Search Results - EGA European Genome-Phenome Archive

RNA Ligation Precedes U6 snRNA/LINE-1 Retrotransposition

Long Interspersed Element-1 (L1) retrotransposons make up approximately 17% of the human genome. L1 moves throughout the genome via a copy-and-paste mechanism termed retrotransposition. L1 retrotransposition also mobilizes other cellular RNAs such as SINES, U6 snRNA and, mRNA, which for the latter results in the formation of processed pseudogenes. In this study we demonstrate that the RNA ligase RtcB can create chimeric RNAs by joining U6 snRNAs to 5'-truncated L1 or other cellular RNAs. We also show that the retrotransposition of U6/L1 chimeric RNA leads to U6/L1 pseudogene formation. In sum, our data suggests that U6 snRNA and RtcB may have biological roles in addition to their essential functions in mRNA and tRNA splicing, and that the retrotransposition of chimeric RNAs could be a mechanism to create novel genes.

Study phs001671

Transcriptome of human trophoblast stem cells derived from normal and HDP placentas

Hypertensive disorders of pregnancy (HDP) is a disease driven by abnormal placenta formation, which is a leading cause of maternal and fetal death. For investigation of genetic and epigenetic regulation of human trophoblast differentiation, we have previously established human trophoblast stem cells (hTSCs) from first-trimester placentas. Those hTSCs were able to differentiate into extravillous trophoblasts (EVTs) and syncytiotrophoblasts (STs), and their transcriptome was similar to that of cytotrophoblasts in human placenta. However, since HDP happens in the second half of pregnancy, the conventional hTSC derivation method was not enough to investigate the nature of HDP trophoblasts. In this analysis, we improved the derivation method and successfully established the hTSCs from normal and HDP term placentas after delivery. We performed RNA-seq of normal and HDP hTSCs, and HDP hTSCs recapitulated abnormalities in gene expression reported in HDP placentas.

Study JGAS000660

The Formation and Propagation of Human Robertsonian Chromosomes

Robertsonian chromosomes are a type of variant chromosome found commonly in nature. Present in one in 800 humans, these chromosomes can underlie infertility, trisomies, and increased cancer incidence. Recognized cytogenetically for more than a century, their origins have remained mysterious. Recent advances in genomics have allowed us to assemble three human Robertsonian chromosomes completely. We identify a common breakpoint and epigenetic changes in centromeres that provide insight into the formation and propagation of common Robertsonian translocations. Further investigation of the assembled genomes of chimpanzee and bonobo highlights the structural features of the human genome that uniquely enable the specific crossover event that creates these chromosomes. Resolving the structure and epigenetic features of human Robertsonian chromosomes at a molecular level will pave the way to understanding how chromosomal structural variation occurs more generally, and how chromosomes evolve.

Study phs003920

LifeChange Data Access Committee

The LifeChange study aimed at tracking the biological consequences of the societal changes undergone by the Yakut people of Far Eastern Siberia, after the colonization of the region by Russians in the 17th century. This study builds upon more than 15 years of archaeological research conducted in Yakutia, Sakha Republic, an autonomous region of the Russian Federation located in northeastern Siberia. The fieldwork was conducted under the MAFSO program (“Mission Archéologique Française en Sibérie Orientale”, or “French Archaeological Mission in Eastern Siberia”), a collaboration between French researchers and local Yakut experts, including scholars from North-Eastern Federal University in Yakutsk. The program was supported by several inter-university collaborative research agreements, notably between Université Paul Sabatier, Krasnoyarsk State Medical University, and North-Eastern Federal University in Yakutsk. It also received endorsement from the Institute of Ecology and Evolution at CNRS through the International Associated Laboratory “Co-evolution Human-Environment in Eastern Siberia”. The LifeChange Data Access Committee, composed of French and Russian archaeogeneticists, geneticists and archaeologists, reviews any access request to LifeChange data, consisting of genomes of ancient and modern Yakut, Eveni and Evenki individuals sampled in Eastern Siberia for the LifeChange study. The DAC grants access to any academic researcher aiming to study the population history of autochthonous peoples from Siberia. When reviewing data access requests, the DAC members ensure that the applicant will not re-use the data to trace present-day descendants of studied ancient individuals. They also ensure that secondary use of the modern genomic data is conducted in full respect of the conditions stipulated in living participants’ informed consent. Specifically, the applicant is not authorised to (i) use the data for diagnostic purposes, (ii) store the data outside of secure servers, (iii) reidentify research participants, and (iv) share the data with a third party.

