3883 results for "RNA AND sequencing OR transcriptome"

in 17.71 milliseconds.

• Biallelic tumor suppressor loss and DNA repair defects in de novo small cell prostate cancer

  Small cell prostatic carcinoma (SCPC) is an aggressive pathology that is managed similar to small cell lung cancer. SCPC can evolve from prostatic adenocarcinoma in response to androgen deprivation therapy but in rare cases is present at initial cancer diagnosis. The molecular etiology of de novo SCPC is incompletely understood due to the scarcity of tumor tissue and the brief life expectancy of patients. Through a retrospective search of our regional oncology pharmacy database, we identified 18 patients diagnosed with de novo SCPC between 2004 and 2017. Ten patients had pure SCPC pathology and the remainder had some admixed adenocarcinoma foci, but all were treated with first line platinum-based chemotherapy. Median overall survival was 28 months. We performed targeted DNA sequencing, whole exome sequencing and mRNA profiling on formalin-fixed paraffin embedded archival tumor tissue. We observed frequent biallelic deletion and/or mutation of tumor suppressors TP53, RB1 and PTEN, similar to treatment related SCPC. Indeed, at the RNA level pure de novo SCPC closely resembled treatment-related SCPC. However, five patients had biallelic loss of DNA repair genes including BRCA1, BRCA2, ATM and MSH2/6: potentially underlying the high genomic instability of this rare disease variant. Two patients with pure de novo SCPC harbored ETS gene rearrangements to androgen-driven promoters, consistent with evolution of de novo SCPC from an androgen-driven ancestor. Overall, our results reveal a highly aggressive molecular landscape underlies this unusual pathologic variant, and propose opportunities for targeted therapy strategies in a disease with few treatment options.

  Study EGAS00001003007

• Pharmacogenomic Analysis Reveals New Therapeutic Options for Pleural Mesothelioma

  Background: Pleural mesothelioma (PM) urgently requires novel effective treatments. Drug repurposing is a relevant strategy to discover new therapeutic options among well-known drugs used in clinical practice. This study aimed to identify new therapies in the context of molecular heterogeneity of PM. Methods: We performed a multi-omics study of the largest cohort of patient-derived primary PM cell lines (n=58) to date, using whole exome sequencing, RNA sequencing and methylome analysis. We also conducted a large-scale drug screening of over 1300 compounds on a subset of cell lines (n=11), as well as an extension screen (n=48) for selected drugs of interest. The best candidates were validated using 3D culture and mouse models. Results: We demonstrated that the molecular landscape of the cell lines cohort recapitulates the main findings in tumours and revealed new specific features of PM. The large-scale drug screening and subsequent validations highlighted notably strong sensitivity to entinostat and fluvastatin. Importantly, both compounds displayed same efficacy in 2D and 3D culture models and single treatment prolonged survival in vivo similarly or even better than standard chemotherapy. Strikingly, combining entinostat treatment with anti-PD1 led to cures in some mice and immunized them against tumour cells. Conclusions: Among several candidates, we identified entinostat, notably in combination with immune checkpoint inhibitor, and to a lesser extent fluvastatin, as promising therapeutic options for patients. We believe our study provides a valuable resource that could contribute to advances in the field and warrants further clinical investigation.

  Study EGAS00001007866

• Dataset for Sarcoma RNA sequencing linked from study EGAS00001004813

  Sequencing data of 410 sarcoma tumor runs, which were uploaded to EGAS00001004813. The sequencing was always paired.

  Dataset EGAD00001010276

• The Genomic and Transcriptomic Landscape of a HeLa Cell Line

  HeLa is the most widely used model cell line for studying human cellular and molecular biology. To date, no genomic reference for this cell line has been released, and experiments have relied on the human reference genome. Effective design and interpretation of molecular genetic studies performed using HeLa cells require accurate genomic information. Here we present a detailed genomic and transcriptomic characterization of a HeLa cell line. We performed DNA and RNA sequencing of a HeLa Kyoto cell line and analyzed its mutational portfolio and gene expression profile. Segmentation of the genome according to copy number revealed a remarkably high level of aneuploidy and numerous large structural variants at unprecedented resolution. Some of the extensive genomic rearrangements are indicative of catastrophic chromosome shattering, known as chromothripsis. Our analysis of the HeLa gene expression profile revealed that several pathways, including cell cycle and DNA repair, exhibit significantly different expression patterns from those in normal human tissues. Our results provide the first detailed account of genomic variants in the HeLa genome, yielding insight into their impact on gene expression and cellular function as well as their origins. This study underscores the importance of accounting for the strikingly aberrant characteristics of HeLa cells when designing and interpreting experiments, and has implications for the use of HeLa as a model of human biology. Copyright Landry et al., "The Genomic and Transcriptomic Landscape of a HeLa Cell Line," G3: Genes | Genomes | Genetics (2013).

