Persistent Mutation Burden Drives Sustained Anti-Tumor Immune Responses
Tumor mutation burden is an imperfect proxy of tumor foreignness and has therefore failed to consistently demonstrate clinical utility in predicting responses in the context of immunotherapy. We evaluated mutations in regions of the genome that are unlikely to undergo loss and discovered that clonal mutations in single-copy regions and those present in multiple copies per cell constitute a persistent tumor mutation burden (pTMB) that is linked with therapeutic response to immune checkpoint blockade. Persistent mutations were retained in the context of tumor evolution under selective pressure of immunotherapy and tumors with a high pTMB content were characterized by a more inflamed tumor microenvironment. pTMB imposes an evolutionary bottleneck that cancer cells cannot overcome and may thus drive sustained immunologic tumor control in the context of immunotherapy.
Study
EGAS00001006660
Multi-omic analyses from a randomized phase II study of epigenetic priming followed by nivolumab in previously treated metastatic non-small cell lung cancer
Emergence of resistance to immune checkpoint blockade (ICB) mandates the development of strategies for ICB sensitization. We aimed to understand the effects of epigenetic priming in re-shaping the tumor microenvironment, together with molecular drivers of therapeutic response of epigenetic therapy followed by ICB in non-small cell lung cancer (NSCLC; NCT01928576). This was done through a multi-omic approach encompassing both genomic and transcriptomic analyses. Findings suggest that epigenetic therapy may reshape the tumor microenvironment towards a more inflamed phenotype and prime responses to immunotherapy.
Study
EGAS50000000913
single cell RNA-seq of small cell lung cancer circulating tumor cells
This study investigated the transcriptomic profile of circulating tumor cells from three small cell lung cancer patients. CTCs were enriched from the blood of three SCLC patients using the CTC-iChip followed by magnetic depletion of RBCs. The enriched samples were processed with the 10x Genomics Chromium platform (Chromium GEM-X Single Cell 3' Kit v4) and sequenced on a NextSeq 2000 system.
Study
EGAS50000001401
Shwachman_Diamond_syndrome__SDS___Exome_sequencing
Shwachman-Diamond syndrome (SDS) is a rare autosomal recessive disorder characterized by exocrine pancreatic insufficiency, bone marrow dysfunction, leukemia predisposition, and skeletal abnormalities. We aim to characterise the structural effects of SDS in patients with this disorder by exome sequencing.
Study
EGAS00001000264
The genomic landscape of pediatric acute lymphoblastic leukemia
Acute lymphoblastic leukemia (ALL) is the most common pediatric cancer and arises from B- or T-lineage lymphocyte precursors. ALL comprises dozens of subtypes, and genomic analyses have largely been performed within these subtypes. Here we analyze pediatric ALL genomes across all subtypes, including 768 whole genomes, 1,729 exomes, and 1,889 transcriptomes in 2,754 patients. Most ALL subtypes harbor 4 or more driver alterations per sample, similar to adult cancers, despite low mutation burdens. Hyperdiploid B-ALL copy gains are likely acquired early and synchronously, with copy gains occurring before ultraviolet-induced mutations. By contrast, ultraviolet-induced mutations precede copy gains in iAMP21 B-ALL. Overall, we identified 378 putative ALL driver genes. Most driver alterations vary in prevalence across ALL subtypes, with B-ALL enriched for Ras and B-lineage-related alterations, and T-ALL enriched for PI3K, JAK, and cell cycle alterations. Most B-ALL (54.3%) and T-ALL (51.2%) samples bear at least one rare driver gene alteration (present in less than 2% of samples), including 30 putative novel cancer driver genes associated with ubiquitination, SUMOylation, non-coding, and other functions. Known or novel alterations associated with poor outcomes in specific subtypes include TBL1XR1 alterations in ETV6-RUNX1 patients, CREBBP in Ph-like-CRLF2, SETD2 in hyperdiploid, and PTEN in TAL1 patients. Intriguingly, DUX4 and KMT2A subtypes separate into CEBPA/FLT3- or NFATC4-expressing subgroups with potential clinical implications. Together, these results deepen understanding of ALL etiology and outcomes, and facilitate ALL model development.