Dac EGAC50000000713

DNA methylation dynamics during early human development

DNA methylation is globally reprogrammed during mammalian preimplantation development, which has been well characterized in the mouse but not in other mammals. Here we report on the single base-resolution DNA methylome of human gametes and blastocysts. Near complete demethylation of the paternal genome was apparent, except for tandem repeat-containing CpG-rich regions, whereas the maternal genome was essentially resistant to replication-dependent global demethylation. The human oocyte methylome was characterized by a unique bimodal distribution of gene body methylation, a particular promoter methylation profile and a high proportion of hypomethylated transposable elements. Methylome and transcriptome comparisons between the human and mouse suggested species-specific regulation of many genes including the important DNA methylation regulators. Our findings are essential to understand the unique gene regulatory mechanisms during early human development and will facilitate preimplantation epigenetic diagnosis of human embryos.

Study JGAS000006

Controlling cell differentiation with precision through understanding the structure and dynamics of gene regulatory networks

We established a set of transgenic human ES cell lines that carry inducible expression gene cassette for singe transcriptional factor induction with Tet-ON system. Transcriptome data was obtained 48h after transgene induction by Microarray. We established inducible human ES lines about more than 700 genes, and achieved microarray analysis on 115 genes. Our data set has multiple characteristic properties; 1) the same platform across data set, 2) analyzed with dynamic cell status, 3) pre-determined initiation point on gene perturbation, 4)inducible in different cell status. In parallele, we also performed RNA sequenncig analysis on 435 transgene induced ES lines as well. 32 transgene induced transcriptome data were obtained from both Microarray and RNA sequencing, normalizing technical gaps between them. We hope those systematic data set to reveal transcriptional network structure and molecular mechanisms of cell differentiation.

Study JGAS000121

Establishment of xenogfafts and cultured cell lines from clinical samples

The purpose of the present study was to clarify the presence or absence of alterations in the molecular properties of patient-derived xenografts (PDXs) with up to eight passages in endometrial carcinomas. Alterations in the proportion of immunohistochemically positive/negative cells for PAX8, estrogen receptor, PAX2, and PTEN were observed in established PDXs of endometrioid carcinomas and carcinosarcomas, whereas proportions of cells with AE1/AE3, TP53, ARID1A PMS2, and MSH6 were maintained. Variants of cancer-associated genes in PDX compared to those in the parental tumors were examined in two cases, a frameshift deletion in BRCA1 was observed in the parental tumor tissue, and additional genomic alterations were found in the PDXs of this case. Genomic and phenotypic alterations in endometrial carcinoma PDXs relative to the parental tumors were observed and were partly associated with endometrial cancer-specific characteristics in cellular differentiation and gene mutations.

Study JGAS000585

Genome wide association study of Coeliac Disease

We performed a second-generation genome-wide association study of 4,533 individuals with celiac disease (cases) and 10,750 control subjects. We genotyped 113 selected SNPs with P(GWAS) < 10(-4) and 18 SNPs from 14 known loci in a further 4,918 cases and 5,684 controls. Variants from 13 new regions reached genome-wide significance (P(combined) < 5 x 10(-8)); most contain genes with immune functions (BACH2, CCR4, CD80, CIITA-SOCS1-CLEC16A, ICOSLG and ZMIZ1), with ETS1, RUNX3, THEMIS and TNFRSF14 having key roles in thymic T-cell selection. There was evidence to suggest associations for a further 13 regions. In an expression quantitative trait meta-analysis of 1,469 whole blood samples, 20 of 38 (52.6%) tested loci had celiac risk variants correlated (P < 0.0028, FDR 5%) with cis gene expression

Study EGAS00000000057

The Multiomics Blueprint of the Individual with the Most Extreme Lifespan

Although centenarians are becoming more common in the demography of human populations, the so-called supercentenarians (over 110 years old) are still a rarity. In Catalonia, the historic nation where the subject lived, the life-expectancy for women is 86 years old, so she exceeded more than 30 years the mean statistical value. In a similar manner that premature aging syndromes, such as Hutchinson-Gilford Progeria and Werner syndrome, can provide relevant clues about the mechanisms of aging; the study of supercentenarians might also shed light in the pathways involved in lifespan. To unfold the biological properties that exhibited such a remarkable human being, we developed a comprehensive multiomics analysis in different tissues of her genomic, transcriptomic, metabolomic, epigenomic and microbiomic landscapes , comparing the results with those observed in non-supercentenarian populations.