  Study phs000643

• Comprehensive molecular and clinicopathological profiling of lung adenocarcinoma in Japanese never or light smokers

  Studies have yet to characterize the differences in molecular profiles of lung adenocarcinoma (LUAD) among divergent ethnic groups. Herein, we conducted comprehensive molecular profiling of LUAD in never or light smokers from Asia in order to discover novel targetable mutations and prognostic biomarkers of this distinct disease entity. Methods: We analyzed 996 cases of Asian LUAD, and performed whole-exome sequencing and/or RNA-seq in 125 cases of Asian LUAD negative for the driver oncogenes defined by conventional laboratory testing. We also investigated the clinical and pathological characteristics among the 996 cases. Results: Driver oncogenes were identified in 88 cases (70.4%) with specific hotspot mutations differing from those in The Cancer Genome Atlas (TCGA) study. Clustering based on mRNA expression profiles, but not genetic mutational ones, could predict patient prognosis. The risk score generated by the expression of a three-gene set was a strong prognostic marker for overall survival and progression-free survival in our cohort, and was further validated using TCGA cohort. Among the 996 cases, each driver alteration is distributed across all histological subtypes. Adenocarcinoma in situ was identified to harbor driver mutations, suggesting that these alterations are early events in the pathogenesis of LUAD. This study indicates the value of applying gene expression profiling for predicting the prognosis after a surgical operation, and that the identification of actionable mutations is important for optimizing targeted drugs in Japanese LUAD.

  Study JGAS000215

• Analysis of CD20 loss in patients treated with Mosunetuzumab

  CD20 is an established therapeutic target in B-cell malignancies. The CD20xCD3 bispecific antibody mosunetuzumab has significant efficacy in B-cell non-Hodgkin lymphomas (NHL). Since target antigen loss is a recognized mechanism of resistance, we evaluated the contribution of CD20 expression to clinical response in patients with relapsed and/or refractory NHL in the phase 1/2 GO29781 trial (ClinicalTrials.gov: NCT02500407) investigating mosunetuzumab monotherapy. CD20 was studied using immunohistochemistry (IHC), RNA sequencing, and whole-exome sequencing performed centrally in biopsies collected prior to treatment, or as paired samples at pre-dose and on-treatment, or at-progression. Prior to treatment, most patients exhibited a high proportion of tumor cells expressing CD20; however, the proportion of CD20+ tumor cells in 14/293 (6%) patients was <10%. Analyses of paired biopsies from patients during treatment revealed that CD20 levels were maintained in 29/30 (97%), vs patients with samples at-progression, in which 11/32 (34%) showed CD20 loss. Reduced transcription or acquisition of truncating mutations explained most but not all cases of CD20 loss. In vitro modeling confirmed the effect of CD20 variants identified in clinical samples on reduction of CD20 expression and confirmed missense mutations in the extracellular domain that could block mosunetuzumab binding. This study expands knowledge about the occurrence of target antigen loss after anti-CD20 therapeutics to CD20-targeting bispecific antibodies and elucidates the underlying mechanisms for reduced CD20 expression at disease progression that may be generalizable to other anti-CD20 targeting agents. These results also establish the utility of readily-available IHC staining for CD20 as a tool to inform clinical decisions.

  Study EGAS50000000151

• T-cell receptor sequencing of tumor-infiltrating lymphocytes (TIL) in breast cancer

