22928 results for "ega"

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• Evolutionary trajectories of IDH-mutant astrocytoma identify molecular grading markers related to cell cycling

  To study the evolutionary processes that drive malignant transformation in IDH-mutant astrocytomas, we performed multi-omics on a large cohort of matched initial and recurrent tumor samples. We find that genome-wide DNA-methylation levels decreased over time, mainly in patients with high-grade recurrences. DNA-demethylation was lifted from specific loci associated with DNA replication, and was associated with upregulation of cell cycling associated genes. Upregulation of cell cycling genes occurred predominantly in proliferating tumor cells, and was associated with tumor grade. Temporal DNA-demethylation and upregulation of cell cycling were hardly affected by chemo- and/or radiotherapy, indicating treatment does not affect the course of disease. Further, we defined a DNA-methylation based signature associated with tumor grade and poor prognostic genetic events, with a prognostic power stronger than CDKN2A/B deletion. We validated its prognostic power on primary tumor samples of patients included in the CATNON randomized phase 3 clinical trial. Therefore this model can serve as a molecular grading marker for IDH-mutant astrocytomas.

  Study EGAS00001007527

• CD8-targeted IL-2 unleashes tumor-specific immunity in human cancer tissue by reviving the dysfunctional T cell pool

  Tumor-specific CD8+ T cells are key effectors of antitumor immunity but are often rendered dysfunctional in the tumor microenvironment. Immune checkpoint blockade can restore antitumor T cell function in some patients, however most do not respond to this therapy, often despite T cell infiltration in their tumors. We here explored a CD8-targeted IL-2 fusion molecule (CD8-IL2) to selectively reactivate intratumoral CD8+ T cells in patient-derived tumor fragments. Treatment with CD8-IL2 broadly armed intratumoral CD8+ T cells with enhanced effector capacity, thereby specifically enabling reinvigoration of the dysfunctional T cell pool to elicit potent immune activity. Notably, the revival of dysfunctional T cells to mediate effector activity by CD8-IL2 depended on simultaneous antigen recognition and was quantitatively and qualitatively superior to that achieved by PD-1 blockade. Finally, CD8-IL2 was able to functionally reinvigorate T cells in tumors resistant to anti-PD-1, underscoring its potential as a novel treatment strategy for cancer patients.

  Study EGAS00001007712

• Efficacy and safety of entrectinib in patients with ROS1-positive advanced/metastatic non-small cell lung cancer (NSCLC) from the Blood First Assay Screening Trial (BFAST)

  BFAST is a global, open-label, multicohort trial that evaluates the efficacy and safety of multiple therapies in patients with advanced/metastatic NSCLC and targetable alterations, identified by blood-based molecular testing. We present data from Cohort D (ROS1-positive). Patients ≥18 years old with stage IIIB/IV, ROS1-positive NSCLC detected by blood-based testing, received entrectinib 600 mg daily. At data cut-off (November 2021), 55 patients were enrolled and 54 had measurable disease. Cohort D met its primary endpoint; the confirmed objective response rate (ORR) by investigator was 81.5% which was consistent with the ORR from the integrated analysis of entrectinib (investigator-assessed ORR: 73.4%, data cut-off May 2019, ≥12 months follow-up). The safety profile of entrectinib was consistent with prior reports. These results demonstrate consistency with those from the integrated analysis of entrectinib in patients with ROS1-positive NSCLC identified by tissue-based testing and support the clinical value of blood-based testing to inform clinical decision-making.

