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)

There are three types of interferons (IFN), alpha, beta and gamma. IFN-alpha is produced in the leukocytes infected with virus, while IFN-beta is from fibroblasts infected with virus. IFN-gamma is induced by the stimulation of sensitized lymphocytes with antigen or non-sensitized lymphocytes with mitogens. It is believed that IFN-alpha and beta originated from the same ancestral gene, whereas IFN-gamma did not. IFN has not only an antiviral activity, but also various kinds of biological activities including cell growth inhibition, immunosuppressive effects, enhancement of macrophage, natural killer (NK) cell, killer (K) cell and neutrophil functions, and cell differentiation-inducing activity. IFN also shows the antitumor activity resulting from the integration of the above-mentioned biological activities. IFN is also deeply involved in the pathogenesis of various diseases, e.g., collagen diseases such as SLE and rheumatoid arthritis, insulin-dependent diabetes mellitus, fulminant hepatitis, severe pancreatitis, nephritis, multiple sclerosis, allergic diseases, and atherosclerosis. At present, IFN is clinically used in therapy against virus infections such as hepatitis B and C, and for malignancies such as renal cell carcinoma, multiple myeloma, malignant melanoma, glioblastoma, skin cancers, malignant lymphoma and chronic myelogenous leukemia.
 ...
PMID:[Interferon-alpha, beta, gamma]. 799 28

Ciglitazone is the prototype of the thiazolidinedione class of compounds currently being developed for the treatment of insulin resistance and non-insulin-dependent diabetes. The effects of thiazolidinediones on blood pressure and cell calcium metabolism are not well defined. In the obese Zucker rat, a widely studied model of insulin resistance associated with mild hypertension, we investigated the effects of ciglitazone on plasma insulin levels and mean arterial pressure. We also evaluated the effects of ciglitazone on the changes in cytosolic calcium induced by platelet-derived growth factor in A172 human glioblastoma cells and rat A10 vascular smooth muscle cells. Oral administration of ciglitazone, approximately 45 mg/kg per day for 4 weeks, induced significant reductions in plasma insulin levels (p < 0.001) and blood pressure (p < 0.05). Ciglitazone was also found to significantly attenuate the capacity of platelet-derived growth factor BB homodimer to induce sustained increases in intracellular free calcium. These findings suggest that thiazolidinediones may offer a novel pharmacological approach to the treatment of hypertension, and raise the possibility that these compounds may affect blood pressure not only by affecting insulin metabolism but also by modifying the cell calcium response to pressor agents, growth factors, or both.
 ...
PMID:Effects of ciglitazone on blood pressure and intracellular calcium metabolism. 850 86

Recently, there have been several reports describing the cloning and characterization of the novel family of protein tyrosine phosphatase-like receptor molecules (known as IA-2 and PTP-NP/PTP-IAR/IA-2beta/phogrin), which may act as autoantigens in diabetes. Here, we report the molecular characterization and chromosomal localization of a new isoform of this family in brain termed PTP-NP-2 (for PTP-NP tyrosine phosphatase isoform), and its function in rat primary hippocampal neurons. PTP-NP-2 has 48% identity to IA-2. The principal difference between PTP-NP-2 and PTP-NP is a 17-amino-acid insert near the N-terminus of PTP-NP that is absent in PTP-NP-2. Genomic DNA analysis indicates that the 17-amino-acid insert is coded by a separate exon, suggesting that both IA-2beta and PTP-NP-2 are isoforms arising by alternate splicing of the same gene. Reverse transcriptase-PCR revealed that both isoforms are present in human SH-SY5Y neuroblastoma cells. PTP-NP-2 mRNA expression is highly restricted, with a 5.5-kb specific transcript in human fetal and adult brain and 5.5 and 3. 8 kb in human adult pancreas. SH-SY5Y neuroblastoma and U87-MG glioblastoma cells showed specific transcripts of 5.5 and 3.8<HSP SP = "0.25">kb, respectively, indicating the existence of several isoforms of this molecule in the nervous system. The human gene encoding PTP-NP-2 was assigned to human chromosome 7q22-qter using Southern blot analysis of genomic DNAs from rodent/human somatic hybrid cell lines. Confocal microscopy analyses of rat primary hippocampal neurons revealed that PTP-NP-2 is abundantly expressed on synaptic boutons in primary neurons. Wild-type PTP-NP-2 showed no measurable tyrosine phosphatase activity using an in-vitro pNPP assay. Examination of the PTP-NP-2 catalytic consensus sequence revealed that this sequence differed from the typical tyrosine phosphatase-domain consensus sequence by an alanine to aspartate change (amino acid 930). Mutation of aspartate 930 to alanine produced a catalytically active enzyme, suggesting that native PTP-NP and its isoform PTP-NP-2 are catalytically inactive receptor protein tyrosine phosphatase homologues. Taken together, these results indicate that the tyrosine phosphatase PTP-NP-2 is a new isoform of PTP-NP tyrosine phosphatase, is expressed on synaptic boutons and may participate in the regulation of synaptic bouton endocytosis.
 ...
PMID:Characterization and chromosomal localization of PTP-NP-2, a new isoform of protein tyrosine phosphatase-like receptor, expressed on synaptic boutons. 971 34

