Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0017636 (glioblastoma)
 18,345 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We established a protocol for the non-isotopic in situ detection of adhesion molecule CD44 messenger RNA (mRNA) in archival formalin-fixed paraffin-embedded sections of human surgical materials. Four brain tumor samples with different histopathologies (a metastatic adenocarcinoma, a metastatic squamous carcinoma, a glioblastoma and a craniopharyngioma) were thus studied using a 157 nt digoxigenin-labeled RNA probe complementary to the common mRNA region to all the CD44 isoforms. The CD44 transcript was detected in the cytoplasm of glioma and such epithelial tumor cells as metastatic carcinoma and craniopharyngioma. A competitive hybridization study confirmed the specificity of the CD44 probe. The optimization of critical conditions are also discussed. This protocol should therefore be useful in making an accurate evaluation of mRNA localization and may also facilitate the successful completion of extensive retrospective studies on a large number of archival samples.
 ...
PMID:Non-isotopic in situ hybridization of CD44 transcript in formalin-fixed paraffin-embedded sections. 1023 50

The glycosaminoglycan hyaluronan, which supports tumor cell migration and metastasis, interferes with fibrin polymerization and leads to increased fiber size and porosity of fibrin clots. Here we have studied the proportionate effect of fibrin polymerization on hyaluronan-mediated migration of glioblastoma cells. The structural and physical properties of hyaluronan-containing fibrin gels were analyzed by turbidity measurement, laser scanning microscopy, compaction assay, and calculation of pore size by liquid permeation. When fibrin polymerized in the presence of hyaluronan or dextran, the resulting gels strongly stimulated cell migration, and migration significantly correlated with fiber mass-to-length ratios and pore diameters. In contrast, cell migration was not induced by addition of hyaluronan to supernatants of already polymerized gels. Hyaluronan-mediated migration was inhibited in fibrin gels by antibodies to alphav- and beta1integrins and the disintegrin echistatin, but not by antibodies to the hyaluronan receptor CD44 (up to 50 microg/ml). As a control, we show that anti-CD44 (10 microg/ml) inhibited cell migration on a pure hyaluronan matrix using a two-dimensional Boyden chamber system. In contrast to three-dimensional migration, the migration of cells on the surfaces of variably structured fibrin gels was not significantly different, indicating that increased gel permeability (porosity) may account for hyaluronan-mediated migration. We conclude that, in complex three-dimensional substrates, the predominant effect of hyaluronan on cell migration might be indirect and requires modulation of fibrin polymerization.
 ...
PMID:Hyaluronan stimulates tumor cell migration by modulating the fibrin fiber architecture. 1036 54

BACKGROUND: Antisense oligodeoxynucleotides (ODNs) have been proposed as a new therapy for patients with cancer, including malignant brain tumors. Antisense ODNs are taken up by tumor cells and selectively block gene expression. Use of ODNs for brain tumors is attractive due to their theoretical specificity, relative ease of production and, to date, paucity of reported adverse effects. This article presents current information regarding antisense ODNs and their possible future use for the treatment of brain tumors. METHODS: The available published experimental and clinical information regarding antisense ODN treatment of glioblastoma cells and administration into the central nervous system (CNS) was reviewed. Other clinically relevant information pertaining to the molecular biology of antisense ODNs was also collected and summarized. RESULTS: Targets for antisense ODN therapy in malignant glioma cells have included c-myc, c-myb, c-sis, c-erb B, CD44, p34cdc2, bFGF, PDGF, TGF-beta, IGF-1, PKC-alpha tumor necrosis factor, urokinase, and S100beta protein. Few in vivo studies of ODN treatment of brain tumors have yet been reported. Systemically administered ODNs enter the brain only in extremely small quantities; therefore, microinfusion into the brain has been recommended. CONCLUSIONS: Antisense ODNs have been used successfully to block glioblastoma gene expression in vitro and expression of multiple genes within the CNS of experimental animals. Upcoming clinical trials will address the safety of antisense ODN use against malignant brain tumors.
 ...
PMID:Antisense Oligodeoxynucleotide Technology: Potential Use for the Treatment of Malignant Brain Tumors. 1076 Oct 27

