Search Results - EGA European Genome-Phenome Archive

To determine the mutational impact of the in vitro culture, clonal human adult and pluripotent stem cell lines were subjected to a second clonal step after 3 months of culture. These subclones were whole genome sequenced to identify all the mutations that accumulated during the 3 month culture period.

Genetic changes acquired during culture pose a potential risk for the successful application of stem cells. To assess the risk of in vitro expansion on mutation accumulation we have performed whole genome sequencing of clonally expanded human induced pluripotent stem cells (iPS cells) and adult stem cells (ASCs) to identify all mutations that accumulated over a fixed culture period. We find that ASCs acquire more single nucleotide variants (SNVs) and indels per population doubling than the iPS cells. When compared with ASCs, iPS cells are more vulnerable to mutations in genes and promoters. Mutational analysis revealed a clear in vitro induced mutational signature that is irrespective of stem cell type. This in vitro signature is characterized by C to G transversions that are probably caused by oxidative stress. Additionally, we observed stem cell specific mutational signatures and differences in transcriptional strand bias, indicating differential activity of DNA repair mechanisms between stem cell types in culture. In conclusion, in vitro culture induces mutation accumulation in iPS cells and ASCs. Culture under low-oxygen tension may help to reduce the number of culture-induced mutations.

Study EGAS00001002955

The Molecular Landscape of Asian Breast Cancers Reveals Clinically Relevant Population-Specific Differences

Molecular profiles of breast cancer have contributed to an improved understanding of the disease, enabled development of molecular prognostic signatures to guide treatment decisions and unveiled new or more accurate therapeutic options for breast cancer patients. However, the extent to which differences in genetic, environmental and lifestyle factors influence molecular profiles in different populations remains poorly characterised, as relatively few large-scale molecular studies of breast tumours in non-Caucasian populations have hitherto been reported. Here, we present the molecular profiles of 560 Asian breast tumours and a comparative analysis of breast cancers arising in Asian and Caucasian women. Compared to the breast tumours in predominantly Caucasian women reported in TCGA and METABRIC, we show an increased prevalence of Her2-enriched molecular subtypes and higher prevalence of TP53 somatic mutations in ER+ Asian breast tumours. Using gene expression and immunohistochemistry, we observed elevated immune scores in Asian breast tumours, suggesting potential clinical response to immune checkpoint inhibitors. Whilst Her2-subtype and enriched immune score are associated with improved survival, presence of TP53 somatic mutations is associated with poorer survival in ER+ tumours. Taken together, these population differences unveil new opportunities to improve the understanding of this disease and lay the foundation for precision medicine in different populations.

Study EGAS00001004518

The Spatial Heterogeneity in Multiple Myeloma - from the Subclonal Architecture to the Immune Microenvironment (partly hipo_K08K)

Multiple myeloma (MM) cells show pronounced heterogeneity not only within a given patient but also between spatially separated tumor loci in the bone marrow. Understanding this spatial heterogeneity is emerging as a critical challenge for the successful treatment of the disease. Yet, our understanding of spatial differences in the subclonal architecture, molecular signatures and interactions with the tumor microenvironment remains very limited. To address this shortcoming, we performed bulk and single-cell multi-region sequencing, including random bone marrow samples from the iliac crest and paired imaging-guided focal lesion specimens from 15 newly diagnosed MM patients. We found a median of 5 subclones per patient and unique subclones in focal lesions. Central features of spatial heterogeneity included a consistent down-regulation of the chemoattractant cytokines CXCL7 and CXCL12 in focal lesion tumor cells as well as a significant depletion of macrophages in the focal lesion microenvironment. In contrast, a site-specific expansion of T-cell clones was not detected in focal lesions. In conclusion, our results demonstrate the relevance of considering spatial heterogeneity with potential implications for immunotherapies and molecular studies analyzing the role of gene signatures and MM-microenvironment interactions in disease progression.

Study EGAS00001006090

Variation and transmission of the human gut microbiota across generations - shotgun data

Although composition and functional potential of the human gut microbiota evolve over lifespan, kinship has been identified as a key covariate of microbial community diversification. To date, sharing of microbiota features within families has however mostly been assessed between parents and their direct offspring. Here, we investigate potential transmission and persistence of familial microbiome patterns and microbial genotypes in a family cohort (N=102) spanning three to five generations over the same female bloodline. We observe microbiome community composition to be associated with kinship, with seven (low-abundant) genera displaying familial distribution patterns. While kinship and current cohabitation emerged as closely entangled variables, our explorative analyses of microbial genotype distribution and transmission estimates point at the latter as a key covariate of strain dissemination. Highest potential transmission rates are estimated between sisters and mother-daughter pairs, decreasing with increasing daughter’s age, and being higher among cohabiting pairs than those living apart. Although rare, we do detect potential transmission events spanning three and four generations, primarily involving species of the genera Alistipes and Bacteroides. Overall, while our analyses confirm the existence of family-bound microbiome community profiles, transmission or co-acquisition of bacterial strains appears to be strongly linked to cohabitation.

Study EGAS00001005649

Variation and transmission of the human gut microbiota across generations - 16S data

Although composition and functional potential of the human gut microbiota evolve over lifespan, kinship has been identified as a key covariate of microbial community diversification. To date, sharing of microbiota features within families has however mostly been assessed between parents and their direct offspring. Here, we investigate potential transmission and persistence of familial microbiome patterns and microbial genotypes in a family cohort (N=102) spanning three to five generations over the same female bloodline. We observe microbiome community composition to be associated with kinship, with seven (low-abundant) genera displaying familial distribution patterns. While kinship and current cohabitation emerged as closely entangled variables, our explorative analyses of microbial genotype distribution and transmission estimates point at the latter as a key covariate of strain dissemination. Highest potential transmission rates are estimated between sisters and mother-daughter pairs, decreasing with increasing daughter’s age, and being higher among cohabiting pairs than those living apart. Although rare, we do detect potential transmission events spanning three and four generations, primarily involving species of the genera Alistipes and Bacteroides. Overall, while our analyses confirm the existence of family-bound microbiome community profiles, transmission or co-acquisition of bacterial strains appears to be strongly linked to cohabitation.

Study EGAS00001005651

Hermansky-Pudlak syndrome type 1 causes impaired anti-microbial immunity through a pathogenic lipid metabolism-mTOR circuit - 10x Genomics scRNAseq

Mendelian diseases that present with immune-mediated disorders can provide insights into the molecular mechanisms that drive inflammation. Hermansky-Pudlak syndrome (HPS) types 1 and 4 are caused by defective vesicle trafficking involving the BLOC-3 complex. The presence of inflammatory complications such as Crohn’s disease-like inflammation and lung fibrosis in these patients remains enigmatic. Using mass cytometry we observe an augmented inflammatory monocyte compartment in HPS1 patient peripheral blood that may be associated with a TNF - and IL-1α-dominated cytokine dysregulation. HPS1 patient monocyte-derived macrophages express an inflammatory TNF-OSM mRNA gene signature and changes in lipid metabolism. Using stimulation experiments and lysosomal proteomics we show that defective lipid metabolism drives RAB32-dependent mTOR signaling, facilitated by the accumulation of mTOR on lysosomes. This pathogenic circuit translates into aberrant bacterial clearance, which can be rescued with mTORC1 inhibition. We reveal that a pathogenic lipid-mTOR signaling circuit acts as a metabolic checkpoint for defective anti-microbial activity. This mechanism may be relevant to the complex pathology of HPS1 patients featuring macrophage lipid accumulation, granuloma formation, defective anti-microbial activity and tissue inflammation. Lastly, this circuit may be present in a wider group of disorders with defective lipid metabolism and cholesterol accumulation.

