12315 results for ""statistically+reactive"+taxa+in+microbial+community"

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• An APOBEC Cytidine Deaminase Mutagenesis in Human Cancers

  Reprinted from Roberts et al. "An APOBEC cytidine deaminase mutagenesis pattern is widespread in human cancers", Nature Genetics, 45:970-976, 2013, with permission of Nature Publishing Group: Recent studies indicate that a subclass of APOBEC cytidine deaminases, which convert cytosine to uracil during RNA editing and retrovirus or retrotransposon restriction, may induce mutation clusters in human tumors. We show here that throughout cancer genomes APOBEC-mediated mutagenesis is pervasive and correlates with APOBEC mRNA levels. Mutation clusters in whole-genome and exome data sets conformed to the stringent criteria indicative of an APOBEC mutation pattern. Applying these criteria to 954,247 mutations in 2,680 exomes from 14 cancer types, mostly from The Cancer Genome Atlas (TCGA), showed a significant presence of the APOBEC mutation pattern in bladder, cervical, breast, head and neck, and lung cancers, reaching 68% of all mutations in some samples. Within breast cancer, the HER2-enriched subtype was clearly enriched for tumors with the APOBEC mutation pattern, suggesting that this type of mutagenesis is functionally linked with cancer development. The APOBEC mutation pattern also extended to cancer-associated genes, implying that ubiquitous APOBEC-mediated mutagenesis is carcinogenic.

  Study phs000677

• KRT17High/CXCL8+ Tumor Cells Display Both Classical and Basal Features and Regulate Myeloid Infiltration in the Pancreatic Cancer Microenvironment

  Recent studies have uncovered the co-existence of basal and classical subtypes within pancreatic ductal adenocarcinoma (PDAC). We sought to characterize these intermediary cells using single-cell RNA sequencing of PDAC. We performed subtyping on 18 single-cell RNA sequencing human PDAC samples to identify multiple intermediary subtypes. We compared single-cell profiling of patient-matched blood and tumor samples to measure changes in the local and systemic immune microenvironments in CXCL8-high tumors vs. CXCL8-low tumors. Finally, we leveraged longitudinally patient-matched blood over the course of chemotherapy. In our studies we identified a cluster of KRT17high intermediary cancer cells that uniquely express high levels of CXCL8 and other cytokines which in turn influence the myeloid compartment both locally and systemically. We utilized sequencing data from dbGaP study accession phs002070. In addition to that, we included sequencing from new specimens which are deposited to this submission, consisting of one additional tumor specimen and 5 PBMC samples, sequenced after chemotherapy (longitudinally matched to PBMC samples in phs002071.v1.p1). FASTQ files of these sequencing runs are available through this dbGaP submission.

  Study phs003436

• Transcriptomic hallmarks and RNA isoform diversity in human neurodegenerative disease

  Single-cell RNA-sequencing (scRNA-seq) has enabled high-throughput RNA analysis at an unprecedented resolution. One staple analysis in scRNA-seq is identifying differentially expressed genes (DEGs) between two populations. However, the mRNA isoforms have often been overlooked in these transcriptomic analyses due to technical limitations. In order to investigate the mRNA isoforms at the single-cell level, we used a targeted single-nucleus long-read RNA-sequencing method combining single-nucleus short-read RNA-seq (snRNA-seq), target gene enrichment, and Iso-Seq. We performed snRNA-seq and targeted single-nucleus Iso-Seq (snIso-Seq) on 25 human frontal cortices from individuals with AD, DLB, or PD, and age-matched controls. Our short-read transcriptome analysis revealed that DLB samples had more overlapping DEGs with AD than PD despite sharing pathological hallmarks with PD. We observed vast RNA isoform diversity in the 50 genes targeted, including genes that were not differentially expressed in our short-read data. We also identified several novel isoforms that are not included in the reference annotation. Our data collectively characterize the transcriptome of various neurodegenerative diseases and illuminate the mRNA isoform diversity.

