13437 results for ""60+mice"+"6+weeks"+diet+study+2014+2017+DOI"

in 23.99 milliseconds.

• Functional single-cell characterization of immune aplastic anemia shows convergence of NK and NK-like CD8+ T cells with disease-associated TCR signature

  Immune aplastic anemia (AA) is a life-threatening bone marrow (BM) failure disorder driven by an autoimmune T cell attack against the hematopoietic stem and progenitor cells (HSPCs). However, the autoantigen targets and the role of other immune cells are unknown. Here, by analyzing an international cohort of 156 AA patients with scRNA+TCRαβ-seq, TCRβ-seq, flow cytometry, and plasma cytokine profiling with comparisons to healthy controls and patients with other hematological disorders, we identify NK cells and CD8+ TEMRA cells expressing NK receptors with AA-associated TCRβ-seq motifs as the most dysregulated immune cell populations in AA BM. Functional co-culture experiments with scRNA-TCRαβ-seq readout utilizing primary HSPCs and immune cells provide evidence that NK cellscannot kill HSPCs alone, but sensitize them to CD8+ T cell-mediated killing. Furthermore, HSPCs induce strong activation of T cell clones with CD8+ TEMRA NK-like phenotype and AA-associated TCR motifs. Our results reveal the convergent evolution of innate and adaptive immune cells in AA, where NK cells support CD8+ T cell-mediated autoimmunity.

  Study EGAS00001007604

• The demographic history and mutational load of African hunter-gatherers and farmers

  The distribution of deleterious genetic variation across human populations is a key issue in evolutionary biology and medical genetics. However, the impact of different modes of subsistence on recent changes in population size, patterns of gene flow, and deleterious mutational load remains unclear. Here, we report high-coverage exomes from various populations of rainforest hunter-gatherers and farmers from central Africa. We find that the recent demographic histories of hunter-gatherers and farmers differed considerably, with population collapses for hunter-gatherers and expansions for farmers, accompanied by increased gene flow. We show that purifying selection against newly arising deleterious alleles is of similar efficiency across African populations, in contrast with Europeans where we detect weaker purifying selection. Furthermore, the per-individual mutation load of rainforest hunter-gatherers is similar to that of farmers, under both additive and recessive models. Our results indicate that differences in the cultural practices and demographic regimes of African populations have not resulted in large differences in mutational burden, and highlight the beneficial role of gene flow in reshaping the distribution of deleterious genetic variation across human populations.

  Study EGAS00001002457

• Evolutionary analysis of primary tumors and metastatic lesions from 20 breast cancer patients (99 samples in total) using exome sequencing data.

  Metastatic breast cancers are still incurable. Characterizing their evolutionary landscape including the role of metastatic axillary lymph nodes to seed distant organ metastasis can provide rational basis for effective treatments. Here, we describe the genomic analyses of the primary tumors and metastatic lesions from 20 breast cancer patients (99 samples). Our evolutionary analyses revealed diverse spreading and seeding patterns governing tumor progression. Although linear evolution to successive metastatic sites was common, parallel evolution from the primary tumor to multiple distant sites was also evident. Metastatic spreading was frequently coupled with polyclonal seeding, where multiple metastatic subclones originated from primary tumor and/or other distant metastases. Synchronous axillary lymph node metastasis, a well-established prognosticator of breast cancer, was not involved in seeding distant metastasis, suggesting haematogenous route for cancer dissemination. Clonal evolution coincided frequently with emerging driver alterations and evolving mutational processes, notably a significant increase in apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like (APOBEC) associated mutagenesis. Our data provide the first genomic evidence regarding the role of axillary lymph node metastasis in seeding distant organ metastasis and elucidates the evolving mutational landscape during cancer progression.

  Study EGAS00001002737

• Defective T-cell expansion in RASGRP1 deficiency

  Inherited CTPS1- CD27- and CD70-deficiencies in humans have revealed key factors of T-lymphocyte expansion, that is a prerequisite for an efficient immunity to Epstein-Barr virus (EBV) infection. RASGRP1 is a T-lymphocyte specific nucleotide exchange factor known to activate the MAP kinases pathway. A deleterious homozygous mutation in RASGRP1 leading to the loss RASGRP1 expression was identified in two siblings who both developed a persistent EBV infection leading to Hodgkin lymphoma. RASGRP1-deficient T cells exhibited defective MAPK activation and impaired proliferation that was restored by expression of wild-type RASGRP1. Similar defects were observed in T cells from healthy individuals when RASGRP1 was downregulated. RASGRP1-deficient T cells also exhibited decreased CD27-dependent proliferation toward CD70-expressing EBV-transformed B cells, a crucial pathway required for expansion of antigen-specific T cells in anti-EBV immunity. Furthermore, RASGRP1-deficient T cells failed to upregulate CTPS1, an important enzyme required for DNA synthesis. These results show that RASGRP1 deficiency leads to susceptibility to EBV infection, and demonstrate the key role of RASGRP1 at the crossroad of pathways required for the expansion of activated T lymphocytes.

