Pilocytic astrocytomas (PA) are the most common brain tumor in pediatric patients and can cause significant morbidity, including chronic neurological deficiencies. They are characterized by activating alterations in the mitogen-activated protein kinase (MAPK) pathway, but little else is known about their development. To further define their molecular development, we analysed the global DNA methylation profiles of 61 PAs and 6 normal cerebellum samples and integrated this data with transcriptome profiling. These data revealed two subgroups of PA that separate according to tumor location (infratentorial versus supratentorial), and identified key neural developmental genes that are differentially methylated between the two groups. Significant expression differences were identified for the majority of differentially methylated genes, and these were unexpectedly associated with a strong positive correlation between methylation and expression. We also identified a large number of differentially methylated/expressed genes between cerebellar PAs and normal cerebellum, which included additional developmental genes.
Differential expression and methylation of brain developmental genes define location-specific subsets of pilocytic astrocytoma.
Sex, Specimen part
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MicroRNA sequence and expression analysis in breast tumors by deep sequencing.
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Integrative DNA methylation and gene expression analysis in high-grade soft tissue sarcomas.
Sex, Age
View SamplesWe used the Infinium HumanHT-12 platform to profile gene expression in 79 primary, untreated high-grade soft tissue sarcomas, representing eight relevant subtypes, two non-neoplastic fat samples and 13 representative sarcoma cell lines.
Integrative DNA methylation and gene expression analysis in high-grade soft tissue sarcomas.
Sex
View SamplesRNA expression profiles are not significantly altered by DDX3 WT or R534H expression as well as by 45 minute exposure of cells to sodium arsenite. Overall design: Cells expressing either DDX3 WT or R534H variant were treated with or without sodium arsenite and lysed in the presence of cyclohexime. Total cellular RNAs were extracted and sequenced.
Medulloblastoma-associated DDX3 variant selectively alters the translational response to stress.
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A biobank of patient-derived pediatric brain tumor models.
No sample metadata fields
View SamplesWe have generated and comprehensively characterized 30 patient-derived orthotopic xenograft (PDOX) models and 7 cell lines represeneting subgroups of medulloblastoma, high-grade glioma, atypical teratoid/rhabdoid tumor, ependymoma and pineoblastoma.
A biobank of patient-derived pediatric brain tumor models.
No sample metadata fields
View SamplesTumor-associated macrophages (TAMs) have immunosuppressive capacity in mouse models of cancer. Here we show that the genetic deletion of the microRNA (miRNA)-processing enzyme DICER in TAMs broadly programs them to a CD11c+MRC1-/low M1-like immunostimulatory phenotype characterized by activated interferon-? (IFN-?)/STAT1/IRF signaling. M1-like TAM programming fostered the recruitment of cytotoxic T-cells (CTLs), including tumor-antigen-specific CTLs, inhibited tumor growth, and enhanced the efficacy of PD1 checkpoint blockade. Bioinformatics analysis of TAM transcriptomes identified a limited set of miRNAs putatively involved in TAM programming. Re-expression of Let-7 in Dicer-deficient TAMs was sufficient to partly rescue the M2-like (protumoral) TAM phenotype and abate tumor CTL infiltration. Targeted suppression of DICER activity in TAMs may, therefore, stimulate antitumor immunity and enhance the efficacy of cancer immunotherapy. Overall design: To explore the role of DICER in the development, activation and immunological functions of TAMs, we crossed homozygous LysM-Cre (Clausen et al., 1999) with Dicerlox/lox (Harfe et al., 2005) mice to obtain mice with myeloid-cell-specific Dicer1 gene deletion (LysM-Cre;Dicer–/–, referred to as D–/–). These mice were then backcrossed to LysM-Cre to obtain the control LysM-Cre; Dicer+/+ mice (referred to as D+/+). Both LysM-Cre and Dicerlox/lox mutations were always homozygous in our experiment. We then inoculated Lewis lung carcinoma (LLC) cells subcutaneously (s.c.) in D–/– and control D+/+ mice. Once the tumors were established, we isolated by fluorescence-activated cell sorting (FACS) tumor-associated macrophages (F4/80+ cells).
Suppression of microRNA activity amplifies IFN-γ-induced macrophage activation and promotes anti-tumour immunity.
Specimen part, Subject
View SamplesPediatric high-grade gliomas (pHGGs) harboring the K27M mutation of H3F3A (histone H3.3) are characterized by global reduction of the repressive histone mark H3K27me3 and DNA hypomethylation.
Reduced H3K27me3 and DNA hypomethylation are major drivers of gene expression in K27M mutant pediatric high-grade gliomas.
Sex, Age, Disease, Disease stage
View SamplesDepletion of immunosuppressive tumor-associated macrophages (TAM) or reprogramming towards a pro-inflammatory activation state represent different strategies to therapeutically target this frequent myeloid population. Here we report that inhibition of colony-stimulating factor-1 receptor (CSF-1R) signaling sensitizes TAM to profound reprogramming in the presence of a CD40 agonist prior to their depletion. Despite the short-lived nature of macrophage hyperactivation, combined CSF-1R/CD40 stimulation of macrophages is sufficient to trigger a productive and durable T cell response in various mouse cancer models. The central role of macrophages in regulating T cell-dependent tumor rejections was substantiated by depletion experiments and transcriptomic analysis of ex vivo sorted TAM. Since CD40 expression on human TAM varies between different tumor types, co-expression of human CSF-1R and CD40 in colorectal adenocarcinoma and mesothelioma can serve as criteria to select these tumor types for clinical development Overall design: Female C57BL/6N mice (6-8 weeks in age, obtained from Charles River) were inoculated with 106 MC38 colorectal adenocarcinoma tumor cells subcutaneously. Tumor growth curves were monitored by caliper measurement and once tumor size reached 250 mm3 in average, groups were allocated for antibody treatment. Ten mice/group were treated with 30 mg/kg IgG1 isotype control antibody clone MOPC-21 (BioXCell), 4 mg/kg anti-CD40 rat IgG2a antibody clone FGK45 (BioXCell), 30mg/kg anti-CSF-1R antibody clone 2G2, 4 mg/kg rat IgG2a control clone 2A3 (BioXCell). For depletion experiments 4mg/kg mouse anti-CD4 antibody clone GK1.5 (Biolegend), 4mg/kg anti-NK1.1 antibody clone PK136 (BioXCell) and 4mg/kg anti-CD8a antibody clone 53-6.7 (BioXCell) were administered when tumor size reached 190mm3 in average. Antibodies were given every second day for four times. In between doses two and three of the depleting antibodies, animals were further treated with vehicle control (0,9% sodium saline), MOPC21, FGK45, 2G2 or combination of FGK45 and 2G2. The anti-CSF-1R antibody or respective IgG1 control antibody were administered weekly until tumors regressed completely or animals reached termination criteria, while the anti-CD40 antibody was only administered once at day 11 simultaneously with the anti-CSF-1R antibody. All antibodies were given intraperitoneally. All procedures were performed in accordance with the National Institutes of Health Guidelines for the Care and Use of Laboratory Animals and European Union directives and guidelines.
Rapid activation of tumor-associated macrophages boosts preexisting tumor immunity.
Specimen part, Treatment, Subject
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