  Study EGAS50000000132

• Vaccine-Expanded Plasmablast-like B Cells Are Associated with Response to Dendritic Cell Therapy in Metastatic Melanoma

  Dendritic cells (DCs), either monocyte-derived (moDCs) or naturally circulating, have been employed in cancer treatment across both metastatic and adjuvant settings. DC vaccines (DC Vax) are capable of inducing tumor-specific immune responses, yet clinical outcomes have thus far fallen short of expectations. Here, we performed a multi-omics analysis of the apheresis product, including CD14⁺ monocytes, and the final DCVax formulation. Among all the components analyzed, the most striking finding was the unexpected presence of CD19⁺ B cells within the DC Vax formulation, which distinguished Responders from Non-Responders to moDC vaccination in metastatic melanoma. The abundance of B cells in DC Vax correlated with their peripheral frequency; however, within the vaccine, these cells acquired a CD20lowCD27hiCD38hi plasmablast-like phenotype, distinct from their autologous circulating B-cell precursors. Notably, a parallel observation was made in Responders, whose pre-treatment lesions were enriched in B cells organized as Tertiary Lymphoid Structures. These results underscore the importance of B cells in both baseline immunity and DCVax formulation, hinting at unexplored mechanisms by which they may influence vaccine effectiveness.

  Study EGAS50000001177

• NCI COVID-19 in Cancer Patients Study (NCCAPS): A Longitudinal Natural History Study

  NCCAPS is a longitudinal prospective cohort study designed to assess patient, disease and treatment factors associated with short- and long-term outcomes in patients with cancer who develop COVID-19. We also aimed to describe COVID-19 symptoms and treatments, and to describe disruptions in cancer treatment due to COVID-19. The study enrolled patients with cancer on active treatment or with a history of stem cell transplant or CAR-T cell therapy with new, active COVID-19, defined as being within 14 days of their first positive SARS-CoV-2 test. The study found that receipt of chemotherapy and baseline history of stroke, atrial fibrillation or pulmonary embolism were associated with a higher risk of hospitalization for COVID-19. Vaccination for SARS-CoV-2 was associated with a lower risk of hospitalization. Death due to COVID-19 was highest in patients with lymphoma, intermediate in those with acute leukemia and lung cancer, and lowest in those with other solid tumors and other hematologic cancers. Disruptions of cancer treatment were frequent in the first 30 days after SARS-CoV-2 infection.

  Study phs004178

• Dynamics of checkpoint receptors in γδ T cell subsets are associated with clinical responses during anti-PD-1 immunotherapies

  Gamma delta (γδ) T cells are innate-like lymphocytes with potent anti-tumor properties. Herein, we show that immune checkpoint receptors (ICRs) display differential expression and regulation by the JAK-STAT pathway in Vδ1 and Vδ2 cells and identify constitutive (e.g. TIGIT, PD-1) and inducible (e.g. TIM-3, LAG-3, CTLA-4) ICRs. In melanoma, all γδ T cell subsets downregulated AP-1 transcription factors, but Vδ1 cells specifically expressed high levels of ICR, TOX and inhibitory killer Ig-like receptor (KIR) transcripts, reminiscent of exhaustion. However, patient-derived cells were functionally competent, although induction of LAG-3 and CTLA-4 was impaired. During anti-PD-1 monotherapy, Vδ1 cells specifically bound high levels of therapeutic antibody but only in patients who responded to treatment, revealing a potential new prognostic marker for evaluating the efficacy of IC blockade (ICB) therapy. Finally, expression of KIR genes in Vδ1 cells was downregulated in response to successful ICB therapy. Collectively, our data indicate an intricate relationship between ICRs and γδ T cells and reveal novel approaches by which these cells can be harnessed in order to discern or improve cancer immunotherapy.

