Apoptosis In C6 Glioma Cells Research Articles

Fatty Acid Amides Suppress Proliferation via Cannabinoid Receptors and Promote the Apoptosis of C6 Glioma Cells in Association with Akt Signaling Pathway Inhibition.

A glioma is a type of tumor that acts on the Central Nervous System (CNS) in a highly aggressive manner. Gliomas can occasionally be inaccurately diagnosed and treatments have low efficacy, meaning that patients exhibit a survival of less than one year after diagnosis. Due to factors such as intratumoral cell variability, inefficient chemotherapy drugs, adaptive resistance development to drugs and tumor recurrence after resection, the search continues for new drugs that can inhibit glioma cell growth. As such, analogues of endocannabinoids, such as fatty acid amides (FAAs), represent interesting alternatives for inhibiting tumor growth, since FAAs can modulate several metabolic pathways linked to cancer and, thus, may hold potential for managing glioblastoma. The aim of this study was to investigate the in vitro effects of two fatty ethanolamides (FAA1 and FAA2), synthetized via direct amidation from andiroba oil (Carapa guianensis Aublet), on C6 glioma cells. FAA1 and FAA2 reduced C6 cell viability, proliferation and migratory potential in a dose-dependent manner and were not toxic to normal retina glial cells. Both FAAs caused apoptotic cell death through the loss of mitochondrial integrity (ΔΨm), probably by activating cannabinoid receptors, and inhibiting the PI3K/Akt pathway. In conclusion, FAAs derived from natural products may have the potential to treat glioma-type brain cancer.

ANTITUMOR EFFECTS OF MESENCHYMAL STEM CELLS

The problem of treatment of oncologic patients is not resolved. Our experiments focused on the ability of autologous mesenchymal stem cells (MSCs) to inhibit glioma cell growth in vitro and in vivo. 28 thousand cells of C6 glioma in 20 μl of culture medium were stereotactically introduced into occipital region of brain (Oc2L) from the right side after craniotomy in experiments on 30 male Wistar rats weighing 250–270 g under ketamine‐xylazine‐acepromazine (55.6, 5.5, and 1.1 mg/kg, respectively) anesthesia. 20 rats received 400 thousand MSCs labeled with CD90s and FITC in 50 μl of culture medium under nasal mucosa during the operation. Brain slices 8 μm in thickness were prepared after decapitation of one rat from each group in one day after surgery. MSCs distribution was visualized using Zeiss AxioVert 200M fluorescence microscope with Zeiss AxioCam HRm CCD camera. Fluorescent MSCs were revealed only in damaged Oc2L area of the rat with previously injected MSCs. 10 rats from the same group (with preimplanted MSCs) received 400 thousand MSCs in 50 μl of culture medium via weekly spray injections into both nasal cavities. Rats with implanted glioma and without MSCs died in 15.0±4.3 days. Rats with implanted glioma and single intranasal MSCs injection died in 21.1±5.2 days. 8 of 10 rats that received both intranasal MSCs injection and subsequent weekly spray MSCs injections died in 33.6±3.4 days. Two rats are still alive (108 days from the date of operation). Morphological examination of brain slices of rat from the last group showed signs of apoptosis of tumor cells. It was assumed that MSCs trigger apoptosis in C6 glioma cells via paracrine way by excretion of exosomes and cytokines.

Sustained release of silibinin‐loaded chitosan nanoparticle induced apoptosis in glioma cells

In this study, a chitosan nanoparticle formulation was synthesized for loading silibinin as a sustained-release drug system to evaluate its effects on apoptosis in C6 glioma cells. This synthesized nanoparticle was analyzed by measurement methods including Fourier transform infrared (FTIR), field emission-scanning electron microscopy (FE-SEM), dynamic light scattering (DLS), X-ray diffraction (XRD), and differential scanning calorimetry (DSC). The formation and amorphization of nanoparticle were confirmed by FTIR and XRD analysis, respectively. The mean diameter of silibinin-loaded chitosan nanoparticles (SCNP) was 50 ± 7 and 188.6 ± 0.17 nm by using FE-SEM and DLS, respectively. In addition, the positive zeta potential of nanoparticles was +11.5. Rhodamine-conjugated SCNP analysis showed the internalization of silibinin to C6 glioma cells. The cytotoxicity assay indicated that the nanoformulation of silibinin was toxic to C6 glioma cells. Although SCNP significantly increased the expression of the both apoptotic genes in C6 cells, Bax and caspase3, it did not have any significant effect on the level of the antiapoptotic gene, Bcl2. In contrast, SCNP did not have any toxic effect on H9C2 cells. In conclusion, the results of the current study indicated that SCNP can be considered as a sustained-release drug system for future cell-based therapeutic strategies.