  Study EGAS50000000105

• Cancer cell and tumor microenvironment biomarkers associated with disease-free survival with adjuvant nivolumab in the phase 3 CheckMate 274 trial

  In the CheckMate 274 trial, adjuvant nivolumab versus placebo demonstrated an improvement in the primary endpoint of disease-free survival (DFS) in patients with high-risk muscle-invasive urothelial carcinoma after radical resection. An extensive analysis of tumor biomarkers, including their associations with DFS, was performed. Analysis of genome-wide differential gene expression and known gene signatures found that immune-related genes and pathways, in particular an IFNγ signature, were predictive of DFS in nivolumab-treated patients. Predictive and prognostic associations, respectively, were found for tumor-infiltrating CD4 and CD8 T cells. Analysis of a composite predictive model suggested that CD4 gene expression and tumor cell PD-L1 expression had the greatest contributions to predicting outcomes in nivolumab-treated patients. These results reinforce recent studies establishing the importance of biomarkers of adaptive immunity, and in particular CD4 T cells, in influencing response to PD-1/PD-L1 blockade and establish the potential predictive rather than solely prognostic nature of such findings.

  Study EGAS50000000560

• Long-read-transcriptome-sequencing of CLL and MDS patients uncovers common molecular effects of SF3B1 mutations

  Mutations in SF3B1 occur frequently in patients with chronic lymphocytic leukemia (CLL) and myelodysplastic syndromes (MDS), and a full-length transcriptome approach can expand our current knowledge on SF3B1 mutation effects on RNA splicing. We applied long-read-transcriptome-sequencing (LRTS) to 44 MDS and CLL patients with and without SF3B1 mutations and found a large fraction (>60%) of novel isoforms. Furthermore, we revealed that mutation effects on alternative splicing were largely common in both cancer types and specifically altered the usage of introns as well as 3’-splice-sites. We combined the LRTS with genome-wide SF3B1-RNA binding maps and show multimodal binding at 3’-splice-sites highlighting a window of 12-21nt upstream of the canonical 3’-splice-site in which a dynamic switch in splice site usage is observable in patients carrying SF3B1 mutations. Our work presents the hitherto most complete LRTS study in CLL and MDS and provides a resource for further research on aberrant splicing in cancer.

  Study EGAS50000000053

• Altered enhancer-promoter interaction leads to MNX1 expression in pediatric acute myeloid leukemia with t(7;12)(q36;p13)

  Acute myeloid leukemia (AML) with the t(7;12)(q36;p13) translocation occurs only in very young children and has a poor clinical outcome. The expected oncofusion between breakpoint partners (MNX1 and ETV6) has only been reported in a subset of cases. However, a universal feature is the strong transcript and protein expression of MNX1, a homeobox transcription factor that is normally not expressed in hematopoietic cells. Here, we map the translocation breakpoints on chromosomes 7 and 12 in affected patients to a region proximal to MNX1 and either introns 1 or 2 of ETV6. The frequency of MNX1 overexpression in pediatric AML (n=1556, own and published data) is 2.4% and occurs predominantly in t(7;12)(q36;p13) AML. Chromatin interaction assays in a t(7;12)(q36;p13) iPSC cell line model unravel an enhancer-hijacking event that explains MNX1 overexpression in hematopoietic cells. Our data suggest that enhancer-hijacking is a more common and overlooked mechanism for structural rearrangement-mediated gene activation in AML.

  Study EGAS50000000130

• Transcriptomics sequencing analysis of pre-invasive lung adenocarcinoma in never-smokers

  The prevalence of lung adenocarcinoma (LUAD) has increased sharply in East Asia. Early diagnosis leads to better survival rates, but this requires an improved understanding of the molecular changes during early tumorigenesis, particularly in non-smokers. We performed whole exome-sequencing and RNA-sequencing for samples from 94 East Asian patients with precancerous lesions (25 with atypical adenomatous hyperplasia [AAH]; 69 with adenocarcinoma in situ [AIS]) and 73 patients with early invasive lesions (minimally invasive adenocarcinoma [MIA]). Cellular analysis revealed that the activities of endothelial and stromal cells could categorize tumors into molecular subtypes within pathology-defined lesion types. These subtypes were linked with the advanced radiology-defined lesion type and coordinated with immune cell infiltration throughout the progression of LUAD. Characterization of these lesion types identified positively selected mutation patterns, and suggested that angiogenesis of the late-stage AIS type potentially contributes to tissue invasion of the MIA type. Our findings offer a novel resource that may help to improve early diagnosis and patient prognosis, and also suggest possible approaches for early disease interception.

