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

MicroRNAs (miR) show characteristic expression signatures in various cancers and can profoundly affect cancer cell behavior. We carried out miR expression profiling of human glioblastoma specimens versus adjacent brain devoid of tumor. This revealed several significant alterations, including a pronounced reduction of miR-128 in tumor samples. miR-128 expression significantly reduced glioma cell proliferation in vitro and glioma xenograft growth in vivo. miR-128 caused a striking decrease in expression of the Bmi-1 oncogene, by direct regulation of the Bmi-1 mRNA 3'-untranslated region, through a single miR-128 binding site. In a panel of patient glioblastoma specimens, Bmi-1 expression was significantly up-regulated and miR-128 was down-regulated compared with normal brain. Bmi-1 functions in epigenetic silencing of certain genes through epigenetic chromatin modification. We found that miR-128 expression caused a decrease in histone methylation (H3K27me(3)) and Akt phosphorylation, and up-regulation of p21(CIP1) levels, consistent with Bmi-1 down-regulation. Bmi-1 has also been shown to promote stem cell self-renewal; therefore, we investigated the effects of miR-128 overexpression in human glioma neurosphere cultures, possessing features of glioma "stem-like" cells. This showed that miR-128 specifically blocked glioma self-renewal consistent with Bmi-1 down-regulation. This is the first example of specific regulation by a miR of a neural stem cell self-renewal factor, implicating miRs that may normally regulate brain development as important biological and therapeutic targets against the "stem cell-like" characteristics of glioma.
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PMID:Targeting of the Bmi-1 oncogene/stem cell renewal factor by microRNA-128 inhibits glioma proliferation and self-renewal. 1901 Aug 82

NY-ESO-1, one of the most immunogenic cancer/testis antigens, provides attractive targets for cancer immunotherapy. NY-ESO-1 has been demonstrated to be expressed in a range of solid tumors via DNA demethylation and/or histone modification; however, it has been rarely expressed in glioma. The reversibility of these epigenetic aberrations is potentially attractive for glioma treatment with DNA-methyltransferase inhibitors (DNMTi) and histone deacetylase inhibitors (HDACi), leading to reactivation of silenced genes. We previously demonstrated de novo induction of NY-ESO-1 in glioma cells by DNMTi. In this study, we show that an anticonvulsant, i.e., valproic acid (VPA), also acting as an HDACi, enhances induction of NY-ESO-1 in synergy with DNMTi. Chromatin assays demonstrated that combination of DNMTi and VPA elicited significant DNA demethylation, histone H3 Lys9 demethylation, and acetylation. These findings not only shed light on an epigenetic immunotherapy, but also suggest that the silencing of NY-ESO-1 is mediated by histone modification.
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PMID:Synergistic induction of NY-ESO-1 antigen expression by a novel histone deacetylase inhibitor, valproic acid, with 5-aza-2'-deoxycytidine in glioma cells. 1903 Jul 81

Nectin-like molecule 1 (NECL1)/CADM3/IGSF4B/TSLL1/SynCAM3 is a neural tissue-specific immunoglobulin-like cell-cell adhesion molecule downregulated at the mRNA level in 12 human glioma cell lines. Here we found that the expression of NECL1 was lost in six glioma cell lines and 15 primary glioma tissues at both RNA and protein levels. Re-expression of NECL1 into glioma cell line U251 would repress cell proliferation in vitro by inducing cell cycle arrest. And also NECL1 could decrease the growth rate of tumors in nude mice in vivo. To further investigate the mechanism why NECL1 was silenced in glioma, the basic promoter region located at -271 to +81 in NECL1 genomic sequence was determined. DNA bisulfite sequencing was performed to study the methylation status of CpG islands in NECL1 promoter; however, no hypermethylated CpG site was found. Additionally, the activity of histone deacetylase (HDACs) in glioma was higher than that in normal brain tissues, and the expression of NECL1 in glioma cell lines could be reactivated by HDACs inhibitor-Trichostatin A (TSA). So the loss of NECL1 in glioma was at least partly caused by histone deacetylation. Luciferase reporter assays, chromatin immunoprecipitation and co-immunoprecipitation (co-IP) assays indicated that Sp1 played an important role in this process by binding to either HDAC1 in untreated glioma cells or p300/CBP in TSA treated cells. Our finding suggests that NECL1 may act as a tumor suppressor in glioma and loss of it in glioma may be caused by histone deacetylation.
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PMID:Loss of NECL1, a novel tumor suppressor, can be restored in glioma by HDAC inhibitor-Trichostatin A through Sp1 binding site. 1906 77

