23217 results for "ega"

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• Cancer of Low survival and UnMet Need – Pathologist Initiated

  Despite significant advances in diagnostic cancer histopathology, a subset of tumors remain unable to be classified using WHO criteria. The resulting diagnostic uncertainty can result in inappropriate clinical management and negative patient outcomes. We investigated whether combining histopathology with whole genome and transcriptome sequencing (WGTS) could improve the classification of tumors that posed diagnostic dilemmas despite extensive histopathology and standard molecular work-up at a quaternary oncology center. We successfully sequenced 45 tumors from an initial set of 54 unclassified tumors (83% success rate). A confident diagnosis was made for 38/45 tumors (84%). Additionally, potential treatment targets were identified in 21/45 tumors (47%). Theoretical comparison with alternative assays demonstrated that WGTS was uniquely capable of detecting critical diagnostic findings in 15/38 tumors (39%). This work supports augmenting histopathology and standard molecular pathology with WGTS in the classification of difficult-to-diagnose tumors.

  Study EGAS00001008112

• Single-cell and spatial transcriptomic profiling of hormone-naïve localised prostate cancer

  Localised prostate cancers (PCa) are heterogeneous and multifocal, with diverse outcomes. Current prognostic methods are epithelium-centric, overlooking the complex cellular landscape within the tumour microenvironment (TME), which remains incompletely characterised. We performed a comprehensive analysis of cancerous and adjacent-benign cores from 24 patients with hormone therapy-naïve localised PCa using single-cell RNA-sequencing. By integrating copy number variation and transcriptional signatures, we classified epithelial cells across a malignant spectrum, revealing widespread molecular perturbation. We found an expansion of Club cell phenotypes, suggestive of Luminal dedifferentiation. We also performed a detailed annotation of stromal phenotypes, focusing on fibroblasts, and identified a novel peri-neural fibroblast population. Spatial transcriptomics elucidated the precise anatomical distribution of CAFs within the PCa TME. This study provides a valuable foundation for advancing our understanding of PCa pathobiology and developing a comprehensive cellular model of the disease.

  Study EGAS00001008332

• Adipose transcriptome and plasma metabolome responses after a 6-day very-low energy fast in obesity: a single-arm feeding trial (FASTOMICS-6)

  Background: Fasting and ketogenic diets have gained popularity due to potential health benefits, in part via autophagy and other protective processes. However, although the basic physiology of fasting is well-established, we lack a deeper understanding of mechanisms on the tissue level and associated metabolome changes, particularly in humans. Method: 4 males and 9 females with severe obesity underwent a very-low-energy in-hospital feeding study (600 kcal/day). Plasma (n=13) and subcutaneous adipose tissue (sAT) samples (n=12) were collected in the morning before and after 6 days and analysed by GC-MS/MS and RNA-sequencing, respectively. Gene set enrichment analysis (GSEA) and weighted gene co-expression network analysis were used to identify biological pathways and modules of affected genes and their correlation with plasma ketones and metabolites.

  Study EGAS50000001015

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

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

  Study EGAS00000000051

• Geographical structure and differential natural selection among North European populations

  European populations and epidemiological cohorts are of special significance in the current era of genomic research aiming to characterize the background of common human diseases. The genome sequence, detailed information of genetic variations between individuals, high-throughput molecular technologies and novel statistical strategies create new possibilities to define genetic and life-style risk factors behind common health problems. Studies of large population cohorts are needed to transform the genetic information to detailed understanding of the predisposing factors in diseases affecting most human populations. European twin cohorts provide a unique competitive advantage for investigations of the role of genetics and environment or life style in the etiology of common diseases. This project will apply and develop new molecular and statistical strategies to analyze unique European twin and other population cohorts to define and characterise the genetic, environmental and life-style components in the background of health problems like obesity, migraine, coronary heart disease and stroke, representing major health care problems worldwide.

  Study EGAS00000000033

• HG_Retroduplications_in_Neurodevelopmental_Disorders

  Mobile genetic Elements (MEs) are pieces of DNA which, through an RNA intermediate, can generate new copies of themselves elsewhere in the host genome. Additionally, MEs can facilitate the duplication of non-ME transcripts, typically genes, through the mechanism of retroduplication. In humans, several disorders have been directly attributed to ME-derived mutagenesis but not to retroduplication events. We propose to whole genome sequence the 7 individuals with putative de novo gene retroduplications in order to identify the site of insertion. This sequencing will serve two primary purposes: 1.) Identify the first documented case of a de novo retrogene insertion event causing a disease in humans 2.) provide additional whole genome sequencing of undiagnosed probands recruited into the DDD This data is part of a pre-publication release. For information on the proper use of pre-publication data shared by the Wellcome Trust Sanger Institute (including details of any publication moratoria), please see http://www.sanger.ac.uk/datasharing/

  Study EGAS00001002907

• NOWAC blood-based breast cancer case-control study

  Tumor-host interactions extend beyond the local microenvironment and cancer development largely depends on the ability of malignant cells to hijack and exploit the normal physiological processes of the host. Although abnormalities in a host’s systemic immunity are associated with increased cancer susceptibility, the functional interplay between tumor cells and circulating immune cells in regulating tumorigenic responses is unclear. We employed the Norwegian Women and Cancer study, a large prospective population-based cohort study, to identify gene expression changes in blood cells that provide a robust and reproducible diagnostic signal specific to breast cancer patients. We further show that circulating blood cells in breast cancer patients are enriched in genes involved in systemic immunosuppression and the motility, metabolism, growth, and proliferation of immune cells. By mining of the cancer-associated blood transcriptome, we identified immune mediators or biomarkers that could permit early detection of breast cancer and open avenues to novel targeted immunotherapies.

  Study EGAS00000000134

• Origination of Ovarian Cancer is Dependent on Specific Aneuploidy Landscape

  Ovarian high-grade serous carcinoma (HGSC), a highly chromosomally instable malignancy, develops through sequential stages of precursors in fallopian tubes including histologically unremarkable but TP53 mutated clones (p53 signature) and serous tubal intraepithelial carcinoma (STIC). Here, we applied RealSeqS to assess aneuploidy in 127 microdissected tubal regions. We found nearly all p53 signatures lost the entire Chr17 chromosome, offering a “two-hit” mechanism of both TP53 and BRCA1 in BRCA1 germline mutation carriers. Proliferatively active STICs harbor gains of 19q12 (CCNE1), 19q13.2, 8q24 (MYCyc), or 8q arm, while proliferatively dormant STICs show 22q loss. Based on aneuploidy patterns in a training set (n= 67), we developed an algorithm, REAL-FAST, to classify NFTE and STICs into 5 clusters. In an independent validation set (n= 72), REAL-FAST was able to detect STIC/HGSC with high sensitivity and specificity. Taken together, REAL-FAST promises a molecular test for diagnosing HGSC precursor lesions based on specific aneuploidy patterns.

