4821 results for "*oma"

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• Luminal breast epithelial cells from wildtype and BRCA mutation carriers harbor copy number alterations commonly associated with breast cancer

  Cancer-associated mutations have been documented in normal tissues, but the prevalence and nature of somatic copy number alterations and their role in tumor initiation and evolution is not well understood. Here, using single cell DNA sequencing, we describe the landscape of CNA variants in >48,000 breast epithelial cells from women with normal or high risk of developing breast cancer. Individual cells with one or two of a specific subset of CNAs (e.g. 1q gain and 16q, 22q, 7q, and 10q loss) are detectable in almost all breast tissues and, in those from BRCA1 or BRCA2 mutations carriers, occurs prior to loss of heterozygosity (LOH) of the wildtype alleles. These CNAs, which are among the most common associated with ductal carcinoma in situ (DCIS) and malignant breast tumors, are enriched almost exclusively in luminal cells and are generally absent from basal myoepithelial cells. Allele-specific analysis of the enriched CNAs reveals that each allele was independently altered, demonstrating convergent evolution of these CNAs in an individual breast. Tissues from BRCA1 or BRCA2 mutation carriers contained a small percentage of cells with extreme aneuploidy, featuring loss of TP53, LOH of BRCA1 or BRCA2, and multiple breast cancer-associated CNAs in addition to one or more of the common CNAs in 1q, 10q or 16q. Notably, cells with intermediate levels of CNAs were not detected, arguing against a stepwise gradual accumulation of CNAs. Overall, our findings demonstrate that chromosomal alterations in normal breast epithelium including from high risk women, link early stage CNAs to clonally expanded tumor genomes .

  Study EGAS00001007716

• Loss of SDHB promotes dysregulated iron homeostasis, oxidative stress and sensitivity to ascorbate

  Succinate dehydrogenase is a key enzyme in the tricarboxylic acid cycle and the electron transport chain. All four subunits of succinate dehydrogenase are tumor suppressor genes predisposing to paraganglioma, but only mutations in the SDHB subunit are associated with increased risk of metastasis. Here we generated an Sdhd knockout chromaffin cell line and compared it to Sdhb-deficient cells. Both cell types exhibited similar SDH loss of function, metabolic adaptation, and succinate accumulation. In contrast, Sdhb-/- cells showed hallmarks of mesenchymal transition associated with increased DNA hypermethylation and a stronger pseudo-hypoxic phenotype compared to Sdhd-/- cells. Loss of SDHB specifically led to increased oxidative stress associated with dysregulated iron and copper homeostasis in the absence of NRF2 activation. High-dose ascorbate exacerbated the increase in mitochondrial reactive oxygen species, leading to cell death in Sdhb-/- cells. These data establish a mechanism linking oxidative stress to iron homeostasis that specifically occurs in SDHB deficient cells and may promote metastasis. They also highlight high-dose ascorbate as a promising therapeutic strategy for SDHB-related cancers.

  Study EGAS00001005279

• Sarcoma long-read nanopore whole-genome sequencing Data Access Committee

  Sarcoma long-read nanopore whole-genome sequencing Data Access Committee.

  Dac EGAC50000000415

• cfDNA methylation profiling on longitudinally collected blood plasma of patients with esophageal adenocarcinoma

  Esophageal adenocarcinoma (EAC) is an aggressive cancer characterized by a high risk of relapse post-surgery. Analyzing cell-free DNA (cfDNA) from blood plasma emerges as a promising avenue for therapy response monitoring. This study aims to evaluate the cost-effective and genome-wide cell-free reduced representation bisulfite sequencing (cfRRBS) method combined with computational deconvolution for effective disease monitoring in EAC patients.

  Study EGAS50000000514

• Patient-Derived Follicular Lymphoma Spheroids recapitulate lymph node signaling and immune profile, uncovering galectin-9 as a novel immunotherapeutic target

  RNA-seq data from CD20+ sorted cells obtained from peripheral blood and lymph node Follicular Lymphoma patients. These samples were unstimulated after thawing and additionally, peripheral blood samples were stimulated during 7 days in culture as described in Dobaño-López C et. al.)

  Study EGAS50000000233

• 3D genome topology distinguishes molecular subgroups of medulloblastoma

  Medulloblastoma (MB) has four molecular subtypes, but their 3D genome architecture differences are unclear. We used in situ Hi-C on 28 surgical specimens and a patient-derived xenograft to reconstruct the 3D genome architecture of MB subtypes, finding that topologically associating domain (TAD) insulation scores could distinguish MB subtypes.

