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Introduction: Glioblastoma (GBM) is the most common primary brain cancer. The average survival time for the majority of patients is approximately 15 months after diagnosis. A major feature of GBM that contributes to its poor prognosis is its high invasiveness. Caveolae are plasma membrane subdomains that participate in numerous biological functions. Caveolin-1 and Caveolae Associated Protein 1 (CAVIN1), formerly termed Polymerase I and Transcript Release Factor, are both necessary for caveola formation. We hypothesized that high expression of caveola-forming proteins in GBM promotes invasiveness via modulation of the production of matrix-degrading enzymes. Methods: The mRNA expression of caveola-forming proteins and matrix proteases in GBM samples, and survival after stratifying patients according to caveolin-1 or CAVIN1 expression, were analyzed from TCGA and REMBRANDT databases. The proteolytic profile of cell lines expressing or devoid of caveola-forming proteins was investigated using zymography and real-time qPCR. Invasion through basement membrane-like protein was investigated in vitro. Results: Expression of both caveolin-1 and CAVIN1 was increased in GBM compared to normal samples and correlated with expression of urokinase plasminogen activator (uPA) and gelatinases. High expression of caveola-forming proteins was associated with shorter survival time. GBM cell lines capable of forming caveolae expressed more uPA and matrix metalloproteinase-2 (MMP-2) and/or -9 (MMP-9) and were more invasive than GBM cells devoid of caveola-forming proteins. Experimental manipulation of caveolin-1 or CAVIN1 expression in GBM cells recapitulated some, but not all of these features. Caveolae modulate GBM cell invasion in part via matrix protease expression. [ABSTRACT FROM AUTHOR]

Cytokine release syndrome (CRS) is a life-threatening complication of several new immunotherapies used to treat cancers and autoimmune diseases1-5. Here we report that atrial natriuretic peptide can protect mice from CRS induced by such agents by reducing the levels of circulating catecholamines. Catecholamines were found to orchestrate an immunodysregulation resulting from oncolytic bacteria and lipopolysaccharide through a self-amplifying loop in macrophages. Myeloid-specific deletion of tyrosine hydroxylase inhibited this circuit. Cytokine release induced by T-cell-activating therapeutic agents was also accompanied by a catecholamine surge and inhibition of catecholamine synthesis reduced cytokine release in vitro and in mice. Pharmacologic catecholamine blockade with metyrosine protected mice from lethal complications of CRS resulting from infections and various biotherapeutic agents including oncolytic bacteria, T-cell-targeting antibodies and CAR-T cells. Our study identifies catecholamines as an essential component of the cytokine release that can be modulated by specific blockers without impairing the therapeutic response. Atrial natriuretic peptide, an anti-inflammatory protein, can protect against cytokine release syndrome induced by therapeutic agents such as tumour-targeting bacteria and CAR-T cells by blocking catecholamine synthesis by macrophages. [ABSTRACT FROM AUTHOR]

Purpose: Meningiomas are a frequent tumor of the central nervous system. Although mostly benign, approximately 5% present as atypical or malignant tumors. Treatments for atypical meningiomas include gross total resection and radiotherapy, but about 33% of patients have recurrent tumors, sometimes as a higher grade. Recently, the brain penetrant anthelmintic drug, mebendazole, has shown promise as an anticancer agent in rodent models of glioblastoma and medulloblastoma.Methods: The half maximal inhibitory concentration (IC50) effect on colony formation, cell proliferation, and caspase-3/7 markers of apoptosis of mebendazole with and without radiation was measured in vitro. Mice intracranially implanted with KT21MG1 human meningioma were administered mebendazole alone or in combination with radiation. Survival benefit was evaluated, while tumors were investigated by immunohistochemical staining for apoptosis, cell proliferation, and vascular density.Results: In vitro experiments on meningioma cell lines showed the IC50 for mebendazole in the range of 0.26-0.42 µM. Mebendazole alone induced cytotoxicity, however the combination had a greater reduction in colony formation and resulted in higher levels of cleaved caspase-3. The in vivo study showed both, mebendazole alone and the combination, to have a survival benefit with an increase in apoptosis, and decreases in tumor cell and vascular proliferation.Conclusion: These preclinical findings indicate that mebendazole alone or in combination with radiation can be considered for the treatment of malignant meningioma. The mechanism of action for this combination may include an increase in apoptosis, a reduction in proliferation and angiogenesis, or a combination of these effects. [ABSTRACT FROM AUTHOR]