  Study EGAS50000000439

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

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

  Study EGAS00001005279

• Blood-based monitoring of relapsed/refractory cHL patients predict responses to PD-1 blockade treatment

  Hodgkin lymphoma (cHL) patients are uniquely susceptible to treatment with programmed cell death-1 (PD-1) treatment. However, monitoring with FDG-PET/CT, the current response detection standard, is challenging. Here, we address the potential applicability of tissue biomarkers and blood-based biomarkers in PD-1 treated cHL patients. We evaluated 9p24.1/PD-L1/PD-L2 alterations, and expression of PD-L1 and antigen presentation molecules (HLA class I/II) in 9 tissue biopsies of 4 patients. In addition, we assessed circulating tumor DNA (ctDNA), extracellular vesicle associated miRNAs (EV-miRNAs), soluble PD-L1 and serum TARC (sTARC) in 26 longitudinal blood samples of these patients during PD-1 treatment. We found that the predictive power of tissue biomarkers is dependent on the timing of the biopsy . The dynamics of blood-based biomarkers: sTARC, EV-miRNAs and ctDNA corresponded well immunotherapy treatment response. Therefore, blood-based biomarkers are promising monitoring strategies in PD-1 treated cHL patients and should be further explored in clinical trials or observational studies.

  Study EGAS00001005894

• IL-27 promotes tumour control by enhancing cytotoxic T cell function

  Cytotoxic CD8+ T lymphocytes (CTL) are essential for anti-tumour immunity but are frequently dysfunctional in established tumours. Here, we show that expression of a CTL signature is strongly associated with IL-27 expression in diverse human and murine tumours. In mice, IL-27 acts directly on tumour-specific CTL to promote their persistence and effector function in the tumor microenvironment. Moreover, treatment with inducible IL-27 overexpression or a half-life-extended IL-27 protein in vivo is well tolerated, induces regression of large established tumours, drives an enhanced cytotoxic program in anti-tumour CTL, and synergizes with PD-L1 blockade. In cancer patients treated with anti-PD-1 or anti-PD-L1 therapy, high expression of IL-27 is associated with improved clinical response. Finally, IL-27 increases cytotoxicity and limits terminal differentiation of human CD8+ T cells during chronic antigen exposure. Our data demonstrate that endogenous IL-27 is essential for anti-tumour immunity and that IL-27 receptor agonism can safely improve anti-tumor T cell responses alone or in combination with PD-L1 blockade.

  Study EGAS50000000694

• Assessment of candidate high-grade serous ovarian carcinoma predisposition genes through integrated germline and tumour sequencing

  High-grade serous ovarian carcinoma (HGSOC) has a significant hereditary component, only half of which is explained. Previously, we performed germline exome sequencing on BRCA1 and BRCA2-negative HGSOC patients, revealing three proposed and 43 novel candidate genes enriched with rare loss-of-function variants. For validation, we undertook case-control analyses using genomic data from disease-free controls. This confirms enrichment for nearly all previously identified genes. Additionally, one-hundred-and-eleven HGSOC tumours from variant carriers were sequenced alongside other complementary studies, seeking evidence of biallelic inactivation as supportive evidence. PALB2 and ATM validate as HGSOC predisposition genes, with 6/8 germline carrier tumours exhibiting biallelic inactivation accompanied by characteristic mutational signatures. Among candidate genes, only LLGL2 consistently shows biallelic inactivation and protein expression loss, supporting it as a novel HGSOC susceptibility gene. The remaining candidate genes fail to validate. Integrating case-control analyses with tumour sequencing is thus crucial for accurate gene discovery in familial cancer studies.