  Study EGAS50000000540

• AYA glioma NGS

  Gliomas are a major cause of cancer-related death in adolescents and young adults (AYA, ages 15-39 years). Different molecular alterations drive gliomas in children and adults leading to distinct biology and clinical consequences. At the convergence of these age groups - the AYA population – little is known about the implications of pediatric vs adult-type alterations. To address this, we analyzed a population-based cohort of 1456 clinically and molecularly characterized gliomas aged 0-39 years. Potentially targetable pediatric-type alterations were found in 31% of AYA gliomas and conferred superior outcomes compared to adult-type alterations. This submission includes the generated NGS data for children, adolescent, and young adults with gliomas. Data includes targeted panel of glioma genes and low-pass WGS (1x coverage).

  Study EGAS50000000383

• CAYA glioma sequencing data

  Low pass WGS and targeted glioma panel sequencing of low and high-grade gliomas in children, adolescent, and young adult patients.. File type is paired-read fastq files (2 per sample). Sequencing was performed on Illumina NextSex instruments. Genes covered on panel: TP53, H3F3A, HIST1H3B, HIST1H3C, IDH1, IDH2, KRAS, PIK3CA, TERT promoter, PTPN11, FGFR1/2/3, MYB, BRAF, MYBL1, EGFR, PDGFRA, MYCN, MYC, CDKN2A.

  Dataset EGAD50000000560

• Mayo Clinic - Fecal Microbiota and Adenomas

  Background: Adenomatous polyps are the most common precursor to colorectal cancer (CRC), the second leading cause of cancer death in the United States. We sought to learn more about early events of carcinogenesis by investigating shifts in the gut microbiota of patients with adenomas. Methods: We analyzed 16S rRNA gene sequences from the fecal microbiota of patients with adenomas (n=233) and without (n=547). Results: Multiple taxa were significantly more abundant in patients with adenomas, including Bilophila, Desulfovibrio, pro-inflammatory bacteria in the genus Mogibacterium, and multiple Bacteroidetes species. Patients without adenomas had greater abundances of Veillonella, Firmicutes (Order Clostridia), and Actinobacteria (family Bifidobacteriales). Many of our findings were consistent with previously reported shifts in the gut microbiota of CRC patients. Importantly, the altered adenoma profile is predicted to increase primary and secondary bile acid production, as well as starch, sucrose, lipid, and phenylpropanoid metabolism. Conclusions: These data suggest that diets rich in refined sugar, protein, and lipids may lead to increased bile acid production, creating a colonic environment that promotes the growth of bile-tolerant microbes such as Bilophilia and Desulfovibrio. In turn, these microbes may produce genotoxic or inflammatory metabolites such as H2S and secondary bile acids, catalyzing adenoma development and eventually CRC. Impact: This study suggests a plausible biological mechanism to explain the links between diet, shifts in the microbiota, and CRC. This represents a first step toward resolving the complex interactions that shape the adenoma-carcinoma sequence of CRC and may facilitate personalized therapeutics focused on the microbiota.

  Study phs001204

• Somatic Mutations in Individual Skin Cells

  Ultraviolet (UV) radiation is the primary cause of melanoma through the acquisition of driver mutations in melanocytes. It also plays a significant role in oncogenesis in other skin cells, such as keratinocytes. However, the mutational profiles vary widely among different skin cancers, and the early mutational processes in different cell types from the same skin, is not well understood. Additionally, our preliminary studies also suggest that the mutation burden in different skin cells vary significantly based on risk factors such as the anatomical site and the use of tanning beds. To explore this, we employed innovative Next Generation Sequencing (NGS) tools to perform a site-matched comparison of the genomic landscapes of melanocytes, keratinocytes, and fibroblasts. From 20 biopsies of physiologically normal skin, collected from various anatomical sites across 16 donors, we have performed DNA-sequencing on 106 melanocytes, 78 keratinocytes and 13 fibroblasts. Of these samples, we have also simultaneously performed RNA-sequencing on 78 melanocytes, 46 keratinocytes and 9 fibroblasts. For normal bulk DNA, we also performed targeted (UCSF500; n=9) or exome sequencing (n=8) of skin or saliva samples from the donors.

  Study phs003683