12214 results for "cancer rna-seq"

in 26.02 milliseconds.

• Melanoma PEACE Dataset

  Dataset for the initial melanoma PEACE paper in Cancer Discovery, March 2023.

  Dataset EGAD00001010877

• NEOPREDICT-Lung: longitudinal whole exome sequencing of non-small cell lung cancers under immunotherapy

  In 43 patients pretreatment tumor biopsies, resected tumors and normal tissue of sufficient quality and quantity were obtained to longitudinally explore the mutational profiles of a comprehensive set of cancer-related genes. For tumor samples, one to four FFPE sections (10 µm thickness, number depending on sample size) were lysed for genomic DNA isolation. Isolation was performed semi-automatically on the Maxwell purification system (Maxwell RSC DNA FFPE Kit, AS1450, Promega) as specified by the manufacturer. DNA was eluted in 50 µl RNase-free water and quantified fluorescently for library preparation using a Qubit 2.0 fluorometer (Life Technology) with its appertaining DNA broad-range assay. Corresponding normal DNA was isolated from blood or PBMCs using routinely available QIAGEN technology. DNA was stored at -20°C before use. Whole-exome sequencing (WES) was performed using the Twist Human Core + RefSeq + Mitochondrial Panel (Twist Bioscience), and 2 x 100 bp fragment sizes were sequenced using a NovaSeq6000 (Illumina). Demultiplexing of sequenced reads was achieved using bcl2fastq (version 2.2).

  Dataset EGAD00001015362

• Type I Interferon Exacerbates Mycobacterium Tuberculosis Induced Human Macrophage Death

  In this study, we tested whether type I interferons (IFN-I), namely IFN-alpha and IFN-beta, may promote Mycobacterium tuberculosis (Mtb) pathogenesis by exacerbating cell death of human monocyte-derived macrophages (MDM) infected with Mtb. We differentiated the MDM under two different published methods (see Document Method.pdf for Table 1 of Methods). To determine if MDM infected with Mtb upregulates IFN-I transcripts, signaling factors, or IFN-I stimulated genes (ISGs), the MDM were infected with Mtb or treated with an activator of stimulator of IFN genes (STING), diamidobenzimidazole (di-ABZI). STING activation acted as a positive control for IFN-I induction and ISG upregulation. Indeed, di-ABZI treated MDM differentiated under both methods upregulated ISGs 24 hpi. At 24 hour post treatment, MDM differentiated under one method, but not under another method, upregulated ISGs, such as ISG15, IFITM3, and CXCL10, upon Mtb infection. MDM differentiated under both methods upregulated ISGs upon di-ABZI treatment.

  Study phs003607

• Understanding human fetal pancreas development using subpopulation sorting and RNA sequencing

  To decipher the populations of cells present in the human fetal pancreas and their lineage relationships, we developed strategies to isolate pancreatic progenitors, endocrine progenitors and endocrine cells. Transcriptome analysis of the individual populationsrevealed a large degree of conservation among vertebrates in the drivers of gene expression changes occurring at different steps of differentiation, althoughnotably, sometimes, different members of the same gene family are expressed. The transcriptome analysis establishes a resource to identify novel genes and pathways involved in human pancreas development. Single cell profiling further captured intermediate stages ofdifferentiation and enabled us to decipher the sequence of transcriptional events occurring during human endocrine differentiation. Furthermore, we evaluate how well individual pancreatic cells derived in vitro from human pluripotent stem cells mirror the natural processoccurring in human fetuses. This comparison uncovers a few differences at the progenitor steps, a convergence at the steps of endocrine induction and the current inability to fully resolve endocrine cell subtypes in vitro.

  Study EGAS00001003127

• Clinical Outcomes by Tumor Mutational Burden and Inflammatory Gene Expression With Combined Nivolumab and Ipilimumab or Monotherapy in Advanced Melanoma_CM67-RNASeq

  Purpose Exploratory analyses of CheckMate 066 and 067 trials were conducted to investigate associations of tumor mutational burden (TMB), a 4-gene inflammatory gene expression signature, and BRAF mutation status with tumor response, progression-free survival (PFS), and overall survival (OS) in patients with advanced melanoma. Patients and Methods Patients with known programmed death ligand 1 (PD-L1) expression and BRAF mutation status received nivolumab (NIVO) or dacarbazine in CheckMate 066 and either NIVO, ipilimumab (IPI), or NIVO+IPI in CheckMate 067. Whole exome sequencing and RNA sequencing were used to determine TMB and inflammatory gene expression signature scores, respectively. These biomarkers were evaluated in terms of their association with PFS and OS. Results In the NIVO, NIVO+IPI, and IPI arms of CheckMate 067, longer survival was associated with high (> median) versus low (≤ median) TMB with hazard ratios (HRs) (95% confidence interval [CI]) for PFS of 0.45 (0.30–0.65), 0.55 (0.38–0.81), and 0.60 (0.43–0.82), and for OS of 0.46 (0.30–0.71), 0.53 (0.34–0.82), and 0.52 (0.36–0.74), respectively. For NIVO-treated patients, these results were confirmed in CheckMate 066. A survival benefit was observed with high TMB and absence of BRAF mutation. Survival was associated with high versus low inflammatory signature scores with HRs (95% CI) for PFS of 0.56 (0.34–0.94), 0.40 (0.23–0.72), and 0.43 (0.27–0.70), and for OS of 0.37 (0.20–0.66), 0.38 (0.19–0.74), and 0.46 (0.27–0.79), in the NIVO, NIVO+IPI, and IPI arms, respectively. Weak correlations were observed between PD-L1, TMB, and the inflammatory signature. Conclusions Combined assessment of TMB, inflammatory gene expression signature, and BRAF mutation status may be predictive for response to immunotherapy in advanced melanoma.

