Homo sapiens
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ABSTRACT:
PROVIDER: PRJNA299304 | ENA |
REPOSITORIES: ENA
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Project description:Pediatric ependymoma has relatively low frequencies of DNA mutations, which suggest that epigenetics may drive tumors. However, the epigenetic mechanisms for recurrent ependymoma are still poorly understood. Here, we performed longitudinal and comprehensive DNA methylation and gene expression analysis for recurrent pediatric ependymoma tumors from 10 patients, total 46 DNA methylomes (including primary tumors and matched recurrent tumors; normal pediatric brain tissues and PDOX tumors). Both RELA and PFA tumors maintained the subtype DNA methylation signatures during repeated relapses. We further identified the potential DNA methylation predictors, drivers and boosters and their potential regulated genes for recurrent ependymoma tumors. Increased DNA methylation levels within H3K4me1 enriched regions indicates disturbed functions of LSD1 gene in recurrent ependymoma tumors. Combining novel LSD1 inhibitor SYC-836 with radiation (XRT) significantly prolonged animal survival times in PDOX models of recurrent PFA ependymoma. Our PDOX models provide a unique platform for preclinical testing drugs and development of new therapy for pediatric recurrent ependymoma.
2022-07-12 | GSE156619 | GEO
Project description:<p>Medulloblastomas are the most common malignant brain tumors in children. Identifying and understanding the genetic events that drive these tumors is critical for the development of more effective diagnostic, prognostic and therapeutic strategies. Recently, our group and others described distinct molecular subtypes of medulloblastoma based on transcriptional and copy number profiles. Here, we utilized whole exome hybrid capture and Illumina sequencing to identify somatic mutations across the coding regions of 92 primary medulloblastoma/normal pairs. Overall, medulloblastomas exhibit low mutation rates consistent with other pediatric tumors, with a median of 0.35 non-silent mutations per megabase. We identified twelve genes mutated at statistically significant frequencies, including previously known mutated genes in medulloblastoma such as <i>CTNNB1</i>, <i>PTCH1</i>, <i>MLL2</i>, <i>SMARCA4</i> and <i>TP53</i>. Recurrent somatic mutations were identified in an RNA helicase gene, <i>DDX3X</i>, often concurrent with <i>CTNNB1</i> mutations, and in the nuclear co-repressor (N-CoR) complex genes <i>GPS2</i>, <i>BCOR</i>, and <i>LDB1</i>, to our knowledge novel findings in medulloblastoma and all cancer. We show that mutant <i>DDX3X</i> potentiates transactivation of a TCF promoter and enhances cell viability in combination with mutant but not wild type beta-catenin. Together, our study reveals the alteration of Wnt, Hedgehog, histone methyltransferase and now <i>N-CoR</i> pathways across medulloblastomas and nominates the RNA helicase <i>DDX3X</i> as a component of pathogenic beta-catenin signaling in medulloblastoma.</p> <p>"Reprinted from 'MEDULLOBLASTOMA EXOME SEQUENCING UNCOVERS SUBTYPE-SPECIFIC SOMATIC MUTATION', with permission from Nature" </p>
| phs000504 | dbGaP
Project description:Medulloblastoma is a highly aggressive pediatric brain tumor, in which expression of the pluripotency factor OCT4 has been recently correlated with poor patient survival. However, the contribution of OCT4 transcript variants to tumor aggressiveness is still poorly understood. In this study, we found that transcripts encoding OCT4A, but not OCT4B or OCT4B1, were significantly correlated with LIN28A expression, which encodes another well-known pluripotency factor. LIN28A was found to specifically bind OCT4A transcripts and interact with poly(A) binding protein and RNA helicase A in polysomal fractions of medulloblastoma cells, favoring increased OCT4A protein levels in these cells. Medulloblastoma cells stably overexpressing OCT4A displayed significantly enhanced clonogenic activity, tumorsphere generation and invasion capability, as well as increased tumorigenicity. In an orthotopic metastatic model of medulloblastoma, OCT4A overexpressing cells generated more developed, aggressive and infiltrative tumors, with tumor-bearing mice attaining advanced metastatic disease and shorter survival rates. Pro-oncogenic effects of OCT4A were found to be expression-level dependent and accompanied by distinct subchromosomal aberrations and differential expression of newly discovered, still poorly characterized, non-coding RNAs. Altogether, our findings support the relevance of pluripotency-related factors in the aggravation of medulloblastoma traits classically associated with poor clinical outcome, and underscore the prognostic and therapeutic value of OCT4A in this challenging type of pediatric brain cancer. Total RNA of 2-3 clones of each cell line (Control and OCT4A overexpression) was extracted with the RNeasy Mini kit (Qiagen), following the manufacturerâs protocol. Gene expression profiling was carried out independently for each sample using Affymetrix GeneChip® Human Gene 2.0 ST whole-transcript arrays (Affymetrix, Santa Clara, CA, USA). The quality control and normalization of data were processed by Affymetrix® Expression Console Software (Affymetrix). Differentially expressed genes were identified with the One-Way ANOVA, with a p-value cutoff of 0.05, using Transcriptome Analysis Console v3.0 (Affymetrix).
2016-02-17 | E-GEOD-77947 | biostudies-arrayexpress
Project description:In this work the objective is identify chromosomal alterations in ependymoma in pediatric patients, we used CGH microarray were performed through the Agilent platform.