Dulcitol suppresses proliferation and migration of hepatocellular carcinoma via regulating SIRT1/p53 pathway

BackgroundHepatocellular carcinoma (HCC) spreads further with continuance and increasing incidence due to its high-grade malignancy and metastasis. More effectual strategies on blocking proliferation and metastasis of cancer cells should be studied in HCC. Dulcitol, a natural product extracted from euonymus alatus, was reported that it could induce apoptosis of C6 glioma cells. However, the underlying mechanism of Dulcitol on HCC remains unclea. PurposeIn this study, we aimed to reveal the effect and potential mechanisms of Dulcitol on hepatocellular carcinoma in vitro and in vivo.Study design and methods The cell proliferation and apoptosis were evaluated by MTT, Ki-67 and Hoechst 33258/PI double staining. The migratory and invasive abilities of HepG2 cells were measured by wound-healing and transwell assays. Pathological changes of tumor tissue were observed by HE staining and IHC methods. The expression levels of protein were detected using Western Blot analysis. ResultsThe results showed that Dulcitol inhibited HepG2 cells proliferation by down-regulating the protein expression of SIRT1, Bcl-2, along with up-regulating p53, acetylated-p53 (K382), cleaved-caspase9, cleaved-caspase3, Bax, and cytochrome c in a dose-dependent manner. Furthermore, Dulcitol surpressed the migration and invasion of HepG2 cells through decreasing the levels of MMP-2, uPA and MMP-9 and increasing E-cadherin associated with tumor invasion. In vivo, Dulcitol distinctly inhibited the growth of HepG2 cancer xenograft tumors via inhibiting SIRT1/p53 pathway. ConclusionsOur findings suggested that Dulcitol acted as a SIRT1 inhibitor, inducing apoptosis and inhibiting proliferation, migration and invasion of HepG2 cells and its modulatory mechanism seemed to be associated with regulation of MMPs, SIRT1/p53 pathways.

Cytotoxic and antiproliferative effects of thymoquinone on rat C6 glioma cells depend on oxidative stress

Thymoquinone (TQ) is a highly perspective chemotherapeutic agent against gliomas and glioblastomas because of its ability to cross the blood-brain barrier and its selective cytotoxicity for glioblastoma cells compared to primary astrocytes. Here, we tested the hypothesis that TQ-induced mild oxidative stress provokes C6 glioma cell apoptosis through redox-dependent alteration of MAPK proteins. We showed that low concentrations of TQ (20-50μM) promoted cell-cycle arrest and induced hydrogen peroxide generation as a result of NADH-quinone oxidoreductase 1-catalyzed two-electron reduction of this quinone. Similarly, low concentrations of TQ efficiently conjugated intracellular GSH disturbing redox state of glioma cells and provoking mitochondrial dysfunction. We demonstrated that high concentrations of TQ (70-100μM) induced reactive oxygen species generation due to its one-electron reduction. TQ provoked apoptosis in C6 glioma cells through mitochondrial potential dissipation and permeability transition pore opening. The identified TQ modes of action on C6 glioma cells open up the possibility of considering it as a promising agent to enhance the sensitivity of cancer cells to standard chemotherapeutic drugs.

Inhibitory effects of plasmid small interfering RNA targeting signal transducer and activator of transcription‑3 in C6 glioma cells.