Study EGAS00001005098

Sclerosing epithelioid fibrosarcoma case report

Sclerosing epithelioid fibrosarcoma (SEF) is a rare and aggressive soft tissue sarcomathought to originate in fibroblasts of the tissues surrounding tendons, ligaments and muscles. Minimally responsive to conventional cytotoxic chemotherapies, greater than 50% of SEF patients experience relapse and/or metastatic disease. SEF is most commonly discovered in middle-aged and elderly adults, but also rarely in children. A common gene fusion occurring between the EWSR1 and CREB3L1 genes has been observed in 80-90% of SEF cases. We describe here the youngest SEF patient reported to date (a 3-year-old Caucasian male) who presented with numerous bony and lung metastases. Additionally, we perform a comprehensive literature review of all SEF-related articles published since the disease was first characterized. The patient described in this report experienced persistent disease progression despite being heavily treated with multiple surgeries, radiation, numerous chemotherapies and targeted therapeutics. Primary tumor, metastatic and relapse sites were sequenced by whole genome, whole exome, and deep transcriptome next generation sequencing with comparison to a patient-matched normal blood sample. Consistent across all sequencing analyses was the disease-defining EWSR1-CREB3L1 fusion as a single feature consensus. We provide an analysis of our genomic findings and a discussion as to potential therapeutic strategies for SEF.

Study EGAS00001005215

Comprehensive Genomic Characterization of Refractory Multiple Myeloma Reveals a Complex Mutational and Structural Landscape Associated with Drug Resistance (H067)

Outcome of patients with multiple myeloma (MM) refractory to immunomodulatory agents (IMiDs) and proteasome inhibitors (PIs) is still very poor. To elucidate the genetic landscape of relapsed/refractory MM (RRMM) we performed whole genome and transcriptome sequencing of 39 heavily pretreated RRMM patients with at least double refractoriness revealing complex structural changes and a high mutational load (H067/K08K). We found a median of 67 structural variants and 116 nonsynonymous exonic mutations per patient. Assessment of oncogenic drivers showed NRAS, BRAF, TP53, KRAS, SLC4A7, FAM46C, DIS3, RB1, KMT2C, MLLT4, EWSR1, HCFC2, and COPS3 as significantly mutated. We found multiple genomic regions with bi-allelic events affecting known tumor suppressor genes, most frequently TP53, RB1, and TRAF3. Supervised analysis of mutational signatures showed a major contribution of Cosmic signature 6 associated with deficiency in DNA mismatch repair and the ‘BRCAness’ signature which coincided with mutations in genes known to confer PARP inhibitor sensitivity. Recurrently mutated gene networks included genes with relevance for PI and IMiD activity, the latter including in particular members of the Cereblon and the COP9 signalosome complex. In conclusion, this comprehensive genomic characterization revealed a complex mutational and structural landscape in RRMM and highlights potential implications for therapeutic strategies.

Study EGAS00001004363

tFL with a PMBL GE signature

We investigated the clinicopathologic features of 5 follicular lymphomas (FL) that transformed to morphologic diffuse large B-cell lymphomas (DLBCL) and had a primary mediastinal large B-cell lymphoma (PMBL)-like gene expression profile. None of the transformed FL (tFL) arose in the mediastinum, all cases tested had a germinal center B-cell immunophenotype, 20% were CD30+, 60% CD23+, 80% MAL+, 20% CD200+, and 0% CD273/PDL2+. Whole exome sequencing detected alterations in genes associated with both FL/DLBCL (CREBBP, KMT2C, KMT2D, ARID1A, HIST1 members, and TNFRSF14) and PMBL (JAK-STAT pathway genes, B2M, and CD58). Copy number (CN) analysis detected gains/amplification of REL in 60% and STAT6 in 40%, gains of chromosome 16, including IL4R, in 40%, and both deletions and gains of 11q in 20%. This cohort, although limited in size, supports a subset of tFL that has blended features between FL/DLBCL and PMBL. Despite having some features that are less common in DLBCL (MAL and CD23 expression, JAK-STAT activation), these cases lack the most characteristic CN alteration seen in PMBL (9p24.1 gain/amplification). This cohort expands the biologic heterogeneity of tFL, illustrating a subset with blended FL/DLBCL and PMBL features, with potential treatment implications that include the use of novel PMBL-targeted therapies.

Study EGAS00001005870

The malaria-protective human glycophorin structural variant DUP4 shows somatic mosaicism and association with hemoglobin levels

Glycophorin A and glycophorin B are red blood cell surface proteins that are both receptors for the parasite Plasmodium falciparum, which is the principal cause of malaria in sub-Saharan Africa. DUP4 is a complex structural genomic variant that carries extra copies of a glycophorin A - glycophorin B fusion gene, and has a dramatic effect on malaria risk by reducing the risk of severe malaria by up to 40% Using fiber-FISH and Illumina sequencing, we validate the structural arrangement of the glycophorin locus in the DUP4 variant, and reveal somatic variation in copy number of the glycophorin A- glycophorin B fusion gene. By developing a simple, specific, PCR-based assay for DUP4 we show the DUP4 variant reaches a frequency of 13% in a malaria-endemic village in south-eastern Tanzania. We genotype a substantial proportion of that village and demonstrate an association of DUP4 genotype with hemoglobin levels, a phenotype related to malaria, using a family-based association test. Taken together, we show that DUP4 is a complex structural variant that may be susceptible to somatic variation, and show that it is associated with a malarial-related phenotype in a non-hospitalizedlongitudinally-followed population.

Study EGAS00001003239

CRISPR/Cas9-mediated genome editing of Schistosoma mansoni acetylcholinesterase

Here we report successful gene knock-in (KI) in the eggs of Schistosoma mansoni by combining CRISPR/Cas9 with single-stranded oligodeoxynucleotides (ssODNs). We targeted the acetylcholinesterase (AChE) gene of S. mansoni using two synthetic guide RNAs (gRNAs), X5 and X7, respectively. Liver eggs of S. mansoni were exposed to CRISPR-vector containing X5 or X7 by electroporation. Simultaneously, eggs were transfected with a ssODN donor encoding a stop codon in all six frames. Next generation sequencing analysis revealed that CRISPR/Cas9-mediated editing in S. mansoni eggs resulted in Homology-Directed Repair (HDR) when template DNA ssODN provided. Furthermore, soluble egg antigen (SEA) from AChE-modified eggs exhibited markedly reduced AChE activity compared with controls, indicative that programmed Cas9 cleavage mutated the AChE gene. Following injection of modified schistosome eggs into the tail veins of mice, a significant decrease in granuloma size in the lungs of these animals. Notably, an enhanced Th2 response induced by eggs in lung, and splenocytes small intestine-draining mesenteric lymph node cells was also generated in mice injected with X5-KI eggs in different methods. These findings further demonstrate the power and utility of CRISPR/Cas9-based genome editing for undertaking functional genomics studies in schistosomes.

Study EGAS00001004455

Sex chromosome aneuploidies give rise to changes in the circular RNA profile

Purpose The landscape of circular RNAs (circRNAs), an important class of non-coding RNAs that regulate gene expression, has never been described in human disorders of sex chromosome aneuploidies. We profiled circRNAs in Turner syndrome females (45,X;TS) and Klinefelter syndrome males (47,XXY; KS) to investigate how circRNAs respond to a missing or an extra X chromosome. Methods Samples of blood, muscle and fat were collected from individuals with TS (n = 33) and KS (n = 22) and from male (n = 16) and female (n = 44) controls. CircRNAs were identified using a combination of circRNA identification pipelines (CIRI2, CIRCexplorer2 and circRNA_finder). Results Differential expression of circRNAs was observed throughout the genome in TS and KS, in all tissues. The host-genes from which several of these circRNAs were derived, were associated with known phenotypic traits. Furthermore, several differentially expressed circRNAs had the potential to capture micro RNAs that targeted protein-coding genes with altered expression in TS and KS. Conclusion Sex chromosome aneuploidies introduce pervasive changes in the circRNA transcriptome, demonstrating that the genomic changes in these syndromes are more complex than hitherto thought. CircRNAs may help explain some of the genomic and phenotypic traits observed in these syndromes.