Study EGAS50000000884

The function of circular RMST in neuroendocrine tumours

Circular RNA (circRNA) is a class of noncoding RNA with regulatory potentials. Its role in the transdifferentiation of prostate and lung adenocarcinoma into neuroendocrine prostate cancer (NEPC) and small cell lung cancer (SCLC) remains unexplored. Here we identified circRMST as an exceptionally abundant circRNA predominantly expressed in NEPC using total RNA-seq profiling of patient samples. In addition, circRMST is also abundantly expressed in SCLC. Functional studies using shRNA, siRNA, CRISPR-Cas13 and Cas9 consistently demonstrate that circRMST is essential for tumour growth and the expression of ASCL1, a master regulator of neuroendocrine fate. Mechanistically, circRMST physically interacts with lineage transcription factors NKX2-1 and SOX2. Loss of circRMST induces NKX2-1 protein degradation through autophagy-lysosomal pathway and alters the genomic binding of SOX2, collectively leading to the loss of ASCL1 transcription.

Study EGAS50000000897

A Comprehensive Catalogue of Somatic Mutations from a Human Cancer Genome

We have carried out complete sequencing of the genome of the human male maligant melanoma cell line COLO-829 using the Illumina Genome Analyzer II. We generated a sequencing library with a median insert size of ~200 bp following random fragmentation and gel fractionation of the genomic DNA. We sequenced 75 bases from both ends of these templates to cover the COLO-829 genome to an average depth of more than 40x. We have carried out purity-filtering (PF) to remove mixed reads, where two or more different template molecules are close enough on the surface of the flow-cell to form a mixed or overlapping cluster. No other filtering of the data has been carried out prior to submission. We have also submitted sequence data for a lymphoblastoid control cell line COLO-829BL from the same individual.

Study EGAS00000000052

Molecular Sub-grouping of CNS-PNET

In our study we aimed to define CNS-PNET subgroups. We performed Expression, Genotyping and/or Immunohistochemistry on 142 samples from 20 worldwide centers. Using these techniques, we have identified three molecular subgroups with distinct expression and copy number patterns, as well as, unique clinical characteristics. Specifically, these molecular subgroups were distinguished by primitive neural (group 1), oligoneural (group 2), and mesenchymal lineage (group 3) gene-expression signatures with differential expression of cell-lineage markers LIN28 and OLIG2. Our report underscores the importance of concerted, collaborative efforts to study large retrospective cohorts of tumours and patients to accelerate biological and ultimately therapeutic studies of rare tumours. The outcome of such a collaboration allowed us to identify LIN28 and OLIG2 as promising diagnostic and prognostic molecular markers for CNS PNET that warrant further assessment in prospective clinical trials.

Study EGAS00000000116

A proteogenomic atlas of the human neural retina

The human neural retina is enriched for alternative splicing, and it is estimated that more than 10% of variants associated with inherited retinal diseases (IRDs) alter splicing. Previous research mainly used short-read RNA-sequencing techniques to investigate retina-specific splicing and splicing factors. However, this technique provides limited information about transcript isoforms. To gain a deeper understanding of the human neural retina and its isoforms, we generated a proteogenomic atlas that combines PacBio long-read RNA-sequencing data with mass-spectrometry and whole-genome sequencing data from three healthy human neural retina samples. About one third of the nearly 60,000 transcript isoforms were novel, and ten novel peptides that confirmed novel isoforms were detected. This study highlights the importance of studying tissue-specific transcriptomes in greater detail to better understand tissue-specific regulation and to identify disease-causing variants.