SOX5 is a member of the high-mobility group superfamily of architectural non-histone proteins involved in gene regulation and maintenance of chromatin structure in a wide variety of developmental processes. Sox5 was identified as a brain tumor locus in a retroviral insertional mutagenesis screen of platelet-derived growth factor B (PDGFB)-induced mouse gliomas. Here we have investigated the role of Sox5 in PDGFB-induced gliomagenesis in mice. We show that Sox5 can suppress PDGFB-induced glioma development predominantly upon Ink4a-loss. In human glioma cell lines and tissues, we found very low levels of SOX5 compared with normal brain. Overexpression of Sox5 in human glioma cells led to a reduction in clone formation and inhibition of proliferation. Combined expression of Sox5 and PDGFB in primary brain cell cultures caused decreased proliferation and an increased number of senescent cells in the Ink4a-/- cells only. Protein analyses showed a reduction in the amount and activation of Akt and increased levels of p27(Kip1) upon Sox5 expression that was dominant to PDGFB signaling and specific to Ink4a-/- cells. Upon inhibition of p27(Kip1), the effects of Sox5 on proliferation and senescence could be reversed. Our data suggest a novel pathway, where Sox5 may suppress the oncogenic effects of PDGFB signaling during glioma development by regulating p27(Kip1) in a p19(Arf)-dependent manner, leading to acute cellular senescence.
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PMID:Sox5 can suppress platelet-derived growth factor B-induced glioma development in Ink4a-deficient mice through induction of acute cellular senescence. 1921 70

Growth factor stimulation results in phosphorylation of histone H3 at ser 10 and this correlated with expression of immediate early genes suggesting that this phosphorylation is associated with transcriptional activation. Although Western immunoblot analysis allows the detection of protein modifications in histones, in order to determine the localization of histones during different phases of cell cycle or during treatment of cells with different drugs we have to use immunohistochemistry. The protocol described here allows the detection of phosphorylated histones in tissue-cultured cells and tissue sections by fluorescent or bright-field immunostaining analysis. Here we used a serine 10 specific P-histone H3 antibody to determine the localization of this phosphoprotein in an asynchronously growing H4 glioma cell line and brain sections. It has been shown that long-term potentiation (LTP) is associated with gene transcription, and histone acetylation plays a major role in LTP formation (Wood et al., Learn Mem 13:241-244, 2006; Wood et al., Hippocampus 15:610-621, 2005; Alarcon et al., Neuron 42:947-959, 2004; Korzus et al., Neuron 42:961-972, 2004). Stimulus-induced phosphorylation of histone H3 at serine 10 has also been implicated in hippocampal neurons and striatal neurons (Li et al., J Neurochem 90:1117-1131, 2004; Crosio et al., J Cell Sci 116:4905-4914, 2003). Co-staining with a cell-specific antibody will allow us to determine the type of cells that show activation of histone phosphorylation in the brain.
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PMID:Detection of histone H3 phosphorylation in cultured cells and tissue sections by immunostaining. 1938 29

Gliomas arise through genetic and epigenetic alterations of normal brain cells, although the exact cell of origin for each glioma subtype is unknown. The alteration-induced changes in gene expression and protein function allow uncontrolled cell division, tumor expansion, and infiltration into surrounding normal brain parenchyma. The genetic and epigenetic alterations are tumor subtype and tumor-grade specific. Particular alterations predict tumor aggressiveness, tumor response to therapy, and patient survival. Genetic alterations include deletion, gain, amplification, mutation, and translocation, which result in oncogene activation and tumor suppressor gene inactivation, or in some instances the alterations may simply be a consequence of tumorigenesis. Epigenetic alterations in brain tumors include CpG island hypermethylation associated with tumor suppressor gene silencing, gene-specific hypomethylation associated with aberrant gene activation, and genome-wide hypomethylation potentially leading to loss of imprinting, chromosomal instability, and cellular hyperproliferation. Other epigenetic alterations, such as changes in the position of histone variants and changes in histone modifications are also likely to be important in the molecular pathology of brain tumors. Given that histone deacetylases are targets for drugs that are already in clinical trial, surprisingly little is known about histone acetylation in primary brain tumors. Although a majority of epigenetic alterations are independent of genetic alterations, there is interaction on specific genes, signaling pathways and within chromosomal domains. Next-generation sequencing technology is now the method of choice for genomic and epigenome profiling, allowing more comprehensive understanding of genetic and epigenetic contributions to tumorigenesis in the brain.
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PMID:Molecular epigenetics and genetics in neuro-oncology. 1956 Jul 34

Vandetanib is a multitargeted tyrosine kinase inhibitor. Our initial studies demonstrated that this agent blocks vascular endothelial growth factor receptor, epidermal growth factor receptor, and platelet-derived growth factor receptor phosphorylation and mitogen-activated protein kinase (MAPK)-mediated signaling in glioma cell lines in a dose-dependent manner. Despite these effects, we observed that vandetanib had little effect on apoptosis induction at clinically achievable concentrations. Because histone deacetylase inhibitors (HDACIs) have been suggested to regulate signaling protein transcription and downstream interactions via modulation of protein chaperone function through the 90-kDa heat shock protein, we investigated whether combining vandetanib with an HDACI could synergistically potentiate signaling pathway inhibition and apoptosis induction in a panel of malignant human glioma cell lines. Proliferation assays, apoptosis induction studies, and Western immunoblot analysis were conducted in cells treated with vandetanib and HDACIs as single agents or in combination. Vandetanib and suberoylanalide hydroxamic acid reduced proliferation in all cell lines when used as single agents, and the combination produced marked potentiation of growth inhibition as assessed by combinatorial methods. These effects were paralleled by potentiation of Akt signaling inhibition and apoptosis induction. Our results indicate that inhibition of histone deacetylation enhances the antiproliferative effect of vandetanib in malignant human glioma cell lines by enhancing inhibition of MAPK, Akt, and other downstream effectors that may have application in combinatorial therapeutics for these tumors.
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PMID:Abrogation of mitogen-activated protein kinase and Akt signaling by vandetanib synergistically potentiates histone deacetylase inhibitor-induced apoptosis in human glioma cells. 1962 15

