4ArrayExpress Uploaderarrayexpress_sidhumanK27Mventricular10femaleWTK27WTfrontal lobe10femaleWTRTK IG34Rtemporal lobe9maleWTG34K27Mthalamic11femaleWTK27WTfrontal lobe13femaleWTMesenchymalWTnan38maleWTRTK IIWTnan40femaleMUTIDHWTnan32femaleMUTIDHWTnan46femaleWTMesenchymalWTnan34maleMUTMesenchymalWTfrontal/temporal20femaleWTRTK IWTnan36maleWTRTK IWTparietal lobe19maleWTRTK IWTnan36maleWTMesenchymalK27Mthalamic23femaleWTK27WTnan33maleMUTIDHWTCerebellar20femaleWTRTK IWTnan38maleWTMesenchymalWTnan48maleMUTIDHG34Rtemporal lobe42femaleWTG34WTnan33maleWTRTK IWTnan40maleWTRTK IIWTnan25femaleMUTIDHWTnan38maleMUTIDHWTfrontal lobe18maleMUTIDHWTnan36maleWTRTK IIK27Mnan10maleWTnanWTnannot specifiedfemalenannanWTnannot specifiedmalenannannanhemisphericnanfemalenannannannannanmalenannanWThemispheric1maleMUTnanG34Vparieto-occipital19femalenannanG34Rtemporo-parietal14malenannanWTnannot specifiedmalenannanK27Mthalamic7femaleWTK27G34Rfrontal lobe17femaleWTG34G34Rnan12femaleWTG34K27Mpons6femaleWTK27WTtemporal lobe5maleWTnanWTcentral region14femaleWTnanWTtemporal lobe5maleWTnanK27Mnan9femaleWTnanG34Rparietal lobe14maleWTnanWTtemporal lobe19femaleMUTnanWTfrontal lobe14femaleWTnan44370http://www.ebi.ac.uk/arrayexpress/experiments/E-GEOD-36245Glioblastoma (GBM) is an incurable brain tumor carrying a dismal prognosis, which displays considerable heterogeneity. We have recently.../profile/8773/arrayexpressuploader646braingbmgenomehistonehistone h3Dec.12, 2014Falsegene-expression-data-from-glioblastoma-tumor-samplE-GEOD-36245_A-AFFY-44Gene expression data from glioblastoma tumor samplesSep.19, 2014Glioblastoma (GBM) is an incurable brain tumor carrying a dismal prognosis, which displays considerable heterogeneity. We have recently identified recurrent H3F3A mutations affecting two critical positions of histone H3.3 (K27, G34) in one-third of pediatric GBM. Here we show that each of these H3F3A mutations defines an epigenetic subgroup of GBM with a distinct global methylation pattern, and are mutually exclusive with IDH1 mutation (characterizing a CpG-Island Methylator Phenotype (CIMP) subgroup). Three further epigenetic subgroups were enriched for hallmark genetic events of adult GBM (EGFR amplification, CDKN2A/B deletion) and/or known transcriptomic signatures. We also demonstrate that the two H3F3A mutations give rise to GBMs in separate anatomic compartments, with differential regulation of OLIG1/2 and FOXG1, possibly reflecting different cellular origins. To further dissect the biological differences between epigenetic glioblastoma subgroups, we looked at the transcriptomic profiles of glioblastoma samples. 46 glioblastoma samples from patients of various ages were selected for RNA extraction and hybridization on Affymetrix Affymetrix Human Genome U133 Plus 2.0 Arrays.E-GEOD-36245http://www.ebi.ac.uk/arrayexpress/experiments/E-GEOD-36245/samples/