The current study investigated the effect of plasmid small interfering RNA(psiRNA)‑mediated silencing of signal transducer and activator of transcription‑3 (STAT3) on the invasion, apoptosis, and expression levels of cyclinD1, caspase‑3 and B‑cell lymphoma‑2(Bcl‑2) in C6 glioma cells. Cell invasion was determined using a Transwell assay, while the apoptosis rate and cell cycle distribution of cells were assessed using AnnexinV‑FITC/PI double staining. The expression levels of cyclinD1, caspase‑3 and Bcl‑2 proteins were measured by western blotting. Transfection with psiRNA‑STAT3 was observed to significantly decrease the number of transmembrane cells compared with the control groups (P<0.05). In addition, the proportion of cells at G0/G1 phase was increased in the psiRNA‑STAT3 group compared with the controls. Western blotting indicated that psiRNA‑STAT3 decreased the expression of cyclinD1, caspase‑3 and Bcl‑2 proteins. Taken together, psiRNA‑STAT3 inhibited the migration and invasive abilities, and induced the apoptosis of C6 glioma cells, possibly through regulation of the expression of cyclinD1, caspase‑3 and Bcl‑2 proteins.

The inhibition of BDNF/TrkB/PI3K/Akt signal mediated by AG1601 promotes apoptosis in malignant glioma.

Malignant glioma is the most aggressive primary brain tumor and has a poor survival rate. Even if extensive methods are preformed to treat glioma, the mortality rate is still very high. It is necessary for discovering and developing new drugs for malignant glioma treatment. AG1601 is one of AG-series drugs, including AG1031 and AG1503, and it has been optimized on the original basis. In our study, we found that AG1601 markedly inhibited proliferation and promoted C6 glioma cell apoptosis in vitro. AG1601 also reduced the size and weight of glioma in vivo. The growth ability of glioma was significantly inhibited after treatment with AG1601. It also showed that the expression levels of BDNF/TrkB/PI3K/Akt signal related proteins were obviously decreased in C6 glioma cells after treatment with AG1601 in vivo and in vitro. We also found thatBDNF, as the activator of BDNF/TrkB/PI3K/Akt signal, reversed the anti-proliferation and pro-apoptosis of C6 glioma cells caused by AG1601. K252a, a specific inhibitor of TrkB, and AG1601 in combination aggravated C6 glioma cell apoptosis. These results indicate that AG1601 has good effects on the anti-proliferation and pro-apoptosis of malignant glioma via BDNF/TrkB/PI3K/Akt signal and could be considered as a potential drug in treating malignant glioma.

Mechanisms of the mixed umbilical cord blood-derived mesenchymal stem cells in inhibiting proliferation and inducing apoptosis of glioma cells

Objective To investigate the possible mechanism of mixed umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs) in vitro to inhibit proliferation and induce apoptosis of C6 glioma cells. Methods The expression of B cell lymphoma/leukemia-2 (bcl-2) and cysteinyl aspartate-specific protease (Caspase)-3 proteins in C6 cells was detected by immunohistochemistry and Western blotting imprinting method, and C6 cell cycle was detected by flow cytometry. Results Different sources of UCB-MSCs have a tendency to increase the expression of apoptosis protein Caspase-3 in C6 cells and reduce the expression of apoptosis protein bcl-2. Different sources UCB-MSCs induce C6 cell apoptosis, E/T=0∶1, 5∶1, (2.5+ 2.5)∶1, 10∶1, (5+ 5)∶1 C6 cells acting on, The percentages of G0/G1 were (65.49±1.83)%, (64.83±2.19)%, (70.30±3.21)%, (69.03±2.19)%, (77.63±3.10)%, and the percentage of C6 cells in G0/G1 increased with the increase of the E/T ratio, showing a proportional dependence. Conclusion After phytohemagglutinin (PHA) stimulation, large doses of UCB-MSCs and mixed UCB-MSCs have inhibitory effects on proliferation of C6 cells in vitro, and this inhibition may be related to apoptosis induction Key words: Mesenchymal stem cells; Induce; Apoptosis

Mechanisms of mixed umbilical cord blood-derived mesenchymal stem cells inhibiting proliferation and inducing apoptosis of C6 glioma cells in vitro

