11769 results for "cancer rna-seq"

in 27.33 milliseconds.

• Contribution of allelic imbalance to colorectal cancer

  Point mutations in cancer have been extensively studied but chromosomal gains and losses have been more challenging to interpret due to their unspecific nature. Here we examine high-resolution allelic imbalance (AI) landscape in 1699 colorectal cancers, 256 of which have been whole genome sequenced (WGSed). The imbalances pinpoint 38 genes as plausible AI targets based on previous knowledge, and unbiased CRISPR-Cas9 knockout and activation screens identified altogether 79 genes within AI peaks regulating cell growth. Genetic and functional data implicates loss of TP53 as a sufficient driver of AI. The WGS highlights an influence of copy number aberrations on the rate of detected somatic point mutations. Importantly, the data reveal several associations between AI target genes, suggesting a role for a network of lineage-determining transcription factors in colorectal tumorigenesis. Overall, the results unravel the contribution of AI in colorectal cancer and provide a plausible explanation why so few genes are commonly affected by point mutations in cancers.

  Study EGAS00001002966

• A living biobank of breast cancer organoids captures disease heterogeneity

  Breast Cancer (BC) comprises multiple distinct subtypes that differ genetically, pathologically, and clinically. Xeno-transplantation and direct culturing of tumor tissue are increasingly used in drug development and personalized medicine strategies. Here, we describe a robust protocol for long-term culturing of human mammary epithelial organoids. Using this protocol, 101 BC organoid lines were generated, broadly recapitulating the diversity of the disease. BC organoid morphologies typically matched the histopathology, hormone receptor-, and HER2 status of the original tumor. DNA copy number variations as well as sequence changes were consistent within tumor-organoid pairs and largely retained even after extended passaging. BC organoids furthermore populated all major gene expression-based classification groups and allowed drug screens in vitro and upon xenotransplantation. This study describes a representative collection of well-characterized BC organoids available for cancer research and drug development, as well as a strategy to assess in vitro drug response in a personalized fashion.

  Study EGAS00001002158

• Genetic and immune landscape evolution defines subtypes of MMR deficient colorectal cancer

  Mismatch repair deficient colorectal cancers have high mutation loads and many respond to immune checkpoint-inhibitors. We investigated how genetic and immune landscapes co-evolve in these tumors. All cases had high truncal mutation loads. Driver aberrations showed a clear hierarchy despite pervasive intratumor heterogeneity: Those in WNT/βCatenin, mitogen-activated protein kinase and TGFβ receptor family genes were almost always truncal. Immune evasion drivers were predominantly subclonal and showed parallel evolution. Pan-tumor evolution, subclonal evolution, and evolutionary stasis of genetic immune evasion drivers defined three MMRd CRC subtypes with distinct T-cell infiltrates. These immune evasion drivers have been implicated in checkpoint-inhibitor resistance. Clonality and subtype assessments are hence critical for predictive immunotherapy biomarker development. Cancer cell PD-L1 expression was conditional on loss of the intestinal homeobox transcription factor CDX2. This explains infrequent PD-L1 expression by cancer cells and likely contributes to the high recurrence risk of MMRd CRCs with impaired CDX2 expression.

  Study EGAS00001005769

• Genome-wide cell-free DNA mutational integration enables ultra-sensitive cancer monitoring

  In many areas of oncology, we lack sensitive tools to track low burden disease. While cell-free DNA (cfDNA) shows promise in detecting cancer mutations, we found that the combination of low tumor fraction (TF) and limited number of DNA fragments restricts low disease burden monitoring through the prevailing deep targeted sequencing paradigm. We reasoned that breadth may supplant depth of sequencing to overcome the barrier of cfDNA abundance. Whole genome sequencing (WGS) of cfDNA allowed ultra-sensitive detection, capitalizing on the cumulative signal of thousands of somatic mutations observed in solid malignancies, with TF detection sensitivity as low as 10-5. The WGS approach enabled dynamic tumor burden tracking and post-operative residual disease detection, associated with adverse outcome. Thus, we present an orthogonal framework for cfDNA cancer monitoring via genome wide mutational integration, enabling ultra-sensitive detection, overcoming the limitation of cfDNA abundance, and empowering treatment optimization in low-disease burden oncology care

  Study EGAS00001004406

• Combined gene expression and digital pathology identifies molecular mediators of T cell exclusion and immune suppression in ovarian cancer