  Study EGAS00001002753

• Somatic IL4R Hotspot Mutations in Primary Mediastinal Large B-cell lymphoma lead to constitutive JAK-STAT activation

  Primary mediastinal large B cell lymphoma (PMBCL) is a distinct subtype of diffuse large B cell lymphoma thought to arise from thymic medullary B cells. Gene mutations underlying the molecular pathogenesis of the disease are incompletely characterized. Here, we describe novel somatic IL4R mutations in 15 out of 62 primary cases of PMBCL (24.2%) and in all PMBCL-derived cell lines tested. The majority of mutations (11/21; 52%) were hotspot single nucleotide variants in exon 8 leading to an I242N amino acid change in the transmembrane domain. Functional analyses establish this mutation as gain-of-function leading to constitutive activation of the JAK-STAT pathway and upregulation of downstream cytokine expression profiles and B cell specific antigens. Moreover, expression of I242N mutant IL4R in a mouse xenotransplantation model conferred growth advantage in vivo. The pattern of concurrent mutations within the JAK-STAT signaling pathway suggests additive/synergistic effects of these gene mutations contributing to lymphomagenesis. Our data establish IL4R mutations as novel driver alterations and provide a strong preclinical rationale for therapeutic targeting of JAK-STAT signaling in PMBCL.

  Study EGAS00001002796

• PATL2 is a key actor of oocyte maturation whose invalidation causes infertility in women and mice

  The genetic causes of oocyte meiotic deficiency (OMD), a form of primary infertility characterised by the production of immature oocytes, remain largely unexplored. Using whole exome sequencing, we found that 26% of a cohort of 23 subjects with OMD harboured the same homozygous nonsense pathogenic mutation in PATL2, a gene encoding a putative RNA-binding protein. Using Patl2 knockout mice, we confirmed that PATL2 deficiency disturbs oocyte maturation, since oocytes and zygotes exhibit morphological and developmental defects respectively. PATL2's amphibian orthologue is involved in the regulation of oocyte mRNA as a partner of CPEB. However, Patl2's expression profile throughout oocyte development in mice, alongside colocalisation experiments with Cpeb1, Msy2 and Ddx6 (three oocyte RNA-regulators) suggest an original role for Patl2 in Mammals. Accordingly, transcriptomic analysis of oocytes from WT and Patl2-/- animals demonstrated that in the absence of Patl2, expression levels of a select number of highly relevant genes involved in oocyte maturation and early embryonic development are deregulated. In conclusion, PATL2 is a novel actor of mammalian oocyte maturation whose invalidation causes OMD in humans.

  Study EGAS00001002903

• Ewings Sarcoma RNA-Seq

  Sarcomas are cancers of the bone and soft tissue often defined by their gene fusions. However, the timing, context, and processes by which these pathogenic fusions arise are unknown. We explored this in Ewing sarcoma, a cancer driven by EWSR1-ETS fusions, with very few cooperating mutations. Combining whole-genome sequencing with enhanced informatics, we found that the EWSR1-ETS fusion arose from striking rearrangement clusters in 42% of cases (52/124). Notably, these were organized in loops that universally contained the fusion at their center, while also weaving up to 18 genes together with it. We found the same pattern of rearrangements in three additional types of sarcoma. From these data, we define a new signature for sarcoma fusions that precedes other somatic changes, in the earliest replicating DNA of the genome. This dramatic, sudden process impinges on many genes – generating multiple coding changes that profoundly affect the transcriptome, with the disease-defining gene fusion at its core. These rearrangement loops emerge in an early ES clone from which both the primary tumor and the lethal relapse emerged, and then evolved in parallel until clinically detected.

