4911 results for "*oma"

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• Recurrent somatic mutations in POLR2A define a distinct subset of meningiomas

  RNA polymerase II mediates the transcription of all protein-coding genes in eukaryotic cells, a process that is fundamental to life. Genomic mutations in this enzyme have not been previously linked to any pathology in humans, a testament to its indispensable role in cell biology. Based on a combination of next-generation genomic analyses of 775 meningiomas, we report that recurrent somatic p.Gln403Lys or p.Leu438_His439del mutations in POLR2A, which encodes the catalytic subunit of RNA polymerase II1, are sufficient to hijack this essential enzyme and drive neoplasia. POLR2A mutant tumors reveal dysregulation of key meningeal identity genes, including WNT6 and ZIC1/ZIC42,3. In addition to POLR2A, NF2, SMARCB1, TRAF7, KLF4, AKT1, PIK3CA and SMO4-8, we also report somatic mutations in AKT3, PIK3R1, PRKAR1A, and SUFU in meningiomas. Our results identify a role for essential transcriptional machinery in driving tumorigenesis and define mutually exclusive meningioma subgroups with distinct clinical and pathological features.

  Study EGAS00001001916

• Germline MBD4 Mutations and Predisposition to Uveal Melanoma

  Uveal melanoma (UM) arises from malignant transformation of melanocytes from the uveal tract. This rare tumor has a poor outcome with frequent liver metastases and primary resistance to treatment1. The only strong predisposing condition for UM is the BAP1 tumor predisposition syndrome due to germline BAP1 deleterious mutations. UMs are generally characterized by a very low tumor mutation burden (TMB). However, some UMs display a high level of CpG to TpG mutations associated with MBD4 inactivation. Here, we explored the incidence of germline MBD4 variants in a consecutive series of 1, 099 primary UMs, and identified 8 deleterious MBD4 mutations, an aprox 10-fold increased incidence compared with the general population. These mutations were associated with a high TMB in tested UMs. We thus demonstrated that MBD4 is the second major predisposing gene for UM.

  Study EGAS00001003941

• Genome-wide DNA-methylation assessment by MethylCap-seq and Infinium HumanMethylation450 BeadChips: an independent large-scale comparison

  DNA-methylation is an important epigenetic feature in health and disease. Two cost-efficient genome-scale methodologies to assess DNA-methylation are MethylCap-seq and Illumina's Infinium HumanMethylation450 BeadChips (HM450). However, objective information regarding the best-suited methodology for a specific research question is scant. Therefore, we performed a large-scale evaluation on a set of 70 brain tissue samples obtained from 65 glioblastoma and 5 non-tumoral brain tissues, using a gold standard free Bayesian modeling procedure. While conditional specificity was adequate for both approaches, conditional sensitivity was systematically higher for HM450. Also the genome-wide characteristics were compared, revealing that the HM450 probes assess less than 10% of the regions identified as methylated by MethylCap-seq. Hence the latter method may detect more potentially relevant DNA-methylation, defined by either functional location or previously reported differentially methylated candidate regions. Our results therefore indicate that – at least for the tissue under study - both methodologies are complementary, with a higher sensitivity for HM450, but a far larger genome-wide coverage for MethylCap-seq. Note that here only the relevant MethylCap-seq data is deposited, for the HM450 data we refer to GEO (GSE60274).

  Study EGAS00001001191

• Sequencing data of multiple sarcoma samples for personalized medicine and endotype identification

  Sequencing data derived from multiple patient samples was used to guide multiple patient-specific experiments and identify potential therapeutic options. These diseases are rare and high-risk (undifferentiated pleomorphic sarcoma, rhabdomyosarcoma) and thus have few available validated clinical options. This leaves the population of patients with few options if, and when, standard therapy fails to cure or control disease. An aspect of the personalize therapy design included the identification of broader disease endotypes (a combination of genetic and clinical data describing patient status) to identify subgroups of the individual disease that could better define treatments and could segment patient populations for deeper preclinical research.

  Study EGAS00001003981

• Genomics of enteropathy associated T cell lymphoma (EATL)

  Enteropathy-associated T cell lymphoma (EATL) is a lethal and the most common neoplastic complication of celiac disease. In this study, we applied whole exome sequencing in 69 EATL tumors to define the genetic landscape of EATLs. The most frequently mutated gene in EATL was SETD2 (32% of cases), with loss of function mutations comprising a large proportion (41%) of those mutations. The JAK-STAT pathway was the most frequently mutated signaling pathway, with mutations in STAT5B being the most common, followed by JAK1, JAK3, STAT3, and the negative regulator of the pathway, SOCS1. We also identified mutations in NRAS and KRAS, as well as TP53 and TERT. Interestingly, the two types of EATL had highly overlapping genetic alterations indicating shared mechanisms underlying their pathogenesis. Gene expression analysis of the two types of EATL identify robust differences in transcriptional profiles. We further modeled the effects of SETD2 loss in vivo by developing a T cell specific knockout mouse model. These mice manifested an expansion of γδ T cells that identify novel roles for SETD2 in T cell development and lymphomagenesis. Together, our data render the most comprehensive genetic portrait yet of this uncommon but lethal disease, and may inform future classification schemes.

