly selective IκB kinase (IKK) inhibitory activity, on apoptosis of glioma cells and the possible mechanisms.Methods Human glioma cells U87MG were treated with different concentrations of BMS-345541. Cell apoptosis was investigated by Annexin V/PI staining assay. B cell lymphoma gene-2 (bcl-2) and Caspase-3 was detected by Western blotting. Nuclear factor-κB (NF-κB) activity was analyzed by NF-κB luciferase reporter gene assay and nuclear translocation of NF-κB was analyzed by Western blotting. Results After incubation with 1,10 and 20 μmol/L BMS-345541 ,apoptosis rates of U87MG cells were (18. 2 ±2. 2)% ,(49. 3 ± 3.6 ) % and ( 73.3 ± 8.9 ) %, respectively ( compared with the control, P ＜ 0. 01 ). BMS-345541 induced the activation of Caspase-3 and decreased expression of bcl-2. Moreover, NF-κB activity was decreased by( 66. 2 ± 5.1 )% ( P ＜ 0. 01 ) and nuclear translocation of NF-κB p65 subunit was inhibited.Conclusion BMS-345541 induced apoptosis of glioma cells involving inhibition of IKK/NF-κB signaling pathway. Key words: BMS-345541; Glioma; IKK; NF-κB; Apoptosis

Reduction of miR-21 induces glioma cell apoptosis via activating caspase 9 and 3

Extensive data indicate that miR-21 plays a critical role in gliomagenesis, however, knowledge is limited on the mechanism of action of miR-21, including cell proliferation, apoptosis, and migration. In this study, we showed that down-regulation of miR-21 expression by antisense oligonucleotides inhibited glioma cell proliferation and induced cell apoptosis. Moreover, reduction of miR-21 activated caspase 9 and 3, which may be mediated by modulating multiple potential target genes, such as TIMP3. Together, these findings indicate that miR-21 plays a key role in regulating cell apoptosis in gliomas and may serve as a target for effective therapies.