Search Results - EGA European Genome-Phenome Archive

Whole-genome bisulfite sequencing analysis of low-grade astrocytomas in the ICGC PedBrain Tumor Project

Pilocytic Astrocytoma (PA) is the most common pediatric brain tumor. While genome and transcriptome landscapes are well-studied, data of the complete methylome, tumor cell composition and immune infiltration are scarce. We generated whole genome bisulfite sequence data (WGBS) of nine PAs to find evidence for a link of focal methylation differences and differential gene expression to immune infiltration.

Study EGAS00001004019

Comparative genomics research for Chinese colorectal cancer

In order to clarify the mechanisms of genesis and development of colorectal carcinoma, in this study, we performed comparative genomics research in Chinese colorectal cancer at various clinical stage via whole exon sequencing or whole genome sequencing. Comparative bioinformatical analysis was perform to find the difference on somatic single-nucleotide variants, short insert/deletion variants, genomic structural variants, and copy number variants between cancer tissue and normal tissue, or among cancer tissues at various clinical stages.

Study EGAS00001002607

Somatic_mutation_and_clonal_evolution_in_the_human_pancreas___WGS

In this study we aim to characterise the landscape of mutation and clonal selection in the human pancreas. The study combines targeted sequencing and whole-genome sequencing of microbiopsies from the pancreas. The range of patients studied will include healthy individuals, both smokers and non-smokers, and patients with pancreatic ductal adenocarcinoma.

Study EGAS00001002626

Ultra-Fast Patient-Derived Xenografts Identify Functional and Spatial Tumour Heterogeneities that Drive Therapeutic Resistance

Treatment of patients with advanced cancers increasingly relies on agents targeting specific molecular or cellular aberrations. These expensive therapies often fail because of pre-existing drug resistance. Intra-tumoural molecular and micro-environmental heterogeneity resistance can create resistance in one or more subclones of a tumour, leading to spatio-functional heterogeneity. We created a rapid approach for quantifying tumour functional phenotypes based on tumour-implantation into the chorioallantoic membrane of chick embryos. We apply this technique to 43 separate biopsies from 6 patients with renal cell carcinoma (RCC) with 36 replicates per biopsy, achieving a 93.6% engraftment rate (1449/1548). Challenging these models with sunitinib, an anti-angiogenic therapy frequently used in RCC allowed us to quantify spatio-functional heterogeneity in individual patients. Prediction of de novo drug resistance in advanced cancer patients would facilitate precision medicine by tailoring systemic therapies and improve clinical trial design outcome measures. We describe a patient-derived xenograft platform where fresh patient tumour samples are implanted into the chorioallantoic membrane (CAM) of chick embryos at high engraftment efficiencies, permitting large scale “tumour avatar” studies to guide the selection of drugs and to predict clinical drug resistance outcomes in renal cell carcinoma (RCC) patients. Applying this “tumour avatar” model in a co-clinical trial on RCC patients, we observe intra-tumoural functional heterogeneity with sunitinib treatment, revealing the presence of drug-resistant clones prior to the initiation of therapy. Multi-regional exome Matched DNA sequencing of the primary tumour and metastases revealed DNA mutational signatures associated with sunitinib resistance at baseline and after treatment. These These studies demonstrate a rapid and affordable method of findings confirm the existence of genetic and surveying functional tumour heterogeneities heterogeneity.