Objective To study the mechanisms of the mixed umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs) inhibiting proliferation and inducing apoptosis of C6 glioma cells in vitro. Methods Cysteinyl aspartate-specific protease (Caspase)-8, B cell lymphoma/leukemia-2 associated X protein (bax), B cell lymphoma/leukemia-2 (bcl-2) and Caspase-3 protein expression in C6 cells was analyzed by immunohistochemistry and Western blotting, respectively. Caspase-8, bax, bcl-2 and Caspase-3 mRNA levels were detected by reverse transcriptase-polymerase chain reaction (RT-PCR). Cell cycle was detected by flow cytometry. Apoptosis of C6 cells was examined by Annexin V-propidium iodide (PI) staining and terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL) methods, respectively. Results The mixed UCB-MSCs had a tendency to increase the expression of Caspase-8, bax, Caspase-3 mRNA, and decrease the expression of bcl-2 mRNA. The expression of apoptosis protein and the number of apoptosis cells increased with the increase of the ratio of E/T (E: effect cells namely UCB-MSCs; T: target cells namely C6 cells), showing a proportional dependence relationship; E∶T=(5+ 5)∶1. The relative expression of Caspase-8, bax, bcl-2, and Caspase-3 mRNA in C6 cells was 0.78±0.13, 0.28±0.03, 0.70±0.08, and 0.76±0.12, respectively. When E/T=0∶1, 5∶1, (2.5+ 2.5)∶1, 10∶1, (5+ 5)∶1, the number of apoptosis C6 cells was (2.9±0.6), (3.1±0.5), (14.5±1.8), (14.3±2.2), and (22.8±4.5) cells, respectively. Conclusion After phytohemagglutinin (PHA) stimulation, the mixed UCB-MSCs could inhibit proliferation of C6 cells in vitro, which was related to induction of apoptosis of glioma cells. Key words: Glioma; Umbilical cord blood; Mesenchymal stem cells; Apoptosis; Proliferation

AG‐1031 induced autophagic cell death and apoptosis in C6 glioma cells associated with Notch‐1 signaling pathway

Glioma is the most common primary brain tumor with high morbidity and poor prognosis. The effect of AG-1031, which is developed as an antineoplastic drug, on C6 glioma cells is still not clear. The aim of this research was to explore the effect of AG-1031 on C6 cells, and tried to find out its potential mechanism on cytotoxicity of C6 cells. The 3-(4,5-dimethylthiazol -2-yl) -2,5- diphenyltetrazolium bromide (MTT) assay showed that AG-1031 inhibited cell viability in a concentration-dependent manner, whereas 3-methyadenine (3-MA) reduced this effect. Results from hoechst 33342 staining and Western blot assay indicated that AG-1031 induced C6 cell apoptosis. Western blot assay presented that AG-1031 notably increased the LC3-II/LC3-I ratio and decreased the expression of P62. Besides, our results showed that bafilomycin A1 increased the expression of LC3-II in cells treated with AG-1031, which indicated that AG-1031 can increase autophagy in C6 cells. Meanwhile, Western blot assay showed that AG-1031 can inhibit Notch-1 signaling by testing relative protein expressions. The expression of the intracellular domain of Notch (NICD) also decreased according to immunofluorescence assay. Additionally, the activation of Notch-1 signaling alleviated AG-1031-induced autophagic cell death and apoptosis. Furthermore, phosphorylated Akt and its downstream effector mechanistic target of rapamycin (mTOR) were reduced with AG-1031. These results suggest that AG-1031 may induce autophagic cell death through the inhibition of Akt-mTOR signaling pathway by down-regulating Notch-1 signaling pathway and activating apoptosis in C6 cells via Notch-1 signaling, which develops a new target spot to treat glioma in the future.

Potential Synergism of Caffeic Acid Phenethyl Ester and Dasatinib in C6 Glioma Cell Model: Adumbrating the Molecular Mechanism