  Study EGAS00001003062

• Low and variable tumor reactivity of the intratumoral TCR repertoire in human cancers

  Infiltration of human cancers by T cells is generally interpreted as a sign of immune recognition, and there is a growing effort to reactivate dysfunctional T cells at such tumor sites. However, these efforts only have value if the intratumoral T cell receptor (TCR) repertoire of such cells is intrinsically tumor-reactive, and this has not been established in an unbiased manner for most human cancers. To address this issue, we analyzed the intrinsic tumor-reactivity of the intratumoral TCR repertoire of CD8+ T cells in ovarian and colorectal cancer – two tumor types for which T cell infiltrates form a positive prognostic marker. Data obtained demonstrate that a capacity to recognize autologous tumor is limited to approximately 10% of intratumoral CD8+ T cells. Furthermore, in two out of four patient samples tested, no tumor-reactive TCRs were identified, despite infiltration of their tumors by T cells. These data indicate that the intrinsic capacity of intratumoral T cells to recognize adjacent tumor tissue can be rare and variable, and suggest that clinical efforts to reactivate intratumoral T cells will benefit from approaches that simultaneously increase the quality of the intratumoral TCR repertoire.

  Study EGAS00001003119

• Genomic Profiling of Thyroid Cancer Reveals a Role for Thyroglobulin in Metastasis -Part II

  Papillary thyroid carcinoma (PTC) has a wide geographic variation in incidence, being highest in Saudi Arabia where it is only second to breast cancer as the most common cancer among females. Genomic profiling of PTC from Saudi Arabia has not been attempted previously. We performed whole-exome sequencing of 101 PTC samples and the corresponding genomic DNA to identify genes with recurrent somatic mutations, followed by sequencing of these genes using a next-generation gene panel approach in further 785 samples. In addition to BRAF, N-RAS and H-RAS, which have previously been shown to be recurrently mutated in PTC, our analysis highlights additional genes, including thyroglobulin (TG), which harbored somatic mutations in 3% of the entire cohort. Surprisingly, although TG mutations were not exclusive to mutations in the RAS-MAP kinase pathway, their presence was associated with a significantly worse clinical outcome, which suggests a pathogenic role beyond driving initial oncogenesis. Analysis of metastatic PTC tissue revealed significant enrichment for TG mutations (p<0.001), including events of apparent clonal expansion. Our results suggest a previously unknown role of TG somatic mutations in the pathogenesis of PTC and its malignant evolution.

  Study EGAS00001003357

• Clinical significance of novel subtypes of acute lymphoblastic leukemia in the context of minimal residual disease-directed therapy

  We evaluate clinical significance of recently identified subtypes of acute lymphoblastic leukemia (ALL) in 598 children treated with minimal residual disease (MRD)-directed therapy. Among the 16 B-ALL and 8 T-ALL subtypes identified by next generation sequencing, ETV6-RUNX1, high-hyperdiploid and DUX4-rearranged B-ALL had the best five-year event-free survival rates (95% to 98.4%); TCF3-PBX1, PAX5alt, T-cell, ETP, iAMP21, and hypodiploid ALL intermediate rates (80.0% to 88.2%); and BCR-ABL1, BCR-ABL1-like and ETV6-RUNX1-like and KMT2A-rearranged ALL the worst rates (64.1% to 76.2%). All but three of the 142 patients with day-8 blood MRD <0.01% remained in remission. Among new subtypes, intensified therapy based on day-15 MRD≥1% improved outcome of DUX4-rearranged, BCR-ABL1-like, and ZNF384-rearranged ALL, and achievement of day-42 MRD<0.01% did not preclude relapse of PAX5alt, MEF2D-rearranged and ETV6-RUNX1-like ALL. Thus, new subtypes including DUX4-rearranged, PAX5alt, BCR-ABL1-like, ETV6-RUNX1-like, MEF2D-rearranged and ZNF384-rearranged ALL have important prognostic and therapeutic implications.