  Study EGAS50000000770

• Transcriptome profiling of patient derived neural stem cells highlights the importance of CTNND2 and WNT signaling in early neuralization

  Loss of CTNND2/δ-catenin function is implicated in neurodevelopmental disorders, including Cri-du-chat syndrome, autism spectrum disorder and attention deficit hyperactivity disorder. CTNND2, the encoded protein, is crucial for the cadherin-catenin cell adhesion complex in the brain. However, the specific impact on neurodevelopment remains unclear. To investigate, we used neuroepithelial stem cells (NESCs) derived from patient-specific induced pluripotent stem cells (iPSCs) with loss of CTNND2. In monolayer cultures, we observed abnormal neural rosette formation and failure to establish stable neural stem cells. 3D organoid cultures confirmed delayed neurogenesis and slower growth in patient-derived iPSC lines. We have built a transcriptomic catalog and observed a dysregulation of the WNT signaling pathway linked to our observed cellular phenotypes. To validate we excluded the WNT activator CHIR99021 from the media, which partially rescued the transcriptomic and morphological phenotype of the patient neural induction. This study enhances our understanding of how CTNND2 loss affects early neurogenesis and neuronal maturation in patient specific cells.

  Study EGAS50000000323

• Whole exome sequencing of pre-invasive lung adenocarcinoma in non-smokers

  The prevalence of lung adenocarcinoma (LUAD) has increased sharply in East Asia. Early diagnosis leads to better survival rates, but this requires an improved understanding of the molecular changes during early tumorigenesis, particularly in non-smokers. We performed whole exome-sequencing and RNA-sequencing for samples from 94 East Asian patients with precancerous lesions (25 with atypical adenomatous hyperplasia [AAH]; 69 with adenocarcinoma in situ [AIS]) and 73 patients with early invasive lesions (minimally invasive adenocarcinoma [MIA]). Cellular analysis revealed that the activities of endothelial and stromal cells could categorize tumors into molecular subtypes within pathology-defined lesion types. These subtypes were linked with the advanced radiology-defined lesion type and coordinated with immune cell infiltration throughout the progression of LUAD. Characterization of these lesion types identified positively selected mutation patterns, and suggested that angiogenesis of the late-stage AIS type potentially contributes to tissue invasion of the MIA type. Our findings offer a novel resource that may help to improve early diagnosis and patient prognosis, and also suggest possible approaches for early disease interception.

  Study EGAS50000000438

• Anti-myeloperoxidase IgM B cells in anti-neutrophil cytoplasmic antibody-associated vasculitis

  Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a prototypic autoimmune disease, with a subset of AAV patients manifesting anti-myeloperoxidase (MPO) IgG. Patients with AAV respond positively to B cell-targeting and complement-targeting therapies, but disease flares are not uncommon. Here, by comparing samples from healthy individuals and MPO+ AVV patients, we show that B cell autoreactivity against MPO in the circulation of patients is dominated by CD27+IgM+ B cells whereas MPO-specific IgG+ cells are infrequent. Additionally, while naive anti-MPO-IgM B cells are present in both patients and controls and produce anti-MPO IgM upon stimulation, anti-MPO-IgM memory B cells and serum anti-MPO IgM are features of patients. Our results thus hint that defective elimination of B cell reactivity to MPO in the human repertoire, the presence of activated IgM+ anti-MPO B cells in disease, and a dominant role for anti-MPO IgM in complement activation, may all contribute to MPO+ AAV etiology and thereby serve as potential target for therapy.

  Study EGAS50000000753

• Copy number variations and fragmentation features in cell-free DNA predict response in advanced non-small cell lung cancer patients under anti-PD-(L)1 therapy

  Anti-PD-(L)1 therapy is routinely used in metastatic NSCLC. However, response rates vary and biomarkers predicting treatment efficacy are lacking. Liquid biopsies allow monitoring of residual disease during therapy. Residual circulating tumor DNA (ctDNA) after therapy represents a predictive marker for adverse outcome. Here, we assessed copy number variations (CNVs) in serial plasma samples of NSCLC patients receiving PD-(L)1 blockade. We profiled CNV and fragmentation features in 118 plasma samples of advanced NSCLC patients by low-coverage whole genome sequencing taken at baseline, after four therapy cycles and at disease progression. CNVs and fragment features (i.e., fragment length, end motifs, position) were significantly altered in patients compared to healthy donors. Furthermore, fragment length changes at baseline and residual CNVs after four therapy cycles correlated with short progression-free survival. Our results highlight the suitability of plasma-based CNV and fragment analysis for disease monitoring and as a predictive marker for response duration in NSCLC patients under anti-PD-(L)1 therapy.

