Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: UMLS:C0017636 (glioblastoma)
18,345 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Vascular endothelial growth factor (VEGF) is abundantly produced by glioma cells especially glioblastoma, the most malignant form of astrocytoma. VEGF, a well known angiogenic factor, acts in a paracrine fashion on endothelial cells to develop tumor vasculature. However, recent studies have found that several tumor cells express VEGF receptors, and an autocrine action of VEGF on tumor cells has been suggested. To test this hypothesis, three human glioma cell lines (U251n, U87 and A172) were checked for VEGF and VEGFR expression. These cells express 0.1-0.6 ng/ml VEGF165 in cell culture medium within 24 hours. Western blot analysis showed that these cells express all of the VEGF receptors, VEGFR-1/Flt-1, VEGFR-2/KDR, Neuropilin-1 (NRP-1) and Neuropilin-2(NRP-2), even though tyrosine kinase receptor VEGFR-2/KDR exhibited baseline levels of expression. VEGF expression was significantly down regulated by phosphorothioate oligodeoxynucleotide (PS-ODN) and VEGF RNAi transfection. However, VEGF RNAi transfection as well as VEGF and VEGFR2 neutralization antibody treatment did not decrease cell proliferation detected by MTT and CyQuant NF proliferation assay except that PS-ODN transfection caused a non-specific decrease on cell proliferation. VEGF RNAi transfection did not alter cell invasion, as demonstrated in a matrigel invasion assay. Matrix metalloproteinase-2 (MMP-2) and MMP-9, facilitating cell invasion and over expressed in glioma cells, were not altered by VEGF RNAi transfection, as shown by zymographic assays. Our data indicate that the decrease of endogenous VEGF expression may not affect glioma cell proliferation and invasion.
...
PMID:Decrease of endogenous vascular endothelial growth factor may not affect glioma cell proliferation and invasion. 1755 62

Sanguinarine is a benzophenanthridine alkaloid that is derived from the root of Sanguinaria canadensis and other poppy fumaria species, and is known to have antimicrobial, antiinflammatory and antioxidant properties. This study investigated the possible mechanisms through which sanguinarine exerts its antiproliferative action in cultured C6 rat glioblastoma cells. The exposure of C6 cells to sanguinarine resulted in growth inhibition and the induction of apoptosis in a dose-dependent manner, as measured by the MTT assay, fluorescence microscopy, agarose gel electrophoresis and annexin-V-based assay. The sanguinarine treatment induced the proteolytic activation of caspases and ICAD/DFF45, which was associated with the modulation of the Bcl-2 family, concomitant degradation of poly(ADP ribose) polymerase and phospholipase C-gamma1 protein, and DNA fragmentation. z-DEVD-fmk, a caspase-3-specific inhibitor, blocked poly(ADP ribose) polymerase degradation, DNA fragmentation and increased the survival rate of sanguinarine-treated C6 cells. Moreover, the activity of extracellular signal-regulated kinase and Akt was downregulated in sanguinarine-treated cells, and PD98059, a specific extracellular signal-regulated kinase inhibitor, and phosphatidylinositol 3'-kinase/Akt inhibitors, LY294002 and wortmanin, sensitized the cells to sanguinarine-induced apoptosis, indicating that the downregulation of the extracellular signal-regulated kinase and Akt signaling pathway may play a key role in sanguinarine-induced apoptosis in C6 cells.
...
PMID:Induction of apoptosis by sanguinarine in C6 rat glioblastoma cells is associated with the modulation of the Bcl-2 family and activation of caspases through downregulation of extracellular signal-regulated kinase and Akt. 1766 97