Study EGAS00001006404

Stereotyped B-cell responses are linked to IgG constant region polymorphisms in multiple sclerosis

Clonally related B cells infiltrate the brain, meninges, and cerebrospinal fluid of multiple sclerosis (MS) patients, but the mechanisms driving the B-cell response and shaping the immunoglobulin repertoires remain unclear. Here, we used single-cell full-length RNA-seq and B-cell receptor reconstruction to simultaneously assess the phenotypes, isotypes, constant region polymorphisms, and the paired heavy- and light-chain repertoires in intrathecal B cells. We detected extensive clonal connections between the memory B cell and antibody-secreting cell compartments and observed clonally related cells of different isotypes, including IgM/IgG1, IgG1/IgA1, IgG1/IgG2, and IgM/IgA1. There was a strong dominance of the G1m1 allotype constant region polymorphisms in antibody-secreting cells, but not in memory B cells. Tightly linked to the G1m1 allotype, we found a preferential pairing of the immunoglobulin heavy-chain variable (IGHV)4 gene family with the κ variable (IGKV)1 gene family. The IGHV4-39 gene was most used and showed the highest frequency of pairing with IGKV1-5 and IGKV1(D)-33. These results link IgG constant region polymorphisms to stereotyped B-cell responses in MS and indicate that the intrathecal B-cell response in these patients could be directed against structurally similar epitopes.

Study EGAS00001005745

Regulatory T cell transcriptomic reprogramming characterizes adverse events by checkpoint inhibitors in solid tumors

Immune checkpoint inhibitors (ICI), which target immune regulatory pathways to unleash antitumor responses, have revolutionized cancer immunotherapy. Despite the remarkable success of ICI immunotherapy, a significant proportion of patients whose tumors respond to these treatments develop immune-related adverse events (irAEs) resembling autoimmune diseases. Although the clinical spectrum of irAEs is well characterized, their successful management remains empiric. This is in part because the pathogenic mechanisms involved in the break-down of peripheral tolerance and induction of irAEs remain elusive. Herein, we focused on regulatory T cells (Tregs) in individuals with irAEs because these cells are vital for maintenance of peripheral tolerance, appear expanded in the peripheral blood of individuals with cancer and abundantly express checkpoint molecules, hence representing direct targets of ICI immunotherapy. Our data demonstrate an intense transcriptomic reprogramming of CD4+CD25+CD127– Tregs in the blood of individuals with advanced metastatic melanoma who develop irAEs following ICI immunotherapy, with a characteristic inflammatory, apoptotic and metabolic signature. This inflammatory signature was shared by Tregs from individuals with different types of cancer developing irAEs and individuals with autoimmune diseases. Our findings propose an inflammatory Treg reprogramming as a feature of immunotherapy-induced irAEs, that may facilitate translational approaches aiming to induce robust antitumor immunity without disturbing peripheral tolerance.

Study EGAS00001004694

Clinical genome sequencing uncovers potentially targetable truncations and fusions of MAP3K8 in spitzoid and other melanomas

Spitzoid melanoma is a specific morphologic variant of melanoma that most commonly affects children and adolescents and ranges on the spectrum of malignancy from low-grade to overtly malignant. These tumors are generally driven by fusions of ALK, RET, NTRK1/3, MET, ROS1 and BRAF. However, in approximately 50% of cases, no genetic driver has been established. Clinical whole genome and transcriptome sequencing (RNA-Seq) of a spitzoid tumor from an adolescent revealed a novel gene fusion of MAP3K8, encoding a serine−threonine kinase that activates MEK. The patient who had exhausted all other therapeutic options was treated with a MEK inhibitor and underwent a transient clinical response. We subsequently analyzed spitzoid tumors from 49 patients by RNA-Seq and found in-frame fusions or C-terminal truncations in 33% of cases. The fusion transcripts and truncated genes all contained MAP3K8 exons 1-8 but lacked the autoinhibitory final exon. Data mining of RNA-Seq from the Cancer Genome Atlas (TCGA) uncovered analogous MAP3K8 rearrangements in 1.5% of adult melanomas. Thus, MAP3K8 rearrangements - uncovered by comprehensive clinical sequencing of a single case - are the most common genetic event in spitzoid melanoma, are present in adult melanomas, and could be amenable to MEK inhibition.

Study EGAS00001003430

Androgen receptor blockade promotes response to BRAF/MEK-targeted therapy

We studied a group of melanoma patients treated with neoadjuvant BRAF/MEK-targeted therapy (NCT02231775, n=51), and observed significantly higher rates of major pathologic response (MPR= <10% viable tumor at resection) and improved recurrence-free survival (RFS) in females versus males (MPR-66% versus 14%, p=0.001; RFS-64% versus 32% at 2 years, p=0.021). Findings were validated in a several additional cohorts 2-4 patients with unresectable metastatic melanoma treated with BRAF and/or MEK-targeted therapy (n=664 patients in total), demonstrating improved progression-free survival (PFS) and overall survival (OS) in females versus males in several of these studies. Studies in pre-clinical models demonstrated significantly impaired anti-tumor activity in male versus female BRAF/MEK-treated mice (p=0.006), with significantly higher expression of androgen receptor (AR) in tumors of male and female BRAF/MEK-treated mice versus control (p=0.0006 and 0.0025). Pharmacologic inhibition of AR signaling improved responses to BRAF/MEK-targeted therapy in male and female mice (p=0.018 and p=0.003), whereas induction of AR signaling (via testosterone administration) was associated with significantly impaired response to BRAF/MEK-targeted therapy in males and females (p=0.021 and p<0.0001).

Study EGAS00001006196

WXS and RNA-seq for 22 patients treated with radiation + immunotherapy

Over 500 active clinical trials are investigating combination radiation (RT) and immune checkpoint blockade (ICB) as a cancer treatment; however, the majority of trials have found no positive interaction. We performed a comprehensive molecular analysis of a randomized phase I clinical trial of patients with non-small cell lung cancer (NSCLC) treated with concurrent or sequential ablative RT and ICB. Concurrent treatment was superior to sequential treatment in augmenting local and distant tumor responses and improving overall survival in a subset of patients with highly aneuploid tumors, but not in those with less aneuploid tumors. Our analysis suggested that concurrent treatment eliminated immunologically cold aneuploid tumors better than sequential treatment and improved patient outcomes. In addition, we report that RT alone decreased intratumoral cytotoxic effector T cell and adaptive immune gene expression signatures, in contrast to upregulation of key immune pathways after concurrent administration of RT and ICB. Our findings distinguish the differential genomic and transcriptomic effects of RT versus RT and ICB and challenge the prevailing paradigm that local ablative RT beneficially stimulates the immune response. We propose the use of tumor aneuploidy as a novel biomarker and therapeutic target in personalizing treatment approaches for patients with NSCLC treated with RT and ICB.

Study EGAS00001006212

MutWP1__CRUK_Grand_Challenge_Mutographs_of_Cancer__clear_cell_renal_cell_carcinoma___2

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. 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 EGAS00001003542

Whole genome sequencing delineates regulatory, structural, and cryptic splice variants in early onset cardiomyopathy

Cardiomyopathy (CMP) is a heritable disorder. Over 50% cases are gene-elusive on clinical gene panel testing. The contribution of variants in non-coding DNA elements that result in cryptic splicing and regulate gene expression has not been explored. We analyzed whole genome sequencing (WGS) data in a discovery cohort of 209 pediatric CMP patients and 1,953 independent replication genomes and exomes. We searched for protein-coding variants, and non-coding variants predicted to affect the function or expression of genes. Thirty-nine % cases harbored pathogenic coding variants in known CMP genes, and 5% harbored high-risk loss-of-function (LoF) variants in additional candidate CMP genes. Fifteen % harbored high-risk regulatory variants in promoters and enhancers of CMP genes (Odds ratio 2.25, p=6.70×10-7 versus controls). Genes involved in α-dystroglycan glycosylation (FKTN, DTNA) and desmosomal signaling (DSC2, DSG2) were most highly enriched for regulatory variants (Odds ratio 6.7-58.1). Functional effects were confirmed in patient myocardium and reporter assays in human cardiomyocytes, and in zebrafish CRISPR knockouts. We provide strong evidence for the genomic contribution of functionally active variants in new genes and in regulatory elements of known CMP genes to early-onset CMP.

