7411 results for "canc*"

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• Multi Omics of glioma in the the Chinese Glioma Genome Atlas (CGGA) project

  Study EGAS00001004729

• Mixed Histology Lung Cancers Driven by Transcriptomic Features rather than Genomic Characteristics

  Study EGAS00001005140

• Mitochondrial DNA sequencing

  Study EGAS00001005540

• Comprehensive genomic characterization of early stage bladder cancer - whole exome sequencing data

  For this project about non-muscle invasive bladder cancer (NMIBC), we analysed WES data from 438 patients. The dataset is composed of 876 BAM files: 438 tumor samples and 438 paired blood samples.

  Study EGAS50000000511

• Perioperative nivolumab or nivolumab plus ipilimumab in resectable diffuse pleural mesothelioma: Primary phase 2 trial results with ctDNA residual disease analyses

  This data set includes sequence files from whole genome sequencing of tumor (n=28), normal (n=28), and blood (n=113) specimens from a phase 2 clinical trial of neoadjuvant nivolumab and nivolumab/ipilimumab in resectable diffuse pleural mesothelioma (NCT03918252).

  Study EGAS50000001195

• Somatic L1 retrotransposition dynamics in high-grade serous ovarian cancer

  Somatic L1 retrotransposition was mapped in high-grade serous carcinoma (HGSC) tumors using LDI-PCR/Nanopore-seq method. This method identifies somatic L1 insertions originating from two active L1 loci at chr22q12.1 and chrXp22.2. Multiple tumors from same patient were utilised to understand L1-mediated intrapatient heterogeneity.

  Study EGAS50000001198

• Non-coding mutations drive persistence of a founder pre-leukemic clone which initiates late relapse in T-ALL

  T-ALL relapse usually occurs early but can occur much later, which has been suggested to represent a de novo leukemia. However, we conclusively demonstrate late relapse can evolve from a pre-leukemic subclone harbouring a non-coding mutation that evades initial chemotherapy.

  Study EGAS50000000129

• Preliminary Results from the Initiative for Molecular Profiling and Advanced Cancer Therapy 2 (IMPACT 2) Study

  Study EGAS00001004964

• Broad utility of ultrasensitive analysis of ctDNA dynamics across solid tumors treated with immunotherapy

  Prior studies have suggested the biomarker potential of plasma circulating tumor DNA (ctDNA) in cancer patients treated with immune checkpoint inhibitors (ICIs). In order to characterize the potential role of ultrasensitive ctDNA detection in the management of these patients we have performed tumor whole-genome-informed, ultrasensitive ctDNA analysis—tracking approximately 1,800 tumor-specific mutations per patient—in a retrospective cohort (n=136) and a prospective validation cohort (n=66) across 24 cancer types treated with ICIs alone or in combination with bispecific antibodies or immune cell engagers. Analyzing 1,455 longitudinal samples, we found that ctDNA molecular response measured as early as 3 weeks after treatment initiation correlated with improved progression-free and overall survival, while ctDNA clearance at any time strongly correlated with radiological response and prolonged survival. Additionally, ctDNA dynamics distinguished true progression from pseudoprogression and predicted outcomes in patients receiving continued immunotherapy beyond initial progression. This study highlights the broader applicability of ultrasensitive ctDNA as a biomarker across cancer types and immunotherapy modalities.

  Study EGAS50000001333

• Adjuvant nivolumab in resected esophageal or gastroesophageal junction cancer: exploratory biomarker analyses from CheckMate 577

  Adjuvant nivolumab demonstrated a significant improvement in disease-free survival (DFS; primary endpoint) versus placebo in patients with resected esophageal or gastroesophageal junction cancer and residual pathologic disease following neoadjuvant chemoradiotherapy (CRT) in the phase III CheckMate 577 study, leading to global approval and widespread adoption. Exploratory biomarker analyses were performed using whole-exome sequencing, RNA sequencing, and immunohistochemistry. Hazard ratios for DFS favored nivolumab versus placebo in patients with higher inflammation and proliferation gene expression signature scores; lower M2 macrophage, endothelial, and stromal GES scores; and higher densities of CD3+/CD8- T cells and natural killer cells. Assessments of pre-CRT and post-CRT tumor tissue found post-CRT increases in programmed death ligand 1 combined positive score in 51% of patients, which appeared to be associated with greater DFS benefit. Through these analyses, we identified patient subpopulations that appear to derive improved DFS benefit from adjuvant nivolumab in this setting.