Study EGAS00001002627

We performed whole-exome sequencing of 20 samples (10 actinic keratosis and 10 cutaneous squamous cell carcinoma) to investigate a potential relationship between DNA methylation-based subtypes and genetic mutation patterns (Rodriguez-Paredes et al., Nat Commun 2017)

Cutaneous squamous cell carcinoma (cSCC) is the second most common skin cancer type and arises from keratinocytes. Most cSCC progress from a UV-induced precancerous lesion termed actinic keratosis (AK). Despite various efforts to characterize these lesions molecularly, the etiology of AK and its progression to cSCC remain only partially understood. Here we have used Infinium MethylationEPIC BeadChips to interrogate the DNA methylation status of about 850.000 CpGs in epidermal preparations from healthy skin, AK and cSCC. Importantly, we found that the premalignant AK samples displayed classical features of cancer methylomes and were highly similar to cSCC methylomes. Further analysis identified typical features of stem cell methylomes, such as a reduced DNA methylation age, non-CpG methylation and stem cell-related keratin and enhancer methylation patterns. Interestingly, this signature was detected only in one half of the AK and cSCC samples, while the other half showed keratin and enhancer methylation patterns that were more closely related to the control epidermis. These findings suggest the existence of two distinct subclasses of AK and cSCC that originate from distinct keratinocyte differentiation stages.

Study EGAS00001002670

The identification of genetic vulnerabilities in head and neck cancers for the development of novel treatments.

The global cancer burden is expected to double by the year 2030 and this will disproportionately affect the Asian continent. Head and neck squamous cell carcinoma (HNSCC) is endemic in Asia. It is the sixth most common cancer worldwide and the second most common in Malaysia, with approximately 600,000 new cases per year globally. Longterm survival remains less than 50%, underscoring the need for better therapeutic strategies. In this proposal we aim to bring new technological advancements in the identification of critical genes in HNSCC and the identification of compounds for the development of new therapies in HNSCC. We propose to genomically characterise 16 unique Asian H&N cancer cell lines, to classify sub groups where identification of essential genes that can be targeted for tumor control can be applied in a more rational way. Further, we propose to use zebrafish, an established drug discovery platform to identify promising pathway-specific compounds that could be further studied using CRISPR/Cas9 lethality screens and biological models to better identify novel therapeutic strategies to combat this major health problem in Asia.

Study EGAS00001002682

Alternative splicing isoforms in patient-derived hepatocellular carcinoma cells

The aim of this study was to obtain a landscape of alternative splicing (AS) in human hepatocellular carcinoma (HCC). We applied hybrid sequencing by integrating Pacbio long-read and Illumina short-read RNA sequencing data from 8 patient-derived HCC cell lines, and used an immortalized hepatocyte cell line as reference. This study revealed features of annotated and novel splice variants in HCC cells, including transcript length, AS type and protein changes. We also identified novel isoforms and tumor specific isoforms, which may represent potential biomarkers and targets for therapeutic development.

Study EGAS00001002697

Extensive three-dimensional intratumor proteomic heterogeneity revealed by multiregion sampling in high-grade serous ovarian tumor specimens

Enriched tumor epithelium, tumor-associated stroma, and whole tissue were collected by laser microdissection from thin sections across spatially separated levels of ten high-grade serous ovarian carcinomas (HGSOCs) and analyzed by mass spectrometry, reverse phase protein arrays, and RNA sequencing. Unsupervised analyses of protein abundance data revealed independent clustering of an enriched stroma and enriched tumor epithelium, with whole tumor tissue clustering driven by overall tumor “purity.” Comparing these data to previously defined prognostic HGSOC molecular subtypes revealed protein and transcript expression from tumor epithelium correlated with the differentiated subtype, whereas stromal proteins (and transcripts) correlated with the mesenchymal subtype. Protein and transcript abundance in the tumor epithelium and stroma exhibited decreased correlation in samples collected just hundreds of microns apart. These data reveal substantial tumor microenvironment protein heterogeneity that directly bears on prognostic signatures, biomarker discovery, and cancer pathophysiology and underscore the need to enrich cellular subpopulations for expression profiling. (Companion proteomic data is available in the ProteomeXchange Consortium, PRIDE: PXD026570).

Study EGAS00001005786

Brain_Disease_Wellcome_Leap_Delta_Tissue_DNA

Investigating how the tumour microenvironment regulates glioblastoma cell states using genomic analysis.