Study EGAS00001004929

Single-cell RNA sequencing reveals the mesangial identity and species diversity of glomerular cell transcriptomes

Molecular characterization of the individual cell types in human kidney as well as model organisms are critical in defining organ function and understanding translational aspects of biomedical research. Previous studies have uncovered gene expression profiles of several kidney glomerular cell types, however, important cells, including mesangial (MCs) and glomerular parietal epithelial cells (PECs), were missing or incompletely described, and a systematic comparison between mouse and human kidney is lacking. To this end, we used Smart-seq2 to profile 4332 individual glomerulus-associated cells isolated from human living donor renal biopsies and mouse kidney. The analysis revealed genetic programs for all four glomerular cell types (podocytes, glomerular endothelial cells, MCs and PECs) as well as rare glomerulus-associated macula densa cells (MDCs). Importantly, we detected heterogeneity in glomerulus-associated Pdgfrb-expressing cells, including bona fide intraglomerular MCs with the functionally active phagocytic molecular machinery, as well as a unique mural cell type located in the central stalk region of the glomerulus tuft. Furthermore, we observed remarkable species differences in the individual gene expression profiles of defined glomerular cell types that highlight translational challenges in the field and provide a guide to design translational studies.

Study EGAS00001004943

Significant and pervasive effects of RNA degradation on Nanopore direct RNA sequencing

Abstract Oxford Nanopore direct RNA sequencing (DRS) is capable of sequencing complete RNA molecules and accurately measuring gene and isoform expression. However, as DRS is designed to profile intact RNA, expression quantification may be more heavily dependent upon RNA integrity than alternate RNA-seq methodologies. It is currently unclear how RNA degradation impacts DRS or if it can be corrected for. To assess the impact of RNA integrity on DRS we performed a degradation time-series using SH-SY5Y neuroblastoma cells. Our results demonstrate that degradation is a significant and pervasive factor that can bias DRS measurements, including a reduction in library complexity resulting in an overrepresentation of short genes and isoforms. Degradation also biases differential expression analyses; however, we find explicit correction can almost fully recover meaningful biological signal. In addition, DRS provided less biased profiling of partially degraded samples than nanopore cDNA-PCR sequencing. Overall, we find samples with RIN > 9.5 can be treated as undegraded and samples with RIN > 7 can be utilised for DRS with appropriate correction. These results establish the suitability of DRS for a wide range of samples, including partially degraded in-vivo clinical and post-mortem samples, whilst limiting the confounding effect of degradation on expression quantification.

Study EGAS00001006542

Interplay of somatic alterations and immune infiltration modulates response to PD-1 blockade in advanced clear cell RCC-- CA209-025

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 EGAS00001004292

T cell responses of ALS patients

In this project, we aimed to understand how T cell responses contribute to the disease progression of amyotrophic lateral sclerosis (ALS). The present data is on single-cell sequencing isolated from human cerebrospinal fluid (CSF) cells from both ALS patients (n=5) and controls (n=4). This analysis was conducted as part of a bigger project which is summarized in the section below. We used flow cytometry to define T cell subsets and phenotypes in blood and CSF samples collected at the time of diagnosis on a cohort of 89 newly diagnosed ALS patients in Stockholm, Sweden. High frequency of CD4+FOXP3- effector T cells in blood and CSF was associated with poor survival whereas high frequency of activated regulatory T (Treg) cells and high ratio between activated and resting Treg cells in blood was associated with better survival. T cell profiles also predicted disease progression rate. On an independent cohort of cases and controls, we used single cell transcriptomics data to demonstrate that ALS patients had altered T cell gene expression patterns and clonally expanded CD4+ and CD8+ T cells in CSF. In summary, T cell responses contribute to disease progression of ALS, supporting modulation of adaptive immunity as a viable therapeutic option.

Study EGAS00001006675

Hexanucleotide repeat expansions in C9orf72 alter microglial responses and prevent a coordinated glial reaction in ALS

Neuroinflammation is an important hallmark in amyotrophic lateral sclerosis (ALS). Experimental evidence has highlighted a role of microglia in the modulation of motor neuron degeneration. However, the exact contribution of microglia to both sporadic and genetic forms of ALS is still unclear. We generated single nuclei profiles of spinal cord and motor cortex from sporadic and C9orf72 ALS patients, as well as controls. We particularly focused on the transcriptomic responses of both microglia and astrocytes. We confirmed that C9orf72 is highly expressed in microglia and shows a diminished expression in carriers of the hexanucleotide repeat expansion (HRE). This resulted in an impaired response to disease, with specific deficits in phagocytic and lysosomal transcriptional pathways. Astrocytes also displayed a dysregulated response in C9orf72 ALS patients, remaining in a homeostatic state. This suggests that C9orf72 HRE alters a coordinated glial response, which ultimately would increase the risk for developing ALS. Our results indicate that C9orf72 HRE results in a selective microglial loss-of-function, likely impairing microglial-astrocyte communication and preventing a global glial response. This is relevant as it indicates that sporadic and familial forms of ALS may present a different cellular substrate, which is of great importance for patient stratification and treatment.

Study EGAS00001006711

Atypical teratoid/rhabdoid tumoroids reveal subgroup-specific drug vulnerabilities RNA-Seq

Atypical teratoid/rhabdoid tumors (ATRTs) represent a rare, but aggressive pediatric brain tumor entity. They are genetically uniquely defined by alterations in the SWI/SNF chromatin remodeling complex members SMARCB1 or SMARCA4. ATRTs can be further classified in different molecular subgroups based on their epigenetic profiles. Although recent studies suggest that the different subgroups have distinct clinical features, subgroup-specific treatment regimens have not been developed thus far. This is hampered by the lack of pre-clinical in vitro models representative of the different molecular subgroups. Here, we describe the establishment of ATRT tumoroid models from the ATRT-MYC and ATRT-SHH subgroups. We demonstrate that ATRT tumoroids retain subgroup-specific epigenetic and gene expression profiles. High throughput drug screens on our ATRT tumoroids revealed distinct drug sensitivities between and within ATRT-MYC and ATRT-SHH subgroups. Whereas ATRT-MYC universally displayed high sensitivity to multi-targeted tyrosine kinase inhibitors, ATRT-SHH showed a more heterogeneous response with a subset showing high sensitivity to Notch inhibitors, which corresponded to high expression of Notch receptors. Our ATRT tumoroids represent the first pediatric brain tumor organoid model, providing a representative pre-clinical model which enables the development of subgroup-specific therapies.

Study EGAS00001006866

Atypical teratoid/rhabdoid tumoroids reveal subgroup-specific drug vulnerabilities DNA-Methylation

Atypical teratoid/rhabdoid tumors (ATRTs) represent a rare, but aggressive pediatric brain tumor entity. They are genetically uniquely defined by alterations in the SWI/SNF chromatin remodeling complex members SMARCB1 or SMARCA4. ATRTs can be further classified in different molecular subgroups based on their epigenetic profiles. Although recent studies suggest that the different subgroups have distinct clinical features, subgroup-specific treatment regimens have not been developed thus far. This is hampered by the lack of pre-clinical in vitro models representative of the different molecular subgroups. Here, we describe the establishment of ATRT tumoroid models from the ATRT-MYC and ATRT-SHH subgroups. We demonstrate that ATRT tumoroids retain subgroup-specific epigenetic and gene expression profiles. High throughput drug screens on our ATRT tumoroids revealed distinct drug sensitivities between and within ATRT-MYC and ATRT-SHH subgroups. Whereas ATRT-MYC universally displayed high sensitivity to multi-targeted tyrosine kinase inhibitors, ATRT-SHH showed a more heterogeneous response with a subset showing high sensitivity to Notch inhibitors, which corresponded to high expression of Notch receptors. Our ATRT tumoroids represent the first pediatric brain tumor organoid model, providing a representative pre-clinical model which enables the development of subgroup-specific therapies.