Microarray analysis of complementary DNA (cDNA) allows large-scale, comparative, gene expression profiling of two different cell populations. This approach has the potential for elucidating the primary transcription events and genetic cascades responsible for increased glioma cell motility in vitro and invasion in vivo. These genetic determinants could become therapeutic targets. We compared cDNA populations of a glioma cell line (G112) exposed or not to a motility-inducing substrate of cell-derived extracellular matrix (ECM) proteins using two sets of cDNA microarrays of 5,700 and 7,000 gene sequences. The data were analyzed considering the level and consistency of differential expression (outliers) and whether genes involved in pathways of motility, apoptosis, and proliferation were differentially expressed when the motility behavior was engaged. Validation of differential expression of selected genes was performed on additional cell lines and human glioblastoma tissue using quantitative RT-PCR. Some genes involved in cell motility, like tenascin C, neuropilin 2, GAP43, PARG1 (an inhibitor of Rho), PLCy, and CD44, were over expressed; other genes, like adducin 3y and integrins, were down regulated in migrating cells. Many key cell cycle components, like cyclin A and B, and proliferation markers, like PCNA, were strongly down regulated on ECM. Interestingly, genes involved in apoptotic cascades, like Bcl-2 and effector caspases, were differentially expressed, suggesting the global down regulation of proapoptotic components in cells exposed to cell-derived ECM. Overall, our findings indicate a reduced proliferative and apoptotic activity of migrating cells. cDNA microarray analysis has the potential for uncovering genes linking the phenotypic aspects of motility, proliferation, and apoptosis.
 ...
PMID:Glioma cell motility is associated with reduced transcription of proapoptotic and proliferation genes: a cDNA microarray analysis. 1171 68

Malignant gliomas are highly proliferative and invasive tumors with poor prognosis. We investigated the influence of Interferon-gamma (IFN-gamma) on the human malignant glioma cell line A172, measuring cell viability (MTT-test), proliferation (3H-thymidine-uptake), cell death (FACS) adhesion to hyaluronic acid (HA, adhesion-assay) and migration (Boyden-chamber). IFN-gamma significantly decreased cell viability and proliferation. Measured by FACS, an up-regulation of CD95 expression has been shown in combination with an increased rate of cell death, first seen after 96 hours IFN-gamma treatment. Adhesion to HA was decreased after pre-treatment with IFN-gamma. This was not mediated by down-regulation of the main HA-receptor CD44, since IFN-gamma did not change CD44 expression. IFN-gamma-treated cells showed a significantly diminished migration rate through a native or HA-coated 8-microm polycarbonate membrane. To summarise, IFN-gamma influences both the main characteristics of malignancy: it decreases cell proliferation and induces cell death, further it diminishes migration of A172 human glioblastoma cells.
 ...
PMID:Interferon-gamma inhibits growth and migration of A172 human glioblastoma cells. 1191 Dec 81

Hyaluronan binding to its cellular receptors CD44 and ICAM-1 appears to enhance the malignant behavior of tumors, including astrocytomas. RHAMM/IHABP, another hyaluronan receptor, has been identified in breast carcinoma cells, but its presence in astrocytomas is yet undetermined. Herein, we report that a monoclonal antibody against plectin (a cytoskeletal protein linker) recognizes on Western blots of U-373 MG glioblastoma cells, a 300-kDa band corresponding to plectin and two bands of 86 and 70 kDa. cDNA cloning and Northern blotting reveals that these two bands represent isoforms of RHAMM/IHABP. Sequence comparisons suggest that the plectin monoclonal antibody recognizes RHAMM/IHABP because this protein and plectin share short peptide sequences of similar primary and secondary structure. Western blotting demonstrates that most human astrocytoma tissues and cell lines express the 86- and 70-kDa isoforms of RHAMM/IHABP. Interestingly, the 70-kDa variant is undetectable in normal brain tissues and in primary cultures of astrocytes suggesting that its expression is tumor-specific. Transfection experiments with epitope-tagged RHAMM/IHABP cDNA established that RHAMM/IHABP associates with microtubules in astrocytoma cells, while in normal astrocytes it either co-localizes with microtubules or has a diffuse cytoplasmic distribution. This suggests that RHAMM/IHABP has the capacity to bind to microtubules in normal and transformed astrocytes, and that neoplasia may favor this association.
 ...
PMID:The hyaluronan receptor RHAMM/IHABP in astrocytoma cells: expression of a tumor-specific variant and association with microtubules. 1222 34

In order to identify response predictors for a post-operative glioblastoma therapy consisting of tamoxifen, carboplatin and radiotherapy, expression of 12 antigens was evaluated in 36 newly diagnosed tumours and 13 recurrences. Results were correlated with the clinical course of the disease. Antigen expression was assessed immunohistochemically for CD44s, TGF-beta2, TGF-alpha, progesterone receptor, estrogen receptor, EGFR, urokinase, urokinase inhibitor 1, CD87, p53 protein and Ki-67. Vessel density was determined by labelling of endothelia with von Willebrand factor. Response to chemotherapy correlated positively with cell density (p < 0.05) and negatively with CD44 over-expression (p < 0.02). Further, a positive correlation between age and CD44 expression (p < 0.05) and a negative correlation between age and p53 accumulation (p < 0.01) was found. In tumour recurrences expression of CD44 was significantly higher in local recurrences than in distant multifocal recurrences (p < 0.02), suggesting that CD44 may predominantly be associated with cell adhesion in glioblastomas.
 ...
PMID:CD44 expression and tumour cell density correlate with response to tamoxifen/carboplatin chemotherapy in glioblastomas. 1501 79