Study EGAS00001005799

Defective Homologous Recombination DNA Repair as Therapeutic Target in Advanced-Stage Chordoma (HIPO_021)

HIPO project: HIPO_021 Importance: Chordomas are rare tumors of the axial skeleton and skull base with few therapeutic options and no clinically validated molecular drug targets. The value of comprehensive genomic analyses for guiding medical therapy of patients with advanced-stage chordoma is unknown.Objective: To identify therapeutically tractable genetic lesions in a cohort of chordoma patients within a genomics-guided precision oncology program and to document the outcome of individualized, molecularly targeted chordoma therapy.Design, Setting, and Participants: We performed whole-exome sequencing of tumor and matched germline control samples from seven patients with locally advanced or metastatic chordoma who were enrolled in a cross-institutional molecular stratification registry trial for younger adults with advanced-stage cancer across all histologies and patients with rare tumors. All patients were heavily pretreated and had progressive disease prior to molecular analysis.Interventions: Individualized medical therapy was administered according to the patients’ molecular profiles.Main Outcomes and Measures: Candidate therapeutic targets identified by whole-exome sequencing and response to genotype-directed therapy.Results: All patients harbored alterations of two or more genes known to be involved in DNA repair via homologous recombination (HR), including heterozygous deletions of ERCC6, FANC family members, RAD51L (n = 6), BRCA2 (n = 5), ATR, CHEK2, RAD18, RAD51B, and XRCC3 (n = 4); inactivating PTEN mutations coupled with loss of heterozygosity (n = 2); and pathogenic germline variants in BRCA2 (n = 1), NBN (n = 1), and CHEK2 (n = 1) that were accompanied by somatic deletion of the corresponding wild-type alleles. Consistently, a mutational signature associated with defective HR was enriched in all samples and co-occurred with extensive genomic instability, as evidenced by HR deficiency scores and high numbers of large-scale state transitions. These results prompted off-label treatment with the poly(ADP-ribose) polymerase (PARP) inhibitor olaparib in a patient whose tumor was refractory to irradiation and systemic treatment with imatinib, which led to a prolonged response and substantial clinical improvement.Conclusions and Relevance: Advanced-stage chordomas are frequently characterized by genomic imprints of defective HR DNA repair. HR deficiency represents a new therapeutic opportunity in this intractable disease through repositioning of PARP inhibitors that warrants further exploration in clinical trials.

Study EGAS00001002720

Single-cell RNA sequencing of 22 Hodgkin lymphoma tumors and 5 reactive lymph nodes

Hodgkin lymphoma (HL) is characterized by an extensively dominant tumor microenvironment (TME) composed of different types of non-cancerous immune cells with rare malignant cells. Characterization of the cellular components and their spatial relationship is crucial to understanding crosstalk and therapeutic targeting in the TME. We performed single-cell RNA sequencing of more than 127,000 cells from 22 HL tissue specimens and 5 reactive lymph nodes, profiling for the first time the phenotype of the HL-specific immune microenvironment at single-cell resolution. Library preparation was performed using the 10x Genomics Chromium system, and Illumina sequencing was used to generate 3' gene expression data for every cell. Downstream analysis was performed in R to identify HL-specific microenvironment patterns and identify novel cell populations.

Study EGAS00001004085

Exon4-mutations in KRAS Affect MEK-ERK and Pi3K-AKT Signaling in Multiple Myeloma

