Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0017638 (glioma)
 30,880 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cancer cell migration is a leading cause of tumor recurrence and treatment failure. Previously, we reported that marchantin C exhibited promising antitumor activity by inducing microtubule depolymerization and apoptosis. In the present study, we investigated the effect of marchantin C on inhibition of migration in T98G and U87 cells. The scratch-induced migration, Boyden chamber and cell invasion assays were applied to determine that the migrating capacity and invasiveness of these glioma cell lines were inhibited when exposed to marchantin C at a low concentration. There are no obvious signs of apoptosis with this dose. Western blot analyses confirmed that MMP-2, a key role in cancer cell migration, was reduced after incubation with marchantin C in both glioma cell lines. In addition, signaling pathway investigations demonstrated that ERK/MAPK might be involved in MMP-2 downregulation, rather than the AKT/PI3K or JAK/STAT3 pathways. Moreover, marchantin C potently suppressed angiogenesis activity in vivo by CAM assay. This is the first study to demonstrate that marchantin C can inhibit glioma cell migration and invasiveness.
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PMID:Marchantin C: a potential anti-invasion agent in glioma cells. 2002 71

Cyclooxygenase-2 (COX-2) and Protein kinase B (PKB/Akt) play a crucial role in the formation of many malignant tumors and have been shown to be the important therapeutic targets. In the present study, we examined immunohistochemical expression of phosphorylated Akt (p-Akt) and COX-2 in 45 gastric adenocarcinomas with different tumor grades. Then, adenovirus-mediated small hairpin RNA (shRNA) expression vectors rAd5-Akt1+COX-2 (rAd5-A+C) that target sequences of human COX-2 and Akt1 were used to examine the inhibitory effects on cell proliferation, invasion and apoptosis in SGC7901 gastric adenocarcinoma and U251 glioma cells. Cell growth was inhibited by over 70%, as indicated by a MTT assay, and was accompanied by G1/G0 phase arrest in the rAd5-A+C treated group, indicating poor cell growth activities. The number of cells invading through the matrigel in the rAd5-A+C treated group was significantly decreased (36.2+/-3.1) compared with that of the control group SGC7901 (105.0+/-4.0) and the nonsense sequence group rAd5-HK (102.5+/-6.4). In addition, the tumor volumes in the SGC7901 subcutaneous nude mouse model treated with rAd5-A+C was significantly smaller than those of the control group and nonsense sequence group rAd5-HK. When COX-2 and Akt1 were dramatically downregulated, Ki-67, CyclinD1, MMP-2, MMP-9 and Bcl-2 were also downregulated. Our results demonstrated that p-Akt and COX-2 were overexpressed in gastric adenocarcinomas and their expression levels were elevated with the ascending order of tumor malignancy; rAd5-A+C targeting COX-2 and Akt1 downregulated their expression significantly in a sequence-specific manner, exerting inhibitory effects on SGC7901 and U251 cell proliferation, invasion and apoptosis. In conclusion, our data suggest a novel mechanism for the regulation of malignant tumor cell growth and provide evidence for combined gene therapy for malignant tumors.
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PMID:Expression of p-Akt and COX-2 in gastric adenocarcinomas and adenovirus mediated Akt1 and COX-2 ShRNA suppresses SGC-7901 gastric adenocarcinoma and U251 glioma cell growth in vitro and in vivo. 1992 30

Although matrix metalloproteinases (MMPs) play a crucial role in the invasion and growth of malignant gliomas, their increased activity in tumor environment can be used as a specific target for chemotherapy. We investigated whether polymer-drug conjugates formed via MMP-cleavable peptide linkages could provide MMP-responsive tumor targeting and cytotoxicity for malignant glioma cells. One end of an MMP-cleavable peptide was attached to the end of methoxy polyethylene glycol (MPEG) while the other end was attached to adriamycin (ADR). The release of drugs in the presence of conditioned media of U87MG cells was investigated. The cytotoxicities of the MMP-cleavable MPEG-peptide-ADR (PPA) conjugates and non-cleavable MPEG-ADR (PA) conjugates were investigated using U87MG cells. The (1)H nuclear magnetic resonance (NMR) spectra confirmed the conjugation of the two ends of the peptide to the ends of MPEG and ADR, respectively. Gelatin zymography showed that MMP-2 was strongly expressed in the media of U87MG cells. The PA conjugate did not release ADR either in the phosphate buffered saline (PBS) or conditioned media of U87MG cells. The PPA conjugate released ADR in the presence of the conditioned media of U87MG cells, but not in PBS only. In the cytotoxicity test using U87MG cells, ADR and PPA conjugate showed similar anti-proliferative activities, while the cytotoxicity of PA conjugate was lower than that of ADR. Considering that the cytotoxicity of the PPA conjugate was similar to that of ADR, MMP-cleavable polymer-drug conjugates can be used as targeting carriers for the purpose of inhibiting the proliferation of malignant glioma cells.
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PMID:Anticancer activity of PEGylated matrix metalloproteinase cleavable peptide-conjugated adriamycin against malignant glioma cells. 1994 19