  Dataset EGAD00001006306

• Clinical Outcomes by Tumor Mutational Burden and Inflammatory Gene Expression With Combined Nivolumab and Ipilimumab or Monotherapy in Advanced Melanoma - CM066-WES

  Purpose Exploratory analyses of CheckMate 066 and 067 trials were conducted to investigate associations of tumor mutational burden (TMB), a 4-gene inflammatory gene expression signature, and BRAF mutation status with tumor response, progression-free survival (PFS), and overall survival (OS) in patients with advanced melanoma. Patients and Methods Patients with known programmed death ligand 1 (PD-L1) expression and BRAF mutation status received nivolumab (NIVO) or dacarbazine in CheckMate 066 and either NIVO, ipilimumab (IPI), or NIVO+IPI in CheckMate 067. Whole exome sequencing and RNA sequencing were used to determine TMB and inflammatory gene expression signature scores, respectively. These biomarkers were evaluated in terms of their association with PFS and OS. Results In the NIVO, NIVO+IPI, and IPI arms of CheckMate 067, longer survival was associated with high (> median) versus low (≤ median) TMB with hazard ratios (HRs) (95% confidence interval [CI]) for PFS of 0.45 (0.30–0.65), 0.55 (0.38–0.81), and 0.60 (0.43–0.82), and for OS of 0.46 (0.30–0.71), 0.53 (0.34–0.82), and 0.52 (0.36–0.74), respectively. For NIVO-treated patients, these results were confirmed in CheckMate 066. A survival benefit was observed with high TMB and absence of BRAF mutation. Survival was associated with high versus low inflammatory signature scores with HRs (95% CI) for PFS of 0.56 (0.34–0.94), 0.40 (0.23–0.72), and 0.43 (0.27–0.70), and for OS of 0.37 (0.20–0.66), 0.38 (0.19–0.74), and 0.46 (0.27–0.79), in the NIVO, NIVO+IPI, and IPI arms, respectively. Weak correlations were observed between PD-L1, TMB, and the inflammatory signature. Conclusions Combined assessment of TMB, inflammatory gene expression signature, and BRAF mutation status may be predictive for response to immunotherapy in advanced melanoma.

  Dataset EGAD00001006309

• Activation of Wnt/β-catenin signalling by mutually exclusive FBXW11 and CTNNB1 hotspot mutations drives salivary gland basal cell adenoma - RNA

  Wnt signalling must be 'just right' to promote tumour growth. Basal cell adenoma (BCA) and basal cell adenocarcinoma (BCAC) of the salivary gland are rare tumours that can be difficult to distinguish from each other and other salivary gland tumour subtypes. Due to their rarity, the genomic profiles of BCA and BCAC have not been explored. Using whole-exome and transcriptome sequencing of BCA and BCAC cohorts, we identify a novel recurrent FBXW11 missense mutation (p.F517S) in BCA, that was mutually exclusive with the previously reported CTNNB1 p.I35T gain-of-functon (GoF) mutation. These driver events collectively accounted for 94% of BCAs. In vitro, mutant FBXW11 had a dominant negative affect, characterised by defective binding to β-catenin and the accumulation of β-catenin in cells. This was consistent with the nuclear expression of β-catenin observed in BCA cases harbouring the FBXW11 p.F517S mutation and activation of the Wnt/β-catenin pathway and defines a novel mechanism of Wnt pathway control. The genomic profiles of BCAC were distinct from BCA, with hotspot DICER1 and HRAS mutations and putative driver mutations affecting PI3K/AKT and NF-κB signalling pathway genes. A single BCAC, which may represent a malignant transformation of BCA, harboured the recurrent FBXW11 mutation. These findings have important implications for the diagnosis and treatment of BCA and BCAC, which, despite histopathologic overlap, may be unrelated entities.