  Study EGAS00001007220

• Colon cancer targeted sequencing study contaning WBCs, primary tumor tissue and plasma samples

  In the setting of localized colon cancer (CC), circulating tumor DNA (ctDNA) monitoring in plasma has shown potential for detecting minimal residual disease (MRD) and predicting higher risk of recurrence. With the tumor-only sequencing approach, however, germline variants may be misidentified as somatic variations, precluding the possibility of tracking in up to 11% of patients due to a lack of known somatic mutations. In this study comprising 148 prospectively recruited localized CC patients, a custom 29-gene panel was utilized to sequence both tumor tissue and matched white blood cells (WBCs) to enhance the accuracy of sequencing results. Performing targeted sequencing of paired tumor tissue and WBCs samples detected additional somatic mutations and increased the number of patients eligible for MRD tracking in plasma, although MRD detection sensitivity was not increased. Furthermore, the germline testing approach revealed the presence of pathogenic germline variants, thereby helping identify patients at elevated risk of hereditary cancer syndromes.

  Study EGAS50000000059

• Oxidative DNA damage and ubiquitin proteasome system dysfunction underpins neurodegeneration in young adults with a DNA repair disorder

  Xeroderma pigmentosum (XP) is caused by defective nucleotide excision-repair of DNA damage. This results in hypersensitivity to ultraviolet light and increased skin cancer risk, as sunlight-induced photoproducts remain unrepaired. However, many XP patients also display early-onset neurodegeneration, which leads to premature death. The mechanism of neurodegeneration is unknown. Here, we investigate XP neurodegeneration using pluripotent stem cells derived from XP patients and healthy relatives, performing functional multi-omics on samples during neuronal differentiation. We have identified substantially increased levels of 5',8-cyclopurine and 8-oxopurine in XP neuronal DNA secondary to marked oxidative stress. Furthermore, we find endoplasmic reticulum stress is upregulated, and, critically, XP neurons exhibit inappropriate downregulation of the protein clearance ubiquitin-proteasome system (UPS). Chemical enhancement of UPS activity improves phenotypes, albeit inadequately, implying that early detection/prevention strategies are necessary to produce clinically impactful outcomes. Thus, we develop an early detection assay predicting neurodegeneration in at-risk patients.

  Study EGAS50000000160

• Oxidative DNA damage and ubiquitin proteasome system dysfunction underpins neurodegeneration in young adults with a DNA repair disorder

  Xeroderma pigmentosum (XP) is caused by defective nucleotide excision-repair of DNA damage. This results in hypersensitivity to ultraviolet light and increased skin cancer risk, as sunlight-induced photoproducts remain unrepaired. However, many XP patients also display early-onset neurodegeneration, which leads to premature death. The mechanism of neurodegeneration is unknown. Here, we investigate XP neurodegeneration using pluripotent stem cells derived from XP patients and healthy relatives, performing functional multi-omics on samples during neuronal differentiation. We have identified substantially increased levels of 5',8-cyclopurine and 8-oxopurine in XP neuronal DNA secondary to marked oxidative stress. Furthermore, we find endoplasmic reticulum stress is upregulated, and, critically, XP neurons exhibit inappropriate downregulation of the protein clearance ubiquitin-proteasome system (UPS). Chemical enhancement of UPS activity improves phenotypes, albeit inadequately, implying that early detection/prevention strategies are necessary to produce clinically impactful outcomes. Thus, we develop an early detection assay predicting neurodegeneration in at-risk patients.

  Study EGAS50000000162

• Oxidative DNA damage and ubiquitin proteasome system dysfunction underpins neurodegeneration in young adults with a DNA repair disorder

  Xeroderma pigmentosum (XP) is caused by defective nucleotide excision-repair of DNA damage. This results in hypersensitivity to ultraviolet light and increased skin cancer risk, as sunlight-induced photoproducts remain unrepaired. However, many XP patients also display early-onset neurodegeneration, which leads to premature death. The mechanism of neurodegeneration is unknown. Here, we investigate XP neurodegeneration using pluripotent stem cells derived from XP patients and healthy relatives, performing functional multi-omics on samples during neuronal differentiation. We have identified substantially increased levels of 5',8-cyclopurine and 8-oxopurine in XP neuronal DNA secondary to marked oxidative stress. Furthermore, we find endoplasmic reticulum stress is upregulated, and, critically, XP neurons exhibit inappropriate downregulation of the protein clearance ubiquitin-proteasome system (UPS). Chemical enhancement of UPS activity improves phenotypes, albeit inadequately, implying that early detection/prevention strategies are necessary to produce clinically impactful outcomes. Thus, we develop an early detection assay predicting neurodegeneration in at-risk patients.

  Study EGAS50000000158

• scRNAseq data of CAP

  Fastq files from scRNAseq data of cancer associated pericytes-like from 3 patients. CAP were isolated from a total of 3 primary BC (surgical residues prior to any treatment) by using BDFACS ARIA III sorter (BD Biosciences). BC were collected directly from the operating room after surgical specimen macroscopic examination and selection of areas of interest by a pathologist. Samples were cut into small pieces (around 1 mm3) and digested in CO2-independent medium (Gibco #18045-054) supplemented with 150 μg/mL liberase (Roche #05401020001) and Dnase I (Roche #11284932001) for 40 min at 37°C with shaking (180 rpm). After digestion, cells were processed and stained as described above (#Flow Cytometry analysis of BC samples). CAP fibroblasts were then gated on the Live/Dead negative fraction and defined as EPCAM- CD45- CD31- CD235a- FAPMed CD29High. CAP scRNA-seq: Upon isolation, CAP cells were directly collected into RNase-free tubes (Thermo Fisher Scientific, #AM12450) precoated with DMEM (GE Life Sciences, #SH30243.01) supplemented with 10% FBS (Biosera, #1003/500). Single-cell capture, lysis, and cDNA library construction were performed using Chromium system from 10X Genomics, with the following kits: Chromium Single Cell 3′ Library & Gel Bead Kit v2 kit (10X Genomics, #120237) and Chromium Single Cell A Chip Kits (10X Genomics, #1000009). Generation of gel beads in Emulsion (GEM), barcoding, post GEM-reverse transcription cleanup and cDNA amplification were performed according to the manufacturer’s instructions. Cells were loaded accordingly on the Chromium Single cell A chips, and 12 cycles were performed for cDNA amplification. cDNA quality and quantity were checked on Agilent 2100 Bioanalyzer using Agilent High Sensitivity DNA Kit (Agilent, #5067-4626) and library construction followed according to 10X Genomics protocol. Libraries were next run on the Illumina HiSeq (for patients P1) and NovaSeq (for patients P2–3) with a depth of sequencing of 50,000 reads per cell.