Approximately 40% of MM cases harbor a point mutation in either KRAS or NRAS. However, it is still unclear whether RAS-mutations are associated with disease outcome. Specifically, no information exists whether KRAS-mutations have an impact on survival in MM patients at diagnosis that were treated with novel agents (e.g. bortezomib, lenalidomide). Targeting KRAS directly for therapeutic purposes is still impossible, but recently the first covalent mutant-specific inhibitor targeting KRASG12C made it into clinical trials. However, other KRAS-hotspot-mutations exist in MM patients, including the less common exon4-mutations. Within the current study, the coding regions of KRAS in 80 MM patients at diagnosis, uniformly treated with bortezomib and high-dose chemotherapy, were deep-sequenced. Moreover, the functional impact of KRASG12A as well as the two exon4-mutations A146T (AMO1) and A146V (MM patient) on different survival pathways was investigated. Specifically, an siRNA-mediated knockdown in AMO1 was performed and KRASWT, KRASG12A, KRAS146T and KRAS146V were overexpressed in the KRASWT cell lines JJN3 and OPM2 using lentiviral transduction and the transposase based Sleeping Beauty system. KRAS-mutations were not associated with survival. Yet, the expression of all KRAS-mutants had an impact on MEK/ERK-signaling in two independent MM cell lines and on AKT/PI3K-signaling in one MM cell line.

Study EGAS00001004110

Gene expression-based prediction of pazopanib efficacy in sarcoma (HIPO, H021)

The multi-receptor tyrosine kinase (RTK) inhibitor pazopanib is approved for the treatment of advanced non-adipocytic soft-tissue sarcoma and has also shown activity in other sarcoma subtypes. However, its clinical efficacy is highly variable, and no reliable predictors exist to date to select patients who are most likely to benefit from this drug. We analyzed the molecular profiles and clinical outcomes of pazopanib-treated sarcoma patients enrolled in a prospective observational study by the German Cancer Consortium, DKTK MASTER, that employs whole-genome/exome sequencing (WGS/WES) and transcriptome sequencing to inform the care of adults with advanced cancer across histologies who are younger than 51 and patients with rare tumors, including rare subtypes of more common entities, regardless of age. Among a total of 109 patients with available WGS/WES data, there was no correlation between clinical parameters, specific genetic alterations, or mutational signatures and clinical outcome. In contrast, analysis of a subcohort of 62 patients who underwent molecular analysis before pazopanib treatment and had transcriptome sequencing data available showed that mRNA levels of NTRK3 (hazard ratio [HR]=0.53, p=0.021), IGF1R (HR=1.82, p=0.027), and KDR (HR=0.50, p=0.011) were independently associated with progression-free survival (PFS). Based on the expression of these RTK genes, i.e., the features NTRK3-high, IGF1R-low, and KDR-high, we developed a pazopanib efficacy predictor (PEP) that stratified patients into three groups with significantly different PFS (p<0.0001). Application of the PEP to an independent cohort of pazopanib-treated sarcoma patients from DKTK MASTER (n=43) confirmed its potential to separate patient groups with significantly different PFS (p=0.02), whereas no such association was observed in sarcoma patients from DKTK MASTER (n=77) or The Cancer Genome Atlas sarcoma cohort (n=256) who were not treated with pazopanib. A score based on the combined expression of NTRK3, IGF1R, and KDR allows identification of sarcoma patients with good, intermediate, and poor outcome following pazopanib therapy and warrants investigation as a predictive tool in prospective studies to optimize the use of this drug in the clinic.

Study EGAS00001005836

Aberrant ERBB4-SRC Signaling as a Hallmark of Group 4 Medulloblastoma Revealed by Integrative Phosphoproteomic Profiling

The four main medulloblastoma subgroups are characterized by distinct biology, clinicopathological features and clinical outcomes. While the WNT and SHH subgroups are characterized by clearly defined aberrant signaling of developmental pathways, the underlying biology of Group 3 and 4 remains poorly understood. Here, we delineate distinct post-translational regulation orchestrating active oncogenic signaling networks in Groups 3 and 4. Specifically, aberrant ERBB4-SRC signaling constitutes a novel hallmark feature of Group 4, with great promise as a novel oncogenic mechanism and potential vulnerability for therapeutic intervention in the most common subgroup. Altogether, this novel integrative proteogenomic landscape demonstrates the added value of proteomics and phosphoproteomics analysis to discover and exploit unexpected oncogenic mechanisms in medulloblastoma and beyond.