  Close proximity between cytotoxic T lymphocytes and tumour cells is required for effective immunotherapy. However, what determines the spatial distribution of T cells in the tumour microenvironment is not well understood. Coupling digital pathology and transcriptome analysis on a large ovarian tumour cohort, we develop a machine learning approach to molecularly classify and characterize tumour-immune phenotypes. Our study identifies two important hallmarks characterizing T cell excluded tumours: 1) loss of antigen presentation on tumour cells and 2) upregulation of TGFb and activated stroma. Furthermore, we identify TGFb as a key mediator of T cell exclusion. TGFb reduces MHC-I expression in ovarian cancer cells in vitro; TGFb also activates fibroblasts and induced extracellular matrix (ECM) production as a potential physical barrier to hinder T cell infiltration. Our findings indicate that targeting TGFb may represent a promising strategy to overcome T cell exclusion and improve clinical benefits of cancer immunotherapy.

  Study EGAS00001003487

• The immunopeptidome landscape associated with T cell infiltration, inflammation and immune-editing in lung cancer

  One key barrier for improving efficacy of cancer immunotherapy remains patient stratification. While patients with CD3+CD8+ T cell inflamed ‘hot’ tumors typically show better response to immune checkpoint inhibitors, it is still unknown if the repertoire of HLA bound peptides (HLAp) presented in ‘hot’ and ‘cold’ tumors is substantially different. We surveyed 61 tumor regions and adjacent non-malignant lung tissues from eight lung cancer patients and performed deep antigen discovery combining immunopeptidomics, genomics, bulk and spatial transcriptomics and explored the heterogenic expression and presentation of tumor (neo)antigens. We associated diverse immune cell populations with the immunopeptidome in CD3+CD8+ T cell excluded, infiltrated, hot and cold tumors and found evidence for lack of immune-editing and higher presentation efficiency of tumor antigens in cold and CD3+CD8+ T cell excluded tumors. This could have implications for the choice of combination therapies tailored to the patient’s mutanome and microenvironment.

  Study EGAS00001006298

• Early on-treatment changes in circulating tumor DNA fraction and response to enzalutamide or abiraterone in metastatic castration-resistant prostate cancer

  On-treatment circulating tumor DNA (ctDNA) quantification is touted as a surrogate biomarker for understanding metastatic cancer response to systemic therapy, but there is relatively little supporting data from standardized patient cohorts. Here, in a prospective observational cohort, we demonstrate that 4-week on-treatment changes in plasma ctDNA levels can accurately identify metastatic castration-resistant prostate cancer that will progress within 6 months of initiating first-line abiraterone or enzalutamide treatment. On-treatment ctDNA measurements outperformed existing clinical variables for predicting disease response and were also closely associated with differential overall survival. Although optimal timing of blood collections and thresholds for ctDNA detection will require further testing, our data highlights the potential for sequential ctDNA measurements to provide an early and reliable read-out for therapy response. The high accuracy of this information suggests that ctDNA could be useful for guiding clinical trials of therapy changes in initially non-responsive metastatic cancers.

  Study EGAS00001006856

• RNAseq of Colorectal cancer organoid-stroma biobank cohort

  In colorectal cancers (CRC) the tumor microenvironment plays a key role for prognosis and therapy efficacy. Patient-derived tumor organoids (PDTOs) show enormous potential for preclinical testing, however, in purely epithelial cultures features including the ‘consensus molecular subtypes’ (CMS) are largely eradicated. To better reflect cell heterogeneity, we established the CRC organoid-stroma biobank of matched PDTOs and cancer-associated fibroblasts (CAFs) from 30 patients. Context-specific phenotyping showed that xenotransplantation or co-culture with CAFs restores the individual transcriptomic status and instructs subtype-specific stromal gene expression. Furthermore, co-culture exposed CMS4-specific resistance to Gefitinib and SN-38 and revealed prognostic gene expression signatures. Chemogenomic library screening identified patient- and therapy-dependent mechanisms of stromal resistance including MET as common target. Our results demonstrate that CRC phenotypes are encrypted in the cancer epithelium in a plastic fashion that strongly depends on the context. Consequently, CAFs are essential for faithful representation of molecular subtypes and therapy responses ex vivo.