  Study EGAS50000001270

• Proteomic predictors of individualized nutrient-specific insulin secretion in health and disease

  Population level variation and molecular mechanisms behind insulin secretion in response to carbohydrate, protein, and fat remain uncharacterized despite ramifications for personalized nutrition. We now define prototypical insulin secretion dynamics in response to the three macronutrients in islets from 140 cadaveric donors, including those diagnosed with type 2 diabetes. We leverage the insulin response heterogeneity and use transcriptomics and proteomics to identify molecular pathways of specific nutrient responsiveness. Surprisingly, we find robust insulin secretion to fatty acid stimulus in ~8% of donors, challenging the idea that fat has negligible effects on insulin release. Distinct islet proteomes with differences in metabolic signalling networks convey this hyper-responsiveness to fat relative to carbohydrate. By comparing human islets to human embryonic stem cell-derived islet clusters, we show that, unlike glucose-responsiveness, fat hyper-responsiveness is equivalent and may be a hallmark of functionally immature cells. Our study represents the first comparison of dynamic responses to nutrients and multi-omics analysis in human insulin secreting cells. Responses of different people’s islets to carbohydrate, protein, and fat lay the groundwork for personalized nutrition.

  Study EGAS00001007241

• Whole-genome sequencing of two probands with hereditary spastic paraplegia reveals novel splice-donor region mutation and known pathogenic mutation in SPG11

  Hereditary spastic paraplegias (SPG) are a group of heterogeneous neurodegenerative disorders, which are often presented with overlapping phenotypes such as progressive paraparesis and spasticity. To assist the diagnosis of SPG subtypes, next-generation sequencing is often used to provide supporting evidence. In this study, we report the case of two probands from the same family with SPG symptoms, including bilateral lower limbs weakness, unsteady gait, cognitive decline, dysarthria and slurring of speech since age of 14. Subsequent whole-genome sequencing revealed that the patients are compound heterozygous for mutations in SPG11 gene, including the paternally inherited c.6856C>T (p.Arg2286*) mutation and the novel maternally inherited c.2316+5G>A splice donor region mutation. Mutations in SPG11 are the common cause of autosomal recessive Spastic Paraplegia type 11. According to the ClinVar database, there are already 101 reported pathogenic mutations in SPG11 that are associated with SPG. To our knowledge, this is the first report of SPG11 mutations in our local population. Novel splice mutation identified in this study would enrich the catalog of SPG11 mutations, potentially leading to better genetic diagnosis of SPG.

  Study EGAS00001001849

• Comprehensive characterization of cell-free tumor DNA in plasma and urine of patients with renal tumors

  Cell-free tumour-derived DNA (ctDNA) allows non-invasive monitoring of various cancers but its utility in renal cell cancer (RCC) has not been well established. A combination of untargeted and targeted sequencing methods, applied to two independent cohorts of patients (n=90) with various renal tumour subtypes, were used to determine ctDNA content in plasma and urine. Our data revealed lower plasma ctDNA levels in RCC relative to other cancers, with untargeted detection of ~33% for both cohorts. A highly sensitive personalised approach, applied to plasma and urine from select patients (n=22), improved detection to ~50%, including in patients with early stage and even benign lesions. A machine-learning based model, applied to untargeted data, predicted this detection, potentially offering a means of triaging patient samples for personalised analysis. We observed that plasma, and for the first time, urine ctDNA may better represent tumour heterogeneity than a single tissue biopsy. Longitudinal sampling of >200 plasma samples revealed that ctDNA can track disease course. These data highlight low ctDNA levels in RCC but indicate potential clinical utility provided improvement in isolation and detection approaches.

  Study EGAS00001003530

• ARAF Mutations Confer Resistance to RAF Dimer Inhibitor Belvarafenib in NRAS- and BRAF- Mutant Melanoma

  Belvarafenib, a potent and selective RAF dimer (type II) inhibitor, exhibits clinical activity in BRAFV600E- and NRAS-mutant melanoma patients. Here, we report the first-in-human phase I study investigating maximum tolerated dose, assessing safety and preliminary efficacy of belvarafenib in BRAF- and RAS-mutated advanced solid tumors (NCT02405065, NCT03118817). Through generation of belvarafenib resistant NRAS- mutant melanoma cells and analysis of circulating tumor DNA from patients treated with belvarafenib, we identified novel recurrent mutations in ARAF within the kinase domain. ARAF mutants conferred resistance to belvarafenib in both a dimer- and kinase activity- dependent manner. Belvarafenib induced ARAF mutant dimers, and dimers containing mutant ARAF were active in the presence of inhibitor. ARAF mutations may serve as a general resistance mechanism for RAF dimer inhibitors as the mutants exhibit reduced sensitivity to a panel of type II RAF inhibitors. The combination of RAF plus MEK inhibition may be used to delay ARAF-driven resistance and suggests a rational combination for clinical use. Taken together, our findings reveal specific and compensatory functions for the ARAF isoform and implicate ARAF mutations as a driver of resistance to RAF dimer inhibitors.