  Dataset EGAD50000000321

• Karyotype Evolution in Response to Chemoradiotherapy and Upon Recurrence of Esophageal Adenocarcinomas

  The genome of esophageal adenocarcinoma (EAC) is highly unstable and might evolve over time. Here, we track karyotype evolution in EACs in response to treatment and upon recurrence through multi-region and longitudinal analysis. To this end, we introduce L-PAC, a bio-informatics technique that allows inference of absolute copy number aberrations (CNA) of low-purity samples by leveraging information of high-purity samples from the same cancer. Quantitative analysis of matched absolute CNAs reveals that the amount of karyotype evolution induced by chemoradiotherapy (CRT) is predictive for early recurrence and depends on the initial level of karyotype intra-tumor heterogeneity. We observe that CNAs acquired in response to CRT are partially reversed back to the initial state upon recurrence. CRT hence alters the fitness landscape to which tumors can adjust by adapting their karyotype. Together, our results indicate that karyotype plasticity contributes to therapy resistance of EACs.

  Study EGAS00001007711

• Multiomic spatial landscape of innate immune cells at central nervous system borders

  The innate immune compartment of the human central nervous system (CNS) is highly diverseand includes several immune cell populations such as macrophages that are frequent in the brain parenchyma (microglia) and less numerous at the brain interfaces as CNS-associated macrophages (CAMs).Due to their scantiness and particular location, little is known about the presence of temporally and spatially restricted CAM subclasses during development, health and perturbation. Here, we combined single-cell RNA-sequencing, time-of-flight mass cytometry and single-cell spatial transcriptomics with fate mapping and advanced immunohistochemistry to comprehensively characterize the immune system at human CNS interfaces. We also provide a comprehensive analysis of resident and engrafted myeloid cells in the brains of 15 individuals with peripheral blood stem cell transplantation, revealing compartment-specific engraftment rates across different CNS interfaces... Our results highlight myeloid diversity at the interfaces of the human CNS with the periphery and provide insights into the complexities of the human brain’s immune system.

  Study EGAS50000000030

• Immunomodulatory effects and improved outcomes with cisplatin- vs carboplatin-based chemotherapy plus atezolizumab in urothelial cancer

  In metastatic urothelial cancer (mUC), cisplatin versus carboplatin leads to durable disease control in a subset of patients. The IMvigor130 trial reveals more favorable effects with atezolizumab combined with gemcitabine and cisplatin (GemCis) versus gemcitabine and carboplatin (GemCarbo). This study investigates the immunomodulatory effects of cisplatin as a potential explanation for these observations. Our findings indicate that improved outcomes with GemCis versus GemCarbo are primarily observed in patients with pretreatment tumors exhibiting features of restrained adaptive immunity. Additionally, GemCis versus GemCarbo ± atezolizumab induces transcriptional changes in circulating immune cells, including upregulation of antigen presentation and T-cell activation programs. In vitro experiments demonstrate that cisplatin, compared with carboplatin, exerts direct immunomodulatory effects on cancer cells, promoting dendritic cell activation and antigen-specific T cell killing. These results underscore the key role of immune modulation in cisplatin's efficacy in mUC and highlight the importance of specific chemotherapy backbones in immunotherapy combination regimens.

  Study EGAS50000000104

• Improved detection of colibactin-induced mutations by genotoxic E. coli in organoids and colorectal cancer

  Co-culture of intestinal organoids with a colibactin-producing pks+ E. coli strain (EcC) revealed mutational signatures also found in colorectal cancer (CRC). E. coli Nissle 1917 (EcN) remains a commonly used probiotic, despite harboring the pks operon and inducing double strand DNA breaks. We determine the mutagenicity of EcN and three CRC-derived pks+ E. coli strains with an analytical framework based on sequence characteristic of colibactin-induced mutations. All strains, including EcN, display varying levels of mutagenic activity. Furthermore, a machine learning approach attributing individual mutations to colibactin reveals that patients with colibactin-induced mutations are diagnosed at a younger age and that colibactin can induce a specific APC mutation. These approaches allow the sensitive detection of colibactin-induced mutations in ~12% of CRC genomes and even in whole exome sequencing data, representing a crucial step towards pinpointing the mutagenic activity of distinct pks+ E. coli strains.

  Study EGAS50000000212

• Somatic mutations of non-malignant T cells

  Somatic mutations in T cells can cause cancer but also have implications for immunological diseases and cell therapies. The mutation spectrum in non-malignant T cells is unclear. Here, we examined somatic mutations in CD4+ and CD8+ T cells from 90 patients with hematological and immunological disorders and used T cell receptor (TCR) and single-cell sequencing to link mutations with T cell expansions and phenotypes. CD8+ cells had higher mutation burden than CD4+ cells. Notably, the biggest variant allele frequency (VAF) of non-synonymous variants was higher than synonymous variants in CD8+ T cells, indicating non-random occurrence. The non-synonymous VAF in CD8+ T cells strongly correlated with the TCR frequency, but not age. We identified mutations in pathways essential for T cell function and often affected in lymphoid neoplasia. Single-cell sequencing revealed cytotoxic Temra phenotypes of mutated T cells. Our findings suggest that somatic mutations contribute to CD8+ T cell expansions without malignant transformation.

  Study EGAS50000000237

• Human Brain Small Extracellular Vesicles Contain Selectively-Packaged, Full-Length mRNA

  Brain cells release and take up small extracellular vesicles (sEVs) containing bioactive nucleic acids. sEV exchange is hypothesized to contribute to stereotyped spread of neuropathological changes in the diseased brain. We assessed mRNA from sEVs of non-diseased (ND) and Alzheimer’s disease (AD) human postmortem brain, using short- and long-read sequencing. sEV transcriptomes were distinct from bulk tissue, showing enrichment for multiple genes including mRNAs encoding ribosomal proteins and L1Hs transposable elements. AD versus ND sEVs showed enrichment of inflammation-related and depletion of synaptic signaling mRNAs. sEV mRNA from cultured murine primary neurons, astrocytes, or microglia showed similarities with human brain sEVs and revealed cell-type specific packaging. Nearly 80% of human brain sEV transcripts sequenced using long-read sequencing were full-length. Motif analyses of sEV-enriched full-length isoforms revealed RNA-binding proteins that may be associated with sEV loading. Collectively, we show that mRNA in brain sEVs is selectively-packaged and altered by disease state.