Study
EGAS00001005250
3D chromatin analysis of clear cell renal cell carcinoma using micro-C
To investigate the 3D structure of chromatin in ccRCC, we performed micro-C on 3 ccRCC cell lines (786-O, A498, UMRC-2), and 1 normal kidney epithelium cell line (HK-2), cultured under normoxic (20% O2) and hypoxic (0.05% O2) conditions
Study
EGAS50000001323
Characterization of DLBCL with a PMBL gene expression signature
Primary mediastinal large B-cell lymphoma (PMBL) is a type of aggressive B-cell lymphoma that typicallyaffects young adults, characterized by presence of a bulky anterior mediastinal mass. Lymphomas withgene expression features of PMBL have been described in non-mediastinal sites, raising questions abouthow these tumors should be classified.Here, we investigated whether these "non-mediastinal PMBLs" are indeed PMBLs or instead represent adistinct group within DLBCL. From a cohort of 325 de novo DLBCL cases, we identified tumors frompatients without evidence of anterior mediastinal involvement that expressed a PMBL expression signature(nm-PMBLsig-pos, n=16, 5%). The majority of these tumors expressed MAL and CD23 – proteins typicallyobserved in bona fide PMBL (bf-PMBL). Evaluation of clinical features of nm-PMBLsig-pos cases revealedclose associations with DLBCL, and the majority displayed a germinal center B-cell-like cell-of-origin(GCB). In contrast to bf-PMBL, nm-PMBLsig-pos patients presented at an older age, did not show pleuraldisease, and bone/bone marrow involvement was observed in three cases. However, while clinicallydistinct from bf-PMBL, nm-PMBL-sig-pos tumors resembled bf-PMBL at the molecular level with upregulationof immune response, JAK-STAT, and NF-kB signatures. Mutational analysis revealed frequent somatic genemutations in SOCS1, IL4R, ITPKB and STAT6, as well as CD83 and BIRC3, with the latter genes beingsignificantly more frequently affected than in GCB-DLBCL and bf-PMBL.Our data establish nm-PMBLsig-pos lymphomas as a group of DLBCL with distinct phenotypic and geneticfeatures, and potential implications for gene expression- and mutation-based subtyping of aggressive Bcell lymphoma and related targeted therapies.
Study
EGAS00001005057
Gene expression profiles in paediatric ETV6-RUNX1 leukemia
Study
EGAS00001007097
Axes of Biological Variation in Diffuse Large B-Cell Lymphoma
To explore the DLBCL molecular and genetic environment, we conducted genome-wide NGS sequencing on 103 DLBCL biopsy samples (named as Cornell-NCI cohort) with NGS platforms, including bulk WES, etc. The raw fastq files of the bulk WES were deposited on the EGA for user access. To obtain other genomic data from the study, please see the data links described in the paper.
Study
EGAS50000001227
A living biobank of patient-derived ductal carcinoma in situ Mouse-INtraDuctal xenografts identifies factors associated with risk of invasive progression
Create a living biobank of patient-derived ductal carcinoma in situ (DCIS) Mouse-INtraDuctal (MIND) xenografts to find factors explaining invasive growth. Samples exist of both primary and pdx samples. Invasive growth was scored in the pdx.
Study
EGAS00001006554
Clonal somatic copy number altered driver events inform drug sensitivity in high-grade serous ovarian cancer
Chromosomal instability is a major challenge to patient stratification and targeted drug development for high-grade serous ovarian carcinoma (HGSOC). Here we show that somatic copy number alterations (SCNAs) in frequently amplified HGSOC cancer genes significantly correlate with gene expression and methylation status. We identified five prevalent clonal driver SCNAs (chromosomal amplifications encompassing MYC, PIK3CA, CCNE1, KRAS and TERT) from multi-regional HGSOC data and reasoned that their strong selection should prioritise them as key biomarkers for targeted therapies. We used primary HGSOC spheroid models to test interactions between in vitro targeted therapy and SCNAs. MYC chromosomal copy number was associated with in-vitro and clinical response to paclitaxel and in-vitro response to mTORC1/2 inhibition. Activation of the mTOR survival pathway in the context of MYC-amplified HGSOC was statistically associated with increased prevalence of SCNAs in genes from the PI3K pathway. Co-occurrence of amplifications in MYC and genes from the PI3K pathway was independently observed in squamous lung cancer and triple negative breast cancer. These results suggest that identifying co-occurrence of clonal driver SCNA genes could be used to tailor therapeutics for precision medicine.