  Study EGAS00001005086

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

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

  Study EGAS00001005144

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

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

  Study EGAS00001003791

• Clonal relationships of ductal carcinoma in situ and recurrent invasive breast cancers defined by genomic analysis

  Ductal Carcinoma In Situ (DCIS) is the most common form of pre-invasive breast cancer and despite treatment a small fraction (5-10%) of DCIS patients present with invasive disease many years later. A fundamental biologic question is whether the invasive disease recurring in the same breast is established by tumor cells in the initial DCIS or represents new unrelated disease. To address this question, we performed genomic analyses on the initial pure DCIS lesion and paired invasive recurrent tumors in 95 patients together with single cell DNA sequencing in a subset of cases. Our data shows that in 75% the invasive recurrence was clonally related to the initial DCIS, suggesting that the tumor cells were not eliminated during the initial treatment with surgery +/- radiotherapy. Surprisingly however, 18% were clonally unrelated to the DCIS, representing new independent lineages, and 7% of cases were ambiguous. Our findings show that although DCIS is often the precursor of invasive recurrence, a significant fraction of invasive recurrences are unrelated to the initial DCIS. This knowledge is essential for accurate risk evaluation of DCIS treatment de-escalation strategies and the identification of predictive biomarkers.

  Study EGAS00001005784

• Clonal relationships of ductal carcinoma in situ and recurrent invasive breast cancers defined by genomic analysis

  Ductal Carcinoma In Situ (DCIS) is the most common form of pre-invasive breast cancer and despite treatment a small fraction (5-10%) of DCIS patients present with invasive disease many years later. A fundamental biologic question is whether the invasive disease recurring in the same breast is established by tumor cells in the initial DCIS or represents new unrelated disease. To address this question, we performed genomic analyses on the initial pure DCIS lesion and paired invasive recurrent tumors in 95 patients together with single cell DNA sequencing in a subset of cases. Our data shows that in 75% the invasive recurrence was clonally related to the initial DCIS, suggesting that the tumor cells were not eliminated during the initial treatment with surgery +/- radiotherapy. Surprisingly however, 18% were clonally unrelated to the DCIS, representing new independent lineages, and 7% of cases were ambiguous. Our findings show that although DCIS is often the precursor of invasive recurrence, a significant fraction of invasive recurrences are unrelated to the initial DCIS. This knowledge is essential for accurate risk evaluation of DCIS treatment de-escalation strategies and the identification of predictive biomarkers.

  Study EGAS00001006306

• MECOM represses myeloid differentiation through CEBPA downregulation in AML

  Transcription factor MECOM, located at 3q26, is essential for hematopoietic stem cells (HSCs) in healthy individuals. Enhancer translocations, due to 3q26 rearrangements, drive out-of-context MECOM expression in an aggressive subtype of leukemia (AML). Aberrantly expressed MECOM is essential for the survival and immature phenotype of these leukemia cells. Direct depletion of MECOM using an endogenous auxin-inducible degron rapidly upregulates expression of myeloid differentiation factor CEBPA. MECOM depletion is also accompanied by a severe loss of CD34 expression and gain of mature myeloid cell surface marker CD15. MECOM exerts its inhibitory effect on differentiation by binding to the +42kb CEBPA enhancer, which is essential for neutrophil development. This is partially dependent on the interaction between MECOM and its essential co-repressor CTBP2, a potential target in this type of AML. We demonstrate that CEBPA overexpression can bypass the MECOM-mediated block of differentiation. In addition, AML patients with MECOM overexpression through enhancer hijacking show significantly reduced CEBPA. Our study provides insight into the mechanism by which MECOM maintains the stem cell state in AML. Furthermore, CEBPA levels are an important read-out for successful targeting of MECOM in 3q26-rearranged AML.