Malignant gliomas including glioblastoma multiforme (GBM) and anaplastic astrocytomas are the most common primary brain tumors. Despite multimodal treatment including surgery, chemotherapy, and radiation, median survival for patients with GBMs is only 12 to 15 months. Identifying molecules critical for glioma progression is crucial for devising effective targeted therapy. In the present study, we investigated the potential contribution of astrocyte elevated gene-1 (AEG-1) in gliomagenesis and explored the possibility of AEG-1 as a therapeutic target for malignant glioma. We analyzed the expression levels of AEG-1 in 9 normal brain tissues and 98 brain tumor patient samples by Western blot analysis and immunohistochemistry. AEG-1 expression was significantly elevated in >90% of diverse human brain tumor samples including GBMs and astrocytic tumors, and also in human glioma cell lines compared with normal brain tissues and normal astrocytes. Knockdown of AEG-1 by small interfering RNA inhibited cell viability, cloning efficiency, and invasive ability of U87 human glioma cells and 9L rat gliosarcoma cells. We also found that matrix metalloproteases (MMP-2 and MMP-9) are involved in AEG-1-mediated invasion of glioma cells. In an orthotopic nude mouse brain tumor model using primary human GBM12 tumor cells, AEG-1 small interfering RNA significantly suppressed glioma cell growth in vivo. Taken together, these provocative results indicate that AEG-1 may play a crucial role in the pathogenesis of glioma and that AEG-1 could represent a viable potential target for malignant glioma therapy.
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PMID:Astrocyte elevated gene-1: a novel target for human glioma therapy. 2005 77

Gliomas are the most common type of primary brain tumors. Despite the improvement in current treatments for gliomas, including surgical resection, radiation, and chemotherapy, there has been very little progress in curing this kind of disease. Stat3 is a member of signal transducer and activator of transcription family. It plays an important role in regulating cell survival, invasion, and apoptosis. This study investigated the influence of low-level expression of Stat3 on invasion and apoptosis in U251 cells. Our data showed that Stat3 is constitutively expressed in human gliomas cell line U251. The invasion activity in U251 cells was weakened and the apoptosis in U251 cells was induced after down-regulation of Stat3. In addition, down-regulation of Stat3 can suppress the expression of MMP-2, Bcl-xL and survivin but not 67LR. These results further indicate that Stat3 plays a key role in the invasion and apoptosis of human glioma cell line U251.
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PMID:Down-regulation of Stat3 decreases invasion activity and induces apoptosis of human glioma cells. 2006 89

RECK is an anti-tumoral gene whose activity has been associated with its inhibitory effects regulating MMP-2, MMP-9, and MT1-MMP. RECK level decreases as gliobastoma progresses, varying from less invasive grade II gliomas to very invasive human glioblastoma multiforme (GBM). Since RECK expression and glioma invasiveness show an inverse correlation, the aim of the present study is to investigate whether RECK expression would inhibit glioma invasive behavior. We conducted this study to explore forced RECK expression in the highly invasive T98G human GBM cell line. Expression levels as well as protein levels of RECK, MMP-2, MMP-9, and MT1-MMP were assessed by qPCR and immunoblotting in T98G/RECK+ cells. The invasion and migration capacity of RECK+ cells was inhibited in transwell and wound assays. Dramatic cytoskeleton modifications were observed in the T98G/RECK+ cells, when compared to control cells, such as the abundance of stress fibers (contractile actin-myosin II bundles) and alteration of lamellipodia. T98G/RECK+ cells also displayed phosphorylated focal adhesion kinase (P-FAK) in mature focal adhesions associated with stress fibers; whereas P-FAK in control cells was mostly associated with immature focal complexes. Interestingly, the RECK protein was predominantly localized at the leading edge of migrating cells, associated with membrane ruffles. Unexpectedly, introduced expression of RECK effectively inhibited the invasive process through rearrangement of actin filaments, promoting a decrease in migratory ability. This work has associated RECK tumor-suppressing activity with the inhibition of motility and invasion in this GBM model, which are two glioma characteristics responsible for the inefficiency of current available treatments.
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PMID:RECK-mediated inhibition of glioma migration and invasion. 2012 10

Glioblastoma multiforme is the most commonly diagnosed malignant primary brain tumour in adults. Invasive behaviour is the pathological hallmark of malignant gliomas; consequently, its inhibition has been suggested as a therapeutic strategy. Tumour cell-derived gelatinases (matrix metalloproteinase-2, matrix metalloproteinase-9) can be considered prime factors in glioma invasiveness: their expression correlates with the progression and the degree of malignancy. Thus, broad spectrum matrix metalloproteinase inhibitors (MMP inhibitors) have been included in clinical trials. In the present study, the invasiveness, viability and progression of the human glioma cell line U87MG were investigated following treatment with N-O-isopropyl sulfonamido-based hydroxamates (compounds 1 and 2) as MMP-2 inhibitors used at nanomolar concentration. A standard broad spectrum MMP-inhibitor belonging to the classical tertiary sulfonamido-based hydroxamates family (CGS_27023A) was used too. The compounds 1 and 2 resulted in potent inhibition of cell invasiveness (P<0.0001) without affecting viability. In some clinical trials, the combined therapy of temozolomide (an alkylating agent used in glioma treatment) plus marimastat (a broad spectrum MMP inhibitor) has provided evidence of the importance of MMPs to tumor progression and invasiveness. On this basis, the effect on U87MG cells of a combined treatment with temozolomide, plus each of the two MMP inhibitors at nanomolar concentration, was investigated. The obtained data demonstrated the inhibition of cell invasiveness and viability after treatment. These results can help in developing clinical combined therapy using MMP inhibitors that, at low doses, increase the anticancer efficacy of chemotherapeutic drugs, probably without causing the side effects typical of broad-spectrum MMP inhibitors.
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PMID:Inhibition of metalloproteinases derived from tumours: new insights in the treatment of human glioblastoma. 2038 6