  Dataset EGAD00001015366

• NHGRI GREGoR Consortium: Genomics Research to Elucidate the Genetics of Rare Disease

  The NHGRI GREGoR (Genomics Research to Elucidate the Genetics of Rare Disease) Consortium was established in June 2021 with the goal of developing novel tools and approaches to advance the discovery of the genetic basis of rare conditions. Numerous types of molecular data are generated in GREGoR and available on the AnVIL cloud platform via dbGaP application, including short- and long-read genome and exome sequencing, transcriptomics, metabolomics, methylomics, and proteomics. De-identified clinical and demographic data is obtained, with a focus on standardized ontologies.Visit the GREGoR Consortium data webpage for summary information about the GREGoR Dataset, including numbers of participants and data types, methods documentation, and Release Notes. The Consortium comprises five Research Centers (RCs - see below), a Data Coordinating Center (DCC), and various partner members and external collaborators.Baylor College of Medicine Research Center (BCM-GREGoR) The Baylor College of Medicine GREGoR program, which is part of the GREGoR consortium, enrolls individuals, families, and cohorts with suspected rare disease across a range of syndromic and non-syndromic phenotypes. Subjects are enrolled from national and international collaborating physician referrals. Subjects provide written informed consent for future re-contact. Data generated and shared include family structure, detailed phenotypes, exome or short-read genome data, and in some cases long-read genome or RNA-sequencing, and these are shared upon completion of standard quality control checks and annotation. Broad Institute (Broad) The Broad Center for Mendelian Genomics, part of the GREGoR consortium uses next-generation sequencing (exome, genome, transcriptome, and long read sequencing), computational approaches, and functional studies to discover the variants and genes that underlie Mendelian conditions with a particularly focus on neuromuscular, neurodevelopmental, and syndromic phenotypes. Samples come from collaborators and direct enrollment through the Rare Genomes Project and we are committed to rapid data sharing without an embargo period. University of California, Irvine (UCI-GREGoR) To accelerate the pace of Mendelian disease gene discovery and clinical implementation, we propose a Mendelian Genomics Research Center, part of the GREGoR Consortium, leveraging the broad pediatric and adult clinical and research expertise at Children's National Hospital and University of California, Irvine. Our goal is to develop best practices to increase the diagnostic yield of rare diseases, engage the community to reduce health disparities for complex diagnoses, while creating a dataset accessible to all. Our Center will unite world class experts combining basic and translational research with innovative approaches to phenotyping, variant identification and functional investigation of both coding and non-coding sequence changes with the goals of discovering novel Mendelian gene variations and identifying variants not detected on current sequencing pipelines, disambiguating uncertain variants into disease-causing versus benign categorizations, and sharing information by working collaboratively with the GREGoR community.GREGoR Stanford Site (GSS) The goal of the GREGoR Stanford Site (GSS) is to provide a platform for functional genomics research and validation to improve diagnosis in Mendelian disease. Participants included individuals with undiagnosed suspected Mendelian disease who had non-diagnostic exome sequencing and their immediate family members. Participants and their family members provided written, informed consent and biological samples from which DNA, RNA, plasma, fibroblasts, PBMCs and other cell types were generated and stored. Samples from research participants and their immediate family members may have undergone short and long-read genome sequencing, transcriptome sequencing, metabolomics and/or lipidomics profiling, methyl-capture-sequencing and ATAC-sequencing. De-identified clinical data extracted from participant medical records are linked to the samples. University of Washington Center for Rare Disease Research (UW-CRDR) The goals of the University of Washington Center for Rare Disease Research are to: (1) maximize novel gene discovery for Mendelian conditions by recruitment, short- and long-read whole genome sequencing, transcriptome sequencing and analysis of families with rare conditions for which the gene is either unknown or the gene is known but no pathogenic variant can be identified via clinical testing; (2) develop new strategies for gene discovery for Mendelian conditions caused by variants that are difficult to detect using conventional testing strategies, variants of unknown function effect (e.g., regulatory, structural variants) or have unusual modes of inheritance; and (3) implement high-throughput screening and targeted follow-up functional studies to prioritize and validate candidate non-coding variants. De-identified data and phenotypic information are shared via MyGene2, ClinVar, and AnVIL.