  Study EGAS00001008005

• Genetic_variation_in_Kuusamo

  The aim of this study is to characterize as completely as possible the genetic variation and structure of Kuusamo and surrounding regions. We will perform low coverage, whole genome sequencing in a relatively limited number (approximately 200) of individuals from the FINRISK study both of whose parents are born in Kuusamo, Posio or Taivalkoski. Sequencing will be performed at the Wellcome Trust Sanger Institute (WTSI). We have previously shown using simulations and genome wide SNP data that the genetic characteristics agree with known genealogical data, and that approximately 200 individuals suffice to capture the majority of the genetic variation in this population.We have also developed methods for long-range haplotyping and long-range imputation, which are more accurate than traditional methods. This will allow us to identify a majority of the founder haplotypes in this population. The information from the haplotypes identified in this study can be used in other studies to impute from genome-wide SNP data the full genome sequence of samples ascertained for specific phenotypes.

  Study EGAS00001000020

• Whole Genome Study for De Novo Mutation Rates

  Germline mutations are the source of evolution and contribute substantially to many health-related processes. In this study, we use whole genome deep sequencing data from parents-offspring trios to examine the de novo point mutations (DNMs) in the offspring. We studied correlation between parental ages with de novo mutation rates. This study is published in Wong WS, Solomon BD, Bodian DL, Kothiyal P, Eley G, Huddleston KC, Baker R, Thach DC, Iyer RK, Vockley JG, Niederhuber JE. New observations on maternal age effect on germline de novo mutations. Nat Commun. 2016 Jan 19;7:10486 (PMID: 26781218. Also, we studied differences in molecular signatures in paternal versus maternal origin of de novo mutations. This study is published in Jakob M. Goldmann, Wendy S.W. Wong, Michele Pinelli, Terry Farrah, Dale Bodian, Anna B. Stittrich, Gustavo Glusman, Lisenka E.L.M. Vissers, Alexander Hoischen, Jared C. Roach, Joseph G. Vockley, Joris A. Veltman, Benjamin D. Solomon, Christian Gilissen, John E. Niederhuber. Parent-of-origin specific signatures of de novo mutations. Nat Genet. 2016 Aug;48(8):935-9, PMID: 27322544.

  Study phs001055

• CHDWB Rare Regulatory Alleles and Gene Expression Study

  In order to evaluate whether rare regulatory variants in the vicinity of promoters are likely to impact gene expression, we conducted a novel burden test for rare variants at the extreme of expression. After targeted sequencing of 2kb promoter regions of 472 genes in 410 healthy adults, burden tests were performed by calculating the summed rare allele counts in ranked expression level bins using Illumina whole blood microarray gene expression data. The results clearly show an enrichment of rare variants at both extremes of gene expression. The rare regulatory variant effects were also partitioned into subsets of genes based on their regulatory functions, positions relative to transcription start sites, disease relatedness, with some intriguing biases. The enrichment of rare regulatory variants in extremely expressed genes was replicated in an independent sample of 75 individuals with RNASeq and whole genome sequence information. Participants were from the Emory-Georgia Tech Center for Health Discovery and Well Being (CHDWB) longitudinal cohort study, but only baseline gene expression data was used.

  Study phs001021

• Genomic Profiling of Sequentially Acquired Metastatic Sites from an "Exceptional Responder" Lung Adenocarcinoma Patient Reveals Extensive Genomic Heterogeneity and Novel Somatic Variants

  We employed next-generation sequencing to identify somatic alterations in multiple metastatic sites from an "exceptional responder" lung adenocarcinoma patient during his seven year course of ERBB2-directed therapies. The degree of heterogeneity was unprecedented, with ~1% similarity between somatic alterations of the lung and lymph nodes. One novel translocation, PLAG1-ACTA2, present in both sites, up-regulated ACTA2 expression. ERBB2, the predominant driver oncogene, was amplified in both sites, more pronounced in the lung, and harbored an L869R mutation in the lymph node. Functional studies demonstrated increased proliferation, migration, metastasis, and resistance to ERBB2-directed therapy due to L869R mutation and increased migration due to ACTA2 overexpression. Within the lung, a nonfunctional CDK12, due to a novel G879V mutation, correlated with down-regulation of DNA damage response genes, causing genomic instability, and sensitivity to chemotherapy. We propose a model whereby a sub-clone metastasized early from the primary site and evolved independently in lymph nodes.