Study EGAS00001006881

Long-term organoid culture of a small intestinal neuroendocrine tumor

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are rare and highly heterogeneous neoplasms whose incidence has markedly increased over the last decades. A grading system based on the tumor cells' proliferation index predicts high-risk for G3 NETs. However, low-to-intermediate grade (G1/G2) NETs have an unpredictable clinical course that varies from indolent to highly malignant. Cultures of human cancer cells enable to perform functional perturbation analyses that are instrumental to enhance our understanding of cancer biology. To date, no tractable and reliable long-term culture of G1/G2 NET has been reported to permit disease modeling and pharmacological screens. Here, we report of the first long-term culture of a G2 metastatic small intestinal NET that preserves the main genetic drivers of the tumor and retains expression patterns of the endocrine cell lineage. Replicating the tissue, this long-term culture showed a low proliferation index, and yet it could be propagated continuously without dramatic changes in the karyotype. The model was readily available for pharmacological screens using targeted agents and as expected, showed low tumorigenic capacity in vivo. Overall, this is the first long-term culture of NETs to faithfully recapitulate many aspects of the original neuroendocrine tumor.

Study EGAS00001007093

Transcriptomics identifies blunted immunomodulatory effects of vitamin D in people with multiple sclerosis

Vitamin D deficiency is a risk factor for developing multiple sclerosis (MS). However, the immune effects of vitamin D in people with MS are not well understood. We analyzed transcriptomic datasets generated by RNA sequencing of immune cell subsets (CD4+, CD8+ T cells, B cells, monocytes) from 33 healthy controls and 33 untreated MS cases. We utilized a traditional bioinformatic pipeline and weighted gene co-expression network analysis (WGCNA) to determine genes and pathways correlated with endogenous vitamin D. In controls, CD4+ and CD8+ T cells had 1079 and 1188 genes, respectively, whose expressions were correlated with plasma 25-hydroxyvitamin D level (P<0.05). Functional enrichment analysis identified association with TNF-alpha and MAPK signaling. In CD4+ T cells of controls, vitamin D level was associated with expression levels of several genes proximal to multiple sclerosis risk loci (P=0.01). Genes differentially associated with endogenous vitamin D by case-control status were enriched in TNF-alpha signaling via NF-κB. WGCNA suggested a blunted response to vitamin D in cases relative to controls. Collectively, our findings provide further evidence for the immune effects of vitamin D, and demonstrate a differential immune response to vitamin D in cases relative to controls, highlighting a possible mechanism contributing to MS pathophysiology.

Study EGAS00001007254

Targeting TRIP13 in Wilms Tumor with Nuclear Export Inhibitors

Wilms tumor (WT) is the most common renal malignancy of childhood. Despite improvements in the overall survival, relapse occurs in ~15% of patients with favorable histology WT (FHWT). Half of these patients will succumb to their disease. Identifying novel targeted therapies in a systematic manner remains challenging in part due to the lack of faithful preclinical in vitro models. We established ten short-term patient-derived WT cell lines and characterized these models using low-coverage whole genome sequencing, whole exome sequencing and RNA-sequencing, which demonstrated that these ex-vivo models faithfully recapitulate WT biology. We then performed targeted RNAi and CRISPR-Cas9 loss-of-function screens and identified the nuclear export genes (XPO1 and KPNB1) as strong vulnerabilities. We observed that these models are sensitive to nuclear export inhibition using the FDA approved therapeutic agent, selinexor (KPT-330). Selinexor treatment of FHWT suppressed TRIP13 expression, which was required for survival. We further identified in vitro and in vivo synergy between selinexor and doxorubicin, a chemotherapy used in high risk FHWT. Taken together, we identified XPO1 inhibition with selinexor as a potential therapeutic option to treat FHWTs and in combination with doxorubicin, leads to durable remissions in vivo.

Study EGAS00001007389

Genomic evolution and transcriptional changes in the evolution of prostate cancer into neuroendocrine and ductal carcinoma types

Prostate cancer is typically of acinar adenocarcinoma type but can occasionally present as neuro-endocrine and/or ductal type carcinoma. These are associated with clinically aggressive disease and the former often arises on a background of androgen deprivation therapy, although it can al-so arise de novo. Two prostate cancer cases were sequenced by exome capture from archival tis-sue. Case 1 was de novo small cell neuroendocrine carcinoma and ductal adenocarcinoma with 3 longitudinal samples over 5 years. Case 2 was a single time point after development of treatment related neuroendocrine prostate carcinoma. Case 1 showed whole genome doubling in all sam-ples and focal amplification of AR in all samples except the first time point. Phylogenetic analysis revealed a common ancestry for the ductal and small cell carcinoma. Case 2 showed 13q loss (involving RB1) in both adenocarcinoma and small cell carcinoma regions, and 3p gain, 4p loss, 17p loss (involving TP53) in the latter. By using highly curated samples, we demonstrate for the first time that small cell neuroendocrine and ductal prostatic carcinoma can have a common an-cestry and the process of evolution over time. We highlight whole genome doubling in a patient with prostate cancer relapse, reinforcing its poor prognostic nature.

Study EGAS00001007412

Genomic evolution and transcriptional changes in the evolution of prostate cancer into neuroendocrine and ductal carcinoma types (RNAseq)

Prostate cancer is typically of acinar adenocarcinoma type but can occasionally present as neuro-endocrine and/or ductal type carcinoma. These are associated with clinically aggressive disease and the former often arises on a background of androgen deprivation therapy, although it can al-so arise de novo. Two prostate cancer cases were sequenced by exome capture from archival tis-sue. Case 1 was de novo small cell neuroendocrine carcinoma and ductal adenocarcinoma with 3 longitudinal samples over 5 years. Case 2 was a single time point after development of treatment related neuroendocrine prostate carcinoma. Case 1 showed whole genome doubling in all sam-ples and focal amplification of AR in all samples except the first time point. Phylogenetic analysis revealed a common ancestry for the ductal and small cell carcinoma. Case 2 showed 13q loss (involving RB1) in both adenocarcinoma and small cell carcinoma regions, and 3p gain, 4p loss, 17p loss (involving TP53) in the latter. By using highly curated samples, we demonstrate for the first time that small cell neuroendocrine and ductal prostatic carcinoma can have a common an-cestry and the process of evolution over time. We highlight whole genome doubling in a patient with prostate cancer relapse, reinforcing its poor prognostic nature.

Study EGAS00001007428

Single cell transcriptomic landscape of pediatric B-cell acute lymphoblastic leukemia: dissection of transcriptional heterogeneity and B-cell developmental state

Introduction: Genomic analyses of bulk ALL samples have improved our understanding of the genetic basis and risk stratification of B-ALL, but do not directly examine intratumor heterogeneity or enable inference of leukemia developmental state and cell of origin. Methods: We profiled 89 B-ALL samples by single-cell RNA-seq (scRNA-seq) (10X Genomics 5’v2) and compared them to a scRNA-seq reference map of normal human B-cell development. Results: Analysis of heterogeneity of inferred DNA copy number alterations at single cell level showed that aneuploid ALL with near haploidy and hyperdiploid harbor chromosomal losses or gains in all blasts, consistent with early, synchronous origin rather than sequential accumulation. Intra-sample heterogeneity was driven by five gene expression signatures: cell cycle, metabolism, differentiation, inflammation, refining leukemic subtyping. An atlas of B cell development was established to map B-ALL samples to specific developmental states. Hyperdiploid samples resembled pro-B cells, while MEF2D-r and TCF3::PBX1 showed high pre-B abundance. Patients with high early lymphoid abundance had poorer outcomes. Conclusions: Understanding variation in transcriptional programs and developmental states of B-ALL blasts by sc transcriptome refines existing clinical and genomic classifications and provides novel prognostic markers.