  The spatial distribution of tumor-infiltrating lymphocytes (TIL) predicts breast cancer outcome and response to systemic therapy, highlighting the importance of an intact tissue structure for characterizing patients’ tumors. Here, we present ST-FFPE, a spatial transcriptomics method for the analysis of formalin-fixed paraffin-embedded samples, which opens the possibility of interrogating widely available archival tissue. The method involves extraction, exome capture and sequencing of RNA from different tumor compartments microdissected by laser-capture, and can be used to study the cellular composition of various tumor environments. Focusing on triple-negative breast cancer (TNBC), we characterized T cells, B cells, dendritic cells, fibroblasts and endothelial cells in both stromal and intra-epithelial compartments. We found a highly variable spatial distribution of immune cell subsets among tumors. This analysis revealed that the immune repertoires of intra-epithelial T and B cells were consistently less diverse than those of stromal T and B cells. T-cell receptor (TCR) sequencing confirmed a reduced diversity and revealed higher clonality of intra-epithelial T cells relative to the corresponding stromal T cells. Analysis of the top ten dominant clonotypes in the two compartments showed a majority of shared but also some unique clonotypes both in stromal and intra-epithelial T cells. Hyperexpanded clonotypes were more abundant among intra-epithelial than stromal T cells. These findings validate the ST-FFPE method and suggest an accumulation of antigen-specific T cells within tumor core. Because ST-FFPE is readily applicable for analysis of previously collected tissue samples, it could be useful for rapid assessment of intratumoral cellular heterogeneity in multiple disease and treatment settings.

  Study EGAS00001007125

• Multiomic Landscape of Multiple Myeloma Precursor and Relapsed Disease

  Multiple myeloma (MM) is a treatable, though incurable, plasma cell malignancy. The molecular mechanisms driving disease onset and the emergence of drug resistance remain elusive. To better characterize the mutational, transcriptional, and epigenetic alterations that accompany MM disease evolution, we accessed molecular data from MM patients treated at Moffitt Cancer Center, with bone marrow biopsies collected between 2011 and 2023.We performed scMultiome (single-cell, paired RNA/ATAC-Seq, 10x Genomics) on 18 CD138+-selected bone marrow aspirate samples, including: 2 healthy donors, 3 patients with monoclonal gammopathy of undetermined significance (MGUS), 4 with smoldering myeloma (SMM), 3 with newly diagnosed MM (NDMM), 1 with early relapse MM (ERMM, 1 to 3 lines of therapy), and 5 with late relapse MM (LRMM, 4 or more lines of therapy). Our dataset includes a sequential sample: a patient with a premalignant condition ("scMultiome_SMM_4") that progressed to active myeloma ("scMultiome_NDMM_3"). These data allow for the assessment of transcriptional and epigenetic dysregulation at the cellular level. Our findings illustrate the dynamic epigenetic and transcriptional landscapes that accompany MM disease progression.We also conducted CUT&Tag analysis on 4 NDMM and 4 LRMM samples to map histone modifications, specifically H3K27ac, to investigate their role in transcriptional reprogramming observed in advanced stages of MM. This analysis revealed sample heterogeneity in terms of super-enhancer-regulated genes associated with active transcription.This cohort also includes samples from the clinical trial NCT04151667, “Daratumumab-Based Response-Adaptive Therapy for Older Adults With Newly Diagnosed Multiple Myeloma.” We performed scRNAseq (single-cell RNA sequencing, 10x Genomics) on 30 CD138+-selected bone marrow aspirate samples and 31 pre-sort samples featuring bone marrow mononuclear cells of various cell types from 5 healthy donors and 11 patients with newly diagnosed MM (NDMM). Our dataset includes sequential samples for all 11 NDMM patients, both prior to induction therapy (denoted by ‘a') with Daratumumab and Dexamethasone, and at cycle 2 day 22 (C2D22, i.e., 60 days after induction therapy start, denoted by ‘b'). For three NDMM patients, we also have samples at relapse (denoted by ‘c'). These data allow for the assessment of transcriptional dysregulation at the single-cell level in both the tumor and immune-tumor microenvironment, associated with Daratumumab treatment in NDMM patients.In addition to the molecular data, demographic, and phenotypic information for all samples is provided.

  Study phs003892

• Single-cell RNA-seq of peripheral blood mononuclear cells in classic Hodgkin lymphoma

  Classic Hodgkin lymphoma (cHL) is a largely MHC class I-negative tumor with recurrent 9p24.1/ PD-L1/ PD-L2 copy gains and the highest reported response rates to PD-1 blockade. We utilized scRNA sequencing to characterize the peripheral immune response to PD-1 blockade and more broadly define non-CD8+ dependent mechanisms of immune evasion in cHL. Peripheral blood mononuclear cells were obtained from 20 patients with relapsed/refractory (R/R) cHL treated with PD-1 blockade (nivolumab) on the CheckMate 205 clinical trial (paired samples from cycle 1 day 1 [C1D1] and cycle 4 day 1 [C4D1]), 11 patients with newly diagnosed, previously untreated cHL and 13 healthy donors.