Integrin-linked kinase (ILK) was assesed as a therapeutic target in glioblastoma xenograft models through multiple endpoints including treatment related changes in the tumor microenvironment. Glioblastoma cell lines were tested in vitro for sensitivity toward the small-molecule inhibitors QLT0254 and QLT0267. Cell viability, cell cycle, and apoptosis were evaluated using MTT assay, flow cytometry, caspase activation, and DAPI staining. Western blotting and ELISA were used for protein analysis (ILK, PKB/Akt, VEGF, and HIF-1alpha). In vivo assessment of growth rate, cell proliferation, BrdUrd, blood vessel mass (CD31 labeling), vessel perfusion (Hoechst 33342), and hypoxia (EF-5) was done using U87MG glioblastoma xenografts in RAG2-M mice treated orally with QLT0267 (200 mg/kg q.d.). ILK inhibition in vitro with QLT0254 and QLT0267 resulted in decreased levels of phospho-PKB/Akt (Ser473), secreted VEGF, G2-M block, and apoptosis induction. Mice treated with QLT0267 exhibited significant delays in tumor growth (treated 213 mm3 versus control 549 mm3). In situ analysis of U87MG tumor cell proliferation from QLT0267-treated mice was significantly lower relative to untreated mice. Importantly, VEGF and HIF-1alpha expression decreased in QLT0267-treated tumors as did the percentage of blood vessel mass and numbers of Hoechst 33342 perfused tumor vessels compared with control tumors (35% versus 83%). ILK inhibition with novel small-molecule inhibitors leads to treatment-associated delays in tumor growth, decreased tumor angiogenesis, and functionality of tumor vasculature. The therapeutic effects of a selected ILK inhibitor (QLT0267) should be determined in the clinic in cancers that exhibit dysregulated ILK, such as PTEN-null glioblastomas.
...
PMID:Suppression of VEGF secretion and changes in glioblastoma multiforme microenvironment by inhibition of integrin-linked kinase (ILK). 1820 10

We investigate the cytotoxic effect of metal protoporphyrins including ferric protoporphyrin (FePP; hemin), cobalt protoporphyrin (CoPP), and tin protoporphyrin (SnPP) in glioblastoma cells C6 and GBM8401. Data of MTT assay show that FePP and CoPP, but not SnPP, significantly reduce the viability of glioma cells C6 and GBM8401 in the absence of serum. In the condition with fetal bovine serum (FBS) or bovine serum albumin (BSA), the cytotoxic effect of FePP and CoPP was completely inhibited. Binding of FePP, CoPP, and SnPP with BSA was examined via spectrophotometer analysis, and the protective effect of serum against FePP and CoPP-induced cell death was abolished by BSA depletion. A loss in the integrity of DNA with an occurrence of apoptotic events including DNA ladders, caspase 3 and PARP protein cleavage, and chromatin-condensed cells is observed in FePP-treated or CoPP-treated C6 cells. An increase in intracellular peroxide level was examined in FePP, but not CoPP, -treated C6 cells, and N-acetyl-l-cysteine (NAC) addition significantly protected C6 cells from FePP, but not CoPP, -induced cell death with reducing FePP-stimulated reactive oxygen species (ROS) production. Activation of extracellular regulated kinases (ERKs) and c-Jun-N-terminal kinases (JNKs) with an increase in the heme oxygenase-1 (HO-1) protein was observed in FePP-treated or CoPP-treated C6 cells in the absence of FBS or BSA, and adding JNKs inhibitor SP600125 (SP), but not ERKs inhibitor PD98059 (PD), significantly attenuated FePP-induced or CoPP-induced HO-1 protein expression in accordance with reducing JNKs protein phosphorylation. However, PD98059, SP600125, or transfection of C6 cells with antisense HO-1 oligonucleotides show no effect on the cytotoxicity elicited by FePP and CoPP in C6 cells. Effect of serum and BSA on the cytotoxicity of metal protoporphyrins in glioma cells is first demonstrated in the present study, and the roles of ROS, MAPKs, and HO-1 were elucidated.
...
PMID:Cytotoxic effects of metal protoporphyrins in glioblastoma cells: roles of albumin, reactive oxygen species, and heme oxygenase-1. 1828 2