Mutational inactivation of the SWI/SNF chromatin regulator ATRX occurs frequently in gliomas, the most common primary brain tumors. Whether and how ATRX deficiency promotes oncogenesis by epigenomic dysregulation remains unclear, despite its recent implication in both genomic instability and telomere dysfunction. Here we report that Atrx loss recapitulates characteristic disease phenotypes and molecular features in putative glioma cells of origin, inducing cellular motility although also shifting differentiation state and potential toward an astrocytic rather than neuronal histiogenic profile. Moreover, Atrx deficiency drives widespread shifts in chromatin accessibility, histone composition, and transcription in a distribution almost entirely restricted to genomic sites normally bound by the protein. Finally, direct gene targets of Atrx that mediate specific Atrx-deficient phenotypes in vitro exhibit similarly selective misexpression in ATRX-mutant human gliomas. These findings demonstrate that ATRX deficiency and its epigenomic sequelae are sufficient to induce disease-defining oncogenic phenotypes in appropriate cellular and molecular contexts. [ABSTRACT FROM AUTHOR]

Mutations in isocitrate dehydrogenase 1 ( IDH1) have been found in the vast majority of low grade and progressive infiltrating gliomas and are characterized by the production of 2-hydroxyglutarate from α-ketoglutarate. Recent investigations of malignant gliomas have identified additional genetic and chromosomal abnormalities which cluster with IDH1 mutations into two distinct subgroups. The astrocytic subgroup was found to have frequent mutations in ATRX, TP53 and displays alternative lengthening of telomeres. The second subgroup with oligodendrocytic morphology has frequent mutations in CIC or FUBP1, and is linked to co-deletion of the 1p/19q arms. These mutations reflect the development of two distinct molecular pathways representing the majority of IDH1 mutant gliomas. Unfortunately, due to the scarcity of endogenously derived IDH1 mutant models, there is a lack of accurate models to study mechanism and develop new therapy. Here we report the generation of an endogenous IDH1 anaplastic astrocytoma in vivo model with concurrent mutations in TP53, CDKN2A and ATRX. The model has a similar phenotype and histopathology as the original patient tumor, expresses the IDH1 (R132H) mutant protein and exhibits an alternative lengthening of telomeres phenotype. The JHH-273 model is characteristic of anaplastic astrocytoma and represents a valuable tool for investigating the pathogenesis of this distinct molecular subset of gliomas and for preclinical testing of compounds targeting IDH1 mutations or alternative lengthening of telomeres. [ABSTRACT FROM AUTHOR]

The Wnt/β-catenin signaling pathway is pathologically activated in cholangiocarcinoma (CCA). Here, we determined the expression profile as well as biological role of activated Wnt/β-catenin signaling in CCA. The quantitative reverse transcription polymerase chain reaction demonstrated that Wnt3a, Wnt5a, and Wnt7b mRNA were significantly higher in CCA tissues than adjacent non-tumor tissues and normal liver tissues. Immunohistochemical staining revealed that Wnt3a, Wnt5a, and Wnt7b were positive in 92.1, 76.3, and 100 % of 38 CCA tissues studied. It was noted that Wnt3 had a low expression in tumor cells, whereas a high expression was mainly found in inflammatory cells. Interestingly, a high expression level of Wnt5a was significantly correlated to poor survival of CCA patients ( P = 0.009). Membrane localization of β-catenin was reduced in the tumors compared to normal bile duct epithelia, and we also found that 73.7 % of CCA cases showed the cytoplasmic localization. Inflammation is known to be a risk factor for CCA development, and we tested whether this might induce Wnt/β-catenin signaling. We found that lipopolysaccharides (LPS) elevated the expression of Wnt3 both mRNA and protein levels in the macrophage cell line. Additionally, the conditioned media taken from LPS-induced activated macrophage culture promoted β-catenin accumulation in CCA cells. Furthermore, transient suppression of β-catenin by siRNA significantly induced growth inhibition of CCA cells, concurrently with decreasing cyclin D1 protein level. In conclusion, the present study reports the abundant expression of Wnt protein family and β-catenin in CCA as well as the effect of inflammatory condition on Wnt/β-catenin activation in CCA cells. Importantly, abrogation of β-catenin expression caused significant CCA cell growth inhibition. Thus, the Wnt/β-catenin signaling pathway may contribute to CCA cell proliferation and hence may serve as a prognostic marker for CCA progression and provide a potential target for CCA therapy. [ABSTRACT FROM AUTHOR]