  Study EGAS50000000441

• Gene expression adaptation of metastases to their host tissue

  The adaptation of metastatic cells to their host tissue critically determines the pathogenicity of a cancer and therefore patient survival. Yet, it remains elusive to what extent the host environment drives gene expression programs in metastatic cells. Here we identify adaptive mechanisms that enable metastases to establish themselves in a novel tissue context. We performed single-cell RNA-sequencing on malignant and benign tissue samples from untreated donors with colorectal adenocarcinoma and liver metastasis to deduce tissue adaptive expression patterns. A novel computational approach identified genes and pathways that consistently adapted to the host tissue at the transition from the primary tumor to the paired metastasis across donors. This analysis revealed that the majority of expression changes in the metastasis reflect an expression signature reminiscent of benign liver epithelial cells. Cellular processes adapting to the liver environment include basic cellular functions such as energy metabolism, as well as tissue-specific pathways such as the regulation of lipid metabolism by PPAR-α. These adaptations potentially increase the pathogenicity of the metastatic cells and may provide new therapeutic strategies.

  Study EGAS50000000817

• Timing and trajectory of BCR-ABL1 driven chronic myeloid leukaemia

  Mutation of some genes provide fitness advantages that drive uncontrolled cell proliferation, leading to clinical manifestations of cancer. The discovery of the Philadelphia chromosome in chronic myeloid leukaemia (CML) provided the very first such genetic link to cancer and the hypothesis that this lesion provided an abnormal growth advantage to cells. However, little is known about the trajectory to CML, the rate of BCR::ABL1 driven clonal expansion, and how this impacts on disease presentation. Here, using whole-genome sequencing of 1013 single-cell-derived colonies from patients with CML, we reconstruct phylogenetic trees of haematopoiesis in 9 patients aged 22 to 81 years at diagnosis. The expected intronic breaks in BCR and ABL1 were not always observed, and out-of-frame exonic breakpoints in BCR, requiring exon skipping to derive BCR::ABL1 fusion transcripts, were noted in several patients. Apart from ASXL1 and RUNX1 mutations, additional somatic mutations in myeloid genes were generally present only in wild-type cells and did not contribute to the CML clone. Using phylogenetic analysis, we infer sustained explosive growth attributed to BCR::ABL1 fusion, with clonal expansions beginning 3-14 years (Cl 2-16 years) before diagnosis and annual growth rates exceeding 70,000% per year in some young patients with the most recent and rapid clonal expansions. Mutation rate was higher in BCR::ABL1-positive cells than in wild-type counterparts, together with markedly shorter telomere lengths, reflecting their excessive cell division history. Clonal expansion rates inferred from phylogenetic trees were in line with mutational signature patterns and telomere attrition, and inversely correlated with the time to diagnosis. Whole genome sequencing of advanced phase CML was characterised by genomic evolution within BCR::ABL1-positive cells. Our findings highlight the oncogenic potency of a single BCR::ABL1 fusion and its capacity to drive fast clonal outgrowth to cancer. These data contrast with the early-in-life, slow, and sequential clonal trajectories typical of most cancers, such as Philadelphia-negative myeloproliferative neoplasms, solid organ malignancies, and patterns of clonal expansion in healthy tissue ageing.