  Study phs003047

• (Epi)genetic Risk Architectures of Opioid-Dependent Brain

  With nearly 20,000 overdose deaths in 2014 alone, opioid addiction (OA) has emerged as one of the most pressing public health crises in recent US history. One-fifth of individuals who try heroin develop an addiction to opioids. Genetics is a major contributor to OA with an estimated 60% heritability, only somewhat less than schizophrenia (80%) which has recently seen substantial gains in identified underlying genetics. Yet, studies to date have failed to uncover most of the genes that predispose individuals to OA, leaving the overwhelming fraction of OA heritability unexplained. The proposed study takes a novel, integrated "omics-based" strategy to investigate the molecular basis of OA and uncover both genetic and epigenetic factors associated with opioid addiction. The premise for our approach is founded on studies from our labs, and others, implicating regulatory variation in common traits and diseases, including those associated with complex brain phenotypes like addiction. We have collected the largest known cohort of postmortem brains from addicts who overdosed on opioids, along with matched control brains from non-users. From both cases and control specimens, we will isolate cells from 2 regions of the brain closely implicated in the addiction phenotype: the Prefrontal Cortex (PFC) and the Nucleus Accumbens (NAc). In Aim 1, we propose ChIP-seq studies to identify regulatory elements that distinguish cases from controls and define the opioid addiction phenotype. The regulatory differences will be connected to their gene targets through high resolution in situ Hi-C. In Aim 2, we propose QTL-based approaches to identify genetic variants that underlie the regulatory differences (hmQTLs). We also propose eQTL analyses to identify genetic variants that underlie differences in transcript levels between cases and controls. Aim 3 leverages the largest heroin addiction GWAS meta-analysis to date to test the hypothesis that SNPs in regions associated with chromatin and expression differences between cases and controls define novel loci for predisposition to OA. Each Aim has the potential for discovery independent of the others (differential HM, RNAexp, QTLs, and variant-phenotype associations) but their synergy is the most powerful component of the proposed study: identifying regulatory pathways that generate, not only phenotype associations, but hypothesized mechanisms for those associations which can be the focus of new opioid addiction prevention and treatment development.

  Study phs002724

• Genetics of Chemotherapy Induced Peripheral Neuropathy in N08C1 and N08CB

  Chemotherapy-induced peripheral neuropathy (CIPN) is a common and potentially dose-limiting toxicity of chemotherapy treatment. CIPN severity varies widely between cancer patients, and previous studies had found evidence of genes and single nucleotide variants (SNV) being associated with CIPN. The goal of this study was to further identify genetic markers and pathways associated with CIPN severity using whole exome sequencing (WES) and whole genome sequencing (WGS) of participants in two clinical studies which collected longitudinal patient-reported outcome (PRO) measures of CIPN. NCCTG/Alliance study N08C1 was a prospective cohort study of the natural history of paclitaxel-associated acute pain syndrome (P-APS) and CIPN. NCCTG/Alliance trial N08CB was a randomized, placebo-controlled trial of calcium and magnesium for prevention of oxaliplatin-induced sensory neuropathy in which the treatment had no significant effect on either acute pain or sensory neuropathy. Both N08C1 and N08CB collected patient assessments of CIPN symptoms before each cycle of chemotherapy using the EORTC QLQ-CIPN20 instrument. For this study, CIPN cases were selected from each of N08C1 and N08CB as those patients with the most severe CIPN symptoms (assessed longitudinally). CIPN controls were selected as those with the least severe symptoms. WGS was obtained for N08C1 samples (WES had been obtained and analyzed previously), and WES was obtained for N08CB samples.

  Study phs001480

• North Carolina Clinical Genomic Evaluation by NextGen Exome Sequencing (NCGENES)

  North Carolina Clinical Genomic Evaluation by Next-generation Exome Sequencing This study is part of a larger consortium project investigating the validity and best use of next-generation sequencing (in particular, whole exome sequencing, or WES) in clinical care. Participants are patients who were either seen in the UNC Cancer and Adult Genetics Clinic or referred to the study by their physician. They will be approached by their physician or a genetic counselor for recruitment. Once enrolled, a clinical geneticist or genetic counselor will obtain consent and collect blood samples to be analyzed using WES. Results may include information related to a diagnosis and incidental information. Medically actionable incidental findings will be CLIA-certified and returned to participants in a routine genetic counseling session, along with diagnostic findings. Eligible adult participants will be randomized to have the opportunity to choose to get certain types of non-medically actionable incidental findings, as well. Their decisions will be investigated, as will psychosocial and behavioral responses to sequencing and receiving sequencing information. This is a longitudinal, mixed methods study (i.e., multiple assessments pre- and post-return of results, with both quantitative and qualitative methods used to gather data). Because only the quantitative component of the study uses randomization, only measures and procedures associated with that component are included here. The third study release includes data of additional n=189 subjects.

  Study phs000827

• Drug screening of patient-derived organoids from colorectal peritoneal metastases

  Colorectal cancer (CRC) patients with peritoneal metastases (CRPM) have limited treatment options and the lowest CRC survival rates. We trialed the possibility of organoid directed precision treatment for CRPM patients. CRPM organoids (peritonoids) isolated from patients underwent next-generation sequencing and medium-throughput drug panel testing ex vivo to identify specific drug sensitivities for each patient. We measured the utility of such a service including: success of peritonoid generation, time to cultivate peritonoids, reproducibility of the medium-throughput drug testing, and documented changes to clinical therapy as a result of the testing. Peritonoids were successfully generated and validated from 68% (19/28) of patients undergoing standard care. Genomic and drug profiling was completed within 8 weeks and a formal report ranking drug sensitivities was provided to the medical oncology team upon failure of standard care treatment. This resulted in a treatment change for 2 patients, one of whom had a partial response despite previously progressing on multiple rounds of standard care chemotherapy. The barrier to implementing this technology in Australia is the need for drug access and funding for off-label indications. In conclusion, our approach is feasible, reproducible and can guide novel therapeutic choices in this poor prognosis cohort, where new treatment options are urgently needed. This platform is relevant to many solid organ malignancies.