  Study EGAS00001001954

• Integrative_Oncogenomics_of_Multiple_Myeloma

  Agilent whole exome hybridisation capture will be performed on genomic DNA derived from Multiple Myeloma patient DNA and matched normal DNA from the same patients. Two lanes of Illumina GA sequencing will be performed on the resulting exome libraries and mapped to build 37 of the human reference genome to facilitate the identification of novel cancer genes.

  Study EGAS00001000036

• Reconstruction of complex rearrangement patterns causing the initiation of clear cell renal cell carcinoma.

  The genomic hallmark of clear cell renal cell carcinoma is the loss of the short arm of chromosome three. This appears to be the earliest genomic event in the formation of these cancers. Often chromosome 3 is lost at the same time as part of chromosome 5 is duplicated via an unbalanced translocation, often with features consistent with focal chromothripsis. In this study, we sought to reconstruct the chromothriptic event that underlies the initiation of kidney cancer. We used long read sequencing (promethION, Oxford Nanopore Technologies) of patient tumour-derived DNA to elucidate how a single cell division error can generate cancer genome complexity.

  Study EGAS00001004015

• Molecular Attributes Underlying Central Nervous System and Systemic Relapse in Diffuse Large B-cell Lymphoma

  Central nervous system (CNS) relapse in diffuse large B-cell lymphoma remains a significant conundrum. While clinical risk scores and biomarkers allow the identification of patients with higher risk of CNS relapse, their predictive ability is low. Herein, we report findings from a comprehensive study examining gene expression changes, mutations and clonal evolution. Firstly, considering diagnostic samples from patients with CNS relapse, systemic relapse or no relapse, we found a striking enrichment of gene expression changes reflecting protein biosynthesis in patients who experienced CNS or systemic relapse. Furthermore, diagnostic specimens of relapsing cases were characterized by low immune infiltrates. The most discriminative gene feature in our analysis was SLAMF1, high expression of which was associated with favourable outcomes. Next, we assessed whether specific gene mutations were associated with subsequent CNS or systemic relapse. Activated B-cell-like genes such as PIM1, CD79B and PRDM1 were more frequently mutated in cases with CNS relapse, whereas TP53, BCL2 and FOXO1 mutations were associated with systemic relapse. Lastly, we performed tumor evolution analysis in five patients, identifying significant clonal divergence that accompanied CNS relapse. In summary, we identified both common biology underlying both CNS and systemic relapse, independent of cell-of-origin (COO), and specific COO-enriched gene mutations that conferred a higher risk of either CNS or systemic relapse. Moreover, we identified a pattern of clonal evolution that can explain difficulties in both predicting and treating CNS relapse.

  Study EGAS00001004057

• Exome sequence data for germline, primary tumor, and relapse tumor of a transformed non-Hodgkins lymphoma patient with unexpected long-time remission

  The patient was diagnosed with a transformed high-grade non-Hodgkin lymphoma stage III, and treated with conventional R-CHOP (Rituximab (R), Cyclophosphamide (C), Doxorubicin (H), Vincristine (O) and Prednisone (P)). Unfortunately, she suffered from severe toxicity but recovered during the following six months remission until a biopsy verified relapse. The patient refused second line combination chemotherapy, but accepted a 3 months palliation with R and Chlorambucil. Unexpectedly, she obtained continuous complete remission and is at present >9 years after primary diagnosis.Molecular studies and data evaluation by principal component analysis, mutation screening, and copy number variations of the primary and relapsed tumor, identified patterns of branched lymphoma evolution, most likely diverging from an unknown in situ follicular lymphoma.

  Study EGAS00001001973

• Genomic characterization of hepatocellular carcinoma in Hispanic patients

  The genomic DNA was extracted from paired tumor and adjacent non-tumor samples of 27 Hispanic HCC patients. The TruSeq Rapid Exome Library Prep kit (Illumina, CA) was used to capture the coding regions of the human genome. The 100 bp paired-end sequencing of every 6-plex whole exome library pool was performed on an Illumina HiSeq 3000 system according to the manufacturer’s recommended protocol to achieve an average coverage of ~100X. The paired-end reads were aligned to the human reference genome (hg19) with decoy sequences (as used in the 1000 Genomes Project) using BWA software. The duplicate reads were marked and removed using Picard and SAMtools, respectively. Local realignment around insertions/deletions (indels) and base quality recalibration were performed using GATK.

  Study EGAS00001007431