  Study EGAS00001005084

• Rucaparib in patients presenting a metastatic breast cancer with Homologous Recombination Deficiency, without germline BRCA1/2 mutation, pronostic value of high LOH genomic score and predictive value of HRDetect (microarray)

  Breast cancer may present genomic alterations leading to homologous recombination deficiency. PARP inhibitors have proved their efficacy in patients with HER2-negative metastatic breast cancer (mBC) harboring germline (g) BRCA1/2 mutations. We conducted the phase 2 RUBY trial to assess the efficacy of rucaparib in HER2-negative mBC with high genomic loss of heterozygosity (LOH) score or somatic, without gBRCA1/2 mutation. 220 of 711 patients with mBC screened for LOH presented high LOH score which was associated with a higher likelihood of death (HR = 1.39, 95% CI: 1.11-1.75, p = 0.005). The primary objective was not reached with a clinical benefit rate (objective response or SD>16 weeks) of 13.5%. Two LOH-high patients, without somatic BRCA1/2 mutation, presented a complete and durable response (14 and 32 months). HRDetect tended to be associated with response to rucaparib, whithout reaching statistical significance (median HRDetect responders versus non responders: 0.465 versus, 0.040, p = 0.2135). Our data suggests that a small subset of patients with high LOH score could derive benefit from PARP inhibitors.

  Study EGAS00001004755

• UAMS Smoldering Myeloma Myeloma Sequencing

  Identifying high risk smoldering myeloma patients and progression mechanism is a prerequisite to implement effective inception strategies and curve myeloma related morbidity and mortality. We hypothesize that genomics may help identify determinants of progression that may help predict outcome and offer effective chemo preventive targets. Eighty-two patients underwent a custom targeted panel sequencing with an additional capture for the translocation loci. These results were compared to 223 newly diagnosed patients (EGAS00001003223 and EGAD00001004117) and 17 MGUS and 10 early myeloma patients. DNA was obtained from either CD138+ cells from the bone marrow of multiple myeloma patients (tumor) or from stem cell harvests or peripheral blood cells from the same patient (control). 100 ng of DNA was fragmented, end-repaired, and adapters ligated using the HyperPlus kit (KAPA Biosystems). After PCR amplification the libraries were hybridized with probes against either a targeted panel consisting of 140 genes and chromosomal regions (Nimblegen) using SeqCap reagents (Nimblegen). Hybridized libraries underwent further amplification before being sequenced on a NextSeq500 (Illumina) using 75 bp paired end reads. Overall, these data highlight the importance of dysregulation of the MAPK pathway in the progression to MM.

  Study EGAS00001003629

• Genomic Profiling of Thyroid Cancer Reveals a Role for Thyroglobulin in Metastasis

  Papillary thyroid carcinoma (PTC) has a wide geographic variation in incidence, being highest in Saudi Arabia where it is only second to breast cancer as the most common cancer among females. Genomic profiling of PTC from Saudi Arabia has not been attempted previously. We performed whole-exome sequencing of 101 PTC samples and the corresponding genomic DNA to identify genes with recurrent somatic mutations, followed by sequencing of these genes using a next-generation gene panel approach in further 785 samples. In addition to BRAF, N-RAS and H-RAS, which have previously been shown to be recurrently mutated in PTC, our analysis highlights additional genes, including thyroglobulin (TG), which harbored somatic mutations in 3% of the entire cohort. Surprisingly, although TG mutations were not exclusive to mutations in the RAS-MAP kinase pathway, their presence was associated with a significantly worse clinical outcome, which suggests a pathogenic role beyond driving initial oncogenesis. Analysis of metastatic PTC tissue revealed significant enrichment for TG mutations (p<0.001), including events of apparent clonal expansion. Our results suggest a previously unknown role of TG somatic mutations in the pathogenesis of PTC and its malignant evolution.

  Study EGAS00001001788

• The proliferative history shapes the DNA methylome of B-cell tumor and predicts clinical outcome

  Here, we provide access to CLL and DLBCL DNA methylation and gene expression data in the context of a systematic analysis of the DNA methylation variability in 1,595 samples of normal cell subpopulations and 14 tumor subtypes spanning the entire human B-cell lineage. This approach showed that differential methylation among tumor entities relates to differences in cellular origin and to de novo epigenetic alterations, which allowed us to build an accurate machine learning-based diagnostic algorithm. We identify extensive patient-specific methylation variability in silenced chromatin associated with the proliferative history of normal and neoplastic B cells. Mitotic activity generally leaves both hyper- and hypomethylation imprints, but some B-cell neoplasms preferentially gain or lose DNA methylation. Subsequently, we construct a DNA methylation-based mitotic clock called epiCMIT, whose lapse magnitude represents a strong independent prognostic variable in B-cell tumors and is associated with particular driver genetic alterations. Our findings reveal DNA methylation as a holistic tracer of B-cell tumor developmental history, with implications in the differential diagnosis and prediction of clinical outcome.