  Study phs002023

• Transformation of Dysplasia in Barrett's Esophagus

  Complex chromosomal alterations are a hallmark of advanced cancers but rarely seen in normal tissue. The progression of precancerous lesions to malignancy is often accompanied by increasing complexity of chromosomal alterations that can drive their transformation through focal oncogenic amplifications. However, the etiology and evolution dynamics of these alterations are poorly understood. Here we study chromosomal copy-number evolution in the progression of Barrett's esophagus (BE) to esophageal adenocarcinoma (EAC) by multi-regional whole-genome sequencing analysis of BE samples with dysplasia and microscopic EAC foci. Through haplotype-specific copy-number analysis of BE genome evolution, we identified distinct patterns of episodic copy-number evolution consistent with the outcomes of abnormal mitosis and dicentric chromosome breakage. While abnormal mitosis, including whole-genome duplication, accounts for most chromosome or arm-level copy-number changes, segmental copy-number alterations display signatures of multi-generational evolution of unstable dicentric chromosomes. Continuous evolution of dicentric chromosomes through breakage-fusion-bridge cycles and chromothripsis rapidly increases genomic complexity and diversity among BE cells, culminating in the generation of distinct focal amplifications. These mutational processes enable multiple subclones within small dysplastic areas to undergo parallel transformation to cancer following acquisition of distinct oncogenic amplifications. Our results demonstrate how chromosomal instability drives clonal diversification in precancer evolution and promotes tumorigenesis in primary human samples.

  Study phs002706

• Germline Genetics of Myelodysplastic Syndromes (MDS) and Acute Myeloid Leukemia (AML)

  Myelodysplastic syndromes (MDS) are part of a heterogeneous and overlapping group of clonal diseases that arise in the hematopoietic stem or progenitor cells and also include acute myeloid leukemia (AML), myeloproliferative neoplasms (MPN), and the hybrid MDS/MPN entities. Individuals with MDS have a high risk of progressing to leukemia, with approximately 30% expected to develop AML. This study evaluates genetic susceptibility to myeloid malignancy using data from population-based case control studies of myelodysplastic syndromes and acute myeloid leukemia in adults (ages 18-85 years) and pediatric MDS cases with banked samples at the Center for International Blood and Marrow Transplant Research (CIBMTR). Adult cases were identified through the Minnesota Cancer Reporting System and controls were recruited from the State Driver's License/Identification Card list. DNA samples were collected via mouthwash collection kits (AML cases and controls) or Oragene saliva collection kits (adult MDS cases and controls). Pediatric MDS samples were banked at CIBMTR prior to receipt of a transplant and DNA was extracted from isolated T cells or whole blood samples. Genotyping data were generated using the Illumina Global Diversity array and quality control and genotype calling was conducted using established best practices. Our primary analyses investigated the contribution of genetic variation to MDS risk and evaluated the role of the killer cell immunoglobulin receptors (KIR) on incidence and survival.

  Study phs002962

• Rituximab-treated lymphoma patients show correlated deficiency in serological and T cell Spike-specific response after SARS-CoV-2 vaccination: insights from the CORSA Study.

  This study is part of the CORSA trial (NCT04345315), a prospective multicentric research project conducted by the Istituto Romagnolo per lo Studio dei Tumori “Dino Amadori” to investigate the immunologic response to mRNA SARS-CoV-2 vaccines in patients with hematologic malignancies (HM) and healthy individuals as controls (HC). The data in this repository refer to two subcohorts: 7 healthy controls and 10 lymphoma patients, randomly selected. Whole blood samples were collected to characterize T cell receptor (TCR) repertoire specificity against SARS-CoV-2 proteins before and after two BNT162b2 vaccination cycles, at baseline (before vaccination), 50 days after the first dose (V1), and 6 months after the first dose (V3). All participants were vaccinated under the Italian national campaign and provided informed consent following the Declaration of Helsinki. We investigated SARS-CoV-2-specific T cell responses through TCR repertoire profiling and examined correlations between serological and cellular responses in both patient and control groups. Using Next-Generation Sequencing (NGS) to characterize the CDR3 sequences of TCR β-chains from peripheral blood, we assessed clonal expansion (depth) and diversification (breadth) of SARS-CoV-2-specific T cell clonotypes over time, aiming to understand how cancer and its treatment influence vaccine-induced immunity in immunocompromised individuals.