  Dataset EGAD00001015473

• Synthetic - FEGA Sweden Heilsa synthetic dataset December 2023

  Synthetic - This submission contains a subset of a synthetic dataset derived from the project Heilsa Tryggvedottir - a Nordic collaboration on sharing sensitive human data. Heilsa Tryggvedottir is funded by the Nordic e-Infrastructure Collaboration (NeIC), the ELIXIR nodes of Finland, Norway, and Sweden, Computerome in Denmark, and the Estonian Scientific Computing Infrastructure (ETAIS). In the synthetic data creation process, it was attempted to strike a fine balance between the usability of the datasets (e.g. technical FEGA development, testing, user training, and basic bioinformatics) and compliance with GDPR. File names and file content (e.g. headers in fastq) are anonymized. Moreover, the X, Y, and mitochondrial sequences have been discarded from the original data since these data can be used for maternal, paternal, or ethnic origin tracing. The dataset does not follow natural haplotype distribution (inherent to imputation panels). The only inputs derived from real sequence data are variant distribution density per chromosome and learning sequencing error models. The synthetic dataset consists of two fastq files, a cram file, a vcf file, and two index files.

  Study EGAS50000000086

• Relation between transcriptome, karyotype and age in cases of sex chromosome aneuploidies.

  Why women live longer than men is still an open question in human biology. Sex chromosomes have been proposed to play a role in the observed sex gap in longevity, and the Y male chromosome has been suspected of having a potential toxic genomic impact on male longevity. It has been hypothesized that transposable element (TE) repression declines with age, potentially leading to detrimental effects such as somatic mutations and disrupted gene expression, which may accelerate the aging process. Given that the Y chromosome is rich in repeats, age-related increases in TE expression could be more pronounced in males, likely contributing to their reduced longevity compared to females. In this work, we first studied whether TE expression is associated with the number of sex chromosomes in humans. We analyzed blood transcriptomic data obtained from individuals of different karyotype compositions: 46,XX females (normal female karyotype), 46,XY males (normal male karyotype), as well as males with abnormal karyotypes, such as 47,XXY, and 47,XYY.

  Study EGAS50000001009

• Bulk and single-cell RNA-sequencing data from five lines of human iPSC-derived (hiPSC-derived) astrocytes (3 in-house and 2 commercial lines), both alone and in co-culture with neurons, to define the molecular response of astrocytes to misfolded alpha-synuclein

  RNA editing is a post transcriptional mechanism that targets changes in RNA transcripts to modulate innate immune responses. We report the role of astrocyte specific, ADAR1 mediated RNA editing in neuroinflammation in Parkinson’s disease. We generated hiPSC-derived astrocytes, neurons and co-cultures and exposed them to small soluble alpha-synuclein aggregates. Oligomeric alpha-synuclein triggered an inflammatory glial state associated with TLR activation, viral responses, and cytokine secretion. This reactive state resulted in loss of neurosupportive functions, and the induction of neuronal toxicity. Notably, interferon response pathways were activated leading to upregulation, and isoform switching of the RNA deaminase enzyme, ADAR1. ADAR1 mediates A-to-I RNA editing, and increases in RNA editing were observed in inflammatory pathways in cells, as well as in post-mortem human PD brain. Aberrant, or dysregulated, ADAR1 responses and RNA editing may lead to sustained inflammatory reactive states in astrocytes triggered by alpha-synuclein aggregation, and this may drive the neuroinflammatory cascade in Parkinson’s.

  Study EGAS50000000751

• Development of a fully human glioblastoma-in-brain-spheroid model for accelerated translational research

  In glioblastoma (GBM) the intricate interplay between tumor cells and the surrounding microenvironment plays a crucial role in tumor progression, invasion, and therapeutic resistance. So far, studying these interactions in a controlled and representative model system has been challenging. Here, we report the development of hGliCS, a human glioma-cortical spheroid model that allows the elucidation of the biology of GBM cells and their interactions with a human-specific brain-like microenvironment and neurons. GBM cells efficiently invade the cortical spheroids, forming a well-connected network of communicating cells. The heterogeneous cellular states of the GBM cells within this model closely resembled findings previously observed in glioblastoma patients and in mouse xenografts. We observed a transition from predominantly mesenchymal-like cells to heterotopic states with a high diversity. In contrast to the substantial changes observed in the tumor cell population, the impact of the GBM cells on the neurons was minimal. We further demonstrate the suitability of hGliCS to test compounds targeting tumor-specific neurobiological features.