Study EGAS00001002757

An integrated molecular study of 20 hepatoblastoma pairs using whole genome sequencing and RNA sequencing

Hepatoblastoma is an uncommon malignant liver cancer occurring in infants and children. The mutant background of hepatoblastoma has not been fully demonstrated. The aim of this study is to genomically depict the mutational landscape of hepatoblastoma through an integrative analysis of whole genome sequencing and RNA sequencing of 20 hepatoblastomas from Chinese individuals.

Study EGAS00001002772

TRACERx Renal 100

Evolutionary dynamics of clear cell renal cell carcinoma (ccRCC) have not been studied prospectively or across all disease stages. Through the multi-centre prospective cohort study, Renal TRACERx Renal, we analysed 1209 primary tumour regions from 101 patients with ccRCC. We detect up to 30 driver events in a single tumour, and show that subclonal diversification is associated with known clinical parameters. Defining driver event co-occurrence, mutual exclusivity and timing at clone level, we reveal deterministic patterns of clonal evolution and disease progression. We find that ccRCC can be grouped into seven distinct evolutionary subtypes, ranging from tumours characterised by early fixation of multiple mutational and copy number driver events that can disseminate widely and rapidly; to highly branched tumours with >10 subclonal drivers and extensive parallel evolution presenting with oligometastatic disease. We identify either heterogeneity or chromosome instability, or both, as determinants of patient outcome. Our insights reconcile the variable clinical behaviour of ccRCC and the benefit of surgical intervention in early and late-stage disease; and offer potential biomarker opportunities to maximise the benefit of both surgery and active surveillance.

Study EGAS00001002793

MutWP1__CRUK_Grand_Challenge_Mutographs_of_Cancer__Oesophageal_adenocarcinoma

The Mutographs project aims to advance our understanding of the causes of cancer through studies of mutational signatures. Led by Mike Stratton, together with Paul Brennan, Ludmil Alexandrov, Allan Balmain, David Phillips and Peter Campbell, this large-scale international research endeavour was awarded a Cancer Research UK Grand Challenge. Different patterns of somatic mutation are generated by the different environmental, lifestyle and genetic factors that cause cancer, many of them are still unknown. Within Mutographs, the International Agency for Research on Cancer is coordinating the recruitment of 5000 individuals with cancer (colorectal, renal, pancreatic, oesophageal adenocarcinoma or oesophageal squamous cancers) across 5 continents to explore whether different mutational signatures explain marked variation in incidence. In brief, through an international network of collaborators around the world, biological materials are collected, along with demographic, histological, clinical and questionnaire data. Whole genome sequences of tumour-germline DNA pairs are generated at the Wellcome Trust Sanger Institute (40X and 20X depth respectively). Somatic mutational signatures are subsequently extracted by non-negative matrix factorisation methods and correlated with risk factors data. Through an enhanced understanding of cancer aetiology, Mutographs unprecedented effort is anticipated to outline modifiable risk factors, lead to new approaches to prevent cancer, and provide opportunities to empower early detection, refine high-risk groups and contribute to further therapeutic development.

Study EGAS00001003702

Whole-Genome Sequencing of Salivary Gland Adenoid Cystic Carcinoma

Adenoid cystic carcinomas (ACCs) of the salivary glands are challenging to understand, treat, and cure. To better understand the genetic alterations underlying the pathogenesis of these tumors, we performed comprehensive genome analyses of 25 fresh-frozen tumors, including whole genome sequencing, expression and pathway analyses. In addition to the well-described MYB-NFIB fusion which was found in 11 tumors (44%), we observed five different rearrangements involving the NFIB transcription factor gene in seven tumors (28%). Taken together, NFIB translocations occurred in 15 of 25 samples (60%, 95%CI=41–77%). In addition, mRNA expression analysis of 17 tumors revealed overexpression of NFIB in ACC tumors compared with normal tissues (p=0.002). There was no difference in NFIB mRNA expression in tumors with NFIB fusions compared to those without. We also report somatic mutations of genes involved in the axonal guidance and Rho family signaling pathways. Finally, we confirm previously described alterations in genes related to chromatin regulation and Notch signaling. Our findings suggest a separate role for NFIB in ACC oncogenesis and highlight important signaling pathways for future functional characterization and potential therapeutic targeting.