  Study EGAS50000001663

• A Comprehensive Catalogue of Somatic Mutations from a Human Cancer Genome

  We have carried out complete sequencing of the genome of the human male maligant melanoma cell line COLO-829 using the Illumina Genome Analyzer II. We generated a sequencing library with a median insert size of ~200 bp following random fragmentation and gel fractionation of the genomic DNA. We sequenced 75 bases from both ends of these templates to cover the COLO-829 genome to an average depth of more than 40x. We have carried out purity-filtering (PF) to remove mixed reads, where two or more different template molecules are close enough on the surface of the flow-cell to form a mixed or overlapping cluster. No other filtering of the data has been carried out prior to submission. We have also submitted sequence data for a lymphoblastoid control cell line COLO-829BL from the same individual.

  Study EGAS00000000052

• Genomic and transcriptomic profiling of colorectal cancer patient-derived organoids

  This study describes controlled-access human sequencing data generated from colorectal cancer patient-derived organoids established using the CTOS method. Whole-exome sequencing (WES) and RNA sequencing (RNA-seq) were performed to characterize genomic alterations and transcriptomic profiles of the organoids.

  Study EGAS50000001669

• Breast Cancer Follow Up Series

  This study's purpose is to use data generated in whole genome and exome Breast Cancer sequencing to target specific areas in multiple other Breast Cancer samples. These areas will then be subjected to PCR in multiple cases, tagged and then pool the resultant amplicons. These amplicons will then be sequenced on the Illumina GAII. This is hoped to show the prevalence of previous findings in multiple individuals in a high throughput method.

  Study EGAS00001000002

• Multifocal_Breast_Project

  Comparison of genomic rearrangements and DNA methylationpatterns between different foci of multiple synchronous(multifocal and multicentric) invasive breast cancers

  Study EGAS00001000004

• Somatic rearrangements causing oncogenic ectodomain deletions of FGFR1 in squamous cell lung cancer

  The discovery of frequent 8p11-p12 amplifications in squamous cell lung cancer (SQLC) has fueled hopes that FGFR1, located inside this amplicon, might be a therapeutic target. In a clinical trial, only 11% of patients with 8p11 amplification (detected by FISH) responded to FGFR kinase inhibitor treatment. To understand the mechanism of FGFR1 dependency, we performed deep genomic characterization of 52 SQLCs with 8p11-p12 amplification, including 10 tumors obtained from patients who had been treated with FGFR inhibitors. We discovered somatically altered variants of FGFR1 with deletion of exons 1-8 that resulted from intragenic tail-to-tail rearrangements. These ectodomain-deficient FGFR1 variants (ΔEC-FGFR1) were expressed in the affected tumors and were tumorigenic in both in vitro and in vivo models of lung cancer. Mechanistically, breakage-fusion-bridges were the source of 8p11-p12 amplification, resulting from frequent head-to-head and tail-to-tail rearrangements. Generally, tail-to-tail rearrangements within or in close proximity upstream of FGFR1 were associated with FGFR1 dependency. Thus, the genomic events shaping the architecture of the 8p11-p12 amplicon provide a mechanistic explanation for the emergence of FGFR1-driven SQLC. Specifically, we believe that FGFR1 ectodomain-deficient and FGFR1-centered amplifications caused by tail-to-tail rearrangements are a novel somatic genomic event that might be predictive of therapeutically relevant FGFR1 dependency.