  Study EGAS50000000029

• Peripheral blood DNA methylation and transcriptomics of vedolizumab and ustekinumab treatment response in patients with Crohn's disease

  Biological therapeutics are now widely used in Crohn’s disease (CD), with evidence of efficacy from randomised trials and real-world experience. Primary non-response is a common, poorly understood problem. We assessed blood methylation as a predictor of response to vedolizumab (VDZ, anti-a4b7 integrin) or ustekinumab (USTE, anti-IL-12/23p40). We report a two-center, prospective cohort study in which we profiled the peripheral blood DNA methylome of adult male and female CD patients. Samples were obtained prior to and during treatment with VDZ or USTE in a discovery and a validation cohort. Response to VDZ or USTE was defined based on a combination of ≥50% reduction in the endoscopic SES-CD score, corticosteroid-free clinical remission (≥3 point drop in HBI or HBI ≤4 and no systemic steroids) and/or biochemical response (C-reactive protein (CRP) and fecal calprotectin (FCP) reduction ≥50% or ≤5 mg/L and fecal calprotectin ≤250 µg/g).

  Study EGAS50000000263

• ZNF703 is a common Luminal B breast cancer oncogene that differentially regulates luminal and basal progenitors in human mammary epithelium.

  The telomeric amplicon at 8p12 is common in oestrogen receptor-positive (ER+) breast cancers. Array-CGH and expression analyses of 1172 primary breast tumours revealed that ZNF703 was the single gene within the minimal amplicon and was amplified predominantly in the Luminal B subtype. Amplification was shown to correlate with increased gene and protein expression and was associated with a distinct expression signature and poor clinical outcome. ZNF703 transformed NIH 3T3 fibroblasts, behaving as a classical oncogene, and regulated proliferation in human luminal breast cancer cell lines and immortalized human mammary epithelial cells. Manipulation of ZNF703 expression in the luminal MCF7 cell line modified the effects of TGFβ on proliferation. Overexpression of ZNF703 in normal human breast epithelial cells enhanced the frequency of in vitro colony-forming cells from luminal progenitors. Taken together, these data strongly point to ZNF703 as a novel oncogene in Luminal B breast cancer.

  Study EGAS00000000082

• Homopolymer switches mediate adaptive mutability in mismatch repair-deficient colorectal cancer

  Mismatch repair (MMR) deficient cancer evolves through the continuous erosion of coding homopolymers in target genes. Curiously, the MMR genes MSH6 and MSH3 also contain coding homopolymers and these are frequent mutational targets in MMR-deficient cancers. The impact of incremental MMR mutations on MMR-deficient colorectal cancer evolution is unknown. We show that microsatellite instability modulates DNA repair by toggling hypermutable mononucleotide homopolymer runs in MSH6 and MSH3 through stochastic frameshift switching. Spontaneous mutation and reversion modulates subclonal mutation rate, mutation bias, and clonal HLA and neoantigen diversity. Patient-derived organoids corroborate these observations and show that in the absence of immune selection MMR homopolymer sequences drift back into reading frame, suggesting a fitness cost of elevated mutation rates. Combined experimental and simulation studies demonstrate that subclonal immune selection favours incremental MMR mutations. Overall, our data demonstrate that MMR-deficient colorectal cancers fuel intratumour heterogeneity by adapting subclonal mutation rate and diversity to immune selection.

  Study EGAS50000000297

• Single cell chromatin accessibility allows analysis of the transposable element landscape, revealing shared features of immune tissue-residency

  Tissue adaptation is required for regulatory T (Treg) cells to function within organs. Whether this program shares similarities between different tissue-localized immune populations is poorly understood. Here, we addressed this by analyzing single-cell chromatin accessibility data, including the transposable element (TE) landscape, of CD45+ immune cells from different tissues. We identified features of organ-specific tissue adaptation across different immune cells. Focusing on tissue-Treg cells, we found that the Treg tissue adaptation program was conserved in other tissue-localized immune cells, such as amphiregulin-producing Th17 cells. Accessible TEs can act as regulatory elements but their contribution to tissue adaptation is unclear. TE landscape analysis revealed an enrichment of specific transcription factor binding motifs in TE regions within accessible chromatin peaks. TEs, specifically from the LTR family, were located in enhancer regions and associated with tissue adaptation. These findings broaden our understanding of immune tissue-residency, an important step towards organ-specific immune interventions.

  Study EGAS50000000350

• Spatially resolved niche and tumor microenvironmental alterations in gastric cancer peritoneal metastases

  Peritoneal metastases (PM) in gastric cancer (GC) portend a poor prognosis, yet our understanding of tumor microenvironmental (TME) characteristics associated with GCPM remain limited. Here, we analyzed intrinsic genomic alterations and transcriptomic programs predictive of GCPM in a prospective cohort of 248 patients, identifying CDH1, PIGR, and ELF3 mutations as predictors. By inspecting the spatial dynamics of the TME, we find that tumor compartment infiltration of pro-tumorigenic cell types such as inflammatory cancer-associated fibroblasts (CAFs) predict peritoneal recurrence. Next, in a cross-sectional study of 205 samples from 55 patients, distinct pathways and immune compositions in GCPM relative to liver metastases highlight the TME's significance in transcoelomic metastases. Notably, several putative therapeutic targets exhibited distinct expression patterns between PTs and PMs. Our findings highlight transcriptomic variations and niche reprogramming in the GCPM peritoneal environment, revealing roles of myeloid dendritic cells, effector memory CD8+ T cells, and CAFs in metastatic progression.

  Study EGAS50000000501

• Ultra-sensitive ctDNA monitoring required for predicting response and resistance to immunotherapy in advanced melanoma

  Circulating tumor DNA (ctDNA) monitoring in peripheral blood has shown promise for disease surveillance and prognostication of ICI response. Yet even in the metastatic context, ctDNA signals can be missed, suggesting the need for increased assay sensitivity. We used a tumor-informed ctDNA assay capable of detection down to 1 part-per-million (PPM) ctDNA to profile 188 plasma samples from 23 melanoma patients receiving ICI over several years. Residual disease was detected in ctDNA over a broad range, from 130,000 PPM down to 2.3 PPM, with approximately a quarter of detections below 50 PPM. Early on-treatment increases in ctDNA level, and both ctDNA-based molecular clearance (mCR) and molecular progression (mPD) were all prognostic of both OS and PFS. Additionally, mCR consistently preceded radiographic imaging. Our results show the importance and utility of an ultra-sensitive ctDNA assay in advanced melanoma treated by ICI with potential implications for other cancers.

  Study EGAS50000000550

• Genome sequencing identifies splice-disrupting variants in childhood heart disease

  We used genome sequencing (GS) to identify cardiac specific splice disrupting variants that were subsequently validated in a subset of participants. In turn, we developed a heart-specific model for canonical and non-canonical splice variants, which was applied to patients with congenital heart disease (CHD). These included patients with two of the most common forms of cyanotic CHD i.e. tetralogy of Fallot (TOF) and dextro-transposition of the great arteries (TGA). In addition to identifying canonical splice-disrupting variants in known CHD-related genes in 1% cases, this approach identified putatively damaging non-canonical splice-disrupting variants in 11% of isolated CHD, with deeply intronic variants representing 53% of non-canonical splice-disrupting variants in CHD genes. GS was critical for the identification of variants that would not be captured by routine clinical genetic tests including exome sequencing, while cardiac RNA-Seq allowed for high specificity in the interpretation of splice-disrupting effects in the heart.