  Study EGAS00001004640

• Identification of rare germline variants in familial multiple myeloma

  The risk of developing multiple myeloma (MM) in first-degree relatives of affected individuals is 2 to 4 fold higher than in the general population, implying the existence of inherited susceptibility. While over 20 common, low-penetrance variants have been associated with MM risk, less is known about rare, high-penetrance germline predisposition. We aimed to identify and characterize high/moderated penetrance germline variants in MM families using whole genome sequencing. For that purpose we identified families with at least two individuals diagnosed with MM or its precursors MGUS and smoldering MM. Also, patients with solitary plasmacytoma and AL amyloidosis were enrolled. We also recruited unaffected family members, and they were screened to exclude undetected MM or its precursor stages. After whole genome sequencing of blood DNA and filtering for rare variants (minor allele frequency <0.1%) and family segregation, variants are prioritized by a range of published in silico tools and literature search. The most promising variants are subjected to experimental validation to evaluate their functional relevance. Our data will provide guidance to worldwide efforts to unravel germline predisposition in MM and validation of the proposed variants and genes.

  Study EGAS00001004734

• Familial psychosis associated with a missense mutation at MACF1 gene combined with the rare duplications DUP3p26.3 and DUP16p23.3, affecting the CNTN6 and CDH13 genes

  Psychosis is a highly heritable and heterogeneous psychiatric condition. Its genetic architecture is thought to be the result of the joint effect of common and rare variants. Families with high prevalence are an interesting approach to shed light on the rare variant's contribution without the need of collecting large cohorts. To unravel the genomic architecture of a family enriched for psychosis, with four affected individuals, we applied a system genomic approach based on karyotyping, genotyping by whole-exome sequencing to search for rare single nucleotide polymorphisms (SNPs) and SNP array to search for copy-number variants (CNVs). We identified a rare non-synonymous variant, g.39914279 C>G, in the MACF1 gene, segregating with psychosis. Rare variants in the MACF1 gene have been previously detected in SCZ patients. Besides, two rare CNVs, DUP3p26.3 and DUP16p23.3, were also identified in the family affecting relevant genes (CNTN6 and CDH13, respectively). We hypothesize that the co-segregation of these duplications with the rare variant g.39914279 C>G of MACF1 gene precipitated with schizophrenia and schizoaffective disorder.

  Study EGAS00001004791

• Risk and modifying factors in Frontotemporal Dementia

  Understanding the molecular mechanisms underlying frontotemporal dementia (FTD) is essential for the development of successful therapies. Here, we present Phase 1 of a multi-omics, multi-model data resource for FTD research which will allows in-depth molecular research into these mechanisms. We have integrated and analysed data from the frontal lobe of FTD patients with mutations in MAPT, GRN and C9orf72 and detected common and distinct dysregulated cellular pathways. Our results highlight that excitatory neurons are the most vulnerable neuronal cell type and that vascular aberrations are a common hallmark in FTD. Via integration of multi-omics data, we detected several transcription factors and pathways which regulate the strong neuroinflammation observed in FTD-GRN. Finally, using small RNA-seq data and verification experiments in cellular models, we identified several up-regulated miRNAs that inhibit cellular trafficking pathways in FTD and lead to microglial activation. In this work we shed light on novel mechanistic and pathophysiological hallmarks of FTD. In addition, we believe that this comprehensive, multi-omics data resource will further mechanistic FTD research by the community.

  Study EGAS00001004895

• Single cell RNA sequencing of synovial B cells in early Rheumatoid Arthritis

  Rheumatoid Arthritis (RA) is a prevalent autoimmune disease characterized by inflammation of the peripheral joints and occurence of autoantibodies, i.e. Rheumatoid Factor (RF) and anti-citrullinated protein antibodies (ACPA), in circulation. Previous studies have shown that there are memory B cells and autoantibody producing plasma cells present in the joint tissue of patients with long-standing RA. However, it has remained unclear, whether these B cell populations are already present in the joint tissue of patients at the disease onset and whether these are autoreactive. Here, we used a single cell RNA sequencing approach to dissect the B cell repertoire at this early timepoint. We found evidence for B and T cell interaction and presence of memory and plasma cell pools in ACPA- and ACPA+ RA. Our results demonstrated clonal relationships between the memory and plasma cell compartments and autoreactivity within the plasma cell pool. These findings challenge our understanding of the local adaptive immune response in the joints of ACPA- and ACPA+ RA patients with direct implications for B and T cell targeting therapy in both patient subgroups.