  Study EGAS50000000757

• Linked-Read Whole Genome Sequencing Profiles Structural Variant Landscape of Gliomas with Barcode-Level Evidence

  Structural variants (SVs) play essential roles in glioma oncogenesis and offer prognostic insights, yet the SV landscape of gliomas has not been completely characterized due to previous technological limitations. To comprehensively profile the SV landscape of gliomas, we performed linked-read whole genome sequencing (LR-WGS) on 31 tumour samples from 20 glioma patients. Using barcode-level evidence, we validated known SVs and identified the presence of extrachromosomal DNA containing the EGFR sequence, which correlates with elevated EGFR expression. Additionally, we uncovered rare SVs affecting genes typically mutated by single nucleotide variants (SNVs), including those in the SWI/SNF chromatin remodeling complex. Our analysis also reveals selective chromosomal vulnerabilities to SVs, highlighting certain chromosomes as hotspots for SV accumulation. Collectively, our results demonstrate the utility of LR-WGS in accurately detecting SVs and thoroughly profiling SV landscapes using barcode-level evidence. The insights gained into the synergistic effects of SNVs and SVs on oncogenes further underscore the importance of integrating SV analysis when examining mutations in gliomas.

  Study EGAS50000000947

• Genome-wide analyses of cell-free DNA for therapeutic monitoring of patients with pancreatic cancer

  Determining response to therapy for patients with pancreatic cancer can be challenging. We evaluated methods for assessing therapeutic response using cell-free DNA (cfDNA) in plasma samples from 40 patients with metastatic pancreatic cancer as part of the CheckPAC trial (NCT02866383). Patients were evaluated before and after initiation of therapy using tumor-informed plasma whole-genome sequencing (WGMAF), and genome-wide cfDNA fragmentation profiles and repeat landscapes (ARTEMIS-DELFI). Of those assessed with WGMAF, molecular responders had a median overall survival (OS) of 319 days compared to 126 days for non-responders (HR=0.29, 95% CI=0.11–0.79, p=0.011). For ARTEMIS-DELFI, patients with low scores after therapy initiation had a longer median OS than patients with high scores (233 days versus 172 days, HR=0.12, 95% CI=0.046-0.31, p<0.0001). We validated ARTEMIS-DELFI in a separate cohort of 40 patients with pancreatic cancer who were part of the PACTO trial (NCT02767557). These analyses suggest that non-invasive mutation and fragmentation-based cfDNA approaches can identify therapeutic response of individuals with pancreatic cancer.

  Study EGAS50000000923

• Ancient tree-topologies and gene-flow processes among human lineages in Africa

  The deep history of human evolution in Africa remain intensely debated. We produced 73 novel high-quality whole genomes from 14 Central and Southern African populations with diverse cultural practices. With extensive simulations and machine-learning Approximate Bayesian Computation inferences, we reconstruct jointly their complex history of divergences and migrations. We find vast genome-wide diversity within and among populations, often uncorrelated with geography and cultural practices. This demonstrates the necessity to explicitly consider local genomic patterns, without merging samples indiscriminately into larger a priori categories, to reconstruct human evolutionary histories. We find that tree-like evolutions with long periods of drift between short periods of unidirectional gene-flow best explain the data, and that the lineage ancestral to Khoe-San populations diverged around 300,000 years ago from a lineage ancestral to rainforest hunter-gatherers and neighboring agriculturalists. We also find that short periods of ancient and recent gene-flow coincide with epochs of major ecological and cultural changes in Sub-Saharan Africa.

  Study EGAS50000001072