The nuclear receptors PPARs (peroxisome proliferator-activated receptors) are transcription factors activated by specific ligands. PPARs play an important role in carcinogenesis, inflammation, atherosclerosis, lipid metabolism and diabetes. There is evidence that activation of PPARs by specific ligands is able to suppress the growth of different types of human cancer by mechanisms including the growth arrest, apoptosis and induction of differentiation, although the detailed signalling pathways have not been completely elucidated to date. The aim of our study was to determine whether synthetic ligands of PPARalpha and PPARgamma could affect the viability, proliferation, differentiation, apoptosis and expression of some cell cycle related proteins in glial tumor cell lines. The study was performed on human glioblastoma cell lines U-87 MG, T98G, A172 and U-118 MG. Cell lines were treated by ligands of PPARalpha (bezafibrate, gemfibrozil) and PPARgamma (ciglitazone). MTT, flow cytometry, TUNEL assay and immunoblotting were used for detection of changes in cell viability, proliferation, differentiation and apoptosis. Bezafibrate, ciglitazone and gemfibrozil inhibited viability of glioblastoma cell lines. The synthetic ligands significantly reduced or induced the expression of cyclins, p27Kip1, p21Waf1/Cip1, MDM-2, Bcl-2, Bax, PARP, Caspase 3, androgen receptors, etc. and did not affect the expression of the differentiation marker GFAP. Flow cytometry confirmed arrest of the cell cycle although the detection of apoptosis was controversial. Apart from hypolipidemic and hypoglycaemic effects, PPAR ligands may also have significant cytostatic effects of potential use in anticancer treatment.
 ...
PMID:Peroxisome proliferator-activated receptors (PPAR) agonists affect cell viability, apoptosis and expression of cell cycle related proteins in cell lines of glial brain tumors. 1580 Jul 11

Conjugated linoleic acid (CLA) has been shown to exert beneficial effects against carcinogenesis, atherosclerosis and diabetes. It has been demonstrated that CLA modulates lipid metabolism through the activation of peroxisome proliferator-activated receptors (PPARs). The PPAR family comprises 3 closely related gene products, PPAR alpha, beta/delta and gamma, differing for tissue distribution, developmental expression and ligand specificity. It has also been demonstrated that activated PPARgamma results in growth inhibition and differentiation of transformed cells. These observations stimulated a great interest toward PPARgamma ligands as potential anticancer drugs to be used in a differentiation therapy. Glioblastomas are the most commonly diagnosed primary tumors of the brain in humans. The prognosis of patients with high-grade gliomas is poor and only marginally improved by chemotherapy. The aim of this work was to study the effects of CLA and of a specific synthetic PPARgamma ligand on cell growth, differentiation and death of a human glioblastoma cell line as well as on parameters responsible for the metastatic behavior of this tumor. We demonstrate here that CLA and PPARgamma agonist strongly inhibit cell growth and proliferation rate and induce apoptosis. Moreover, both treatments decrease cell migration and invasiveness. The results obtained show that CLA acts, directly or indirectly, as a PPARgamma activator, strongly suggesting that this naturally occurring fatty acid may be used as brain antitumor drug and as a chemopreventive agent. Moreover, the gamma-agonist, once experimented and validated on man, may represent a useful coadjuvant in glioblastoma therapy and in the prevention of recurrences.
 ...
PMID:PPARgamma-dependent effects of conjugated linoleic acid on the human glioblastoma cell line (ADF). 1598 37