  Study EGAS00001007300

• WES of Colorectal cancer organoid-stroma biobank cohort

  In colorectal cancers (CRC) the tumor microenvironment plays a key role for prognosis and therapy efficacy. Patient-derived tumor organoids (PDTOs) show enormous potential for preclinical testing, however, in purely epithelial cultures features including the ‘consensus molecular subtypes’ (CMS) are largely eradicated. To better reflect cell heterogeneity, we established the CRC organoid-stroma biobank of matched PDTOs and cancer-associated fibroblasts (CAFs) from 30 patients. Context-specific phenotyping showed that xenotransplantation or co-culture with CAFs restores the individual transcriptomic status and instructs subtype-specific stromal gene expression. Furthermore, co-culture exposed CMS4-specific resistance to Gefitinib and SN-38 and revealed prognostic gene expression signatures. Chemogenomic library screening identified patient- and therapy-dependent mechanisms of stromal resistance including MET as common target. Our results demonstrate that CRC phenotypes are encrypted in the cancer epithelium in a plastic fashion that strongly depends on the context. Consequently, CAFs are essential for faithful representation of molecular subtypes and therapy responses ex vivo.

  Study EGAS00001007301

• Sensitive and Frequent Identification of High Avidity Neo-epitope Specific CD8 + T-cells in Immunotherapy-naïve Ovarian Cancer

  Immunotherapy directed against private tumor neo-antigens derived from non-synonymous somatic mutations is a promising strategy of personalized cancer immunotherapy. However, feasibility in low mutational load tumor types remains unknown. Comprehensive and deep analysis of circulating and tumor-infiltrating lymphocytes (TILs) for neo-epitope specific CD8 + T cells allowed prompt identification of oligoclonal and polyfunctional such cells from most immunotherapy-naïve patients with advanced epithelial ovarian cancer studied. Neo-epitope recognition was discordant between circulating T cells and TILs, and was more likely to be found among TILs, which displayed higher functionalavidity and unique TCRs with higher predicted affinity than their blood counterparts. Our results imply that identification of neo-epitope specific CD8 + T cells is achievable even in tumors with relatively low number of somatic mutations, and neo-epitope validation in TILs extends opportunities for mutanome-based personalized immunotherapies to such tumors.

  Study EGAS00001002803

• MATISSE WES and bulk RNA-sequencing data

  High-risk cutaneous squamous cell carcinoma is frequently seen in frail, elderly patients and often requires mutilating surgical treatment and adjuvant radiotherapy (RT). The MATISSE trial (NCT04620200) was conducted to improve clinical prospects in CSCC patients eligible for extensive curative surgery, and evaluated early treatment response and immune dynamics following ultra-short neoadjuvant immunotherapy prior to standard of care surgery with or without radiotherapy. Fifty patients were randomized to receive two courses of nivolumab 3 mg/kg (NIVO, weeks 0&2) or nivolumab 3 mg/kg (weeks 0&2) and one course of ipilimumab 1 mg/kg (week 0 only, NIVO/IPI before surgery at week 4, with the primary objective being histopathological response based on residual viable tumor cells in the surgical specimen. Ten patients choose not to undergo surgery, of whom nine reached a clinical complete response during follow up, and were disease-free at median 34 months follow up. Serial tumor and blood samples at baseline, week 1, week 2 and week 4, enabled to investigate dynamical changes through bulk WES and RNA sequencing to potentially aid future de-escalation trials.

  Study EGAS50000001003

• 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

• Small cell cancer NDS Oxford DAC

  Dac EGAC00001003350

• Cancer Team Data Access Committee

  Dac EGAC00001002762

• Small cell cancer NDS Oxford DAC

  Dac EGAC00001003343

• Asian lung cancer genome data

  Dac EGAC00001000248

• MCCB Breast Cancer Data Access Committee

  Dac EGAC00001000854

• Rectal Cancer Samples Data Access Committee

  Dac EGAC00001001034

• University of Florida Brain Cancer DAC

  Dac EGAC00001001035

• DAC for Familial Breast Cancer study EGAS00001003305

  Dac EGAC00001001087

• OSBREAC (Oslo Breast Cancer Research Consortium)

  Dac EGAC00001001186

• Ewha-Samsumg Lung cancer collaboration DAC

  Dac EGAC00001001237

• Ewha-Samsung Lung cancer collaboration DAC

  Dac EGAC00001001283

• UCL Cancer Institute Data Access Committee

  Dac EGAC00001001360

• Yale Cancer Center Data Access Commitee

  Dac EGAC00001001437