  Study EGAS50000000586

• MutWP6__CRUK_Grand_Challenge_Mutographs_of_Cancer__alkylating_agents

  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. Within Mutographs, work lead by the Sanger Institute will investigate whether detection of somatic mutations and mutational signatures in circulating white blood cells can be developed into a practical, generic system for surveying and monitoring multiple different endogenous and exogenous exposures, providing an ‘observatory’ on somatic mutational processes in humans. Whole genome sequences are generated at the Wellcome Sanger Institute (Illumina HiSeqX). Somatic mutational signatures are subsequently extracted by non-negative matrix factorisation methods. 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 EGAS00001003637

• MutWP6__CRUK_Grand_Challenge_Mutographs_of_Cancer__oncology_agents

  he 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. Within Mutographs, work lead by the Sanger Institute will investigate whether detection of somatic mutations and mutational signatures in circulating white blood cells can be developed into a practical, generic system for surveying and monitoring multiple different endogenous and exogenous exposures, providing an ‘observatory’ on somatic mutational processes in humans. Whole genome sequences are generated at the Wellcome Sanger Institute (Illumina HiSeqX). Somatic mutational signatures are subsequently extracted by non-negative matrix factorisation methods. 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 EGAS00001004125

• Spatial atlas of human atherosclerosis highlights role of the microvasculature in disease

  Atherosclerosis is a pervasive contributor to ischemic heart disease and stroke. Despite the advance of lipid lowering-therapies and antihypertensive agents, the residual risk of an atherosclerotic event remains high and developing therapeutic strategies has proven challenging. This is due to the complexity of atherosclerosis with a spatial interplay of multiple cell types within the vascular wall. Here we generate an integrative high-resolution map of human atherosclerotic plaques combining single-cell RNA-seq from multiple studies and spatial transcriptomics data from 12 human specimens, with different stages of atherosclerosis. We show cell-type and atherosclerosis-specific expression changes and spatially constrained alterations in cell-cell communication. We highlight the possible recruitment of lymphocytes via ACKR1 endothelial cells of the vasa vasorum, the migration of vascular smooth muscle cells towards the lumen by transforming into fibromyocytes, and cell-cell communication in the plaque region, indicating an intricate cellular interplay within the adventitia and the subendothelial space in human atherosclerosis.

  Study EGAS50000000660

• Single-cell RNA sequencing of human skin tumors (BCC, SCC and Melanoma)

  Cancer-associated fibroblasts (CAFs) play a key role in cancer progression and treatment outcome. Here, we elucidate the yet unresolved intra-tumoral CAF variety in three skin cancer types at molecular and spatial single-cell resolution in a large cohort. We show that two out of three CAF subtypes contribute to tumor immune surveillance with distinct mechanisms. Matrix CAFs (mCAFs) ensheath tumor nests and synthesize extracellular-matrix to prevent T cell invasion. Immunomodulatory CAFs (iCAFs), which express proinflammatory and immunomodulatory factors, are only detected in high abundance in aggressive tumors. Strikingly, iCAFs but not tumor cells are (apart from immune cells) the exclusive cell type producing chemokines and, thus, play a key role in immune cell recruitment and activation. Mechanistically, we show that cancer cells transform adjacent healthy fibroblasts into cytokine-expressing iCAFs, which subsequently recruit immune cells and modulate the immune response. In conclusion, targeting CAF variants holds promise for improved efficacy of immunotherapy.

  Study EGAS50000000365

• Base-excision repair pathway shapes 5-methylcytosine deamination signatures in pan-cancer genomes

  Transition of cytosine to thymine in CpG dinucleotides is the most frequent type of mutation in cancer. This increased mutability is commonly attributed to spontaneous deamination of 5-methylcytosine (5mC), which is normally repaired by the base-excision repair (BER) pathway. However, the contribution of 5mC deamination in the increasing diversity of cancer mutational signatures remains poorly explored. Here, we integrate mutational signatures analysis in a large series of tumor whole genomes with lineage-specific epigenomic data to draw a detailed view on 5mC deamination in cancer. We uncover tumor type-specific patterns of 5mC deamination signatures in CpG and non-CpG contexts. We demonstrate that the BER glycosylase MBD4 preferentially binds to open chromatin domains, which correlates with lower mutational burden in these domains. We validate our findings by modelling BER deficiencies in isogenic cell models. Overall, we establish MBD4 as the main actor responsible for 5mC deamination repair in humans.

  Study EGAS50000000536

• Neoadjuvant nivolumab or nivolumab plus ipilimumab in early-stage triple negative breast cancer: phase 2 adaptive BELLINI trial. WES

  The adaptive BELLINI trial explored whether short combination ICI induces immune activation (primary endpoint: two-fold increase in CD8+ T cells or IFNG), providing rationale for neoadjuvant ICI without chemotherapy. In window of opportunity cohorts A (4 weeks anti-PD1) and B (4 weeks anti-PD1 + anti-CTLA4), we observed immune activation in 53% (8/15) and 60% (9/15) of patients, respectively. High tumor-infiltrating lymphocytes (TILs) correlated with response. Based on these data, we opened cohort C for patients with high TILs (≥50%) who received 6 weeks neoadjuvant anti-PD1 + anti-CTLA4 followed by surgery (primary endpoint: pathological complete response, pCR). 53% (8/15) of patients had major pathological response (< 10% viable tumor) at resection, with 33% (5/15) having pCR. All cohorts met Simon’s two-stage threshold for expansion to stage II. In conclusion, neoadjuvant immunotherapy without chemotherapy demonstrates potential efficacy and warrants further investigation in patients with early TNBC.

  Study EGAS50000000568

• Neoadjuvant nivolumab or nivolumab plus ipilimumab in early-stage triple negative breast cancer: phase 2 adaptive BELLINI trial. RNA-Seq

  The adaptive BELLINI trial explored whether short combination ICI induces immune activation (primary endpoint: two-fold increase in CD8+ T cells or IFNG), providing rationale for neoadjuvant ICI without chemotherapy. In window of opportunity cohorts A (4 weeks anti-PD1) and B (4 weeks anti-PD1 + anti-CTLA4), we observed immune activation in 53% (8/15) and 60% (9/15) of patients, respectively. High tumor-infiltrating lymphocytes (TILs) correlated with response. Based on these data, we opened cohort C for patients with high TILs (≥50%) who received 6 weeks neoadjuvant anti-PD1 + anti-CTLA4 followed by surgery (primary endpoint: pathological complete response, pCR). 53% (8/15) of patients had major pathological response (< 10% viable tumor) at resection, with 33% (5/15) having pCR. All cohorts met Simon’s two-stage threshold for expansion to stage II. In conclusion, neoadjuvant immunotherapy without chemotherapy demonstrates potential efficacy and warrants further investigation in patients with early TNBC.