Study EGAS00001002812

THE GENOMIC LANDSCAPE OF ACTINIC KERATOSIS

Actinic keratoses (AK) are lesions of epidermal keratinocyte dysplasia and are pre-cursor lesions to invasive cutaneous squamous cell carcinoma (cSCC). Identifying the specific genomic alterations driving the progression of normal skin to AK and invasive cSCC is challenging due to the massive, ultraviolet radiation-induced mutational burden characteristic to these lesions. Here, we present the largest whole exome sequencing study to date on AK with matched cSCC and demonstrate that AK and cSCC are almost indistinguishable at the genomic level, in terms of mutational burden, patterns of driver gene mutations and copy number alterations. We identified 44 significantly mutated AK driver genes through our established bioinformatics pipeline and demonstrate these genes are similarly mutated in cSCC. We also identified mutational signature-32 exclusively in AK from patients exposed to azathioprine, providing further, compelling evidence for this drug’s role in keratinocyte carcinogenesis, likely through its blocking of transcription coupled repair. We demonstrated that cSCC had higher levels of intra-sample heterogeneity than AK and that several signaling pathways, including immune-related signaling and TGF-beta signaling were significantly more mutated in cSCC. Integrating our findings with independent gene expression data confirms that dysregulated TGF-beta signaling may represent the critical pathway in the progression from AK to cSCC.

Study EGAS00001004243

Genomic landscape and PD-1 blockade in Natural-killer/T cell lymphoma

Natural killer/T-cell lymphoma (NKTL) is an aggressive malignancy with a predilection for Asian, Mexican and South American populations. With the exception of Japan, it is the most common mature T-cell lymphoma in Asia. NKTL presents as extranodal disease and mostly affects the upper aerodigestive tract. Neoplastic cells are invariably infected by the Epstein-Barr virus (EBV) and characterized by a cytotoxic phenotype. The genetic landscape of NKTL has been recently unraveled by discoveries describing recurring mutations altering the JAK-STAT pathway, epigenetic modifiers, the DDX3X gene and genetic predisposition in the HLA-DPB1 gene.The genomic landscape of NKTL has been interrogated by whole-exome sequencing, targeted sequencing and single nucleotide polymorphism arrays, but has yet been studied with whole-genome sequencing (WGS). In this study, we will use a combination of WGS, targeted-capture sequencing (TCS) and RNA sequencing data to explore the genetic landscape and its relevance to immunotherapy in NKTL

Study EGAS00001003828

New Brain Tumor Entities Emerge from Molecular Classification of CNS-PNETs

Primitive neuroectodermal tumors of the central nervous system (CNS-PNETs) are highly aggressive, poorly differentiated embryonal tumors occurring predominantly in young children but also affecting adolescents and adults. Herein we demonstrate that a significant proportion of institutionally diagnosed CNS-PNETs display molecular profiles indistinguishable from those of various other well defined CNS tumor entities, facilitating diagnosis and appropriate therapy for patients with these tumors. From the remaining fraction of CNS-PNETs we identify four new CNS tumor entities, each associated with a recurrent genetic alteration and distinct histopathological and clinical features. These new molecular entities, designated “CNS neuroblastoma with FOXR2 activation (CNS NB-FOXR2)”, “CNS Ewing sarcoma family tumor with CIC alteration (CNS EFT-CIC)”, “CNS high grade neuroepithelial tumor with MN1 alteration (CNS HGNET-MN1)”, and “CNS high grade neuroepithelial tumor with BCOR alteration (CNS HGNET-BCOR)”, will enable meaningful clinical trials and the development of therapeutic strategies for patients affected by poorly differentiated CNS tumors.