To explore the molecular mechanisms by which glioblastomas are resistant to tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), we examined TRAIL signalling pathways in the tumours. TRAIL has four membrane-anchored receptors, death receptor 4/5 (DR4/5) and decoy receptor 1/2 (DcR1/2). Of these receptors, only DR5 was expressed consistently in glioblastoma cell lines and tumour tissues, ruling out the role of DcR1/2 in TRAIL resistance. Upon TRAIL binding, DR5 was homotrimerized and recruited Fas-associated death domain (FADD) and caspase-8 for the assembly of death-inducing signalling complex (DISC) in the lipid rafts of the plasma membrane. In the DISC, caspase-8 was cleaved and initiated apoptosis by cleaving downstream caspases in TRAIL-sensitive glioblastoma cells. In TRAIL-resistant cells, however, DR5-mediated DISC was modified by receptor-interacting protein (RIP), cellular FADD-like interleukin-1beta-converting enzyme inhibitory protein (c-FLIP) and phosphoprotein enriched in diabetes or in astrocyte-15 (PED/PEA-15). This DISC modification occurred in the non-raft fractions of the plasma membrane and resulted in the inhibition of caspase-8 cleavage and activation of nuclear factor-kappaB (NF-kappaB). Treatment of resistant cells with parthenolide, an inhibitor of inhibitor of kappaB (I-kappaB), eliminated TRAIL-induced NF-kappaB activity but not TRAIL resistance. In contrast, however, targeting of RIP, c-FLIP or PED/PEA-15 with small interfering RNA (siRNA) led to the redistribution of the DISC from non-rafts to lipid rafts and eliminated the inhibition of caspase-8 cleavage and thereby TRAIL resistance. Taken together, this study indicates that the DISC modification by RIP, c-FLIP and PED/PEA-15 is the most upstream event in TRAIL resistance in glioblastomas.
 ...
PMID:DR5-mediated DISC controls caspase-8 cleavage and initiation of apoptosis in human glioblastomas. 1943 16

A 58-year-old man presented with a rare case of glioblastoma masquerading as intracerebral hemorrhage (ICH). He had been medicated for hypertension and diabetes for 10 years before collapsing at home. Brain computed tomography (CT) showed ICH in the right putamen, but CT with contrast medium showed no underlying lesion. He was treated initially with intravenous administration of anti-hypertensive agent under a diagnosis of hypertensive putaminal hemorrhage. ICH aspiration surgery was performed, and serial CT showed ICH resorption. However, he was again admitted for unstable gait and mildly altered mental status 3 months after discharge. Magnetic resonance (MR) imaging with gadolinium showed an enhanced ring-shaped mass around the hematoma cavity. Open biopsy was performed. The histological diagnosis was glioblastoma multiforme, and he was treated with radiation therapy and oral chemotherapy with temozolomide. MR imaging showed marked shrinkage of the tumor, but he died of pneumonia 3 months after the second surgery. In this case, the cause of the hemorrhage was not identified after the seemingly successful hematoma evacuation surgery, and no definitive diagnosis was made until tumor regrowth. Brain tumor should be suspected as a cause of ICH even if the patient has a history of hypertension and the location is typical for hypertensive ICH. Clinical/radiological follow up is essential for detecting subtle neurological deterioration to avoid diagnostic delay.
 ...
PMID:Glioblastoma masquerading as a hypertensive putaminal hemorrhage: a diagnostic pitfall. 1977 91