  Study EGAS50000000567

• IL-17B uses IL-17RA and IL-17RB to induce Type-2 inflammation from human lymphocytes

  IL-17 family cytokines are critical to host defense responses at cutaneous and mucosal surfaces. Whereas IL-17A, IL-17F, and IL-17C induce overlapping inflammatory cascades to promote neutrophil-mediated immunity, IL-17E/IL-25 drives type 2 immune pathways and eosinophil activity. Genetic and pharmacological studies reveal the significant contribution these cytokines play in antimicrobial and autoimmune mechanisms. However, little is known about the related family member, IL-17B, with contrasting reports of both pro- and anti-inflammatory function in rodents. We demonstrate that in the human immune system, IL-17B is functionally similar to IL-25 and elicits type 2 cytokine secretion from innate type 2 lymphocytes, NKT, and CD4+ CRTH2+ Th2 cells. Like IL-25, this activity is dependent on the IL-17RA and IL-17RB receptor subunits. Furthermore, IL-17B can augment IL-33–driven type 2 responses. These data position IL-17B as a novel component in the regulation of human type 2 immunity.

  Study EGAS50000000579

• ROCHE PD 92 Multiome dataset

  This dataset contains 10X Multiome data generated on post-mortem brain from 92 individuals (70 PD, 22 controls). For the Roche_PD dataset, nuclei were isolated using Nuclei Pure Prep Nuclei Isolation Kit (Sigma Aldrich) with the following modifications. The tissue was lysed in Nuclei Pure Lysis Solution with 0.1% Triton X, 1mM DTT and 0.4U/ul SUPERase-In™ RNase Inhibitor (ThermoFisher Scientific) freshly added before use and homogenized with the help first of a 23G and then of a 29G syringe. Cold 1.8M Sucrose Cushion Solution, prepared immediately before use with the addition of1mM DTT and 0.4U/ul RNase Inhibitor, was added to the suspensions before they were filtered through a 30μm strainer. The lysates were then carefully and slowly layered on top of 1.8M Sucrose Cushion Solution previously added in new Eppendorf tubes. Samples were centrifuged for 45 minutes at 16000xg at 4°C. Pellets were re-suspended in Nuclei Storage Buffer with RNase Inhibitor, transferred in new Eppendorf tubes and centrifuged twice for 5 minutes at 500xg at 4°C. Finally purified nuclei were re-suspended in Nuclei Storage Buffer with RNase Inhibitor, stained with trypan blue and counted using Countess II (Life technology). After count, nuclei permeabilization was carried out following the demonstrated protocol for single cell multiome ATAC + Gene Expression sequencing from 10x Genomics. A total of 12,000 estimated nuclei from each sample was used for the transposition step and then loaded on the Chromium Next GEM Single Cell Chip J. ATAC library and gene expression library construction was performed using the Chromium Next GEM Single Cell Multiome ATAC + Gene Expression kit according to the manufacturer’s instructions. Libraries were sequenced using Illumina NovaSeq 6000 System and NovaSeq 6000 S2 Reagent Kit v1.5 (100 cycles), aiming at a minimum sequencing depth of 30K reads/nucleus. Genotype was generated as previously described (Bryois et al, Nature Neuroscience, 2022).

  Dataset EGAD50000000964

• Epstein-Barr Virus status drives morphological and molecular intra-tumour heterogeneity in gastric cancer: insights from a case report and literature review

  This case report describes a rare case of bi-phenotypic gastric cancer with two distinct, but clonally related, histological components. The first component, associated with Epstein-Barr virus (EBV) infection, exhibited the morphological features of gastric carcinoma with lymphoid stroma, suggesting that EBV, as an effective immunogenic factor, may trigger a prominent immune response within the tumour microenvironment. The second component, which was EBV-negative, displayed tubular/papillary morphology and features of increased biological aggressiveness, such as high-grade areas and lymphatic invasion. Immunohistochemical and molecular studies confirmed that, despite the differing morphologies and immunophenotypes, both components were clonally related, with especially the EBV-negative area showing more complex DNA aberrations, reminiscent of Chromosomally instable (CIN) lesions. This case describes clonally related EBV-positive and negative components within a single gastric cancer, contributing to a better understanding of EBV role in tumour heterogeneity and progression and highlighting the impact of EBV loss on tumour behaviour.

  Study EGAS50000000706

• Plasma mutation profile of precursor lesions and colorectal cancer using the Oncomine Colon cfDNA Assay

  Colorectal cancer (CRC) is the second leading cause of cancer death worldwide. Early detection of precursor lesions or early-stage cancer could hamper cancer development or improve survival rates. Liquid biopsy, which detects tumor biomarkers, such as mutations, in blood, is a promising avenue for cancer screening. To assess the presence of genetic variants in plasma cell-free tumor DNA from patients with precursor lesions and colorectal cancer using the commercial Oncomine Colon cfDNA Assay. Cell-free DNA (cfDNA) samples from the blood plasma of 52 Brazilian patients were analyzed. Eight patients did not have any significant lesions (five normal colonoscopies and three hyperplastic polyps), 24 exhibited precursor lesions (13 nonadvanced adenomas, ten advanced adenomas, and one sessile serrated lesion), and 20 patients with cancer (CRC). The mutation profile of 14 CRC-associated genes were determined by next-generation sequencing (NGS) using the Oncomine Colon cfDNA Assay in the Ion Torrent PGM/S5 sequencer.

  Study EGAS50000000471

• Single-cell Analysis of Neoplastic Plasma Cells Identifies Myeloma Pathobiology Mediators and Potential Targets

  Multiple myeloma is a clonal plasma cell (PC) dyscrasia that arises from precursors and has been studied utilizing approaches focused on CD138+ cells. By combining single-cell (sc)RNA- with scB-cell receptor (BCR)-sequencing, we differentiate monoclonal/neoplastic from polyclonal/normal PCs, and find more dysregulated genes, especially in precursor patients, than by analyzing bulk PCs. To determine if this approach can identify oncogenes that contribute to disease pathobiology, MAD2L1 and MAT2A are validated as targets with drug-like molecules that suppress myeloma growth in pre-clinical models. Moreover, functional studies show a role of LAMP5, which is uniquely expressed in neoplastic PCs, in tumor progression and aggressiveness via interactions with c-MYC. Finally, a monoclonal antibody recognizing cell-surface LAMP5 shows efficacy as an antibody-drug conjugate and in a chimeric antigen receptor-guided T-cell format. These studies provide additional insights into myeloma biology and identify potential targeted therapeutic approaches that can be applied to reverse myeloma progression.