  Study EGAS00001005144

• Epigenome wide DNA methylation assay of gingivo-buccal oral squamous cell carcinoma using single base resolution high throughput array

  Gingivo-buccal oral squamous cell carcinoma (OSCC-GB) is the most common cancer among men in India and is associated with high mortality. Although OSCC-GB is known to be quite different from tongue cancer in its genomic presentation and its clinical behavior, it is treated identically as tongue cancer. Predictive markers of prognosis and therapy that are specific to OSCC-GB are, therefore, required. To achieve this, we have carried out epigenomic (n=87) profiling of paired tumor-normal tissues collected from OSCC-GB patients from India and genome-wide DNA methylation assays were performed. DNA was isolated using DNeasy Blood and Tissue Kit (Qiagen). The purity and concentration was estimated using NanoDrop 2000 (Thermo Fisher Scientific). Approximately 500 ng genomic DNA from each sample was used for sodium bisulfite conversion using the EZ DNA methylation Gold Kit (Zymo Research, USA). Genome-wide DNA methylation was assayed using iScan (Illumina), for paired tumour and adjacent normal samples of 25 patients using the Infinium Human Methylation450 BeadChip and of 62 patients using the Infinium MethylationEPIC BeadChip.

  Study EGAS00001003896

• Whole genome sequence and RNA-seq data from paired tumour and germline samples from mesothelioma patients.

  Malignant pleural mesothelioma (MPM) has a poor overall survival with few treatment options. Whole genome sequencing (WGS) combined with RNA sequencing (RNA-seq) analysis of the immune features of MPM offers the prospect of identifying changes that could inform future clinical trials. We analysed somatic mutation and RNA-seq data from 229 MPM samples, including 58 MPM samples that had undergone WGS from our own institutions, together with other published data. This combined analysis identified somatic driver genes, including newly identified candidate genes. Whole genome doubling was a frequent event that correlated with shorter survival. Mutational signature analysis revealed dominant signatures and showed that defects in homologous recombination repair were infrequent in our cohort. Within the tumour immune environment we identified high M2 macrophage infiltrate linked with MMP2, MMP14, TGFB1 and CCL2 expression, representing an immunosuppressive environment. A small subset of samples had a higher proportion of CD8 T cells and a high cytolytic score, suggesting a ‘hot’ immune environment which is independent of the somatic mutations. We propose that our findings on genomic changes and subtypes of immune microenvironments may influence therapeutic planning in the future.

  Study EGAS00001005196

• The molecular basis of T-PLL is an actionable perturbation of TCL1/ATM- and epigenetically instructed damage responses

  T-cell prolymphocytic leukemia (T-PLL) is a rare and poor-prognostic mature T-cell malignancy. To address its incomplete molecular concept, we integrated large-scale profiling data of alterations in gene expression, allelic copy number (CN), and nucleotide sequences in 111 well-characterized patients. Besides prominent signatures of T-cell activation and prevalent clonal variants, we also identified novel hot-spots for CN variability, fusion molecules, alternative transcripts, and progression-associated dynamics. The overall lesional spectrum of T-PLL is mainly annotated to axes of DNA damage responses, T-cell receptor/cytokine signaling, and histone modulation. We formulate a multi-dimensional model of T-PLL pathogenesis centered around a unique combination of TCL1 overexpression with damaging ATM aberrations as initiating core lesions. The effects imposed by TCL1 cooperate with compromised ATM towards a leukemogenic phenotype of impaired DNA damage processing. Dysfunctional ATM appears inefficient in alleviating elevated redox burdens and telomere attrition and in evoking a p53-dependent apoptotic response to genotoxic insults. As non-genotoxic strategies, synergistic combinations of p53 reactivators and deacetylase inhibitors reinstate such cell death execution.