  Study EGAS00001007569

• Exploring the driver events of eccrine poromas and porocarcinomas: A retrospective, cross-institutional study of 90 cases

  Eccrine poroma (EP) and porocarcinoma (EPC) are rare benign and malignant adnexal neoplasms of the terminal sweat gland duct, respectively. Both can arise de novo, however, EPCs can also arise from a pre-existing EP. To-date, genetic investigation of these tumors has involved studies with small sample sizes and/or limited analyses. To comprehensively compare the driver events and mutational landscape of these tumors, we performed a retrospective multi-institutional whole-exome sequencing and RNA sequencing study on the largest cohort of EPs and EPCs to-date (n=90). We uncovered novel events and delineated different pathways of tumorigenesis underlying these tumors, with EPs driven largely by fusion genes, and EPCs driven largely by somatic mutations, with rare YAP1 and frequent PAK gene novel fusions.

  Dataset EGAD00001015376

• Exploring the driver events of eccrine poromas and porocarcinomas: A retrospective, cross-institutional study of 90 cases

  Eccrine poroma (EP) and porocarcinoma (EPC) are rare benign and malignant adnexal neoplasms of the terminal sweat gland duct, respectively. Both can arise de novo, however, EPCs can also arise from a pre-existing EP. To-date, genetic investigation of these tumors has involved studies with small sample sizes and/or limited analyses. To comprehensively compare the driver events and mutational landscape of these tumors, we performed a retrospective multi-institutional whole-exome sequencing and RNA sequencing study on the largest cohort of EPs and EPCs to-date (n=90). We uncovered novel events and delineated different pathways of tumorigenesis underlying these tumors, with EPs driven largely by fusion genes, and EPCs driven largely by somatic mutations, with rare YAP1 and frequent PAK gene novel fusions.

  Dataset EGAD00001015377

• Multiple Myeloma treated with anti-BCMA T-cell-redirecting therapy (1st Batch)

  Bone marrow samples were collected from patients treated with either anti-BCMA CART and/or anti-BCMA TCE. All samples were sorted using the StemCell EasySep Human CD138 positive selection kit II (StemCell, Cambridge, MA). The positive CD138+ were submitted for WGS, using peripheral blood mononuclear cells as normal matched. WGS was carried out by the Molecular Genomics Core Facility at Moffitt Cancer Center contingent on the availability of high-quality pre-treatment samples. Germline DNA was obtained from peripheral blood mononuclear cells, while tumor DNA was extracted from CD138-enriched bone marrow aspirate specimens using magnetic bead-based selection. Genomic DNA was isolated using the AllPrep DNA/RNA/miRNA Universal Kit (Qiagen). For library preparation, 100 ng of genomic DNA was fragmented using the Covaris ML230 focused ultrasonicator (Covaris, Inc.), followed by library construction with the TruSeq DNA Nano Library Prep Kit (Illumina) in accordance with manufacturer instructions. Library quality and fragment size distribution were assessed via Agilent TapeStation, and quantification was performed using the Kapa Library Quantification Kit (Roche). Sequencing was conducted on the Illumina NovaSeq 6000 system using S4-300 reagent kits with a 2×150 bp paired-end configuration. Tumor samples were sequenced to a median coverage of 60×, and matched germline controls to 30×. Reference Genome: GRCh38.

  Dataset EGAD50000002632

• BRAIN Cell EncyclOpeDia of Transcribed Elements (BRAINcode)

  BRAINCODE: How Does the Human Genome Function in Specific Brain Neurons? The human brain comprises about 86 billion neurons whose function is central to human biology. How does the human genome program high performing neurons and neural networks in response to experience? What subprograms does the genome express in physiologically and morphologically distinct brain cells? The goal of the BRAIN Cell encyclOpeDia of transcribed Elements Consortium (BRAINcode) is to provide a map of gene expression - both protein-coding and non-coding - in specific cell types, not in culture, but in situ in brains of people. Going beyond traditional mRNA sequencing, polyadenylated and non-polyadenylated transcripts were ultra deeply sequenced using ribo-depleted RNA from neurons laser-captured from human post-mortem brains. Three prototypical neuron types, dopamine neurons, pyramidal neurons, and Betz cells, were prioritized because of their key biologic roles and differential vulnerability to important neurodegenerative diseases such as Parkinson's or Alzheimer's disease. Genetic variation between individuals was examined for correlation with differences in transcribed sequences to identify regions of the genome that influence whether, how, and how much a transcript is expressed in specific cell types in human brains. Our results indicate a vast universe of annotated and novel non-coding RNAs expressed in brain cells and suggest a more diverse and much more complex transcriptional architecture than previously imagined.