  Study EGAS50000000802

• Cell-type eQTLs for single-cell Mendelian Randomisation

  The following study mapped eQTLs in the post-mortem human brain from snRNA-seq generated on 391 individuals. Following eQTL discovery and identification of state-specific eQTLs (dynamic associations interacting with disease), colocalisation and MR was performed integrating GWAS from 42 traits, for the identification of putatively causal genes with cell-type specific context. This study contains raw sequencing data and genotype for two datasets used in this work; - The MRC 60 dataset, which contains snRNA-seq generated on post-mortem brain from 60 control individuals (104 samples total, split across prefrontal cortex and hippocampus). Samples were pooled into 27 distinct pools, each of which was split across 4 lanes. Following sequencing and mapping using cellranger, demultiplexing was done using Demuxlet using the pool-specific genotype data (which contain sample IDs). - The Roche PD dataset, which is 10X multiome data generated on on 70 PD and 22 control individuals.

  Study EGAS50000000687

• Multiplexing cortical brain organoids for the longitudinal dissection of developmental traits at single cell resolution

  Dissecting human neurobiology at high resolution and with mechanistic precision requires a major leap in scalability, given the need for experimental designs to multiple individuals and, prospectively, population cohorts. To lay the foundation for this, we have implemented and benchmarked complementary strategies to multiplex brain organoids by pooling cells from different pluripotent stem cell lines (PSC) either during organoid generation (mosaic models) or before single cell-RNAseq library preparation (downstream multiplexing). We have also developed a new computational method, SCanSNP, and a consensus call to deconvolve cell identities, overcoming current criticalities in doublets prediction and low quality cells identification. We validated both multiplexing methods for charting neurodevelopmental trajectories at high resolution, thus linking specificity to genetic variation. Finally, we modelled their scalability across different multiplexing combinations and showed that mosaic organoids represent an enabling method for high-throughput settings. Together, this multiplexing suite of experimental and computational methods provides a highly scalable resource for disease modelling.

  Study EGAS50000000698

• Oncogenic FOXL2C134W has gain-of-function chromatin remodeling activity that reprograms glucocorticoid receptor occupancy to promote ovarian granulosa cell tumor growth

  Adult type ovarian granulosa cell tumors (AGCTs) are rare malignancies with near universal somatic mutation c.C402G (p.Cys134Trp) in FOXL2, a forkhead box-family transcription factor important for ovarian function. Relapsed AGCT is incurable and the mechanism of the unique FOXL2 mutation remains incompletely understood. To identify FOXL2C134W-dependent pharmacologic synergies, we created and characterized endogenous FOXL2 isogenic AGCT cells and an AGCT tumoroid biobank. A drug screen identified that glucocorticoids promote FOXL2C134W-dependent AGCT growth. Epigenetic investigation revealed that the Cys134Trp mutation exposes latent DNA sequence-specific pioneering activity in FOXL2, a unique oncogenic mechanism. FOXL2C134W pioneering activity redirects glucocorticoid receptor chromatin occupancy to drive hyaluronan synthase 2 gene expression and increase extracellular hyaluronan secretion. Treatment of AGCT models with hyaluronidase reduces viability and this effect can be rescued by dexamethasone. Thus, gain-of-function pioneering activity contributes to the oncogenic mechanism of FOXL2C134W and creates a potentially targetable synergy with glucocorticoid signaling.

  Study EGAS50000000622

• Single cell sequencing data of PBMC and CSF from a cohort of Multiple Sclerosis patients and other neurological disease controls

  Neuroinflammation is often characterised by immune cell infiltrates in the cerebrospinal fluid (CSF). Here we apply single-cell RNA sequencing to explore the functional characteristics of these cells in patients with various inflammatory, infectious and non-inflammatory neurological disorders. We show that CSF is distinct from the peripheral blood in terms of both cellular composition and gene expression. We report that the cellular and transcriptional landscape of CSF is altered in neuroinflammation, but is strikingly similar across different neuroinflammatory disorders. We find clonal expansion of CSF B and T cells in all disorders but most pronounced in inflammatory diseases, and we functionally characterise the transcriptional features of these cells. Finally, we explore the genetic control of gene expression in CSF lymphocytes. Our results highlight the common features of immune cells in the CSF compartment across diverse neurological diseases and may help to identify new targets for drug development or repurposing in Multiple Sclerosis.

  Study EGAS50000000739

• MethylBERT enables read-level DNA methylation pattern identification and tumour deconvolution using a Transformer-based model

  DNA methylation (DNAm) is a key epigenetic mark that shows profound alterations in cancer. Read-level methylomes enable more in-depth DNAm analysis due to the broad coverage and preservation of rare cell-type signals, compared to array-based data such as 450K/EPIC array. Here, we propose MethylBERT, a novel Transformer-based model for read-level methylation pattern classification. MethylBERT identifies tumour-derived sequence reads based on their methylation patterns and genomic sequence and the method estimates tumour cell fractions within bulk samples. In our evaluation, MethylBERT outperforms existing deconvolution methods and demonstrates high accuracy regardless of methylation pattern complexity, read length and read coverage. Moreover, we show its applicability to cell-type deconvolution as well as non-invasive early cancer diagnostics using liquid biopsy samples. MethylBERT represents a significant advancement in read-level methylome analysis and enables accurate tumour purity estimation. The broad applicability of MethylBERT will enhance studies on both tumour and non-cancerous bulk methylomes.

  Study EGAS50000000806

• Aberrant RNA-splicing (neojunctions) offers a new source for targets, and our neoantigen discovery platform (SNIPP) characterizes a novel class of clonally-expressed splicing-derived neoantigens that elicit a CD8+ T-cell-mediated tumor killing response.

  RESULTS: Our pipeline identified 789 public neojunctions, with 32 neojunctions concurrently identified in transcriptomic and proteomic glioma data and predicted to be presented by HLA-A*02:01 with high confidence. IVS and subsequent 10x VDJ scRNA-seq identified TCR clonotypes reactive against neojunctions in RPL22 (n=7) and GNAS (n=1), the latter being highly intratumorally-conserved (detected in &gt; 90% of spatially-mapped biopsies across 17/56 patients (26.78%)). TCR-transduced T-cells demonstrated recognition and immunogenic activation against endogenously processed and presented neoantigens in multiple GBM PDX cell lines. Furthermore, IDH1-mutant oligodendroglioma samples demonstrated significantly elevated expression of neojunctions over IDH1-mutant astrocytoma and IDH1wt subtypes. Differential gene expression (DESeq2) identified decreased expression of splicing factors due to oligodendroglioma-specific co-deletion of Chromosomes 1p/19q. siRNA knockdown of these splicing factors (e.g. SF3A3, SNRPD2) in IDH1wt glioma cells resulted in significantly increased expression of corresponding neojunctions.