Lithium, besides mood stabilization, might be involved in neuroprotection. Previously we have found that the treatment with lithium increased the levels of p21(WAF/Cip1 and survivin in human glioblastoma A1235 cells. The aim of the present study was to examine the cytotoxic effect of glutamate on these cells, and to determine whether lithium can protect A1235 cells against toxic effects of glutamate. Cytotoxicity of glutamate was examined by spectrophotometric MTT assay, while the expression of apoptosis related genes was examined by Western blot method. Glutamate was excessively cytotoxic for A1235 cells only in concentrations higher than 100 mM. It did not induce apoptosis, but rather suppressed survivin expression and increased the level of p21(WAf/Cip1). Pretreatment with lithium (2 mM) partially reverted change in survivin expression induced by glutamate, suggesting that lithium may have beneficial effect on glutamate induced cell damage in glioblastoma cells.
...
PMID:Lithium effect on glutamate induced damage in glioblastoma cells. 1840 64

IMP preferring cytosolic 5'-nucleotidase (cN-II) is an ubiquitous nucleotide hydrolysing enzyme. The enzyme is widely distributed and its amino acid sequence is highly conserved among vertebrates. Fluctuations of cN-II activity have been associated with the pathogenesis of neurological disorders. The enzyme appears to be involved in the regulation of the intracellular availability of the purine precursor IMP and also of GMP and AMP, but the contribution of this activity and of its regulation to cell metabolism and to CNS cell functions remains uncertain. To address this issue, we used a vector based short hairpin RNA (shRNA) strategy to knockdown cN-II activity in human astrocytoma cells. Our results demonstrated that 53 h after transduction, cN-II mRNA was reduced to 17.9+/-0.03% of control cells. 19 h later enzyme activity was decreased from 0.7+/-0.026 mU/mg in control ADF cells to 0.45+/-0.046 mU/mg, while cell viability (evaluated by the MTT reduction assay) decreased up to 0.59+/-0.01 (fold vs control) and caspase 3 activity increased from 136+/-5.8 pmol min(-1) mg(-1) in control cells to 639+/-37.5 pmol min(-1) mg(-1) in silenced cells, thus demonstrating that cN-II is essential for cell survival. The decrease of enzyme activity causes apoptosis of the cultured cells without altering intracellular nucleotide and nucleoside concentration or energy charge. Since cN-II is highly expressed in tumour cells, our finding offers a new possible therapeutical approach especially against primary brain tumours such as glioblastoma, and to ameliorate chemotherapy against leukemia.
...
PMID:Knockdown of cytosolic 5'-nucleotidase II (cN-II) reveals that its activity is essential for survival in astrocytoma cells. 1844 85

Tetrazolium violet (TV), a tetrazolium salt, has been applied in several fields, including estimating respiration rate, as a redox indicator of microbial growth, and for estimating the number of viable animal cells. It has recently been found that TV is capable of inducing apoptosis in rat glioblastoma cells by way of an elusive mechanism. In this study, we demonstrated that TV also induced apoptosis in mouse breast tumor C127 cells as evidenced by nucleus condensation and nucleus fragmentation. Our data showed that TV caused activation of caspase-3 and caspase-8, but not caspase-9. An enhancement in Fas and its two ligands, membrane-bound Fas ligand (mFasL) and soluble Fas ligand (sFasL), might be responsible for the apoptotic effect induced by TV. Also, the results first reported that TV not only inhibited C127 cells proliferation but also blocked cell cycle progression in the G1 and G2 phase, determined by MTT assay and flow cytometry analysis. Immunofluorescence assay demonstrated that TV significantly increased the expression of p53 protein, which caused cell cycle arrest. Taken together, p53, Fas/FasL, and the caspase apoptotic system may participate in the antiproliferative activity of TV in C127 cells.
...
PMID:Tetrazolium violet inhibits cell growth and induces cell death in C127 mouse breast tumor cells. 1854 55