  Study phs001556

• Integrated Metabolic Profiling and Gene Expression Analysis Reveals Therapeutic Modalities in Breast Cancer

  In this study, we performed metabolite profiling and RNA-sequencing on human breast cancer tumors and normal breast tissue samples, including triple negative breast cancer (TNBC), estrogen receptor positive breast cancer (ER+) and paired normal samples, and patient-derived xenografts (PDX) samples. Here, we report two distinctive groups defined by metabolites; a TNBC-HIGH group that shows high levels of pyrimidine pathway metabolites and biosynthetic enzymes, and an ER-HIGH group that shows high levels of fatty acid and arginine biosynthesis intermediates. We identify different metabolic enrichment profiles between cell lines grown in vitro vs. in vivo; cell lines grown in vivo recapitulate patient tumors metabolic profiles. Further, we identify a subset of genes that strongly correlates with the TNBC-HIGH metabolic profile using integrated metabolic and gene expression profiling, which strongly predicts patient prognosis when tested on larger human datasets. As a proof-of-principle, when we target TNBC-HIGH metabolic dysregulation with a pyrimidine biosynthesis inhibitor (Brequinar), and/or a glutaminase inhibitor (CB-839), we observe therapeutic efficacy and decreased tumor growth in representative TNBC cell lines, murine p53-null mammary tumors, and in vivo patient-derived xenografts (PDXs) upon multi-agent drug treatment. This study highlights potential new therapeutic opportunities in breast cancers guided by a genomic biomarker, which could prove impactful for breast cancers that rapidly proliferate.

  Study phs002396

• Genetic and Hormonal Contributions to Gene Expression in Immune Cells

  The origins of sex differences in human disease are elusive, in part because of difficulties in separating the effects of sex hormones and sex chromosomes. To isolate the effects of testosterone, estradiol, and sex chromosome complement (XX or XY) in humans, we implemented a four-state, cross-sectional study design of trans- and cisgender individuals, the former receiving exogenous testosterone or estradiol for at least a year as part of their gender-affirming medical care. This study design allowed us to compare four combinations of sex hormones and sex chromosomes in humans: XX individuals treated with exogenous testosterone (n=21), XY individuals treated with exogenous estradiol (n=13), untreated XX individuals (n=20), and untreated XY individuals (n=15). We chose to focus on the human immune system because it displays an impressively broad range of sex-differential biology. We collected blood samples from each individual and isolated PBMCs the same day. We performed 10X Genomics 3' single-cell RNA-sequencing (scRNA-seq) on PBMCs from the 69 individuals. We generated 150-bp paired end reads from a total of 358,426 cells (with an average of 48,007 reads/cell) and identified 18 distinct immune cell types. We found that testosterone, estradiol, and sex chromosome complement have unique, non-overlapping effects on PBMC cell abundances and gene expression.

  Study phs003860

• Investigating Host Genetic Risk Factors for Tuberculosis in Highly Endemic South African Populations

  It is apparent from our recent population genetic and admixture mapping work 1–3 that a substantial part of the ancestral input into the South African Coloured (SAC) population is from the San or Khoe groups, which are not well represented in publicly available genetic databases. It is a reasonable assumption that the SAC population in the Western Cape may have derived more genetic input from the present KhoeSan population in the Northern Cape than the San residing in Namibia. It was concluded by our group that it is indeed the southern African KhoeSan group, the ≠Khomani, that best represent the KhoeSan contribution seen in the SAC 4. More recently, it has been shown that there are ancestry related increases in TB susceptibility, especially with increased Bantu-speaking African and KhoeSan ancestry 5. We aim to elucidate the epidemiological and human-host genetic risk factors for TB and the immunological pathways modulating TB infection. The proposed sub-study will enroll people evaluated for TB at Northern Cape community health clinics and their contacts from their households and/or community. We will conduct a demographic interview, collect saliva, which will be used for genetic analysis, and blood to determine latent TB infection status and capture immunological responses to mycobacterial infections at the cellular level and RNA sequencing.