  Study EGAS00001007986

• A Comprehensive Genetic Study of Classical Hodgkin Lymphoma Using Circulating Tumour DNA

  This study on classical Hodgkin lymphoma (cHL) used advanced methods to analyse circulating tumour DNA (ctDNA) in 297 cases, offering insights into its genetic landscape and linking it to disease pathophysiology and clinical progression. Key findings include the identification of whole genome duplication as a predictor of poor chemotherapy response. Additionally, a highly recurrent somatic expression quantitative trait locus of the BCL6 gene was discovered, implicating regulatory mutations in cHL pathophysiology and highlighting BCL6 as both a vulnerability and therapeutic target. Consensus clustering identified two cHL subtypes distinguished by the underlying mechanisms of genetic instability, rather than by specific genetic mutations or EBV infection. The study also linked the number and clonality of neoantigens with tumour microenvironment and response to checkpoint blockade. Finally, our results suggested ctDNA analysis as a tool to distinguish ambiguous PET/CT-positive lesions persisting after treatment, aiming to reduce unnecessary medical interventions.

  Study EGAS50000000873

• Identification and targeting of extremely high-risk gamma delta T-ALL in children

  Acute lymphoblastic leukemia expressing the gamma delta T cell receptor (γδ T-ALL) is an uncommon, poorly understood disease. We studied 200 pediatric γδ T-ALL enrolled on clinical trials to understand the clinical and genetic features of this disease, which showed variation in outcome according to age and genetic driver. γδ T-ALL diagnosed in children under three years of age was extremely high-risk and enriched for genetic alterations leading to both LMO2 activation and STAG2 inactivation. Using patient samples and isogenic cell lines, we show that inactivation of STAG2 profoundly perturbs chromatin organization by altering enhancer-promoter looping and results in deregulation of gene expression related to T-cell differentiation. High throughput drug screening identified a vulnerability in DNA repair pathways arising from STAG2 inactivation, which was efficaciously targeted by PARP inhibition. These data provide a diagnostic and therapeutic framework for classification and risk stratification of pediatric γδ T-ALL.

  Study EGAS50000000018

• Nivolumab plus chemotherapy or ipilimumab in gastroesophageal cancer: CheckMate 649 biomarker analyses

  First-line nivolumab-plus-chemotherapy demonstrated superior overall survival (OS) versus chemotherapy for advanced gastroesophageal adenocarcinoma (CheckMate 649). Nivolumab-plus-ipilimumab provided durable responses and higher survival rates versus chemotherapy; however, the prespecified OS significance boundary was not met. To identify biomarkers predictive of differential efficacy outcomes, exploratory analyses were performed using whole-exome sequencing and RNA sequencing. Nivolumab-based therapies demonstrated improved efficacy versus chemotherapy in hypermutated and, to a lesser degree, Epstein Bar Virus-positive tumors compared with chromosomally unstable and genomically stable tumors. Within the KRAS-altered subgroup, only patients treated with nivolumab-plus-chemotherapy demonstrated improved OS benefit versus chemotherapy. Low stroma gene expression signature scores were associated with OS benefit with nivolumab-based regimens; high regulatory T-cell signatures were associated with OS benefit only with nivolumab-plus-ipilimumab. Our analyses suggest that distinct and overlapping pathways contribute to the efficacy of nivolumab-based regimens in gastroesophageal adenocarcinoma.

  Study EGAS50000000747

• Sensitive neoantigen discovery by real-time mutanome-guided immunopeptidomics - RNAseq

  Targeting cancer-specific HLA-peptide complexes is a promising immunotherapy approach, with mutated neoantigens offering high value for their immunogenicity and cancer-specificity. Selecting immunogenic targets requires personalized prioritization of cancer-specific immunopeptides. Mass spectrometry (MS)-based immunopeptidomics supports this process by directly identifying cancer-specific antigens and informing global presentation patterns to refine immunogenicity predictions. Clinical pipelines, however, must balance global depth and target sensitivity compounded by low input samples and time constraints. Here, we present NeoDiscMS, an extension of the NeoDisc pipeline, enabling personalized immunopeptidomics data acquisition. By leveraging real-time NGS-guided spectral acquisitions, NeoDiscMS maximizing sensitivity with minimal loss of global depth. NeoDiscMS improves TAA-derived peptide detection up to 20% and enhances neoantigen identification confidence compared to the clinical gold standard method. Designed for effectiveness and ease of use, it requires minimal effort for implementation. NeoDiscMS advances personalization in clinical antigen discovery by enabling more sensitive neoantigen detection while seamlessly integrating into existing workflows.

  Study EGAS50000000977

• Single-cell transcriptional mapping reveals genetic and hierarchy-based determinants of aberrant differentiation in AML

  Therapeutic targeting of acute myeloid leukemia (AML) has in part been hampered by profound cell state heterogeneity among leukemia cells. To develop a more precise understanding of leukemia cell states in AML, we constructed a reference atlas of human hematopoiesis from 263,519 single cell transcriptomes spanning 55 cellular states. Using this atlas, we mapped over 1.2 million single-cell transcriptomes spanning 318 myeloid leukemia samples. This uncovered twelve recurrent patterns of aberrant differentiation in AML and additional leukemia cell states involving lymphoid and erythroid progenitors. Systematic mapping of genotype-to-phenotype associations revealed specific differentiation landscapes associated with >45 genetic drivers. Importantly, AML samples sharing common genetic driver alterations can have distinct cellular origins which inform the cellular identity of their disease-sustaining leukemia stem cell (LSC). Further, distinct LSC-driven hierarchies can co-exist within individual patients. Thus, precise mapping of malignant cell states provides insights into leukemogenesis, refines disease classification, and informs therapy development.

  Study EGAS50000000918

• Liquid Biopsy Detection of Tumor-specific Structural Variants in High Grade Serous Ovarian Cancer

  WGS Liquid Biopsy. Recurrence is frequent for most patients with high grade serous ovarian cancer (HGSOC), even after effective chemotherapy induced remission. However, after achievement of complete clinical response, the minimal residual disease is often insufficient for genomic analysis. Therefore, methods to interrogate the clonal composition and molecular properties of minimal residual disease are needed to better understand the mechanisms of HGSOC relapse. To address this unmet need, we developed and validated a novel cfDNA-based approach for tracking disease burden using NGS-informed tumor specific structural variants (SVs). Methods: The optimization of the methodology was first performed using synthetic cfDNA generated by ultrasonication of gDNA from ovarian cancer cell lines. Following the optimized workflow, whole genome sequencing of multisite biopsies from pre-treatment HGSOC patients were performed and high confidence SVs were called by consensus of multiple published SV callers. Real-time PCR and digital droplet PCR (ddPCR) were used for assays development.

  Study EGAS50000001044