  Study EGAS50000001205

• Genomic characterization of retinoblastoma (targeted sequencing)

  Retinoblastoma is the most frequent intraocular malignancy in children, originating from a maturing cone precursor in the developing retina. Little is known on the molecular basis underlying the biological and clinical behavior of this cancer. Here, using multi-omics data, we demonstrate the existence of two retinoblastoma subtypes. Subtype 1, of earlier onset, includes most of the heritable forms. It harbors few genetic alterations other than the initiating RB1 inactivation and corresponds to differentiated tumors expressing mature cone markers. By contrast, subtype 2 tumors harbor frequent recurrent genetic alterations including MYCN-amplification. They express markers of less differentiated cone together with neuronal/ganglion cell markers with marked inter- and intra-tumor heterogeneity. The cone dedifferentiation in subtype 2 is associated with stemness features including low immune and interferon response, E2F and MYC/MYCN activation and a higher propensity for metastasis. The recognition of these two subtypes, one maintaining a cone-differentiated state, and the other, more aggressive, associated with cone dedifferentiation and expression of neuronal markers, opens up important biological and clinical perspectives for retinoblastomas. In this study, we performed targeted sequencing of the exonic regions of RB1, BCOR and ARID1A on 37 samples from the series of 102 retinoblastomas. Among them, 23 samples were not subjected to whole-exome sequencing, and 14 samples have the whole-exome sequencing data (deposited in EGAS00001005248).

  Study EGAS00001005550

• Transposable Elements Shape Stemness in Normal and Leukemic Hematopoiesis

  Despite most acute myeloid leukemia (AML) patients achieving complete remission after induction chemotherapy, two-thirds will relapse with fatal disease within five years. AML is organized as a cellular hierarchy sustained by leukemia stem cells (LSC) at the apex, with LSC properties directly linked to tumor progression, therapy failure, and disease relapse 1–5. Despite the central role of LSC in poor patient outcomes, little is known about the genetic determinants driving their stemness properties. As LSCs share many functional and molecular properties with normal hematopoietic stem cells (HSC) 6, we investigated accessible chromatin unique across normal hematopoietic and cancer cell states and identified transposable elements (TEs) as genetic determinants of both primitive populations in comparison with their downstream mature progeny. A clinically-relevant TE chromatin accessibility-based LSCTE121 signature was developed that enabled patient classification based on survival outcomes. Through functional assays, primitive cell specific-TE subfamilies were found to serve as docking sites for stem cell-associated regulators of genome topology or lineage-specific transcription factors, including LYL1 in LSCs. Finally, using chromatin editing tools, we establish that chromatin accessibility at LTR12C elements in LSCs are necessary to maintain stemness properties. Our work identifies TEs as genetic drivers of primitive versus mature cell states, where distinct TE subfamilies account for stemness properties in normal versus leukemic hematopoietic stem cells.

  Study EGAS50000001141

• Transposable Elements Shape Stemness in Normal and Leukemic Hematopoiesis

  Despite most acute myeloid leukemia (AML) patients achieving complete remission after induction chemotherapy, two-thirds will relapse with fatal disease within five years. AML is organized as a cellular hierarchy sustained by leukemia stem cells (LSC) at the apex, with LSC properties directly linked to tumor progression, therapy failure, and disease relapse 1–5. Despite the central role of LSC in poor patient outcomes, little is known about the genetic determinants driving their stemness properties. As LSCs share many functional and molecular properties with normal hematopoietic stem cells (HSC) 6, we investigated accessible chromatin unique across normal hematopoietic and cancer cell states and identified transposable elements (TEs) as genetic determinants of both primitive populations in comparison with their downstream mature progeny. A clinically-relevant TE chromatin accessibility-based LSCTE121 signature was developed that enabled patient classification based on survival outcomes. Through functional assays, primitive cell specific-TE subfamilies were found to serve as docking sites for stem cell-associated regulators of genome topology or lineage-specific transcription factors, including LYL1 in LSCs. Finally, using chromatin editing tools, we establish that chromatin accessibility at LTR12C elements in LSCs are necessary to maintain stemness properties. Our work identifies TEs as genetic drivers of primitive versus mature cell states, where distinct TE subfamilies account for stemness properties in normal versus leukemic hematopoietic stem cells.

  Study EGAS50000001147

• Enrichment of oral-derived bacteria in inflamed colorectal tumors and distinct associations of Fusobacterium in the mesenchymal subtype

  The association between colorectal cancer (CRC) clinical variables and Fusobacterium, but not other intra-tumoral bacteria, has been extensively studied. Here we leveraged whole-transcriptome sequencing from 807 CRC tumor samples from the AVANT phase III trial to dually characterize tumor gene expression and intra-tumoral bacteria. After stringent filtering, 74 high-confidence taxa were identified. 17 of these species, including 4 Fusobacterium spp., were classified as orally-derived and had a robust signal within right-sided, MSI-H, and BRAF mutant tumors. Across consensus molecular subtypes (CMS), integration of Fusobacterium animalis presence and tumor gene expression revealed that F. animalis had the greatest number of associations in mesenchymal CMS4 tumors, despite an overall lower prevalence than in immune CMS1 tumors. Pathway analysis within CMS4 revealed that F. animalis, but not other highly prevalent species, was uniquely associated with pathways for collagen degradation and formation as well as IL-6 and IL-1 cytokine signaling. These associations could explain in part why Fusobacterium has been previously associated with reduced survival in mesenchymal populations. Overall, this study identified oral-derived bacteria, including Fusobacterium, as broadly more prevalent in inflamed CRC tumors compared to the other subtypes, and the association of intra-tumoral bacteria on tumor gene expression is context- and species-specific.