  Study EGAS00001007850

• INSPIRE - Investigator-initiated Phase 2 Study of Pembrolizumab Immunological Response in Metastatic Solid Tumors

  Whole exome and RNA sequencing source data for: Clouthier, D.L., Lien, S.C., Yang, S.Y.C. et al. An interim report on the investigator-initiated phase 2 study of pembrolizumab immunological response evaluation (INSPIRE). j. immunotherapy cancer 7, 72 (2019). https://doi.org/10.1186/s40425-019-0541-0 Bratman S*, Yang SYC*, Iafolla MAJ, Liu Z, Hansen AR, Bedard P, Lheureux S, Spreafico A, Razak AA, Shchegrova S, Louie M, Billings P, Zimmerman B, Sethi H, Aleshi A, Torti D, Marsh K, Eagles J, Cirlan I, Hanna Y, Clouthier D, Lien SC, Ohashi PS, Xu W, Siu LL, Pugh TJ. Personalized circulating tumor DNA analysis as a predictive biomarker in solid tumor patients treated with pembrolizumab. Nature Cancer. 2020:1:873-881. https://doi.org/10.1038/s43018- 020-0096-5. Yang SYC, Lien SC, Wang BX, Clouthier DL, Hanna Y, Cirlan I, Zhu K, Bruce JP, El Ghamrasni S, Iafallo MAJ, Oliva M, Hansen AR, Spreafico A, Bedard PL, Lheureux S, Razak A, Speers V, Berman HK, Aleshin A, Haibe-Kains B, Brooks DG, McGaha TL, Butler MO, Bratman SV, Ohashi PS, Siu LL, and Pugh TJ. Pan-cancer analysis of longitudinal metastatic tumors reveals genomic alterations and immune landscape dynamics associated with pembrolizumab sensitivity. Nature Comm 2021:12, 5137. https://doi.org/10.1038/s41467-021-25432-7

  Study EGAS00001003280

• A prognostic human brain network for diffuse midline glioma

  Diffuse midline glioma (DMG) are near-universally lethal tumours of the paediatric central nervous system. In animal models, DMG form brain-wide, integrated networks through neuron-to-glioma synapses and glioma-to-glioma gap junctional coupling. This extensive connectivity robustly promotes the growth and invasion of DMG and other glial malignancies through paracrine mechanisms and direct neuron-to-glioma synapses. The organisation and clinical implications of these connections in the living human brain, however, remain to be elucidated. Here, we develop tumour network mapping to compute the brain-wide connectivity profile of DMG: defining a conserved brain network across pontine and thalamic DMG associated with patient short-term survival (DMG network). Tumour functional connectivity with the DMG network was independently predictive of patient overall survival across two external validation cohorts. Tumour growth mapped to DMG network-specific trajectories and peak, in-network neurometabolic changes across development spatiotemporally aligned with the peak age incidence of DMG. Single-nucleus RNA-sequencing confirmed diverse synaptic gene enrichment in high-connectivity DMG. Strikingly, incidental surgical resection of high-connectivity thalamic DMG tissue conferred a significant survival advantage. Collectively, these data define a conserved and prognostically important brain network in children with DMG, consistent with the hypothesis that DMG exploit otherwise healthy brain circuits to promote tumour growth.

  Study EGAS50000001752

• scRNA-seq of HGSC tumor and ascites

  Immune regulatory metabolites are key features of the tumor microenvironment (TME), yet with a few notable exceptions, their identities remain largely unknown. We uncovered the immune regulatory metabolic states and metabolomes of sorted tumor and stromal, CD4+, and CD8+ cells from the tumor and ascites of patients with high-grade serous ovarian cancer (HGSC) using high-dimensional flow cytometry and metabolomics supplemented with single cell RNA sequencing. Flow cytometry revealed that tumor cells show a consistently greater uptake of glucose than T cells, but similar mitochondrial activity. Cells within the ascites and tumor had pervasive metabolite differences, with a striking enrichment in 1-methylnicotinamide (MNA) in T cells infiltrating the tumor compared to ascites. Despite the elevated levels of MNA in T cells, the expression of nicotinamide N-methyltransferase, the gene encoding the enzyme that catalyses the transfer of a methyl group from S-adenosylmethionine to nicotinamide, was restricted to fibroblasts and tumor cells. Treatment of T cells with MNA resulted in an increase in T cell-mediated secretion of the tumor promoting cytokine tumor necrosis factor alpha. Thus, the TME-derived metabolite MNA contributes to an alternative and non-cell autonomous mechanism of immune modulation of T cells in HGSC. Collectively, uncovering the tumor-T cell metabolome may reveal metabolic vulnerabilities that can be exploited using T cell-based immunotherapies to treat human cancer.