1.1 Background: Gliomas are one of the most invasive, highly recurrent, heterogeneous cancers resistant to most of the current treatment regimes and hence almost incurable. CAPE and Dasatinib when used in a congruous combination and durations, present an antitumor potential for glioma. 1.2 Objective: CAPE and Dasatinib in combination have been shown to inhibit proliferation and induce apoptosis in C6 glioma cells. However, the signaling pathway of their antiproliferative and apoptotic effects remains unknown. In this study, the antiproliferative effects of combination treatment on C6 glioma cells were investigated. 1.3 Methods: Expression analysis of proteins thought to be mediating proliferation, cell motility, angiogenesis, and invasion was carried out to delineate the molecular mechanism entailing antineoplastic action of CAPE and Dasatinib. 1.4 Results: Co-treatment induces a change in cellular and nuclear morphology followed by apoptosis and a significant decrease in the activity of catalase and MMP-2, Pro-MMP 2, MMP-9 and Pro-MMP 9 in C6 glioma cells. Moreover, CAPE and Dasatinib modulate the expression of proteins having potential interactive crosstalk with major oncogenic pathways involved in glioma progression. Our results showed that combination treatment modulates the expression of p53, ERK1/2, and AKT in C6 glioma cells. p53, EGFR and PCNA transcript expressions were attuned in co-treated C6 cells. 1.5 Conclusion: Importantly, antineoplastic effects of CAPE and Dasatinib were far greater than those afforded by treatment with a single drug. Together these drugs reduce glioma proliferation and invasion felicitously implying that combination treatment could be a useful therapy for treatment of glioma.

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

Objective: To investigate the effects of different concentrations of isorhamnetin on C6 rat glioma cells in vitro from January 2015 to June 2015. Methods: The blank control group, blank solvent control group and four concentration groups were used to observe the cell growth status under a microscope. MTT colorimetric assay was used to detect the effect of isorhamnetin on C6 glioma cells in vitro and the cell inhibition rate And survival rate were measured. The apoptotic and apoptotic rates were measured by flow cytometry in the treatment group and the control group. The relationship between the different concentrations of isorhamnetin and C6 glioma cell apoptosis was analyzed the total protein was extracted and the total AKT protein and Ser473 AKT protein content were detected by Western 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

Brain-derived neurotrophic factor propeptide inhibits proliferation and induces apoptosis in C6 glioma cells.

There are several forms of brain-derived neurotrophic factor (BDNF), the precursor of BDNF, mature BDNF, and BDNF propeptide. They exert different effects through different transmembrane receptor signaling systems. Precursor of BDNF is enzymatically cleaved, either by intracellular or by extracellular proteases, to generate mature BDNF and its propeptide (BDNF propeptide). The aim of this study was to evaluate the potential molecular mechanisms that underlie the inhibition of glioma cell growth by the BDNF propeptide. To achieve this, we examined the expression of BDNF propeptide in C6 glioma cells. The 3-(4,5-dimethylthiazol-2-Yl)-2,5-diphenyltetrazolium bromide assay and the apoptosis assay were used to assess the effects of the BDNF propeptide on the growth and apoptosis of glioma cells. We found that the BDNF propeptide promoted C6 glioma cell apoptosis and decreased in-vitro cell growth. We also found using western blot that cleaved caspase3 and B cell lymphoma 2 (Bcl2)-associated X protein abundances increased, whereas Bcl2 abundance decreased. Our data suggest that the BDNF propeptide may have an inhibitory effect on glioma through activation of the caspase3 pathway.

The investigation of the effect of Tripterine combined with Cisplatin on the apoptosis of C6 glioma cells

Objective To clarify the inhibitory effect of Tripterine combined with Cisplatin on C6 glioma cells and its apoptosis mechanism. Methods C6 glioma cells were treated with Tripterine, Cisplatin, or Tripterine combined with Cisplatin. CCK-8 assay was used to detect the growth inhibition rate in each group. Flow cytometry analysis was used to test the cell apoptosis rate. The expressions of apoptosis-related proteins including Bcl-2, Bax, XIAP, NF-kB were analyzed by ELISA. Results Compared with Tripterine- or Cisplatin-treated group, the inhibition ratio of cell growth in Tripterine and Cisplatin combination group was (69.76±7.28)%, which could significantly inhibit the growth of C6 glioma cells(t=23.78, P<0.01). The apoptosis rate was significantly higher(47.75±5.63)%in combination group than in Tripterine or Cisplatin treated group. The results of ELISA showed that the expression of Bax was significantly higher and Bcl-2, XIAP, NF-κB were obviously lower in the combination group than in Tripterine or Cisplatin treated group (t=35.27, P<0.01). Conclusion The combination of Tripterine and Cisplatin significantly increases the inhibition rate on C6 glioma cells through upregulating Bax and inhibiting Bcl, XIAP and NF-kB to induce the apoptosis of C6 glioma cells. Key words: 【Keywords】 Tripterine; Cisplatin; C6 glioma cell; Apoptosis