  Study EGAS50000001368

• Using RNA-sequencing to characterize the resistance to lirafugratinib

  In addition to Exome-sequencing, we used RNA-sequencing to also characterize resistance to lirafugratinib with whole exome sequencing in patients with FGFR2-driven cancers, treated in the phase 1/2 ReFocus trial (NCT04526106) and enrolled in the UNLOCK program at Gustave Roussy

  Study EGAS50000001370

• Kaposi_sarcoma_exome

  Agilent whole exome hybridisation capture will be performed on genomic DNA derived from Kaposi sarcoma cancer and matched normal DNA from the same patients. Next Generation 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 EGAS00001000032

• Analysis of Multiparametric MR imaging and tumor tissue sampling to identify response and acquired resistance to HIF-2 inhibition in patients with advanced clear cell renal cell carcinoma enrolled in a phase 1, multiple-dose, dose-escalation trial of PT2385, a HIF-2alpha inhibitor

  Study EGAS00001003506

• Immunoreactive_p53_areas_in_human_skin_2

  Previous work has suggested that in mice there may be a difference in mutational burden between areas expressing stabilised p53 protein and others. We wish to see if this observation holds true in human sun-exposed epidermis. We will take 0.25mm punch biopsies from peeled human skin epidermis which will be submitted to the low input pipeline prior to sequencing.

  Study EGAS00001004463

• Using Exome-sequencing to characterize the resistance to lirafugratinib

  We characterized resistance to lirafugratinib with whole exome sequencing in patients with FGFR2-driven cancers, treated in the phase 1/2 ReFocus trial (NCT04526106) and enrolled in the UNLOCK program at Gustave Roussy

  Study EGAS50000001371

• CIAO Clinical Trial

  Whole exome and RNA sequencing for samples from CIAO (Checkpoint Inhibitors Assessment in Oropharynx cancer) (NCT03144778) clinical trial testing neoadjuvant anti-PD-L1 durvalumab with or without the anti-CTLA-4 tremelimumab in oropharynx cancer

  Study EGAS50000001174

• A Comprehensive Catalogue of Somatic Mutations from a Human Cancer Genome

  We previously reported the whole-genome sequencing of the well-studied human malignant melanoma cell line, COLO-829, and a lymphoblastoid cell line from the same individual, providing the first comprehensive catalogue of somatic mutations from an individual cancer (Pleasance et al. (2010) Nature 463, 191). This initial study was carried out using the Illumina Genome Analyzer II, largely using paired-end reads of 75 bases from standard Illumina paired-end libraries. Here we report the results of sequencing the genomes of COLO-829 and its matched lymphoblastoid sample using HiSeq2000 with v3 cluster-generation and sequencing chemistries. This has significantly improved the evenness and completeness of genomic coverage, particularly in areas of extreme sequence composition that were underrepresented in the initial study.

  Study EGAS00001000245

• Circulating cell-free DNA methylation profiling for detection, distinction, and estrogen receptor status classification of advanced breast cancer

  We developed cell-free DNA (cfDNA) methylation signatures for minimally invasive breast cancer detection, distinction, and estrogen receptor (ER) status classification with cell-free Methylated DNA Immunoprecipitation and Sequencing (cfMeDIP-seq). We profiled peripheral blood plasma from 87 patients with mBC spanning ER-positive/HER2-negative (ER+/HER2-), HER2-positive, and triple-negative breast cancer (TNBC).

  Study EGAS50000001675

• Multi-modal spatial characterization of tumor-immune microenvironments in diffuse large B-cell lymphoma

  We have leveraged spatial transcriptomics together with proteomic and genomic analysis to investigate the spatial immunology and pathobiology of DLBCL. We define distinct cellular niches that differ in frequency across tumors, related to both Epstein-Barr virus (EBV) infection status and the anatomical site of the tumor, and show that residence within different cellular niches is associated with divergent functional states of T-cells and tumor B-cells due to different patterns of cell-cell communication. This provides a framework for understanding stereotyped patterns of spatial organization in DLBCL and immunological interactions associated with heterogeneity in immune cell infiltration and function across patients.