Study
EGAS00001006200
Whole Exome sequencing of Gingivo-buccal Cancer : ICGC-India Project_Batch04
Whole Exome Sequencing of Gingivo-buccal Cancer: ICGC-India ProjectAs a part of the ICGC, India has undertaken genomic studies on gingivobuccal cancer of the oral cavity, which is the most prevalent form of cancer among men in India. There are various known environmental (life-style) correlates of this cancer, the most important of which are tobacco chewing and HPV infection. Exome of paired DNA samples – isolated from the tumor tissue and from the blood of 47 patients – have been performed to catalog germline and somatic mutations. Association between each observed genomic alteration and exposure to environmental risk factors is being explored. Detailed clinical characterization of the patients, collection of data on demographic and environmental exposures, and isolation of DNA samples from blood and tumor tissues collected from each patient are being done at the Advanced Centre for Research, Treatment and Education on Cancer, Mumbai. Whole exome sequencing is being performed at the National Institute of Biomedical Genomics, Kalyani.
Study
EGAS00001002852
Whole-genome plasma sequencing reveals focal amplifications as a driving force in metastatic prostate cancer
Genomic alterations in metastatic prostate cancer remain incompletely characterized. Here we analyze 493 prostate cancer cases from the TCGA database and perform whole-genome plasma sequencing on 95 plasma samples derived from 43 patients with metastatic prostate cancer. From these samples, we identify established driver aberrations in a cancer-related gene in nearly all cases (97.7%), including driver gene fusions (TMPRSS2:ERG), driver focal deletions (PTEN, RYBP, SHQ1), and driver amplifications (AR, MYC). In serial plasma analyses, we observe changes in focal amplifications in 40% of cases. The mean time interval between new amplifications was 26.4 weeks (range: 5-52 weeks), suggesting that they represent rapid adaptations to selection pressure. An increase in neuron-specific enolase is accompanied by clonal pattern changes in the tumor genome, most consistent with subclonal diversification of the tumor. Our findings suggest a high plasticity of prostate cancer genomes with newly occurring focal amplifications as a driving force in progression
Study
EGAS00001001018
High-throughput Detection of Clinically Relevant Mutations in Archived Tumor Samples By Multiplexed PCR and Next Generation Sequencing
PURPOSE: Tailoring cancer treatment to tumor molecular characteristics promises to make personalized medicine a reality. However, reliable genetic profiling of archived clinical specimens has been hindered by limited sensitivity and high false positive rates. Here, we describe a novel methodology, MMP-seq, which enables sensitive and specific high-throughput, high content genetic profiling in archived clinical samples. EXPERIMENTAL DESIGN: We first validated MMP-seq’s technical performance in 66 cancer cell lines and a Latin square cross-dilution of known somatic mutations. We next characterized the performance of MMP-seq in 17 formalin-fixed paraffin embedded (FFPE) clinical samples using matched fresh frozen (FF) tissue from the same tumors as benchmarks. To demonstrate the potential clinical utility of our methodology, we profiled FFPE tumor samples from 73 endometrial cancer patients. RESULTS: We demonstrated that MMP-seq enabled rapid and simultaneous profiling of a panel of 88 cancer genes in 48 samples, and detected variants at frequencies as low as 0.4%. We identified DNA degradation and deamination as the main error sources and developed practical and robust strategies for mitigating these issues, and dramatically reduced the false positive rate. Applying MMP-seq to a cohort of endometrial tumor samples identified extensive, potentially actionable alterations in the PI3K and RAS pathways, including novel PIK3R1 hotspot mutations that may disrupt negative regulation of PIK3CA. CONCLUSIONS: MMP-seq provides a robust solution for comprehensive, reliable and high- throughput genetic profiling of clinical tumor samples, paving the way for the incorporation of genomic-based testing into clinical investigation and practice.
Study
EGAS00001000674
The evolutionary steps from primary to metastatic prostate cancer are largely uncharted, and the ability to use DNA present in body fluids as correlates of aggregate metastatic status is under-examined. We reconstructed phylogenies in ten prostate cancer patients with fatal disease using deep targeted sequencing of the prostate, adjacent and distant organs, as well as plasma, serum, and cerebrospinal fluid at various time points. A total of 163 samples are studied.
The evolutionary steps from primary tumor to metastasis in prostate cancer are largely uncharted, and the ability to use serum, plasma, and cerebrospinal fluid as a correlate of aggregate metastatic tumor genomic status has not been tested. We used deep targeted sequencing to reconstruct tumor evolution in ten prostate cancer patients with fatal disease encompassing examination of the prostate and adjacent and distant organs, as well as plasma, serum, and cerebrospinal fluid at various time points. We show that there is substantial evolution from a common ancestor within the prostate that results in branching to multiple lineages which form an intermixed multi-clonal primary tumor mass. After the occurrence of key driver aberrations, one of these lineages will metastasize to multiple sites in a sequential fashion. These metastatic sites are then susceptible to being populated by cells from other intra-prostatic lineages or from other metastases. Genomic representation of metastases in body fluids is not uniform. Cerebrospinal fluid analysis can detect lineages not detected in circulating DNA, suggesting possible clinical utility.