Phosphatidylinositol 3-kinase (PI3K) signaling plays a critical role in cholangiocarcinoma (CCA), as well as anti-cancer drug resistance and autophagy, the type II program cell death regulation. In this work, we aimed to: (1) determine the expression levels of several key components of PI3K signaling and (2) evaluate whether NVP-BEZ235, a novel dual PI3K/mTOR inhibitor, could inhibit CCA cell growth. Immunohistochemistry for p85α, p110α, AKT, p-AKT (T308), mTOR, p-mTOR (S2448), GSK-3β, p-GSK-3β (S9), PTEN, and p-PTEN (S380, T382/383) was performed in 30 CCA patients. Western blotting was used to analyze PTEN and p-PTEN expression in the cell lines (KKU-OCA17, KKU-100, KKU-M055, KKU-M139, KKU-M156, KKU-M213, and KKU-M214). The effects of NVP-BEZ235 on CCA cells were evaluated using a growth inhibition assay, flow cytometer and migration assay. Increased activation of PI3K/AKT signaling was reproducibly observed in the CCA tissues. The expression of p85α, mTOR, and GSK-3β was significantly correlated with metastasis. Interestingly, PTEN suppression by loss of expression or inactivation by phosphorylation was observed in the majority of patients. Furthermore, NVP-BEZ235 effectively inhibited CCA cell growth and migration through reduced AKT and mTOR phosphorylation and significantly induced G1 arrest without apoptosis induction, although increase autophagy response was observed. In conclusion, the constitutive activation of PI3K/AKT pathway in CCA is mainly due to PTEN inactivation by either loss of expression or phosphorylation along with an increased expression in its pathway components heralding a poor prognosis for CCA patients. This work also indicates that inhibition of PI3K and mTOR activity by the inhibitor NVP-BEZ235 has anti-cancer activity against CCA cells which might be further tested for CCA treatment. [ABSTRACT FROM AUTHOR]

Improving therapy for patients with cholangiocarcinoma (CCA) presents a significant challenge. This is made more difficult by a lack of a clear understanding of potential molecular targets, such as deregulated kinases. In this work, we profiled the activated kinases in CCA in order to apply them as the targets for CCA therapy. Human phospho-receptor tyrosine kinases (RTKs) and phospho-kinase array analyses revealed that multiple kinases are activated in both CCA cell lines and human CCA tissues that included cell growth, apoptosis, cell to cell interaction, movement, and angiogenesis RTKs. Predominately, the kinases activated downstream were those in the PI3K/Akt, Ras/MAPK, JAK/STAT, and Wnt/β-catenin signaling pathways. Western blot analysis confirms that Erk1/2 and Akt activation were increased in CCA tissues when compared with their normal adjacent tissue. The inhibition of kinase activation using multi-targeted kinase inhibitors, sorafenib and sunitinib led to significant cell growth inhibition and apoptosis induction via suppression of Erk1/2 and Akt activation, whereas drugs with specificity to a single kinase showed less potency. In conclusion, our study reveals the involvement of multiple kinase proteins in CCA growth that might serve as therapeutic targets for combined kinase inhibition. [ABSTRACT FROM AUTHOR]

Glioblastoma Multiforme (GBM) is a malignant brain cancer that develops after accumulating genomic DNA damage that often includes gene amplifications and/or deletions. These copy number changes can be a critical step in brain tumor development. To evaluate glioblastoma genomic copy number changes, we determined the genome-wide copy number alterations in 31 GBMs. Illumina Bead Arrays were used to assay 22 GBMs and Digital Karyotyping was used on 8 GBM cell lines and one primary sample. The common amplifications we observed for all 31 samples was GLI/CDK4 (22.6%), MDM2 (12.9%) and PIK3C2B/MDM4 (12.9%). In the 22 GBM tumors, EGFR was amplified in 22.7% of surgical biopsies. The most common homozygously deleted region contained CDKN2A/CDKN2B (p15 and p16) occurring in 29% of cases. This data was compiled and compared to published array CGH studies of 456 cases of GBMs. Pooling our Illumina data with published studies yielded these average amplification rates: EGFR—35.7%, GLI/CDK4—13.4%, MDM2—9.2%, PIK3C2B/MDM4—7.7%, and PDGFRA—7.7%. The CDKN2A/CDKN2B locus was deleted in 46.4% of the combined cases. This study provides a larger assessment of amplifications and deletions in glioblastoma patient populations and shows that several different copy number technologies can produce similar results. The main pathways known to be involved in GBM tumor formation such as p53 control, growth signaling, and cell cycle control are all represented by amplifications or deletions of critical pathway genes. This information is potentially important for formulating targeted therapy in glioblastoma and for planning genomic studies. [ABSTRACT FROM AUTHOR]

The Fibroblast Growth Factor (FGF) signaling pathway is reported to stimulate glioblastoma (GBM) growth. In this work we evaluated the effect of FGF2, FGF receptor (FGFR), and small molecule inhibition on GBM cells grown in traditional media, or cultured directly in stem-cell media. These lines each expressed the FGFR1, FGFR3 and FGFR4 receptors. Addition of FGF2 ligand showed significant growth stimulation in 8 of 10 cell lines. Disruption of FGF signaling by a neutralizing FGF2 monoclonal antibody and FGFR1 suppression by RNA interference both partially inhibited cell proliferation. Growth inhibition was temporally correlated with a reduction in MAPK signaling. A receptor tyrosine kinase inhibitor with known FGFR/VEGFR activity, PD173074, showed reproducible growth inhibition. Possible mechanisms of growth suppression by PD173074 were implicated by reduced phosphorylation of AKT and MAPK, known oncogenic signal transducers. Subsequent reduction in the cyclin D1, cyclin D2 and CDK4 cell cycle regulators was also observed. Our results indicate that FGF signaling pathway inhibition as a monotherapy will slow, but not arrest growth of glioblastoma cells. [ABSTRACT FROM AUTHOR]