  Study EGAS50000001146

• NIBIT-EPI-MESO study samples

  Multi-omics analysis of pre-immuno checkpoint inhibitors (ICI) therapy lesions from 91 pleural mesothelioma (PM) patients enrolled in the multicenter NIBIT-EPI-MESO study. Neoplastic lesions were characterized using multiple molecular platforms, including RNA sequencing (n=82), Whole Exome Sequencing (WES) (n=87), Reduced Representation Bisulfite Sequencing (RRBS) (n=83) and cell-free methylated immunoprecipitation sequencing (cfMeDIP-seq) (n=18). Tumor samples were collected during the standard diagnostic pleuroscopy or thoracoscopy before ICI therapy. Matched Peripheral Blood Mononuclear Cells (PBMC) were collected from PM patients before ICI therapy.

  Study EGAS50000001478

• Processing of tissue and cfDNA samples of CRC patients using Active-seq

  In this study, we have developed a novel technology called Active-Seq (Azide Click Tagging for In Vitro Epigenomic sequencing), a base conversion-free technology used to profile the DNA methylation status of a sample, based on the isolation of DNA containing unmodified CpG sites using a mutated bacterial methyltransferase enzyme and a synthetically prepared cofactor analogue. We procured samples from colorectal cancer (CRC) patients including tumour tissue as well as normal adjacent tissues. The data enabled us to identify CRC-specific markers that could then be used to track and monitor the presence of tumour DNA in cell-free DNA plasma (cfDNA) samples procured in the same patients. The FASTQ files of all the colorectal cancer tissues, normal adjacent tissues as wells as the cfDNA samples are available in this submission. The data made available in this study have been used to outline an approach for tumour-informed disease profiling in colorectal cancer cfDNA samples using Active-Seq.

  Study EGAS50000001226

• Biological and Therapeutic Implications of a Unique Subtype of NPM1 Mutated AML

  Study EGAS00001004872

• Single-cell RNA-seq profiling of patient derived organoids

  The aim of this study was to profile developement of resistance to cancer treatments using organoids. Two patient derived colorectal cancer organoids were profiled using single cell RNAseq after treatment with a combination of different anticancer drugs. The organoids were profiled both after 4 weeks of treatment and after a drug holiday of 2 weeks.

  Study EGAS50000001025

• _WGS__Somatic_mutation_in_skin_epidermis__SMS_

  Previously we have sequenced 2mm2 biospies of human epithelia at high depth using a custom bait set. This has identified a range of mutations. Some of the biospies are predicted to be clonal and we would like to perform WGS to give an insight into mutational burden, and CNV which may be associated with these mutations.

  Study EGAS00001004464

• Axes of Biological Variation in Diffuse Large B-Cell Lymphoma

  To explore the DLBCL molecular and genetic environment, we conducted genome-wide NGS sequencing on 103 DLBCL biopsy samples (named as Cornell-NCI cohort) with NGS platforms, including bulk WES, etc. The raw fastq files of the bulk WES were deposited on the EGA for user access. For additional information regarding the genomic data associated with the study, please also see the paper companion website at https://llmpp.ccr.cancer.gov/local/DLBCL_singlecell/

  Study EGAS50000001227

• CHEK2 molecular manuscript

  This study investigated the molecular landscape of 17 tumors from 9 individuals with biallelic germline pathogenic variants in CHEK2. Tumors included breast and non-breast cancers, and WES and sWGS bam files from the tumors are included in this submission. WES data was aligned to GRCh37 and sWGS data to GRCh38.

  Study EGAS50000000080

• WGS_skin_punches

  We wish to understand the degree of copy number alterations in normal human sun exposed skin. We have collected small punches of epithelia and using a bait set design have shown the these span a clone. WGS will provide copy number information on these.