Glioblastoma 3 (Gli3) is a transcription factor involved in patterning and oncogenesis. Here, we demonstrate a role for Gli3 in thymocyte development. Gli3 is differentially expressed in fetal CD4- CD8- double-negative (DN) thymocytes and is most highly expressed at the CD44+ CD25- DN (DN1) and CD44- CD25- (DN4) stages of development but was not detected in adult thymocytes. Analysis of null mutants showed that Gli3 is involved at the transitions from DN1 to CD44+ CD25+ DN (DN2) cell and from DN to CD4+ CD8+ double-positive (DP) cell. Gli3 is required for differentiation from DN to DP thymocyte, after pre-T-cell receptor (TCR) signaling but is not necessary for pre-TCR-induced proliferation or survival. The effect of Gli3 was dose dependent, suggesting its direct involvement in the transcriptional regulation of genes controlling T-cell differentiation during fetal development.
 ...
PMID:The transcription factor Gli3 regulates differentiation of fetal CD4- CD8- double-negative thymocytes. 1585 76

The involvement of beta-secretase and gamma-secretase in producing the beta-amyloid component of senile plaques found in the brain of Alzheimer's patients has fueled a major research effort to design selective inhibitors of these proteases. Interestingly, gamma-secretase cleaves several proteins including Notch, E-cadherin, CD44 and ErbB-4 (erythroblastic leukemia viral oncogene homolog 4), which are important modulators of angiogenesis. The beta-amyloid precursor protein, which is cleaved by beta-secretase and gamma-secretase to produce beta-amyloid, is highly expressed in the endothelium of neoforming vessels suggesting that it might play a role during angiogenesis. These data prompted us to explore the effects of beta and gamma-secretase inhibitors of different structures on angiogenesis and tumor growth. Both the gamma and beta-secretase inhibitors tested reduce endothelial cell proliferation without inducing cellular toxicity, suppress the formation of capillary structures in vitro and oppose the sprouting of microvessel outgrowths in the rat aortic ring model of angiogenesis. Moreover, they potently inhibit the growth and vascularization of human glioblastoma and human lung adenocarcinoma tumors xenotransplanted into nude mice. Altogether these data suggest that the gamma and beta-secretases play an essential role during angiogenesis and that inhibitors of the beta and gamma-secretases may constitute new classes of anti-angiogenic and anti-tumoral compounds.
 ...
PMID:Inhibition of angiogenesis and tumor growth by beta and gamma-secretase inhibitors. 1587 19

Glioblastoma multiforme (GBM) is the most aggressive brain tumor that, by virtue of its resistance to chemotherapy and radiotherapy, is currently incurable. Identification of molecules whose targeting may eliminate GBM cells and/or sensitize glioblastoma cells to cytotoxic drugs is therefore urgently needed. CD44 is a major cell surface hyaluronan receptor and cancer stem cell marker that has been implicated in the progression of a variety of cancer types. However, the major downstream signaling pathways that mediate its protumor effects and the role of CD44 in the progression and chemoresponse of GBM have not been established. Here we show that CD44 is upregulated in GBM and that its depletion blocks GBM growth and sensitizes GBM cells to cytotoxic drugs in vivo. Consistent with this observation, CD44 antagonists potently inhibit glioma growth in preclinical mouse models. We provide the first evidence that CD44 functions upstream of the mammalian Hippo signaling pathway and that CD44 promotes tumor cell resistance to reactive oxygen species-induced and cytotoxic agent-induced stress by attenuating activation of the Hippo signaling pathway. Together, our results identify CD44 as a prime therapeutic target for GBM, establish potent antiglioma efficacy of CD44 antagonists, uncover a novel CD44 signaling pathway, and provide a first mechanistic explanation as to how upregulation of CD44 may constitute a key event in leading to cancer cell resistance to stresses of different origins. Finally, our results provide a rational explanation for the observation that functional inhibition of CD44 augments the efficacy of chemotherapy and radiation therapy.
 ...
PMID:CD44 attenuates activation of the hippo signaling pathway and is a prime therapeutic target for glioblastoma. 2019 61


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