Study EGAS00001007512

Ewing and Ewing-like-sarcoma tumoroid biobank reveals distinct drug sensitivities: translocation makes the difference

Ewing sarcoma (ES) and Ewing-like sarcomas (ELS) are highly aggressive tumors found in soft tissues and bone of mostly children and young adults. Despite being different in many aspects, including genetics, possible cell-of-origin, and pathology, patients with any of these entities all receive the same therapeutic regimen. Currently, there is a lack of preclinical cell models that can predict drug response of these entities in vitro. Here, we describe a pediatric ES and ELS tumor organoid (tumoroid) biobank containing tumoroids with different translocations, including EWSR1::FLI1, EWSR1::ERG, CIC::DUX4, and BCOR-rearrangements. Using histology, whole genome sequencing and RNA sequencing, we demonstrate that these tumoroids retain key properties of their matching patient tumors. In addition, we traced tumor subclones in the tumoroids across patient-matched longitudinal samples, which showed that cellular heterogeneity was maintained. We subsequently performed drug screening on the tumoroid models, which unveiled entity-specific drug sensitivity to various cytotoxic compounds and targeted compounds, including MCL-1 inhibitors for CIC::DUX4 sarcomas. Taken together, this newly established ES and ELS patient-derived tumoroid biobank generates a unique source of material for future basic cancer research and drug-screening.

Study EGAS00001007941

PSCP_bisulphite analysis in hESCs (2018-08-13)

Many studies over the past 10 years, culminating in the recent report of the International Stem Cell Initiative (ISCI, 2011) have shown that hPSC acquire genetic and epigenetic changes during their time in culture. Many of the genetic changes are non-random and recurrent, probably because they provide a selective growth advantage to the undifferentiated cells. Some are shared by embryonal carcinoma cells, the malignant counterparts of ES cells. The origins of these growth advantages are poorly understood, but may come from altered cell cycle dynamics, resistance to apoptosis or altered patterns of differentiation. Less is known about the nature and consequences of epigenetic changes, but it is likely that these similarly affect hPSC behaviour; e.g., enhanced expression of DLK1, an imprinted gene, is associated with altered hPSC growth (Enver et al 2005). Inevitably, these genetic and epigenetic changes will impact on our ability to use hPSC for regenerative medicine, either because malignant transformation of the undifferentiated cells or their differentiated derivatives to be used for transplantation compromises safety, or because they impede the function of those differentiated derivatives, or because they affect the efficiency with which the undifferentiated cells can be expanded and differentiated into desired cell types. Focusing initially upon the existing clinical grade hESC lines, later moving to iPSC, we will Consolidate and extend knowledge of the rate, type and functional impact of the genetic variations that occur during hPSC culture. We will use whole genome and exome sequencing as well as SNP arrays, together with clonal analysis and other cytogenetics techniques. Common changes will be compared with those found in the normal human population, at low frequency in the original cell population or observed during iPSC generation in the HIPSCI project currently based at the WTSI. These studies will provide a better understanding of the range of genetic changes that occur in hPSC beyond the CNVs already identified. In conjunction with cancer genome resources and expertise at WTSI, bioinformatic analyses of these hPSC data will allow us to assess potential impact on hPSC behaviour pertinent to applications in regenerative medicine, notably the likelihood that specific changes arising in undifferentiated PSC cultures may be associated with potential malignant transformation of differentiated progeny. This data is part of a pre-publication release. For information on the proper use of pre-publication data shared by the Wellcome Trust Sanger Institute (including details of any publication moratoria), please see http://www.sanger.ac.uk/datasharing/ . This dataset contains all the data available for this study on 2018-08-13.

Dataset EGAD00001004295

Mutational landscape of normal epithelial cells in Lynch Syndrome patients

Lynch Syndrome (LS) is an autosomal dominant disease conferring a high risk of colorectal cancer due to germline heterozygous mutations in a DNA mismatch repair (MMR) gene. Although cancers in LS patients show elevated somatic mutation burdens, information on mutation rates in normal tissues and understanding of the trajectory from normal to cancer cell is limited. Here we whole-genome sequenced 152 crypts from normal and neoplastic epithelial tissues from LS patients. In normal tissues the repertoire of mutational processes and mutation rates were similar to those found in wild type individuals. A morphologically normal colonic crypt with an increased mutation burden and mutational signatures consistent with MMR deficiency was identified, which may represent a very early stage of LS pathogenesis. Phylogenetic tress of tumour crypts indicated that the most recent ancestor cell of each tumour was already MMR deficient and had experienced multiple clonal evolution cycles. This study demonstrates the genomic stability of epithelial cells with heterozygous germline MMR gene mutations and highlights important differences in the pathogenesis of LS from other colorectal cancer predisposition syndromes.

Dataset EGAD00001008092

RNA-Seq in Patients with Primordial Dwarfism

Transcriptome studies in patients with rare genetic diseases can potentially aid in the interpretation of likely causal genetic variation through identification of altered transcript abundance and/or structure. RNA-Seq is the most sensitive assay for both investigating transcript structure and abundance The primary aim of this pilot project is to investigate to what degree integrating exome-Seq and RNA-Seq data on the same individual can accelerate the identification of causal alleles for rare genetic diseases. There are two main strands to this: (i) identifying which variants discovered in exome-seq appear to be having a functional impact on transcripts, and (ii) identifying transcript outliers, especially among known causal genes, that may not necessarily have a causal variant identified from exome sequencing. The latter may identify the presence of causal variants that lie far from coding regions (e.g. the formation of cryptic splice sites deep within introns, or loss of long range regulatory elements), which can be confirmed with further targeted genetic assays. Just over 50% of all disease-causing variants recorded in the Human Gene Mutation Database (HGMD) affect transcript structure and abundance (e.g. nonsense SNVs, essential splice site SNVs, frameshifting indels, CNVs). This pilot project will study RNA from lymphoblastoid cell-lines from 12 patients with primordial dwarfism syndromes, for 10 of these samples we have previously generate exome data as part of our collaboration with the group of Prof Andrew Jackson. The two remaining samples are positive controls where the causal mutation is known, and is known to affect transcript structure and/or abundance. Primordial dwarfism is a prime candidate for these RNA-seq studies because all known causal mutations to date have key roles in DNA replication and thus, unsurprisingly, the products of the causal genes are typically ubiquitously expressed. Each RNA will be sequenced, with two technical replicates (independent RT-PCR and libraries) per sample, and each replicate run in 1/2 of a HiSeq lane using 100bp paired reads. Samples preparation was as follows :The cells were grown to confluency, then pellets frozen at -80. RNA samples were prepared using the Qiagen RNeasy kit, then nanodropped and analyzed using the bioanalyzer to determine concentration and purity. This data is part of a pre-publication release. For information on the proper use of pre-publication data shared by the Wellcome Trust Sanger Institute (including details of any publication moratoria), please see http://www.sanger.ac.uk/datasharing/

Dataset EGAD00001000640

MutWP1__CRUK_Grand_Challenge_Mutographs_of_Cancer__clear_cell_renal_cell_carcinoma

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. 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 EGAS00001002608

Diverse_outcomes_of_controlled_human_malaria_infection_originate_from_host_intrinsic_immune_variation_and_not_var_gene_switching