  Study EGAS00001002744

• MutWP4__CRUK_Grand_Challenge_Mutographs_of_Cancer__Gastric_Organoids

  The Mutographs project aims to advance our understanding of the causes of cancer through studies of mutational signatures. Led by Mike Stratton, together with Paul Brennan, Ludmil Alexandrov, Allan Balmain, David Phillips and Peter Campbell, this large-scale international research endeavour was awarded a Cancer Research UK Grand Challenge. Different patterns of somatic mutation are generated by the different environmental, lifestyle and genetic factors that cause cancer, many of them are still unknown. Within Mutographs, Kings College London will characterise the mutational signatures induced by putative human carcinogens in order to identify the origins of mutational signatures found in human cancers. To achieve this human organoid cell cultures will be exposed to a representative catalogue of known or suspected human carcinogens and mutagens and, using whole genome sequencing, the patterns of mutations induced by them will be determined. Somatic mutational signatures will be subsequently extracted by non-negative matrix factorisation methods and correlated with exposure data. Through an enhanced understanding of cancer aetiology, Mutographs unprecedented effort is anticipated to outline modifiable risk factors, lead to new approaches to prevent cancer, and provide opportunities to empower early detection, refine high-risk groups and contribute to further therapeutic development.

  Study EGAS00001003151

• Whole-Genome Sequencing of Salivary Gland Adenoid Cystic Carcinoma

  Adenoid cystic carcinomas (ACCs) of the salivary glands are challenging to understand, treat, and cure. To better understand the genetic alterations underlying the pathogenesis of these tumors, we performed comprehensive genome analyses of 25 fresh-frozen tumors, including whole genome sequencing, expression and pathway analyses. In addition to the well-described MYB-NFIB fusion which was found in 11 tumors (44%), we observed five different rearrangements involving the NFIB transcription factor gene in seven tumors (28%). Taken together, NFIB translocations occurred in 15 of 25 samples (60%, 95%CI=41–77%). In addition, mRNA expression analysis of 17 tumors revealed overexpression of NFIB in ACC tumors compared with normal tissues (p=0.002). There was no difference in NFIB mRNA expression in tumors with NFIB fusions compared to those without. We also report somatic mutations of genes involved in the axonal guidance and Rho family signaling pathways. Finally, we confirm previously described alterations in genes related to chromatin regulation and Notch signaling. Our findings suggest a separate role for NFIB in ACC oncogenesis and highlight important signaling pathways for future functional characterization and potential therapeutic targeting.

  Study EGAS00001002812

• Cell-free DNA analysis reveals POLR1D-mediated resistance to bevacizumab in colorectal cancer

  Bevacizumab is an approved anti-angiogenic drug for patients with metastasized colorectal cancer (mCRC) targeting VEGF. The survival benefit of anti-VEGF therapy in mCRC patients is limited to a few months and acquired resistance mechanisms are greatly unknown. Using plasma DNA, we studied the evolution of tumor genomes in a cohort of patients with mCRC (n=150) and observed a recurrent focal amplification (8.7% of cases) on chromosome 13q12.2. Analysis of TCGA data (n=619) suggested an association with later stages, which we confirmed by longitudinal plasma analyses. We defined the minimally amplified region and studied the mechanistic consequences of copy number gain of the involved genes. The amplification of one gene, POLR1D, impacted cell proliferation, resulting in upregulation of VEGFA, an important regulator of angiogenesis which has been implicated in the resistance to bevacizumab. In several patients, we observed the emergence of this 13q12.2 amplicon under bevacizumab treatment, which was invariably associated with evolution of therapy resistance. Hence, we describe a novel resistance mechanism against a widely applied treatment in mCRC patients which will impact clinical management

  Study EGAS00001003791

• Circulating tumor cells Exome sequencing from breast cancer

  Single cell technologies allow interrogating the extent of tumor heterogeneity, providing novel insights into tumor evolution and treatment resistance mechanisms. Here, we investigated the level of genetic heterogeneity among circulating tumor cells (CTCs) at the single nucleotide variation and copy number aberration (CNA) levels and compared it to synchronous matched primary tumor/metastatic lesion from 3 metastatic breast cancer patients with triple-negative (TNBC), HER2-positive (HER2+) and estrogen-receptor-positive (ER+) tumors. Whole exome sequencing was performed on 3 synchronous bulk tumor tissue and 21 single/pooled CTC samples. When comparing bulk tissue with CTCs from the same patient, we found similar CNA profiles and the same patient-specific driver mutations for the HER2+ and TNBC tumors. Different CNA profiles and driver mutations were found for the ER+ tumor, with two distinct clones being identified in the CTCs, one harboring an activating ESR1 mutation, the other one bearing a TP53 mutation. These data suggest that tumor tissue and CTCs provide in a subset of patients complementary clinically relevant information to map tumor heterogeneity and monitor tumor evolution. Further validation is needed.

  Study EGAS00001005228