  Study EGAS00001004465

• RESOLVE_trial_targeted_sequencing_data

  RESOLVE: Abemaciclib + Letrozole +/_- Metformin, Zotatifin, or Gedatolisib in Endometrial or Low-Grade Serous Ovarian Cancer

  Study EGAS50000001202

• Tumour evolvability metrics predict recurrence in advanced localised prostate cancer (tumour data)

  Study EGAS00001006096

• HSC_population_dynamics___KX007_samples

  My research project aims to use the clonal dynamics of spontaneously occurring somatic mutations to answer fundamental questions about human haematopoietic stem cell (HSC) biology. The four major questions I will address are: 1. How do age and aging affect normal human HSC dynamics in vivo? 2. How do in vivo perturbations, particularly chemotherapy and increased levels of reactive oxygen species, affect HSC population dynamics? 3. Is response to in vitro perturbation heritable and/or correlated with other features such as age of individual and contribution of the lineage to peripheral blood? 4. How are HSC dynamics altered in people with early driver mutations (clonal haematopoiesis)?

  Study EGAS00001004193

• Characterization of UV DNA damage in B-cell precursor acute lymphoblastic leukemia

  Study EGAS00001008128

• Multi-Region WES of Metastatic Colorectal Cancer

  Study EGAS00001003573

• Detection of brain cancer using genome-wide cell-free DNA fragmentomes

  Diagnostic delays in patients with brain cancer are common and can impact patient outcome. Development of a blood-based assay for detection of brain cancers could accelerate brain cancer detection. In this study, we analyzed genome-wide cell-free (cfDNA) fragmentomes, including fragmentation profiles and repeat landscapes, from the plasma of individuals with (n=148) and without (n=357) brain cancer. Machine learning analyses of cfDNA fragmentome features detected brain cancer across all grade gliomas (AUC=0.90, 95% CI: 0.87-0.93) and these results were validated in an independent prospectively collected cohort. cfDNA fragmentome changes in patients with gliomas represented a combination of fragmentation profiles from glioma cells and altered white blood cell populations in the circulation. These analyses reveal the properties of cfDNA in patients with brain cancer and open new avenues for noninvasive detection of these individuals.

  Study EGAS50000000986

• Primary breast tumor heterogeneity through therapy

  We performed whole-exome sequencing on multiple regions (n=2-3) from four primary untreated breast tumors (n=1 HER2+, n=2 ER+/HER2-, n=1 triple-negative), as well as matched normal. We also performed whole-exome sequencing on one region from the pre-treatment diagnostic core biopsy and multiple regions (n=2-6) from the post-treatment surgical specimen for five HER2+ primary breast tumors, as well as matched normal; all were treated with combination chemotherapy and trastuzumab. Analysis of these specimens allows characterization of breast tumor heterogeneity and clonal evolution.

  Study EGAS00001003168

• Validation of a targeted sequencing panel for multiple myeloma

  Study EGAS00001006164

• Spatial predictors of response to immunotherapy in microsatellite stable metastatic colorectal cancer

  Microsatellite stable (MSS) colorectal cancers (CRC) are largely unresponsive to immune checkpoint inhibition (ICI), prompting investigation into strategies to enhance sensitivity. The MAYA trial, which utilized temozolomide (TMZ) in MGMT-silenced MSS mCRC, hypothesized that TMZ-induced hypermutation could sensitize tumors to ICI. This phase II trial met its primary endpoint, demonstrating durable clinical responses with TMZ combined with ipilimumab and nivolumab. To elucidate factors influencing response heterogeneity, we conducted multi-omic spatial profiling of samples from patients who participated in the MAYA trial, including baseline and on-treatment tissue and blood specimens. While increased neoantigen load following TMZ exposure did not consistently predict for deep responses, spatial profiling revealed key determinants. Lymphocyte proportions, particularly CD8+KI67+ cells, within stromal and tumor compartments, along with macrophage composition (CD68+CD163+ cells) at the tumor-stromal interface, were predictive of response. Treatment pressures dynamically altered the tumor microenvironment composition and activated peripheral immune cells. This study is the first to identify spatial predictors of response to this promising novel treatment approach for MSS CRC.