The Ptdlns-3-kinase (PI3-K) signaling pathway plays a vital role in cell survival, proliferation, apoptosis and differentiation in normal cells, as well as in diseases such as cancer and diabetes. Quantification of phospho-Akt is a standard way of assessing the activity of the PI3-K signaling pathway in both cells and tumors. This measurement is traditionally performed semiquantitatively using immunoassays such as Western blot. Here we report an LC-MS method to accurately measure the stoichiometry of Akt phosphorylation in biological samples. The procedure includes immunoprecipitation, gel electrophoresis, in-gel digestion, addition of isotopicaly labeled internal standards and LC-MS/MS. Two proteolytic enzymes, chymotrypsin and trypsin, were used to generate suitable peptide fragments for measuring Thr308 and Ser473 phosphorylation, respectively. The interday imprecision was estimated to be 3.8% and 2.3% for Thr308 and Ser473, respectively. This method has been tested on human T-cells grown in presence and absence of pervanadate and with or without a PI3-K inhibitor and on human glioblastoma cells (U-87 MG) grown in presence and absence of wortmannin (PI3-K inhibitor).The results of T cells suggest that the levels of Akt phosphorylation in untreated cells were below 1% for both phosphorylation sites. Pervanadate treatment provoked an 18-fold increase in phosphorylation of Thr308 and the PI3-K inhibitor partially reversed the increase. A comparison between LC-MS/MS and Western blotting suggests that the LC-MS based method is of comparable sensitivity and provides a more accurate phosphorylation stoichiometry, a wider dynamic range and more in-depth information. The application of the new method and its utility to providing predictive markers of response to targeted therapies is discussed.
 ...
PMID:Stoichiometric quantification of Akt phosphorylation using LC-MS/MS. 1990 31

As current treatments for glioblastoma commonly fail to cure, the need for more effective therapeutic options is overwhelming. Here, we summarize experimental evidence in support of the suggestion that metformin and olanzepine have potential to enhance the cytotoxic effects of temozolomide, an alkylating chemotherapeutic agent commonly used to treat glioblastoma. Although the primary path leading to temozolomide-induced cell death is formation of O-6-methylguanine and apoptotic signalling triggered by O-6-methyl G:T mispairs, that apoptotic signalling goes through a step mediated by AMP-activated protein kinase (AMPK). Metformin or olanzapine have been shown independently to enhance AMPK activation. Metformin to treat diabetes and olanzapine to treat psychiatric disorders are well tolerated and have been used clinically for many years. Thus it should be feasible to increase AMPK activation and add to the pro-apoptotic effects of temozolomide, by adding metformin and olanzapine to the therapeutic regimen. Clinical assessment of the potential benefit of such combined therapy against glioblastoma is warranted.
 ...
PMID:Can the therapeutic effects of temozolomide be potentiated by stimulating AMP-activated protein kinase with olanzepine and metformin? 2141 Apr 56

Almost all diseases, especially cancer and diabetes, manifest abnormal oxygen metabolism. Accurately measuring the metabolic rate of oxygen (MRO(2)) can be helpful for fundamental pathophysiological studies, and even early diagnosis and treatment of disease. Current techniques either lack high resolution or rely on exogenous contrast. Here, we propose label-free metabolic photoacoustic microscopy (mPAM) with small vessel resolution to noninvasively quantify MRO(2) in vivo in absolute units. mPAM is the unique modality for simultaneously imaging all five anatomical, chemical, and fluid-dynamic parameters required for such quantification: tissue volume, vessel cross-section, concentration of hemoglobin, oxygen saturation of hemoglobin, and blood flow speed. Hyperthermia, cryotherapy, melanoma, and glioblastoma were longitudinally imaged in vivo. Counterintuitively, increased MRO(2) does not necessarily cause hypoxia or increase oxygen extraction. In fact, early-stage cancer was found to be hyperoxic despite hypermetabolism.
 ...
PMID:Label-free oxygen-metabolic photoacoustic microscopy in vivo. 2180 64


1 2 3 4 5 Next >>