Study
EGAS00001003848
Error-corrected flow-based sequencing at whole genome scale and its application to circulating cell-free DNA profiling
Differentiating sequencing errors from true variants is a central genomics challenge calling for error suppression strategies that balance costs when sparse material or ultra-rare variants require high-accuracy methods. For example, circulating cell-free DNA (ccfDNA) sequencing for cancer monitoring is limited by sparsity of circulating tumor DNA (ctDNA), abundance of genomic material in samples, library preparation error rates and sequencing errors. Whole-genome sequencing (WGS) can overcome the low abundance of ccfDNA by integrating signal across the mutation landscape, but higher cost limits adoption compared with targeted panels, where ccfDNA abundance limits maximal coverage depths. Here we applied deep (~120x) lower-cost WGS (Ultima Genomics) with analytic error correction for tumor-informed ctDNA detection within the part-per-million range. We further developed high-coverage duplex error-corrected WGS of ccfDNA, achieving 7.7x10-8 error rates, to assess disease burden in melanoma and urothelial cancer patients without matched tumor sequencing. Together, we show that deeply sequenced error-corrected WGS accurately calls somatic variants, demonstrating the feasibility of WGS for tumor-informed and tumor-agnostic ctDNA detection.
Study
EGAS50000000844
Comprehensive genomic characterization of early stage bladder cancer - nanopore sequencing
For this project about non-muscle invasive bladder cancer (NMIBC), we analysed long read sequencing data from 4 patients using the Nanopore platform. The dataset is composed of 8 BAM files: 4 tumor samples and 4 paired blood samples.
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EGAS50000000510
Comprehensive genomic characterization of early stage bladder cancer - shallow whole genome sequencing data
For this project about non-muscle invasive bladder cancer (NMIBC), we analysed shallow WGS data from 362 patients. The dataset is composed of 392 BAM files: 362 tumor samples, 15 female normal samples and 15 male normal samples.
Study
EGAS50000000513
54 metastatic colorectal cancer patients from Schleswig-Holstein in North Germany
Personalized treatment vs standard of care is much debated, especially in clinical practice. Here we investigated whether overall survival differences in metastatic colorectal cancer patients are explained by their tumor mutation profiles or by their treatment differences in real clinical practice.
Study
EGAS00001004108
cell-Free DNA Genomic Profiling and its Clinical Implementation in Advanced Prostate Cancer
Sixty-eight patients with advanced prostate cancer in castration-resistant or castration-sensitive settings undergoing treatment at the University Hospital Basel or the St. Claraspital Basel (Switzerland) were selected for targeted parallel sequencing analysis on liquid biopsy (plasma cfDNA) and matched formalin-fixed, paraffin-embedded (FFPE) tumor tissue samples.
Study
EGAS50000000234
Spatial and temporal diversity in genomic instability processes define early stage lung cancer evolution.
Deciphering the complexity of non-small cell lung cancer (NSCLC) evolutionary histories may elucidate the basis for its dismal outcome. We performed multi-region sequencing on 25 regions from seven early-stage NSCLCs. Spatial dissection revealed branched tumor evolution, with driver mutations occurring before and after subclonal diversification. Intra-tumor heterogeneity in DNA copy number alterations, translocations and endogenous APOBEC mutational processes, demonstrates that NSCLC may follow multiple distinct evolutionary trajectories simultaneously. In smokers, despite maintained carcinogen exposure, temporal dissection reveals a proportional decrease in smoking-related mutations during tumor progression, accompanied by an increase in APOBEC-related mutations. We observed genome-doubling events early in tumor development of ex-smokers, suggesting prolonged latency periods before clinical detection. Multi-region sequencing demonstrates the relentless and heterogeneous nature of genomic instability processes in early-stage NSCLCs.
Study
EGAS00001000840
Interactions between the tumor and the systemic response of breast cancer patients
Breast cancer (BC) research has largely focused on the molecular properties of the tumor proper. However, to understand how cancer progresses and ultimately modulates patient outcome, we also require an understanding of the molecular changes in the patient systemic response (SR). Toward this end, we generated and analyzed RNA profiles from tumor and matched blood samples in 173 BC patients. We designed a system (MIxT) to explore and link tightly co-expressed gene sets (modules) across matched tissues. The gene composition of modules, and their expression, largely vary across tissues. Distinct patterns of expression in the SR are predominantly detected in highly immunogenic BC subtypes. We also find that the expression pattern of a module in one tissue is correlated to the expression pattern of a module in the other tissue in a fashion that depends on subtype. For example, systemic immunosuppression is detected in basalL patients in a fashion that is proportional to the level of expression of several tumor modules highlighting immune evasion mechanisms active in these particular cancers.