  Study EGAS50000001567

• Chromosomal instability shapes the tumor microenvironment of oesophageal adenocarcinoma via a cGAS–chemokine–myeloid axis

  This study employed whole-genome sequencing (WGS) to investigate genomic alterations in oesophagogastric adenocarcinoma, with a focus on mechanisms of chromosomal instability. Twelve tumour samples were analysed, including specimens obtained prior to neoadjuvant chemotherapy and at surgical resection. WGS was used to identify structural variants, quantify tumour mutational burden, and detect potential driver mutations across samples. The study aimed to correlate genomic measures of chromosomal instability with clinicopathological features to improve understanding of tumour biology.

  Study EGAS50000001561

• Massive Genomic Rearrangment Acquired in a Single Catastrophic Event During Cancer Development

  Cancer is driven by mutation. Using Agilent exome hybridisation capture and Illumina GA massively parallel sequencing technology, we aim to sequence ~1600 microRNAs plus the protein coding genome of 25 matched human renal cancer samples. Bespoke algorithms are being developed to identify the somatically acquired point mutations, insertions and deletions in these samples. This project will give unprecedented insights into mutational processes, cellular repair pathways and gene networks associated with renal cancer development.Agilent whole exome hybridisation capture will be performed on genomic DNA derived from 25 renal cancers and matched normal DNA from the same patients. Three lanes of Illumina GA sequencing will be performed on the resulting 50 exome libraries and mapped to build 37 of the human reference genome to facilitate the identification of novel cancer genes.

  Study EGAS00000000029

• A small cell lung cancer genome reports complex tobacco exposure signatures

  Cancer is driven by mutation. Worldwide, tobacco smoking is the major lifestyle exposure that causes cancer, exerting carcinogenicity through 60 chemicals that bind and mutate DNA. Using massively parallel sequencing technology, we sequenced a small cell lung cancer cell line, NCI-H209, to explore the mutational burden associated with tobacco smoking. 22,910 somatic substitutions were identified, including 132 in coding exons. Multiple mutation signatures testify to the cocktail of carcinogens in tobacco smoke and their proclivities for particular bases and surrounding sequence context. Effects of transcription-coupled repair and a second, more general expression-linked repair pathway were evident. We identified a tandem duplication that duplicates exons 3-8 of CHD7 in-frame, and another two lines carrying PVT1-CHD7 fusion genes, suggesting that CHD7 may be recurrently rearranged in this disease. These findings illustrate the potential for next-generation sequencing to provide unprecedented insights into mutational processes, cellular repair pathways and gene networks associated with cancer.

  Study EGAS00000000051

• Various_Cancer_Fusion_Gene_Sequencing

  Genomic libraries (500 bps) will be generated from total genomic DNA derived from 50 commomon epithelial cancer samples and subjected to total of eight lanes of 37 bp, paired end sequencing on the llumina GA. Paired reads will be mapped to build 37 of the human reference genome to facilitate the generation of genome wide copy number information, and the identification of novel rearranged cancer genes and gene fusions.