2016-03-15 | E-MTAB-3850 | biostudies-arrayexpress
Project description:We compared molecular characteristics of primary and recurrent pediatric ependymoma to identify sub-group specific differences. Gene expression profiles were used to identify unique immunobiologic sub-types of posterior fossa pediatric ependymoma. Gene expression profiles were generated from surgical tumor (ependymoma) (n=65) using Affymetrix HG-U133plus2 chips (Platform GPL570). Normalization was performed on our entire cohort of ependymoma. Of the 65 samples, a sub-set of 58 were used in the corresponding manuscript. Excluded samples are noted. Gene expression profiles were filtered to obtain gene expression of key immune cell markers. Comparative analyses between tumor samples were used to identifiy unique immunobiology between posterior fossa sub-groups.
2013-08-30 | E-GEOD-50385 | biostudies-arrayexpress
Project description:We compared molecular characteristics of primary and recurrent pediatric ependymoma to identify sub-group specific differences. Gene expression profiles were used to identify unique immunobiologic sub-types of posterior fossa pediatric ependymoma.
2013-08-30 | GSE50385 | GEO
Project description:A series of mouse models designed to mimic pediatric medulloblastoma types in humans were tested by microarray and compared to published human medulloblastoma data
2012-02-29 | GSE33200 | GEO
Project description:METTL3-mediated RNA N6-methyladenosine (m6A) is the most prevalent modification participates in tumor initiation and progression via regulating expression of their target genes in cancers. However, its role in tumor cell metabolism remains poorly appreciated. In this study, we conducted a multi-omics analysis including m6A microarray and quantitative proteomics to explore the potential effect and mechanism of METTL3 on the metabolism in gastric cancer cells. Our results found that significant alterations in the protein and m6A modification profile which induced by METTL3 overexpression in GC cells. Gene Ontology (GO) enrichment results showed that down-regulated proteins were significantly enriched in intracellular mitochondrial oxidative phosphorylation (OXPHOS), and the Protein-Protein Interaction (PPI) network analysis found that these differentially expressed proteins were significantly associated with OXPHOS. Subsequently, a prognostic model constructed based on the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases, and the high-risk group showed a worse prognosis in GC patients. Meanwhile, the Gene Set Enrichment Analysis (GSEA) showed a significant enrichment in the energy metabolism signaling pathway. Then, combined with the results of the m6A microarray analysis, the intersection molecules of DEPs and differential methylation genes (DMGs) were significantly correlated with the genes involved in OXPHOS. Besides, there were also significant differences in prognosis and GSEA enrichment between the two clusters of GC patients classified according to consensus clustering algorithm. Finally, we focused on highly expressed, highly methylated molecules regulated by METTL3 and identified three (AVEN, DAZAP2, DNAJB1) genes that were significantly associated with poor prognosis in patients with GC. These results indicated that METTL3-regulated DEPs in GC cells were significantly associated with OXPHOS. After combined with m6A microarray analysis, the results suggested that these proteins might be involved in cell energy metabolism through m6A modifications thus influencing the prognosis of GC patients. Overall, our study revealed that METTL3 involved in cell metabolism through an m6A-dependent mechanism in GC cells, and indicated a potential biomarker for prognostic prediction in GC.
2023-03-10 | PXD036773 | Pride
Project description:Medulloblastoma, the most common malignant pediatric brain tumour, disseminates by shedding cells into the cerebrospinal fluid, which then re-implant to cover the surface of the brain and spinal cord. Metastases are a very poor prognostic sign at presentation and are usually lethal at recurrence. Mechanisms driving dissemination have been described in the bulk primary tumour, with the underlying assumption that primary tumour and metastases are biologically similar. Here we show that in both mouse and human medulloblastoma, multiple metastases from a single animal are extremely similar, but are genetically highly divergent from the primary tumour. Clonal genetic events in the metastases can be demonstrated in a restricted sub-clone of the primary tumour, suggesting that only rare cells within the primary tumour have the ability to metastasize. Failure to account for the bicompartmental nature of primary and metastatic medulloblastoma represents a major barrier to the development of effective targeted therapies. Affymetrix SNP arrays were performed according to the manufacturer's directions on DNA extracted from cryopreserved human medulloblastoma tissue samples. Copy number analysis of Affymetrix SNP6 arrays was performed for 17 pediatric medulloblastoma samples. Samples comprise a series of 7 patient-matched primary/metastatic cases.
2011-12-09 | E-GEOD-34280 | biostudies-arrayexpress
Project description:Medulloblastoma, the most common malignant pediatric brain tumour, disseminates by shedding cells into the cerebrospinal fluid, which then re-implant to cover the surface of the brain and spinal cord. Metastases are a very poor prognostic sign at presentation and are usually lethal at recurrence. Mechanisms driving dissemination have been described in the bulk primary tumour, with the underlying assumption that primary tumour and metastases are biologically similar. Here we show that in both mouse and human medulloblastoma, multiple metastases from a single animal are extremely similar, but are genetically highly divergent from the primary tumour. Clonal genetic events in the metastases can be demonstrated in a restricted sub-clone of the primary tumour, suggesting that only rare cells within the primary tumour have the ability to metastasize. Failure to account for the bicompartmental nature of primary and metastatic medulloblastoma represents a major barrier to the development of effective targeted therapies. DNA methylation analysis of 15 pediatric medulloblastoma samples consisting of 6 primary-metastatic pairs and 4 normal cerebella samples profiled in Illumina Infinium HumanMethylation27 Beadchip v1.2
2011-12-13 | E-GEOD-34355 | biostudies-arrayexpress