  Study EGAS00001006757

• Analysis_of_genomic_integrity_of_disease_corrected_human_induced_pluripotent_stem_cells_by_exome_sequencing

  Induced pluripotent stem (iPS) cells hold great promise for autologous cell transplantation. In order to apply this therapy to monogenic disorder, disease-causing mutations must be corrected prior to transplantation. We generated iPS cells from patients with alpha-1 antitrypsin deficiency, which is caused by homozygous non-synonymous mutation in the SERPINA1 gene. In vitro differentiation of patient-derived iPS cells to hepatocytes showed recapitulation of the disease phenotype. We corrected the mutations by gene targeting using zinc finger nuclease (ZFN) and piggyBac transposon technologies. Our mutation correction is highly accurate. There is no exogenous sequence left behind at the targeted site. The corrected iPS cell-derived hepatocytes were indistinguishable from healthy hepatocyte, suggesting that the corrected gene was fully functional. The genomic integrity was also analyzed by CGH and SNP array, showing no genomic alterations. These are important points to ensure clinical safety as well as functional restoration of the corrected gene. One remaining question is if these corrected iPS cells are clinically safe at the single base-pair level. Recent publications suggested that cancer-related mutations are significantly accumulated during iPS cell propagation. We aim to assess the clinical safety of the corrected iPS cells by using exome sequencing. Outcome from this project would bring iPS cell technology one step closer to clinical applications.

  Study EGAS00001000055

• Comparison of 133/144bp dominant phenotype vs 166bp dominant phenotype.

  Background: Previous studies found that cell-free DNA (cfDNA) generated from tumors was shorter than that from healthy cells, and selecting short cfDNA could enrich for tumor cfDNA and improve its usage in early cancer diagnosis and treatment monitoring; however, the underlying mechanism of shortened tumor cfDNA was still unknown, which potentially limits its further clinical application.Results: Using targeted sequencing of cfDNA in a large cohort of solid tumor patient, sequencing reads harboring tumor-specific somatic mutations were isolated to examine the exact size distribution of tumor cfDNA. For the majority of studied cases, 166bp remained as the peak size of tumor cfDNA, with tumor cfDNA showing an increased proportion of short fragments (100-150bp). Less than 1% of cfDNA samples were found to be peaked at 134/144bp and independent of tumor cfDNA purity. Using whole-genome sequencing of cfDNA, we discovered a positive correlation between cfDNA shortening and the magnitude of chromatin inaccessibility, as measured by transcription, DNase I hypersensitivity, and histone modifications. Tumor cfDNA shortening occurred simultaneously at both 5’ and 3’ ends of the DNA wrapped around nucleosomes. Conclusions: Tumor cfDNA shortening exhibited two distinctive modes. Tumor cfDNA purity and chromatin inaccessibility were contributing factors but insufficient to trigger a global transition from 166bp dominant to 134/144bp dominant phenotype.

  Study EGAS00001004135

• Genomic analysis reveals novel secondary drivers and progression pathways in skin basal cell carcinoma

  Basal cell carcinoma of the skin (BCC) is the most common malignant neoplasm in humans. BCC is primarily driven by the aberrant activation of the Sonic Hedgehog (Hh) pathway. However, its extensive phenotypical variation remains to be explained. The genetic profiling of 293 BCCs revealed the highest mutation rate observed in cancer (65 Mutations/Mb), with strong prevalence of UV-light signature mutations. 85% of BCCs harbored mutations in Hh pathway genes: mutually exclusive PTCH1 (73%) and SMO (20%) (P=6.6x10-8), SUFU (8%), and in TP53 (61%). 85% of BCCs also harbored secondary driver mutations in other genes implicated in BCC tumorigenesis. Recurrent secondary driver mutations were observed in MYCN (30%), PPP6C (15%), STK19 (10%), LATS1 (8%), ERBB2 (4%), PIK3CA (2%), RAC1 (1%) and N/K/H-RAS (2%). Loss of function (LoF) and deleterious missense mutations were observed in PTPN14 (23%), RB1 (8%) and FBXW7 (5%). In line with the mutational profiles detected by RNAseq, we observed activation of the Hh pathway as well as upregulation of target genes of the Hippo-YAP pathway and activation of MYCN target genes. The functional analysis of the novel tumorigenic driver mutations in MYCN, PTPN14 and LATS1 demonstrates their relevance in BCC tumorigenesis and provides an expanded molecular understanding of BCC.