  Study EGAS00001000012

• The patterns and dynamics of genomic instability in metastatic pancreatic cancer

  Pancreatic cancer is an aggressive malignancy with a five-year mortality of 97–98%, usually due to widespread metastatic disease. Previous studies indicate that this disease has a complex genomic landscape, with frequent copy number changes and point mutations, but genomic rearrangements have not been characterized in detail. Despite the clinical importance of metastasis, there remain fundamental questions about the clonal structures of metastatic tumours, including phylogenetic relationships among metastases, the scale of ongoing parallel evolution in metastatic and primary sites, and how the tumour disseminates. Here we harness advances in DNA sequencing to annotate genomic rearrangements in 13 patients with pancreatic cancer and explore clonal relationships among metastases. We find that pancreatic cancer acquires rearrangements indicative of telomere dysfunction and abnormal cell-cycle control, namely dysregulated G1-to-S-phase transition with intact G2–M checkpoint. These initiate amplification of cancer genes and occur predominantly in early cancer development rather than the later stages of the disease. Genomic instability frequently persists after cancer dissemination, resulting in ongoing, parallel and even convergent evolution among different metastases. We find evidence that there is genetic heterogeneity among metastasis-initiating cells, that seeding metastasis may require driver mutations beyond those required for primary tumours, and that phylogenetic trees across metastases show organ-specific branches. These data attest to the richness of genetic variation in cancer, brought about by the tandem forces of genomic instability and evolutionary selection.

  Study EGAS00000000064

• CLL_Cancer_Whole_Genome_Sequencing

  Genomic libraries (500 bps) will be generated from total genomic DNA derived from a range of cancer samples and subjected paired end sequencing on the llumina GA. Paired reads will be mapped to build 37 of the human reference genome to facilitate the generation of genome wide copy number information, and the identification of novel rearranged cancer genes and gene fusions.

  Study EGAS00001000014

• TMD_AMLK_Exome_Study

  Agilent whole exome hybridisation capture will be performed on genomic DNA derived from 20 Primary Acute Megakaryocytic Leukemia samples and matched normal DNA from the same patients. Three lanes of Illumina GA sequencing will be performed on the resulting 100 exome libraries and mapped to build 37 of the human reference genome to facilitate the identification of novel cancer genes

  Study EGAS00001000027

• Recurrent somatic DICER1 mutations in non-epithelial ovarian tumors

  Background: Germline truncating mutations in DICER1, an RNase III-type endoribonuclease essential for processing of microRNAs, are seen in families with the pleuropulmonary blastoma-family tumor and dysplasia syndrome; these individuals have a propensity to develop non-epithelial ovarian tumors (i.e. sex-cord stromal and germ cell tumors). Methods: We sequenced the whole transcriptomes or exomes of 14 non-epithelial ovarian tumors and noted closely clustered mutations in the RNase IIIb domain of DICER1 in four cases. Using Sanger sequencing, we then analyzed additional ovarian tumors for mutations in this region. The impact of the mutations on the enzymatic activity of Dicer1 was determined using in vitro RNA cleavage assays. Results: RNase IIIb domain DICER1 mutations were found in 30/102 non-epithelial ovarian tumors (29%), predominantly Sertoli-Leydig cell tumors (26/43, 60%), including 4/4 from individuals with germline DICER1 mutations. The mutations were restricted to metal binding sites within the RNase IIIb catalytic centres critical for miRNA interaction and cleavage, and were somatic in all 14 cases where germline DNA was available for testing. Of 266 epithelial ovarian and endometrial cancers tested, one case, an ovarian carcinosarcoma, had a hotspot mutation. In vitro, the mutant DICER proteins showed reduced RNase IIIb activity but retained RNase IIIa activity. Conclusions: Somatic missense mutations of the RNase IIIb domain of DICER1 are common in non-epithelial ovarian tumors. Genetic, pathologic, and functional evidence suggest that these mutations do not obliterate DICER1 function, rather, they alter it in specific cell types, a novel mechanism through which perturbed microRNA expression is oncogenic.

  Study EGAS00001000135

• μSeq: Universal mutation rate quantification via deep sequencing of a single clonal expansion

  We use patient-derived colorectal cancer organoids to introduce µSeq, a universal framework for inferring mutation rates in diverse biological systems. Our approach extracts mutation rates from deep sequencing of single clonal expansions, with a time gain of tenfold or more compared to a mutation-accumulation line, at the cost of three billion read whole-genome sequencing.

  Study EGAS50000001761