  Study EGAS00001004829

• Single cell transcriptomics of hESC-derived midbrain dopaminergic neurons generated by a new human development-based protocol

  Recent advances in stem cell technologies provide new opportunities for regenerative medicine and Parkinson’s disease modelling. However, the precise composition and quality of human embryonic stem cell (hESC)-derived preparations at the single cell level, compared to endogenous brain standards, remains to be determined. In addition, multiple developmental pathways important for midbrain dopaminergic (mDA) neuron development remain to be implemented in hESCs. Here we use mouse developmental knowledge and human single cell RNA-sequencing (scRNA-seq) data to generate a new development-based protocol to differentiate hESCs into mDA neurons. We found that Laminin 511, dual WNT activation with CHIR99021 and WNT5A, together with FGF8b, improved different aspects of midbrain patterning. Moreover, mDA neurogenesis and differentiation were enhanced by activation of liver X receptors and inhibition of fibroblast growth factor signaling. Analysis of hESC-derived midbrain cultures by scRNA-seq revealed multiple hESC-derived clusters, which resembled those in the endogenous human ventral midbrain. Moreover, high quality mDA neurons were detected and found to progressively acquire functionality in vitro. Thus, we hereby provide a hESC differentiation protocol that recapitulates several aspects of endogenous mDA neuron development, and a strategy to determine cell composition and quality of hESC-derived preparations that can be useful for disease modeling and cell therapy.

  Study EGAS00001006313

• BMP4 and temozolomide synergize in the majority of patient derived glioblastoma cultures

  The poor prognosis of patients with glioblastoma is partly due to resistance to standard treatment, which combines chemoradiation using temozolomide (TMZ). The concept of cancer stem cells provided new insight into tumor resistance and management, and isolated Glioblastoma stem-like cells (GSCs) which contribute to this therapy resistance. Bone morphogenetic protein 4 (BMP4) is a differentiation factor that stimulates astroglial differentiation of such GSCs, thereby reducing their self-renewal. Exposing GSCs to BMP4 could therefore sensitize them to chemotherapy with TMZ, but previous studies with various treatment paradigms have produced contradictory results in this matter. Therefore, we re-defined the optimal treatment paradigm for the combination of TMZ and BMP4 and subsequently re-assessed the inter-tumoral variability in response to co-treatment with TMZ+BMP4 in vitro. First, the simultaneous treatment was found more effective than sequential therapy. Second, after application of our optimized treatment protocol, 70% of a total of 20 patient-derived glioblastoma cultures showed synergy when the treatments were combined. The synergistic effect was a result of increased cellular apoptosis and not of decreased proliferation. Comparative RNA-sequencing suggested that combination treatment results in decreased MAPK signaling. We conclude that addition of BMP4 to standard therapy with TMZ could enlarge the group of patients with good therapeutic response.

  Study EGAS00001007095

• Resistance to Checkpoint Blockade Therapy Through Inactivation of Antigen Presentation

  Although immune checkpoint blockade (CPB) leads to prolonged responses in 15-40% of patients with metastatic melanoma, treatment refractory disease and progression after initial response remain major causes of mortality. While predictors of response have been reported, the common mechanisms of both primary and acquired resistance are poorly understood. To identify mechanisms of resistance and examine the evolving landscape in response to CPB, we performed whole exome sequencing (WES), immunohistochemistry (IHC), and RNA-sequencing (RNAseq) of longitudinal tumor biopsies from 17 metastatic melanoma patients treated with various CPB therapies. We found no significant changes in both mutational and neoantigen loads over time between responders and nonresponders. However, we identified abnormalities in one gene, beta-2-microglobulin (B2M), an essential component of MHC Class I antigen presentation, that were present in samples during disease progression but not regression. In total, we identified B2M aberrations in 29.4% of patients, including multiple early frameshift mutations, loss of heterozygosity (LOH) overlapping B2M, and absence of tumor-specific B2M protein expression. Additional defects in the antigen presentation and IFNγ pathways were identified but were not restricted to progressing lesions in our cohort. In two independent cohorts of 105 and 38 melanoma patients treated with ipilimumab (anti-CTLA4) and pembrolizumab (anti-PD1) respectively, we found that B2M LOH was enriched 3-fold in nonresponders (~30%) vs. responders (~10%) and associated with poorer overall survival (log-rank p=0.01, p=0.006). Loss of both copies of B2M was found only in nonresponders. We also found evidence for association of LOH overlapping IFNGR1 with poorer overall survival exclusively in the anti-PD1 cohort. Thus, B2M loss is likely a common mechanism of primary and acquired resistance to therapies targeting CTLA4 or PD-1.