Scientists have sequenced the human genome and identified most of its genes. Now it is time to use these genomic data, and the high-throughput technology developed to generate them, to tackle major health problems such as cancer. To accelerate our understanding of this disease and to produce targeted therapies, further basic mutational and functional genomic information is required. A systematic and coordinated approach, with the results freely available, should speed up progress. This will best be accomplished through an international academic and pharmaceutical oncogenomics initiative. [ABSTRACT FROM AUTHOR]

In this study, we generated three SAGE libraries from melanoma tissues. Using bioinformatics tools usually applied to microarray data, we identified several genes, including novel transcripts, which are preferentially expressed in melanoma. SAGE results converged with previous microarray analysis on the importance of intracellular calcium and G-protein signaling, and the Wnt/Frizzled family. We also examined the expression of CD74, which was specifically, albeit not abundantly, expressed in the melanoma libraries using a melanoma progression tissue microarray, and demonstrate that this protein is expressed by melanoma cells but not by benign melanocytes. Many genes involved in intracellular calcium and G-protein signaling were highly expressed in melanoma, results we had observed earlier from microarray studies (Bittner et al., 2000). One of the genes most highly expressed in our melanoma SAGE libraries was a calcium-regulated gene, calpain 3 (p94). Immunohistochemical analysis demonstrated that calpain 3 moves from the nuclei of non-neoplastic cells to the cytoplasm of malignant cells, suggesting activation of this intracellular proteinase. Our SAGE results and the clinical validation data demonstrate how SAGE profiles can highlight specific links between signaling pathways as well as associations with tumor progression. This may provide insights into new genes that may be useful for the diagnosis and therapy of melanoma.Oncogene (2004) 23, 2264-2274. doi:10.1038/sj.onc.1207337 Published online 2 February 2004 [ABSTRACT FROM AUTHOR]

Over 1.4 million transcript tags expressed in 20 different human medulloblastomas were counted using serial analysis of gene expression. Digital gene expression profiles in the medulloblastoma were compared to multiple regions of the normal human brain, revealing 30 transcripts with high expression in multiple tumors and little or no expression in the normal cerebellum and other adult and pediatric brain regions. Using independent medulloblastoma samples and normal tissue, real-time PCR verified eight of nine selected genes as candidate tumor-associated antigens. Differential protein expression for CD24, prolactin and Topo2A was further confirmed by immunohistochemical analysis using medulloblastoma and normal brain sections and a tissue microarray. The genes highly expressed in the medulloblastoma include PRAME, a cancer-testis antigen and potential targets for immunotherapy.Oncogene (2003) 22, 7687-7694. doi:10.1038/sj.onc.1207043 [ABSTRACT FROM AUTHOR]

Presents research which showed that chromosomal instability (CIN) is consistently associated with the loss of function of a mitotic checkpoint in human cancers. Genetic instability and neoplasia in two different forms; CIN and aneuploidy; Impact of loss of mitotic checkpoint; Role of BUB1 gene; How normal mitotic checkpoints become defective.

Mutational inactivation of ATRX (α-thalassemia mental retardation X-linked) represents a defining molecular alteration in large subsets of malignant glioma. Yet the pathogenic consequences of ATRX deficiency remain unclear, as do tractable mechanisms for its therapeutic targeting. Here we report that ATRX loss in isogenic glioma model systems induces replication stress and DNA damage by way of G-quadruplex (G4) DNA secondary structure. Moreover, these effects are associated with the acquisition of disease-relevant copy number alterations over time. We then demonstrate, both in vitro and in vivo, that ATRX deficiency selectively enhances DNA damage and cell death following chemical G4 stabilization. Finally, we show that G4 stabilization synergizes with other DNA-damaging therapies, including ionizing radiation, in the ATRX-deficient context. Our findings reveal novel pathogenic mechanisms driven by ATRX deficiency in glioma, while also pointing to tangible strategies for drug development. ATRX deficiency is linked to genomic stability in cancer cells. Here, the authors show that ATRX inactivation induces G-quadruplex formation, leading to genome-wide DNA damage, and the use of G-quadruplex stabilisers can be exploited therapeutically in ATRX deficient gliomas. [ABSTRACT FROM AUTHOR]

A correction to the article "Glioblastoma cell growth is suppressed by disruption of fibroblast growth factor pathway signaling" which was published in a previous issue is presented.