Synthesis and in vitro evaluation of 4-substituted furano[3,2-c] tetrahydroquinolines as potential anti-cancer agents

A convenient and mild method for the synthesis of substituted furano [3,2-c]tetrahydroquinoline derivatives was developed, using the multi-component Povarov reaction. Of the synthesized tetrahydroquinoline derivatives, compound 10a displayed the greatest cellular proliferation inhibitory activities with IC50 values of 2.5–16.7 μmol/l. In addition, 10a induced murine C6 glioma cell apoptosis in a dose-dependent manner by up-regulating the expression of Bax, caspase-3, and caspase-9, and by down-regulating Bcl-2. Our findings suggest that these novel compounds have potential as therapeutic agents via inducing mitochondrial apoptosis.

DAW22, a natural sesquiterpene coumarin isolated from Ferula ferulaeoides (Steud.) Korov. that induces C6 glioma cell apoptosis and endoplasmic reticulum (ER) stress

2,3-Dihydro-7-hydroxy-2R*,3R*-dimethyl-2-[4,8-dimethyl-3(E),7-nonadienyl]-furo[3,2-c]coumarin (named DAW22), a sesquiterpene coumarin isolated from the roots of Ferula ferulaeoides (Steud.) Korov., has been reported to bear anti-proliferative activities toward different types of cancer cells. In this study, we demonstrated that DAW22 induced apoptosis in C6 glioma cells. Subsequently, we found that DAW22-induced apoptosis in C6 glioma cells occurred via the mitochondria-mediated and death-receptor pathways. Moreover, we found a massive cytoplasmic vacuolization, a dramatic change of endoplasmic reticulum (ER), up-regulation of CHOP and cleavage of caspase-12, suggesting that DAW22-induced apoptosis is involved in ER stress. In addition, we revealed that DAW22 treatment induced the activation of PERK, ATF6α and IRE1α. We further found that knockdown of CHOP affected DAW22-induced apoptosis, and DAW22-stimulated down-regulation of Bcl-2, caspase-8 activation and PARP cleavage were inhibited. Taken together, these results demonstrate that DAW22 induces apoptosis by ER stress and mitochondrial/death-receptor pathways, which may provide a new clue for exploiting this compound as a potential anti-neoplastic drug in future glioma cancer therapy.

Natural Bioactives in Cancer Treatment and Prevention

Natural bioactives are generally referred to the compounds exclusive of essential nutrients that have specific biological activity to human. From several decades ago to now, cancer continues to be the leading lethal cause worldwide. Studies have shown that natural phytochemicals derived from certain plants have the capability to prevent carcinogenesis. In this special issue, we collected numerous studies which provide novel evidence to support the opinion. For instance, epigallocatechin gallate inhibits migration of human uveal melanoma cells; marine sponge Hyrtios sp. extract induces apoptosis in human colorectal carcinoma RKO cells with different p53 status; Andrographolide induces apoptosis of C6 glioma cells via the ERK-p53-caspase 7-PARP pathway; and osthole induces human colon cancer cell death and inhibits migratory activity. We also collected some review articles in this special issue. A paper evaluated the cancer therapeutic potential of cardiac glycosides. A paper proposed vitamin A as the potent anticancer agent on targeting cellular retinol binding proteins. Three other papers addressed the anticancer molecular mechanisms of betulin, Goniothalamin, and Zerumbone. In summary, it is therefore believed that the appropriate application of natural bioactives should be a supplementary and safe way that enhances the efficacy of cancer therapy. Yih-Shou Hsieh Shun-Fa Yang Gautam Sethi Dan-Ning Hu

Cytoprotective Effects of Platycodon grandiflorus (Jacq.) A.DC on C6 Glioma Cell Apoptosis by Oxidative Stress