Sotos syndrome is an autosomal dominant condition characterized by overgrowth resulting in tall stature and macrocephaly, together with an increased risk of tumorigenesis. The disease is caused by loss-of-function mutations and deletions of the nuclear receptor SET domain containing protein-1 (NSD1) gene, which encodes a histone methyltransferase involved in chromatin regulation. However, despite its causal role in Sotos syndrome and the typical accelerated growth of these patients, little is known about the putative contribution of NSD1 to human sporadic malignancies. Here, we report that NSD1 function is abrogated in human neuroblastoma and glioma cells by transcriptional silencing associated with CpG island-promoter hypermethylation. We also demonstrate that the epigenetic inactivation of NSD1 in transformed cells leads to the specifically diminished methylation of the histone lysine residues H4-K20 and H3-K36. The described phenotype is also observed in Sotos syndrome patients with NSD1 genetic disruption. Expression microarray data from NSD1-depleted cells, followed by ChIP analysis, revealed that the oncogene MEIS1 is one of the main NSD1 targets in neuroblastoma. Furthermore, we show that the restoration of NSD1 expression induces tumor suppressor-like features, such as reduced colony formation density and inhibition of cellular growth. Screening a large collection of different tumor types revealed that NSD1 CpG island hypermethylation was a common event in neuroblastomas and gliomas. Most importantly, NSD1 hypermethylation was a predictor of poor outcome in high-risk neuroblastoma. These findings highlight the importance of NSD1 epigenetic inactivation in neuroblastoma and glioma that leads to a disrupted histone methylation landscape and might have a translational value as a prognostic marker.
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PMID:Epigenetic inactivation of the Sotos overgrowth syndrome gene histone methyltransferase NSD1 in human neuroblastoma and glioma. 2001 18

Cancer stem cells are an important target for effective therapy, since they show tumorigenicity, chemoresistance, and radioresistance. We isolated cancer stem cells from glioma cell lines and tissues and examined the expression of cancer testis antigen (CTA) genes as potential target molecules for cancer vaccine therapy. CTA genes were highly and frequently expressed in cancer stem cells compared with differentiated cells. In addition, histone acetylation levels in the promoter regions of CTA genes were high in cancer stem cells and low in differentiated cells, while DNA methylation analysis of the promoter regions revealed hypomethylation in cancer stem cells. This epigenetic difference between cells leads to heterogeneous expression of CTA genes in the tumor mass, which consists of cells at various levels of differentiation. Moreover, the expression level of HLA class I antigens was not affected by the differentiation status, suggesting that CTA genes may present as surface antigens in cancer stem cells. Taken together, these findings suggest that CTA genes may be attractive candidates for targeted vaccine therapy against cancer stem cells in glioma patients.
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PMID:Enhanced expression of cancer testis antigen genes in glioma stem cells. 2008 19

Epigenetic parameters (DNA methylation, histone modifications, and miRNAs) play a significant role in cancer. To identify the common epigenetic signatures of both the individual matrix metalloproteinases (MMPs) and the additional genes, the function of which is also linked to proteolysis, migration, and tumorigenesis, we performed epigenetic profiling of 486 selected genes in unrelated non-migratory MCF-7 breast carcinoma and highly migratory U251 glioma cells. Genome-wide transcriptional profiling, quantitative reverse transcription-PCR, and microRNA analyses were used to support the results of our epigenetic studies. Transcriptional silencing in both glioma and breast carcinoma cells predominantly involved the repressive histone H3 Lys-27 trimethylation (H3K27me3) mark. In turn, epigenetic stimulation was primarily performed through a gain in the histone H3 Lys-4 dimethylation (H3K4me2) and H3 hyperacetylation and by a global reduction of H3K27me3. Inactive pro-invasive genes in MCF-7 cells but not in U251 cells frequently exhibited a stem cell-like bivalent mark (enrichment in both H3K27me3 and H3K4me2), a characteristic of developmental genes. In contrast with other MMPs, MMP-8 was epigenetically silenced in both cell types, thus providing evidence for the strict epigenetic control of this anti-tumorigenic proteinase in cancer. Epigenetic stimulation of multiple collagen genes observed in cultured glioma cells was then directly confirmed using orthotopic xenografts and tumor specimens. We suggest that the epigenetic mechanisms allow gliomas to deposit an invasion-promoting collagen-enriched matrix and then to use this matrix to accomplish their rapid migration through the brain tissue.
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PMID:Microarray-based transcriptional and epigenetic profiling of matrix metalloproteinases, collagens, and related genes in cancer. 2040 28


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