Falciparum malaria is clinically heterogeneous and the relative contribution of parasite and host factors in shaping disease severity remains unclear. We set out to explore the interaction between host inflammation and parasite variant surface antigen (VSA) expression, asking whether this relationship underpins the variation observed in controlled human malaria infection. We uncovered marked heterogeneity in the response of naive hosts to blood challenge with some volunteers maintaining a state of immune quiescence, others triggering interferon-stimulated inflammation and a small group showing transcriptional evidence of myeloid cell suppression. Significantly, only inflammatory volunteers experienced hallmark symptoms of clinical malaria. When we then tracked temporal changes in parasite VSA expression to ask whether variants associated with severe disease preferentially expand in naive hosts (as predicted by current theory) we found that var gene profiles were essentially unchanged after 10-days of blood-stage infection. These data therefore show that the diverse clinical outcomes of CHMI largely originate from host-intrinsic variation and there is no evidence for switching or selection of var genes in naïve hosts. This data is part of a pre-publication release. For information on the proper use of pre-publication data shared by the Wellcome Trust Sanger Institute (including details of any publication moratoria), please see http://www.sanger.ac.uk/datasharing/

Study EGAS00001003766

Identification of biomarkers of response to preoperative talazoparib monotherapy in treatment naïve gBRCA+ breast cancers

Germline mutations in BRCA1 or BRCA2 exist in ~2-7% of breast cancer patients, which has led to the approval of PARP inhibitors in the advanced setting. We have previously reported a phase II neoadjuvant trial of single agent talazoparib for patients with germline BRCA pathogenic variants with a pathologic complete response (pCR) rate of 53%. As nearly half of the patients treated did not have pCR, better strategies are needed to overcome treatment resistance. To this end, we conducted multi-omic analysis of 13 treatment naïve breast cancer tumors from patients that went on to receive single-agent neoadjuvant talazoparib. We looked for biomarkers that were predictive of response (assessed by residual cancer burden) after 6 months of therapy. We found that all resistant tumors exhibited either the loss of SHLD2, expression of a hypoxia signature, or expression of a stem cell signature. These results indicate that the deep analysis of pre-treatment tumors can identify biomarkers that are predictive of response to talazoparib and potentially other PARP inhibitors, and provides a framework that will allow for better selection of patients for treatment, as well as a roadmap for the development of novel combination therapies to prevent emergence of resistance.

Study EGAS00001005676

Multi-organ landscape of therapy-resistant melanoma

Metastasis and failure of present-day therapies represent the most common causes of mortality in patients with cutaneous melanoma. To identify the underlying genetic and transcriptomic landscapes, here we analyzed multi-organ metastases and tumor-adjacent tissues from eleven rapid autopsies after treatment with MAPK inhibitor (MAPKi) and/or immune checkpoint blockade (ICB) and death due to acquired resistance. Either treatment elicits shared genetic alterations that suggest immune-evasive, cross-therapy resistance mechanisms. Large, non-clustered deletions, inversions, and inter-chromosomal translocations dominate rearrangements. Using 345 therapy-naïve TCGA melanoma and 131 patient-matched melanoma pre-and-post acquired resistance to only either treatment, we performed cross-cohort analyses to identify MAPKi and ICB as respective contributors to gene amplifications and deletions enriched in autopsy versus therapy-naïve tumors. Private/late mutations and structural variants display shifted mutational and rearrangement signatures, with MAPKi specifically selecting for signatures of defective homologous-recombination, mismatch, and base-excision repair. Transcriptomic signatures and cross-talks with tumor-adjacent macroenvironments nominate organ-specific adaptive pathways. An immune-desert, CD8+-macrophage-biased archetype, T-cell exhaustion, and type-2 immunity characterize the immune contexture. This multi-organ analysis of lethal, therapy-resistant melanoma presents preliminary insights with potential to improve therapeutic strategies.

Study EGAS00001006644

Liquid biopsy for molecular characterization of diffuse large B-cell lymphoma and early assessment of minimal residual disease

Circulating tumor DNA (ctDNA) allows genotyping and minimal residual disease (MRD) detection in lymphomas. Using a NGS approach (Euroclonality-NDC), we evaluated clinical and prognostic value of ctDNA in a series of R-CHOP-treated DLBCL patients at baseline (n=68) and after 2-cycles (n=59), monitored by metabolic imaging (PET/CT). A molecular marker was identified in 61/68 (90%) ctDNA samples at diagnosis. Pre-treatment high ctDNA levels significantly correlated with elevated LDH, advanced stage, high risk IPI and a trend to shorter 2-year PFS. Valuable NGS data after 2-cycles of treatment were obtained in 44 cases, and 38 achieved major molecular response (MMR; 2.5-log drop in ctDNA). PFS curves displayed statistically significant differences among those achieving MMR vs. those not achieving MMR (2yr PFS of 76% vs. 0%, p<0.001). Similarly, more than 66% reduction in SUVmax by PET/CT identified two subgroups with different prognosis (2yr PFS of 83% vs. 38%; p<0.001). Combining both approaches MMR and SUVmax reduction, a better stratification was observed (2yr PFS of 84% vs. 17% vs. 0%, p<0.001). Euroclonality-NDC panel allows the detection of a molecular marker in the ctDNA in 90% of DLBCL. ctDNA reduction at 2 cycles and its combination with interim PET results improves patient prognosis stratification.

Study EGAS50000000215

Detection of rare mutations, copy number variation, and DNA methylation in the same template DNA molecules

The analysis of cell-free DNA (cfDNA) from plasma offers great promise for the earlier detection of cancer. At present, changes in DNA sequence, methylation, or copy number are the most sensitive ways to detect the presence of cancer. To further increase the sensitivity of such assays with limited amounts of sample, it would be useful to be able to evaluate the same template molecules for all these changes. Here we report an approach, called MethylSaferSeqS, that achieves this goal, and can be applied to any standard library preparation method suitable for massively parallel sequencing. The innovative step was to copy both strands of each DNA-barcoded molecule with a primer that allows the subsequent separation of the original strands (retaining their 5-methylcytosine residues) from the copied strands (in which the 5-methylcytosine residues are replaced with unmodified cytosine residues). The epigenetic and genetic alterations present in the DNA molecules can then be obtained from the original and copied strands, respectively. We applied this approach to plasma from 265 individuals, including 198 with cancers of the pancreas, ovary, lung and colon, and found the expected patterns of mutations, copy number alterations, and methylation. Furthermore, we could determine which original template DNA molecules were methylated and/or mutated. MethylSaferSeqS should be useful for addressing a variety of questions relating genetics and epigenetics in the future.

Study EGAS00001006839

Genetic and Phenotypic Analysis of Multiple Sclerosis in Hispanics

We sought to identify MS susceptibility variants specific to the Major Histocompatibility Complex and to assess the effect of ancestral risk modification within 2652 Latinx and Hispanic individuals, as well as 2435 Black and African American individuals ascertained in collaboration with the Alliance for Research in Hispanic MS (ARHMS). All DNA samples were obtained through whole blood extraction and were genotyped on the MS Chip, an Illumina Infinium custom genotyping array that contains targeted and dense coverage of the extended MHC, specifically designed for imputation. Classical HLA alleles, SNPs, and amino acid residues were imputed simultaneously from genotyped SNPs using HLA-TAPAS and a multi-ethnic reference panel of 2504 samples from the 1000 Genomes Project. We have identified several novel susceptibility alleles which are rare in European populations including HLA-B*53:01, and we have identified an independent role for HLA-DRB1*15:01 and HLA-DQB1*06:02 on MS risk. We found a decrease in Native American ancestry in MS cases vs controls across the MHC, peaking near the previously identified MICB locus; and we have identified several susceptibility variants for which MS risk is modified by global or local ancestry. We are making data on all genotyped and imputed SNPs, classical HLA alleles, and amino acid residues available through dbGaP for the Hispanic and African American samples utilized in these analyses.