  Study phs001159

• 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

• 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

• Anti-TIGIT antibody tiragolumab improves PD-L1 blockade via myeloid and Treg cells

  Tiragolumab, an anti-TIGIT antibody with an active IgG1/kappa Fc, demonstrated improved outcomes in the phase 2 CITYSCAPE trial (NCT03563716) when combined with atezolizumab (anti-PD-L1) versus atezolizumab alone1. However, there remains little consensus on the mechanism(s) of response with this combination2. We found that high baseline intratumoral macrophages and Tregs were associated with better outcomes in patients treated with atezolizumab plus tiragolumab but not with atezolizumab alone. Serum sample analysis revealed that macrophage activation was associated with clinical benefit in patients receiving the combination treatment. In mouse tumor models, tiragolumab surrogate antibodies inflamed tumor-associated macrophages, monocytes, and dendritic cells through Fc gamma receptors (FcɣR), in turn driving anti-tumor CD8+ T cells from an exhausted effector-like state to a more memory-like one. These results uncover a mechanism of action by which TIGIT checkpoint inhibitors can remodel immunosuppressive tumor microenvironments, and suggest that FcɣR engagement is an important consideration in anti-TIGIT antibody development.

  Study EGAS50000000251

• LEF1 knockdown effects on human T cell transcriptome and chromatin accessibility profiles.

  LEF1 (Lymphoid Enhancer-Binding Factor 1) is a key transcription factor in T cell development and function, and its dysregulation has been implicated in various immune-related disorders. This study aimed to comprehensively characterize the transcriptional and epigenetic changes induced by LEF1 knockdown in human T cells. CD3+ T cells isolated from three healthy donors were transfected with either LEF1-specific siRNA or control siRNA, followed by activation with CD3/CD28 Dynabeads and culture in IL-2-containing media. Cells were harvested at 24, 48 and 72 hours post-transfection for multi-omics analysis including bulk RNA-seq, bulk ATAC-seq, single-cell CITE-seq (For CITE-seq, 48 and 72 hours only). This dataset provides insights into LEF1-dependent gene regulatory networks and chromatin accessibility patterns in activated human T cells, contributing to our understanding of T cell biology and potential therapeutic targets. This dataset is part of a comprehensive study investigating functional roles of risk polymorphisms in autoimmune diseases, particularly focusing on the rs58107865 variant at the LEF1 locus.

  Study JGAS000818

• CNA differences between RNA-based subtypes of PDAC

  Pancreatic ductal adenocarcinomas (PDAC) have a dismal prognosis with a 5-year survival of <5%. Chemoresistance and recurrences, seen in approximately 70% of PDAC patients, may partly be explained by intratumor heterogeneity (ITH) through which tumors may develop ‘escape routes’. In the Pancreas Multibiopsy (PM)-project we have obtained multiple fragments from pancreatic and other peri-ampullary carcinomas in order to reveal potential ITH and identify genetic aberrations that predict outcome after surgery and response to chemotherapy. CNA-profiles were used to complement the characterization of liabilities in PDAC that we identified previously using RNAseq in the form of epithelial, secretory, compound pancreatic, and mesenchymal subgroups that showed survival outcomes. Comparison of CNA-profiles between these transcriptomics-based subgroups (with 8, 3, 6, and 6 tumors respectively per group) showed differences, ranging from ‘quiet’(i.e. hardly any CNA) to ‘wild’(i.e. lots of CNA), but these were not statistically significant (Chi2 0.09). When differentiating between the classical and basal-like molecular subtypes of PDAC differences in CNA (high or low) were even less statistically significant (Chi2 0.292).

  Study EGAS50000001218

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

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

  Study EGAS50000001333