3798 results for "*oma"

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• DNA methylation and somatic mutations converge on cell cycle and define similar evolutionary histories in brain tumors

  The evolutionary history of tumor cell populations can be reconstructed from patterns of genetic alterations. In contrast to the stability of genetic events, epigenetic states are reversible and sensitive to the microenvironment, prompting the question whether epigenetics can be similarly used to discover tumor phylogeny. We examined the spatial and temporal dynamics of DNA methylation in a cohort of low-grade gliomas and their patient-matched recurrences. Genes upregulated through promoter hypomethylation during malignant progression to high-grade glioblastoma were enriched in cell cycle function, evolving in parallel with genetic alterations that deregulate the G1/S cell cycle checkpoint. Moreover, phyloepigenetic relationships robustly recapitulated phylogenetic patterns inferred from somatic mutations. These findings highlight widespread co-dependency of genetic and epigenetic events throughout brain tumor evolution.

  Study EGAS00001001255

• Search for new loci and low-frequency variants influencing glioma risk by exome-array analysis

  To identify protein altering variants (PAVs) for glioma we analysed Illumina HumanExome BeadChip exome array data on 1,882 glioma cases and 8,079 controls from three independent European populations. In addition to single variant tests we incorporated information on the predicted functional consequences of PAVs and analysed sets of genes with a higher likelihood of having a role in glioma on the basis of the profile of somatic mutations documented by large-scale sequencing initiatives. Globally tThere was a strong relationship between effect size and SNPs predicted to be damaging (P=2.29x10-49); however, these variants which are most likely to impact on risk, are rare (MAF<5%). While no single variant showed an association which was statistically significant at the genomewide threshold a number of represented promising Notable associations - were seen with the BRCA2:c.9976A>T, p.(Lys3326Ter)BRCA2 p.Lys332X variant, which has been shown documented to influence breast and lung cancer risks (OR=2.3, P=4.00x10-4 for glioblastoma [GBM]) and IDH2:c.782G>A, p.(Arg261His)IDH2 p.Arg261His (OR=3.21, P=7.67x10-3, for non-GBM). Additionally, gene burden tests revealed a statistically significant association for HARS2 and risk of GBM (P=2.20x10-6). Genome scans of low frequency PAVs represent a complementary strategy to identify disease-causing variants compared with scans based on tagSNPs. Strategies to lessen the multiple testing burden by restricting analysis to PAVs with higher priors affords an opportunity to maximise study power.

  Study EGAS00001001258

• Whole exome sequencing of papillary thyroid carcinoma in the Chinese population

  Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer. Here we submitted the sequencing results for PTC using 91 tumor-normal pairs through exome sequencing in the Chinese Han population.

  Study EGAS00001001268

• Growth Hormone (GH) -secreting Pituitary Adenoma

  Data from 12 fresh-frozen somatotropinomas and their corresponding blood samples. Details are given in Valimaki et al. Whole-genome sequencing of Growth Hormone (GH) -secreting Pituitary Adenoma. Provisionally accepted, 2015.

  Study EGAS00001001293

• Integrated molecular analysis of adult T-cell leukemia/lymphoma

  This study is an integrated molecular study of adult T-cell leukemia/lymphoma which includes whole-exome (n = 81), whole-genome (n = 48), and transcriptome sequencing data (n = 57) as well as methylation (n = 109) and SNP array data (n = 426)

  Study EGAS00001001296

• Characterization of MCSP+ melanoma DCC and MelDCC lines

  To dissect the sequence of genotypic and phenotypic progression during early metastatic colonization, we searched for the earliest detectable disseminated cancer cells (DCC) and identified MCSP+ melanoma cells as strong candidates for metastasis founder cells (MFC) in lymph nodes. We isolated MCSP+ DCC from various stages of metastatic colony-formation, performed scRNA-seq and unravelled their phenotypic progression. Further we performed bulk sequencing on patient-derived DCC models (MelDCC) and showed that they exhibit an immunosuppressive activity on CD8 T cells.

  Study EGAS00001006702

• Carcinoma of the oral tongue (OTSCC) genomic landscape characterisation

  Carcinoma of the oral tongue (OTSCC) is the most common malignancy of the oral cavity, characterized by frequent recurrence and poor survival. The last three decades has witnessed a change in the OTSCC epidemiological profile, with increasing incidence in younger patients, females and never-smokers. Here, we sought to characterize the OTSCC genomic landscape and to determine factors that may delineate the genetic basis of this disease, inform prognosis and identify targets for therapeutic intervention.

  Study EGAS00001001329

• Genomic analysis of HPV positive versus HPV negative esophageal adenocarcinoma

  High-risk human papillomavirus (hr-HPV) has been implicated in a subset of patients with esophageal adenocarcinoma (EAC). We therefore hypothesized that HPV associated EAC may have distinct genomic aberrations compared with viral negative esophageal cancer as shown in Head and Neck cancer and cervical cancer. Whole exome sequencing (WES) was performed to explore the mutational landscape and potential molecular signature of HPV positive versus HPV negative EAC, which includes four hr-HPV-positive and 8 HPV-negative treatment naive fresh-frozen EAC tissue specimens and matched normal tissues.

  Study EGAS00001001340

• Independent development of lymphoid and histiocytic malignancies from a shared early precursor

  Recent reports have described lineage flexibility in patients with recurrent hematologic malignancies. We encountered a boy with T-lineage acute lymphoblastic leukemia, non-Langerhans cell histiocytosis and histiocytic sarcoma. All tumors showed identical T-cell receptor rearrangements, but SNP arrays and whole exome sequencing revealed unique aberrations in each tumor. From the genetic data we conclude that the tumors were derived from a precursor cell with lineage plasticity for both lymphoid and myeloid development. From this precursor cell, the tumors evolved with independent genetic progression in a non-linear manner.

  Study EGAS00001001353

• Genomes of Relapsing Neuroblastoma

  Neuroblastoma is a malignancy of the developing sympathetic nervous system that is often lethal when relapse occurs, but the molecular mechanisms behind this process are poorly defined. We here used whole-exome sequencing, mRNA expression, array CGH and DNA methylation analysis to holistically characterize 16 paired samples from neuroblastoma patients at diagnosis and relapse. The mutational burden significantly increased in relapsing tumors accompanied by altered mutational signatures and reduced subclonal heterogeneity. Global allele frequencies at relapse indicated clonal mutation selection during disease progression. Promoter methylation patterns were consistent over disease course and patient-specific. Recurrent alterations at relapse included mutations in the putative CHD5 neuroblastoma tumor suppressor, chromosome 9p losses, DOCK8 mutations, inactivating mutations in PTPN14 and a relapse-specific activity pattern for the PTPN14 target gene, YAP. Recurrent new mutations in HRAS, KRAS, DOCK8 and genes mediating cell-cell interaction in 13/16 relapse tumors also indicate disturbances in signaling pathways mediating mesenchymal transition. Our data shed first light on genetic alteration frequency, identity and evolution in neuroblastoma.

  Study EGAS00001001387