Study EGAS00001001632

Sequencing of an organoid biobank for childhood soft tissue sarcoma.

Rhabdomyosarcomas are diverse tumors of mesenchymal origin and the most common childhood soft tissue sarcoma. Patients receive intense treatment with a nevertheless poor prognosis for high-risk patients. New therapy would benefit from additional preclinical models and their rapid establishment. Tumor organoid models (tumoroids) have so far only been established from epithelial cancers. Here, we describe generation and characterization of a collection of pediatric RMS tumoroids comprising all major subtypes.

Study EGAS00001005912

Germline SDHB-inactivating mutation in gastric spindle cell sarcoma (HIPO-021)

Gastrointestinal stromal tumors (GISTs) are the most frequent mesenchymal tumors of the gastrointestinal tract. Inactivating mutations or epigenetic deregulation of succinate dehydrogenase complex (SDH) genes are considered defining features of a subset of GIST occurring in the stomach. Based on comprehensive molecular profiling and biochemical analysis within a precision oncology program, we identified hallmarks of SDH deficiency (germline SDHB-inactivating mutation accompanied by somatic loss of heterozygosity, lack of SDHB expression, global DNA hypermethylation, and elevated succinate/fumarate ratio) in a 40-year-old woman with undifferentiated gastric spindle cell sarcoma that did not meet the diagnostic criteria for other mesenchymal tumors of the stomach, including GIST. These data reveal that the loss of SDH function can be involved in the pathogenesis of non-GIST sarcoma of the gastrointestinal tract.

Study EGAS00001004277

Interplay of somatic alterations and immune infiltration modulates response to PD-1 blockade in advanced clear cell RCC -- CA209-010

Immune checkpoint inhibitors targeting the PD-1 pathway have transformed the management of many advanced malignancies, including clear cell renal cell carcinoma (ccRCC), but the drivers and resistors of PD-1 response remain incompletely elucidated. Here, we analyzed 592 tumors collected from advanced ccRCC patients enrolled in prospective clinical trials of treatment with PD-1 blockade (or mTOR inhibition as control arm) by whole-exome and RNA-sequencing, integrated with immunofluorescence analysis, to define the somatic alteration landscape of late-stage ccRCC and to uncover the immunogenomic determinants of therapeutic response. While conventional genomic markers (tumor mutation burden, neoantigen load) and degree of CD8+ T cell infiltration were not associated with clinical response, we discovered numerous chromosomal alterations in advanced ccRCC associated with response or resistance to PD-1 blockade. These advanced tumors were highly CD8+ T cell infiltrated, with only 22% and 5% with an immune desert and immune excluded phenotype, respectively. Our analysis revealed that CD8+ infiltrated tumors are depleted of favorable PBRM1 mutations and are enriched for unfavorable chromosomal losses of 9p21.3 when compared to non-infiltrated tumors. These data demonstrate how the interplay of somatic alterations and immunophenotypes impacts therapeutic efficacy.

Study EGAS00001004291

Molecular profiling of metastatic uveal melanoma

Metastatic uveal melanoma is less well understood than its primary counterpart, has a distinct biology compared to skin melanoma and lacks effective treatments. Here we genomically profile metastatic tumors and infiltrating lymphocytes. BAP1 alterations were overrepresented and occurred in 29/32 of cases. An outlier tumor had high mutational burden associated with UV-damage. CDKN2A deletions also occurred, which are rarely present in primaries. We profiled recurrent copy number alterations associated with metastasis and performed a focused knockdown screen on overexpressed targets. We investigated the role of BAP1 by reintroducing a functional allele into a deficient patient-derived cell line, revealing a broad shift towards a transcriptomic subtype associated with better prognosis. Tumor-infiltrating lymphocytes were in several cases tumor-reactive, but expression of the immune checkpoint receptors TIM-3, TIGIT and LAG3 was abundant. This study represents the largest whole-genome analysis of uveal melanoma to date and presents an updated view of the metastatic disease.

Study EGAS00001004296

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