Liver-type glutaminase (LGA) is a glutaminase isoform that has been implicated in transcription modulation. LGA mRNA is absent from postoperative samples of primary gliomas and is low in cultured astrocytes. In this study, stable transfection of T98G cells with a vector carrying human LGA sequence increased the expression of LGA mRNA and protein, and the ability of the cells to degrade glutamine (Gln), as manifested by a three-fold reduction of their steady-state Gln content and a 2.5-fold increase of their glutamate (Glu) content. The transfected cells (TLGA cells) showed a 40% decrease of cell survival as assessed by colony formation, well correlated with significant reduction of mitochondrial activity as demonstrated with MTT test. Also, a 45% reduction of cell migration and a 47% decrease of proliferation index (Ki67 immunostaining) were found as compared with sham-transfected cells. Microarray analysis, which included over 47,000 transcripts, revealed a significantly altered expression of 85 genes in TLGA, but not in sham-transfected or control cells (P < 0.005). Microarray data were confirmed with real-time PCR analysis for eight genes potentially relevant to malignancy: S100A16, CAPN2, FNDC3B, DYNC1LI1, TIMP4, MGMT, ADM, and TIMP1. Of these changes, decreased expression of S100A16 and MGMT can be best reconciled with the current views on the role of their protein products in glioma malignancy. Malignancy-reducing effect of newly inserted LGA mRNA in glioblastoma cells can be reconciled with a hypothesis that absence of such a modulatory mechanism in glia-derived tumors deprived of LGA mRNA may facilitate some aspects of their progression.
...
PMID:Transfection with liver-type glutaminase cDNA alters gene expression and reduces survival, migration and proliferation of T98G glioma cells. 1906 76

Stress can affect the brain and lead to depression; however, the molecular pathogenesis is unclear. An association between stress and stress-induced hypersecretion of glucocorticoids occurs during stress. Dexamethasone (a synthetic glucocorticoid steroid) has been reported to induce apoptosis and increase the activity of monoamine oxidase (MAO) (Youdim et al. 1989). MAO is an enzyme for the degradation of aminergic neurotransmitters; dopamine, noradrenaline and serotonin and dietary amines and MAO inhibitors are classical antidepressant drugs. In this study, we have compared the ability of rasagiline (Azilect) and its main metabolite, R-aminoindan with selegiline (Deprenyl) in prevention of dexamethasone-induced brain cell death employing human neuroblastoma SH-SY5Y cells and glioblastoma 1242-MG cells. Dexamethasone reduced cell viability as measured by MTT test, but rasagiline, selegiline, and 1-R-aminoindan could significantly prevent dexamethasone-induced brain cell death. Among three drugs, rasagiline had the highest neuroprotective effect. Furthermore, the inhibitory effects of these drugs on MAO B catalytic activity and on apoptotic DNA damage (TUNEL staining) were examined. Rasagiline exhibited highest inhibition on MAO B enzymatic activity and prevention on DNA damage as compared to selegiline and 1-R-aminoindan. In summary, the greater neuroprotective effect of rasagiline may be associated with the combination of the parent drug and its metabolite 1-R-aminoindan.
...
PMID:Comparative neuroprotective effects of rasagiline and aminoindan with selegiline on dexamethasone-induced brain cell apoptosis. 1938 1

The purpose of this study is to evaluate in vivo antitumor efficacy and subacute toxicity of docetaxel (DTX) prodrug comprising a conjugate between DTX and low molecular weight chitosan (LMWC) after oral administration. DTX was covalently attached to LMWC via a cleavable linker so as to be released from LMWC-DTX conjugate in body. In vitro cytotoxicity of LMWC-DTX conjugate was evaluated by MTT assay against two human cancer cell lines, showing similar IC(50) values to the parent DTX. The pharmacokinetic data of the conjugate after oral administration revealed that half-life in blood circulation was increased by approximately 15-fold and AUC((0-infinity)) was 3.8-6.2 times higher in comparison with the intravenously injected DTX (i.v.). In vivo antitumor efficacy was evaluated in nude mice bearing human non-small cell lung carcinoma (NCI-H358) and glioblastoma (U87MG), respectively. The orally administered LMWC-DTX conjugate (10 mg DTX equivalent/kg) showed comparable antitumor efficacy to the same dose of DTX (i.v.) for both NCI-H358 and U87MG models, but revealed much lower subacute toxicity as seen in body weight loss and hematological toxicity.
...
PMID:In vivo antitumor effects of chitosan-conjugated docetaxel after oral administration. 1971 14


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---