This study is designed to investigate cytoprotective effects of Platycodon grandiflorus (Jacq.) A.DC on C6 glioma cell apoptosis by oxidative stress. Experimental C6 glioma cells were classified into four groups as follows: normal group, PGE group, chemical groups, PGE+chemical groups. Oxidative stress that caused by chemicals in the C6 glioma cell, check the impact to Chemical group was administered normal group. Apoptotic effect protecting in order to observe the chemical group was administered PGE. We to observe effects of PGE on SOD inhibition, total glutathione production in C6 glioma cells were administered PGE. In case of administration PGE, apoptosis induced by Paraquat was significantly decreased. In case of administration PGE, apoptosis induced by SNP was significantly decreased. In case of administration PGE, apoptosis induced by H₂O₂ was significantly decreased. In case of administration PGE, apoptosis induced by Rotenone was decreased, but the statistical significance was not. In case of administration PGE, SOD inhibition activities significantly decreased. In case of administration PGE, Total glutathione did not affect the content. These results suggest that PGE is able to treat a disease caused by oxidative stress and prevent a aging. These results suggest that PGE is a disease caused by oxidative stress and aging, the prevention and treatment of food shall be able to be applied.

Calcium overload and in vitro apoptosis of the C6 glioma cells mediated by sonodynamic therapy (hematoporphyrin monomethyl ether and ultrasound).

The objective of this study was to investigate the role of intracellular calcium overload in the in vitro apoptosis of C6 glioma cells mediated by low level ultrasound and hematoporphyrin monomethyl ether (HMME) therapy. The frequency of ultrasound was optimized by the cell viability assay using 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). The apoptotic rate, reactive oxygen species (ROS) and decreased mitochondrial membrane potential (MMP) were determined by flow cytometry. Morphological changes were observed by the transmission electron microscope. Concentrations of intracellular Ca2+, [Ca2+]i were detected by a confocal microscopic laser scanning, and the release of cytochrome-c (cyt-c) was measured by western blotting. Results: The SDT-mediated apoptotic effect involved an overload of [Ca2+]i derived from the intra- and extracellular sources during the early progression of apoptotosis. The process was associated with an increased ROS production, a decreased MMP, and a release of cyt-c. In conclusion,the combined use of low level ultrasound and HMME improved the apoptotic rate of C6 glioma cells mediated by ultrasound alone. The [Ca2+]i overload involving activation of mitochondrial signaling played a pivotal role in the SDT-induced apoptosis.

Activation of neutral-sphingomyelinase, MAPKs, and p75 NTR-mediating caffeic acid phenethyl ester-induced apoptosis in C6 glioma cells.

BackgroundCaffeic acid phenethyl ester (CAPE), a component of propolis, is reported to possess anti-inflammatory, anti-bacterial, anti-viral, and anti-tumor activities. Previously, our laboratory demonstrated the in vitro and in vivo bioactivity of CAPE and addressed the role of p53 and the p38 mitogen-activated protein kinase (MAPK) pathway in regulating CAPE-induced apoptosis in C6 glioma cells.ResultsC6 cancer cell lines were exposed to doses of CAPE; DNA fragmentation and MAPKs and NGF/P75NTR levels were then determined. SMase activity and ceramide content measurement as well as western blotting analyses were performed to clarify molecular changes. The present study showed that CAPE activated neutral sphingomyelinase (N-SMase), which led to the ceramide-mediated activation of MAPKs, including extracellular signal-regulated kinase (ERK), Jun N-terminus kinase (JNK), and p38 MAPK. In addition, CAPE increased the expression of nerve growth factor (NGF) and p75 neurotrophin receptor (p75NTR). The addition of an N-SMase inhibitor, GW4869, established that NGF/p75NTR was the downstream target of N-SMase/ceramide. Pretreatment with MAPK inhibitors demonstrated that MEK/ERK and JNK acted upstream and downstream, respectively, of NGF/p75NTR. Additionally, CAPE-induced caspase 3 activation and poly [ADP-ribose] polymerase cleavage were reduced by pretreatment with MAPK inhibitors, a p75NTR peptide antagonist, or GW4869.ConclusionsTaken together, N-SMase activation played a pivotal role in CAPE-induced apoptosis by activation of the p38 MAPK pathway and NGF/p75NTR may explain a new role of CAPE induced apoptosis in C6 glioma.