  Study EGAS00001001540

• Whole-Genome and Epigenomic Landscapes of Etiologically Distinct Subtypes of Cholangiocarcinoma

  Cholangiocarcinoma (CCA) is a hepatobiliary malignancy exhibiting high incidence in countries with endemic liver-fluke infection. We analyzed 489 CCAs from 10 countries, combining whole-genome (71 cases), targeted/exome, copy-number, gene expression, and DNA methylation information. Integrative clustering defined 4 CCA clusters-fluke-positive CCAs (clusters 1/2) are enriched in ERBB2 amplifications and TP53 mutations; conversely, fluke-negative CCAs (clusters 3/4) exhibit high copy-number alterations and PD-1/PD-L2 expression, or epigenetic mutations (IDH1/2, BAP1) and FGFR/PRKA-related gene rearrangements. Whole-genome analysis highlighted FGFR2 3' untranslated region deletion as a mechanism of FGFR2 upregulation. Integration of noncoding promoter mutations with protein-DNA binding profiles demonstrates pervasive modulation of H3K27me3-associated sites in CCA. Clusters 1 and 4 exhibit distinct DNA hypermethylation patterns targeting either CpG islands or shores-mutation signature and subclonality analysis suggests that these reflect different mutational pathways. Our results exemplify how genetics, epigenetics, and environmental carcinogens can interplay across different geographies to generate distinct molecular subtypes of cancer.SIGNIFICANCE: Integrated whole-genome and epigenomic analysis of CCA on an international scale identifies new CCA driver genes, noncoding promoter mutations, and structural variants. CCA molecular landscapes differ radically by etiology, underscoring how distinct cancer subtypes in the same organ may arise through different extrinsic and intrinsic carcinogenic processes.

  Study EGAS00001001653

• Molecular analysis of post-colonoscopy CRC (PCCRC)

  Background: Post-colonoscopy colorectal cancers (PCCRCs, i.e. CRC diagnosed after a colonoscopy that excluded cancer) pose a challenge in clinical practice. In a retrospective cohort study, we compared clinical and molecular features of PCCRCs and prevalent CRCs. Methods: PCCRCs were defined according to the WEO classification, as cancers occurring within 10 years after a complete index colonoscopy, which excluded CRC. Whole genome chromosomal copy number changes and mutation status of genes commonly affected in CRC (APC, KRAS, BRAF, FBXW7, PIK3CA, NRAS, SMAD4 and TP53) were examined by low-coverage WGS and targeted sequencing, respectively. MSI and CIMP status were also determined. Results: In total, 122 PCCRCs and 98 prevalent CRCs were examined. PCCRCs are more often located proximally in the colon (p<0.001), non-polypoid appearing (p=0.004), early stage (p=0.009), and poorly differentiated (p=0.006) compared to prevalent CRCs. PCCRCs contain less frequently 18q deletions (p<0.001) than prevalent CRCs. MSI (p=0.029) and CIMP (p=0.014) are more frequently observed in PCCRCs. Conclusion: Although no PCCRC specific pathway could be defined, PCCRCs’ molecular features are more associated with MSI and hypermethylation pathways than canonical CIN pathway. The clinical and molecular features observed in PCCRCs support the hypothesis that sessile serrated lesions and non-polypoid CRNs are contributors to the development of these cancers."

  Study EGAS00001004686

• Structural variant analysis of homologous recombination-deficient genomes

  Homologous recombination (HR) deficiency causes DNA breaks and cytogenetic aberrations. Paradoxically, the types of DNA rearrangements specifically associated with HR-deficient cancers only minimally impact chromosomal structure. Addressing this, we combined a genome graph analysis of short-read whole genome sequencing (WGS) profiles across thousands of tumors with deep linked-read (LR) WGS of 46 BRCA1 or BRCA2 mutant breast cancers to discover a distinct class of HR deficiency-enriched rearrangements called reciprocal pairs. LR WGS showed that reciprocal pairs with identical rearrangement orientations gave rise to one of two distinct chromosomal outcomes, distinguishable only with long molecule data. While one (cis) outcome corresponded to the copy and pasting of a small segment to a distant site, a second (trans) outcome was a quasi-balanced translocation or multi-megabase inversion with substantial (10kb) duplications at each junction. The full spectrum of reciprocal pair outcomes could be explained by an HR-independent replication restart repair mechanism. LR WGS additionally identified single-strand annealing (SSA) as a BRCA2-deficiency specific repair pathway in human cancers. Replication restart- and SSA-associated SVs improved BRCA1- vs. BRCA2- deficiency classification and identified metastatic cancer cases with favorable chemotherapy responses. Our data reveal classes of BRCA1- and BRCA2-deficiency specific rearrangements as drivers of cytogenetic aberrations in HR deficient cells.

  Study EGAS00001007186