  Study phs001427

• A Phase I Study With a Personalized Neoantigen Cancer Vaccine in Glioblastoma Multiforme

  Neoantigens, which are derived from tumor-specific protein-coding gene mutations, are exempt from central tolerance, can generate robust immune responses and function as bona fide antigens that facilitate tumor rejection. A strategy of using multi-epitope and personalized neoantigen vaccination has previously been tested in patients with high-risk melanoma. We demonstrated that this strategy is feasible for glioblastoma (GBM) which typically has a relatively low mutation load and an immunologically 'cold' tumor microenvironment. We conducted whole exome sequencing (WES) of tumor and normal cells from individual GBM patients to identify tumor-specific mutations. We assessed the expression of mutated alleles by RNA-sequencing of tumor, and used personalized neoantigen-targeting vaccines to immunize newly diagnosed GBM patients following surgical resection and conventional radiotherapy in a phase I/Ib study. Patients who did not receive dexamethasone, a highly potent corticosteroid that is frequently prescribed to treat cerebral oedema in GBM patients, generated circulating polyfunctional neoantigen-specific CD4+ and CD8+ T cell responses that were enriched in a memory phenotype and showed an increase in the number of tumor-infiltrating T cells. Using single-cell T cell receptor analysis, we provided an evidence that neoantigen-specific T cells from the peripheral blood can migrate into an intracranial GBM tumor. Neoantigen-targeting vaccines thus have the potential to favorably alter the immune environment of GBM.In order to discover cancer antigens derived from annotated and unannotated protein-coding regions of the genome, we carried out matched ribosome profiling (Ribo-Seq) on two GBM samples. We discovered novel or unannotated open reading frames (nuORFs) and their expression levels as well as somatic mutations within the nuORFs, which could be used to predict potential neoantigens.

  Study phs001519

• THAP11 mutations in a patient with a cblX-like phenotype implicates THAP11 in the regulation of cobalamin metabolism and early vertebrate development

  Mutations in HCFC1 are associated with cblX (MIM309541), an X-linked recessive disorder, characterized by defects in cobalamin metabolism and other developmental defects. HCFC1 is a transcriptional co-regulator, which interacts with transcription factors to regulate the expression of a myriad of genes. Notably, HCFC1 regulates cobalamin metabolism via the regulation of MMACHC expression through its interaction with THAP11, a THAP domain-containing transcription factor. In addition, the HCFC1/THAP11 complex potentially regulates genes involved in diverse cellular functions including cell cycle, proliferation, and transcription. Thus, it is likely that mutations in THAP11 may also result in biochemical and other phenotypes similar to those observed in patients with cblX. We report a patient who presented with phenotypic features that overlap cblX, but did not have any mutations in either MMACHC or HCFC1. We sequenced THAP11 by Sanger sequencing and discovered a potentially pathogenic, homozygous variant in THAP11, c.240C>G (p.Phe80Leu). Functional analysis in the developing zebrafish embryo, demonstrate that both THAP11 and HCFC1 regulate the proliferation and differentiation of neural precursors, suggesting important roles in normal brain development. Further, the loss of THAP11 in zebrafish embryos, results in craniofacial abnormalities including the complete loss of Meckel’s cartilage, the ceratohyal, and all of the ceratobranchial cartilages. These data are consistent with our previous work which demonstrated a role for HCFC1 in vertebrate craniofacial development. Furthermore, our high throughput RNA-sequencing analysis reveals several overlapping gene targets of HCFC1 and THAP11 that likely contribute to the phenotypes associated with cblX and related disorders. Thus, both HCFC1 and THAP11 play important roles in the regulation of cobalamin metabolism as well as other pathways involved in early vertebrate development.

  Study EGAS00001002201

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

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

  Study EGAS00001004564