Despite recent advances in the understanding of its cell biology, glioma remains highly lethal. Development of effective therapies requires a cost-effective in vitro tumor model that more accurately resembles the in vivo tumor microenvironment as standard two-dimensional (2D) tissue culture conditions do so poorly. Here we report on the use of a three-dimensional (3D) chitosan-alginate (CA) scaffold to serve as an extracellular matrix that promotes the conversion of cultured cancer cells to a more malignant in vivo-like phenotype. Human U-87 MG and U-118 MG glioma cells and rat C6 glioma cells were chosen for the study. In vitro tumor cell proliferation and secretion of factors that promote tumor malignancy, including VEGF, MMP-2, fibronectin, and laminin, were assessed. The scaffolds pre-cultured with U-87 MG and C6 cells were then implanted into nude mice to evaluate tumor growth and blood vessel recruitment compared to the standard 2D cell culture and 3D Matrigel matrix xenograft controls. Our results indicate that while the behavior of C6 cells showed minimal differences due to their highly malignant and invasive nature, U-87 MG and U-118 MG cells exhibited notably higher malignancy when cultured in CA scaffolds. CA scaffolds provide a 3D microenvironment for glioma cells that is more representative of the in vivo tumor, thus can serve as a more effective platform for development and study of anticancer therapeutics. This unique CA scaffold platform may offer a valuable alternative strategy to the time-consuming and costly animal studies for a wide variety of experimental designs.
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PMID:Chitosan-alginate 3D scaffolds as a mimic of the glioma tumor microenvironment. 2041 55

Invasion into adjacent brain parenchyma is the key cause of recurrent human glioblastoma multiforme (GBM). The role of interleukin 6 (IL-6) in the malignant progression of glioma remains undefined. Here, we found that IL-6 promotes the invasion of U87 MG human glioma cells but not in U343 cells. An advanced level of STAT3 activity, and increased expression and secretion of MMP-2, induced by IL-6 in U87 MG cells were observed. Blocking the STAT3 pathway with specific inhibitors of STAT3, JSI-124 or small interfering RNA (siRNA), inhibited the invasion of U87MG promoted by IL-6 with concomitant down-regulation of MMP-2. Furthermore, rapid up-regulation of fascin-1 (a cell motility-related protein) induced by IL-6 was apparent in U87MG cells. However, this up-regulation of fascin-1 was not inhibited by JSI-124 or siRNA. These results suggest that the STAT3 pathway and fascin-1 may play crucial roles in the invasiveness of U87MG cells promoted by IL-6.
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PMID:IL-6 augments the invasiveness of U87MG human glioblastoma multiforme cells via up-regulation of MMP-2 and fascin-1. 2042 9

Osteopontin (OPN) is widely overexpressed in various cancers, including gliomas, and plays an important role in tumorigenesis. However, the expression pattern and functions of OPN splice variants expressed in gliomas remain unclear. The aims of our current study were to examine the expression pattern and functions of OPN splice variants in gliomas. In present study, the mRNA levels of OPN splice variants are markedly increased in gliomas tissues, and all OPN splice variants were also found in U251 and U87 cells. Furthermore, knock-down and regain of function experiments were designed to explore the functions of OPN splice variants in U251 and U87 cells. Lentiviral vectors of OPN small interference RNA (siRNA) targeting all three endogenous mRNAs of OPN and OPN splice variants synonymous mutant that were not silenced by OPN siRNA were constructed. Our results showed that all OPN splice variants synonymous mutant-protected glioma cells from apoptosis induced by OPN siRNA through alteration of the levels of Bcl-2 family proteins and OPN-b Mu elicted a significant effect. Both OPN-a Mu and -c Mu promoted glioma cell invasion through alteration of the levels of uPA, MMP-2, and MMP-9 expressions and the activities of MMP-2 and MMP-9 via activation PI-3K/AKT/NF-kappaB signaling pathway. Moreover, OPN-c Mu showed the strongest effect on glioma cell invasion, while OPN-b Mu showed no effect on the invasion of U251 and U87 cells. Thus, different splice variants of OPN have divergent functions in regulating apoptosis and invasion of glioma cells, which broadens their importance in glioma biotherapy.
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PMID:Expression pattern of osteopontin splice variants and its functions on cell apoptosis and invasion in glioma cells. 2051 Nov 84


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