Study phs003105

Whole Exome Sequencing and RNA-Seq to Characterize the Somatic Breast Cancer Landscape Among Latinas in California

Somatic mutational profiles are increasingly being used to guide treatment. However, there is a dearth of data from non-European populations. To address this gap, we conducted paired tumor/normal whole exome paired-end sequencing and tumor RNA-Seq on 146 breast tumors from 140 Hispanic/Latina (H/L) women with breast cancer. We characterized somatic mutations, copy number alterations, tumor subtypes [Prediction Analysis of Microarray 50 (PAM50)], Catalogue Of Somatic Mutations In Cancer (COSMIC) mutation signatures and expression profiles, and compared them to breast tumors from non-Hispanic White (White) women in The Cancer Genome Atlas (TCGA). Using MutSigCV, we found that the most commonly mutated genes, including TP53, RUNX1, PTEN, PIK3CA, MAP3K1, GATA3, CDH1 and CBFB, were similar to those in breast tumors from non-Hispanic white women. Novel findings were that outliers of BLTP2 (aka KIAA0100) over-expression and COSMIC mutational signature 16 were more common in tumors from H/L women than White women. We also identified that the known germline APOBEC3A/B deletion variant was significantly more common in H/L women and was associated with indigenous American ancestry. Data available through dbGaP will be whole-exome sequencing (WES) and RNA sequencing (RNA-Seq) data, as well as phenotypic data, including estrogen receptor, progesterone receptor, and HER2 receptor status, tumor histology, stage, and grade, and age at diagnosis.

Study phs003218

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

The Research Institute at Nationwide Children's Hospital Genetics of Congenital Heart Disease (CHD)

Congenital heart disease (CHD) is the most common type of birth defect, but the cause for the majority of cardiac birth defects remains unknown. Numerous epidemiologic studies have demonstrated evidence that genetic factors likely play a contributory, if not causative, role in CHD. A few genes have been identified by us and other investigators using traditional genetic approaches, but these genes only account for a small portion of the non-syndromic CHDs. Therefore, we are now utilizing whole exome sequencing (WES) and whole genome sequencing (WGS), with the addition of more traditional genetic techniques such as chromosomal microarray or traditional linkage analysis, to identify genetic causes of familial and isolated CHD. With WES/WGS, we are able to sequence all of the genes of an individual and apply different data analysis techniques based on whether we are analyzing a multiplex family or a cohort of trios (mother, father and child with CHD) with a specific isolated CHD. Therefore, WES/WGS is a robust method for identification of novel genetic causes of CHD, which will have important diagnostic and therapeutic consequences for these children. Subjects provided blood samples, skin biopsy, or saliva samples for DNA extraction and creation of cell lines. Tissue remaining after surgical procedures was also collected. Medical records were searched for detailed phenotype data and subjects were followed longitudinally for outcome.

Study phs002010

Genomics of Hepatocellular Carcinoma

Despite the growing incidence of hepatocellular carcinoma (HCC) due to increased hepatitis C virus infection and non-alcoholic steatohepatitis in Western populations, the genetic determinants of this cancer have yet to be established. A minority (15-20%) of HCC occurs in livers without cirrhosis or other chronic disease. Because the liver is functionally preserved in these patients and surgical resection of the tumor may be performed safely, and because of the scarcity of livers available for transplantation, non-cirrhotic patients undergo surgical resection for HCC treatment. These resected tumors present investigatory opportunities in two ways: First, they provide tumor specimen which have not been treated with chemotherapy and embolization. Second, the absence of cirrhosis may provide an unconfounded background from which to investigate the genetic tumorigenesis of HCC. In livers with cirrhosis, genetic instability is prevalent as assessed by assays for microsatellite instability, loss of heterozygosity and aberrant DNA methylation. In contrast, in livers without cirrhosis, the non-tumor tissue surrounding HCC have been found to have fewer genetic aberrations. It has been postulated that the pathologic process of cirrhosis may result in the accumulation of many "passenger"; as well as "driver" mutations, and that the examination of the HCC cancer genome may be facilitated in non-cirrhotic livers because of the absence of an accumulated background noise of mutations.

Study phs001106

Center for Common Disease Genomics [CCDG] - Cardiovascular: Genetics of Coronary Heart Disease - Characterizaton of Coronary Prone Pedigrees

The primary cohort includes samples from 499 men and 154 women who survived a myocardial infarction, percutaneous transluminal angioplasty, or coronary artery bypass grafting (CABG) by age 55 years for men or age 65 years for women. Patients were seen at least six months after their acute event. Samples from another 488 men and 541 women that showed a nearly identical age, gender, and measured blood pressure distribution were collected as population-based controls. These controls tended to live in urban Salt Lake City, where the vast majority of the population is Caucasian. Blood samples were collected in the morning after 12h to 16h of fasting and prepared according to guidelines of the Lipid Research Clinic's program Manual of Laboratory Operations. All samples have serum, DNA and/or white blood cells, and a host of measurements (e.g. standard clinical chemistries, LDL and HDL cholesterol, triglycerides, glucose, HbA1C, insulin, blood pressures, anthropometric data, information on medical conditions and drug use, etc.). Additional details about the cohort or sample preparation were published previously. Here we present in total 1,475 patients that were successfully sequenced. This number includes 228 women, 419 men, and 7 of unreported gender survivors as well as 339 women and 482 men that served as population-based controls.

Study phs001901

Whole exome and transcriptome analysis of UV-exposed epidermis and carcinoma in situ reveals early drivers of carcinogenesis

Squamous cell carcinoma in situ (SCCIS) is a prevalent precancerous lesion that can progress to cutaneous squamous cell carcinoma (cSCC). Although SCCIS is common, its pathogenesis remains poorly understood. To better understand SCCIS development, we performed laser-captured microdissection of human SCCIS and adjacent epidermis to isolate genomic DNA and RNA for next generation sequencing. Whole exome sequencing (WES) identified UV-signature mutations in multiple genes including Notch 1-3 (GeneID:4851, GeneID:4853, GeneID:4854) in the epidermis and SCCIS and oncogenic TP53 (GeneID:7157) mutations in SCCIS. Novel gene families, including SCHLAFEN genes, contained UV/oxidative-signature disruptive (UVD) epidermal mutations that manifested positive selection in SCCIS. The frequency and distribution of NOTCH and TP53 mutations indicate that NOTCH mutations may precede TP53 mutations. RNA sequencing identified 1166 differentially expressed genes; the top 5 enriched GO biological processes included: 1) immune response, 2) epidermal development, 3) protein phosphorylation, 4) regulation of catalytic activity, and 5) cytoskeletal regulation. The NEURL1 ubiquitin ligase, which targets Notch ligands for degradation, was upregulated in SCCIS. Neuralized 1 protein was found to be elevated in SCCIS suggesting that increased levels could represent a novel mechanism for downregulating Notch during UV-induced carcinogenesis. The data from DNA and RNA sequencing of epidermis and SCCIS provide insights regarding SCCIS formation.

Study phs002019

Human CD4 Memory T Cell Activation Time Course

We performed a high-resolution time course RNA-seq experiment on CD4+ memory T cells during activation with anti-CD3/CD28 beads. We performed this in 24 adult individuals of European ancestry with no autoimmune diseases. We used 1 million cells as starting material, per time point (up to 8 time points per individual from 0 to 72 hours). We identified widespread dynamic allele-specific expression (dynASE) across the genome, i.e. ASE that changes with time after activation, which reflects cell state-dependent genetic regulatory effects. DynASE events were enriched in risk loci for multiple autoimmune diseases. This highlights the importance of studying multiple cellular states in order to elucidate the mechanisms of autoimmune disease. It also provides a successful framework to do it in other cellular systems relevant for other traits. We also showed an unprecedented amount of regulatory variation for HLA genes. HLA-DQB1 has 3 distinct regulatory haplotypes with expression profiles that could come from 3 different genes. We performed ATAC-seq in replicate for CD4+ memory T cells stimulated for 72 hours from another healthy individual. These data, together with genetic fine-mapping, CRISPR editing, EMSA and luciferase assays, helped us find a SNP in the promoter of HLA-DQB1 that causes at least part of the large cell state-dependent change in expression, at the RNA and protein levels.

Study phs002259

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