Study
EGAS00001001804
Monitoring of leukemia clones in B-cell acute lymphoblastic leukemia at diagnosis and during treatment by single-cell DNA amplicon sequencing
Acute lymphoblastic leukemia (ALL) is characterized by the presence of chromosomal changes, including numerical changes, translocations and deletions, which are often associated with additional single nucleotide mutations. In this study we used single-cell targeted DNA sequencing to determine the clonal heterogeneity of B-cell ALL at diagnosis and during chemotherapy treatment. With a customly designed DNA amplicon library targeting the most common mutations (in 110 genes) present in ALL, we analyzed bone marrow samples and/or blood samples from 12 B-ALL cases at diagnosis. For 4 cases where we detected multiple mutational clones at diagnosis, we also studied blood samples during the first weeks of chemotherapy treatment. This study shows that B-ALL cases with either a ETV6-RUNX1 or a BCR-ABL1 fusion have a low mutational burden, while cases with PAX5 alterations or hyperdyploidy have multiple clones at diagnosis, often with mutations in the JAK-STAT signaling pathway and the RAS signaling pathway.
As expected, it can be observed that these clones disappear during treatment of the leukemia with almost no mutated cells left after two weeks of treatment.
Study
EGAS00001005029
Cell-free DNA TAPS for early cancer detection
Multimodal, genome-wide characterization of epigenetic and genetic information in circulating cell-free DNA (cfDNA) could enable more sensitive early cancer detection. However, due to technological challenges associated with DNA methylation sequencing in low input cfDNA samples, most studies have been limited by DNA damage caused by bisulfite sequencing, or the qualitative nature of enrichment-based sequencing. Recently, we developed TET-assisted Pyridine Borane Sequencing (TAPS), which is a mild, bisulfite-free method for base-resolution direct DNA methylation sequencing. Here we optimized TAPS for cfDNA (cfTAPS) to provide high-quality and high-depth whole-genome cell-free methylomes. We applied cfTAPS to 85 cfDNA samples from patients with hepatocellular carcinoma (HCC) or pancreatic ductal adenocarcinoma (PDAC) and non-cancer controls. From just 10 ng cfDNA (1-3 mL of plasma), we generated the most comprehensive cfDNA methylome to date. We demonstrated that cfTAPS provides multimodal information about cfDNA characteristics, including DNA methylation, tissue of origin, and DNA fragmentation. Integrated analysis of these epigenetic and genetic features enables accurate identification of early HCC and PDAC.
Study
EGAS00001004962
Mutational Landscape and Tumor Burden Assessed by Cell-Free DNA in Diffuse Large B-Cell Lymphoma: a Population-based Study
Purpose: We analyzed the utility of cfDNA in a prospective population-based cohort to determine the mutational profile, assess tumor burden, and estimate its impact in response rate and outcome in patients with DLBCL.
Experimental Design: One-hundred patients were diagnosed with DLBCL during the study period. Mutational status of 112 genes was studied in cfDNA by targeted next-generation sequencing. Paired formalin-fixed paraffin-embedded samples and volumetric PET/CT were assessed when available.
Results: Appropriate cfDNA to perform the analyses was obtained in 79/100 cases. At least one mutation could be detected in 69/79 cases (87%). The sensitivity of cfDNA to detect the mutations was 68% (95% CI: 56.2-78.7). The mutational landscape found in cfDNA samples was highly consistent with that shown in the tissue and allowed genetic classification in 43% of the cases. A higher amount of ctDNA significantly correlated with clinical parameters related to tumor burden (elevated LDH and β2-microglobulin serum levels, advanced stage, and high-risk IPI) and total metabolic tumor volume assessed by PET/CT. In patients treated with curative intent, high ctDNA levels (>2.5 log hGE/mL) were associated with lower complete response (65% vs. 96%, P<0.004), shorter progression-free survival (65% vs. 85%, P=0.038) and overall survival (73% vs. 100%, P=0.007) at 2 years, although it did not maintain prognostic value in multivariate analyses.
Conclusions: In a population-based prospective DLBCL series, cfDNA resulted an alternative source to estimate tumor burden and to determine the tumor mutational profile and genetic classification, which have prognostic implications and may contribute to a future tailored
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EGAS00001004733