Study EGAS50000000070

Clonally heritable gene expression imparts a layer of diversity within cell types

Cell types can be classified according to shared patterns of transcription. Non-genetic variability among individual cells of the same type has been ascribed to stochastic transcriptional bursting and transient cell states. Using high coverage single cell RNA profiling, we asked whether long-term, heritable differences in gene expression can impart diversity within cells of the same type. Studying clonal human lymphocytes and mouse brain cells, we uncovered a vast diversity of heritable gene expression patterns among different clones of cells of the same type in vivo. We combined chromatin accessibility and RNA profiling on different lymphocyte clones to reveal thousands of regulatory regions exhibiting interclonal variation which could be directly linked to interclonal variation in gene expression. Our findings identify a source of cellular diversity, which may have important implications for how cellular populations are shaped by selective processes in development, aging and disease.

Study EGAS50000000161

Evolutionary Trajectories of Small Cell Lung Cancer under Therapy

Small cell lung cancer (SCLC) is one of the deadliest human cancers with a five-years survival rate of less than 7%. The standard of care for extensive-stage SCLC consists of systemic treatment with platinum and etoposide, recently combined with PD-L1 immune checkpoint inhibitors (ICI). SCLC patients show high sensitivity to platinum-based chemotherapy, followed by rapid recurrence, which distinguishes SCLC from most human cancers. Unfortunately, second-line treatment with other chemotherapeutics or immunotherapy is only marginally effective, and patients ultimately succumb to their disease. We performed whole exome sequencing, whole genome sequencing and transcriptome sequencing of multiple tumor regions from 65 patients with SCLC. We determined tumor phylogenies at diagnosis and throughout chemotherapy and immunotherapy by multi-region sequencing of 160 tumors from 65 patients, to thus decipher the evolutionary processes underlying the remarkable sensitivity of small cell lung cancer (SCLC) to chemotherapy.

Study EGAS50000000169

The Emirati T2T-level Pangenome: A complete Diploid Graph of 58 Genomes

This study presents a comprehensive Emirati telomere-to-telomere level (T2T) pangenome, constructed from 116 haplotype-resolved assemblies generated from 58 individuals, including 28 trio-based and 30 single-sample assemblies. The assemblies exhibit high contiguity (median 150 Mb) and high consensus accuracy (median QV 59), with 71.9% of chromosomes reaching T2T-level scaffold status. The resulting pangenome graph captures both globally shared and regionally enriched genetic variation, including sequences in complex regions that are inaccessible to less complete assemblies. Comparisons indicate diversity levels comparable to those of the Human Pangenome Reference Consortium, while highlighting unique Emirati genomic features. This reference forms a key resource for human pangenomics and precision medicine in the UAE. This work provides a foundational resource to improve variant discovery and genome annotation, contributing vital diversity data to global pangenomics efforts and enabling precision medicine in the region.

Study EGAS50000001232

"Distinct immunometabolic signatures in circulating immune cells define disease outcome in acute-on-chronic liver failure"

We performed single-cell transcriptomics of PBMC’s from healthy (n= 3), acute decompensated (AD) (n= 3) and Acute-on-chronic liver failure (ACLF) patients. Lay Summary: Acute-on-chronic liver failure (ACLF) develops in cirrhotic patients and is characterized by an hyper-inflammatory immune state driving multiple organ failure(s). As a paradox, circulating immune cells also show transcription and metabolic evidence of exhaustion, explaining why these patients are often susceptible to secondary infections. We characterized at a transcriptional level all circulating immune cells of ACLF patiens, and specifically unraveled a distinct recovery and non-recovery ACLF signature within the monocyte population. Moreover, these changes were closely linked to metabolic differences within these cells. The described alterations allowed for a robust prediction of recovery and non-recovery of patients at admission to the hospital.

Study EGAS50000000391

Identification and characterization of tertiary lymphoid structures in brain metastases

Brain metastases (BrM) are the most common cancers in the brain. We performed transcriptome-wide gene expression profiling combined with spatial immune cell profiling to characterize the tumor immune microenvironment in BrM from different primary tumors. We found that BrM from lung carcinoma and malignant melanoma showed overall higher immune cell infiltration as compared to BrM from breast carcinoma. RNA sequencing-based immune cell deconvolution revealed gene expression signatures indicative of tertiary lymphoid structures (TLS) in subsets of BrM from lung cancer and melanoma. This finding was corroborated by multiplex immunofluorescence staining of immune cells in BrM tissue sections. Detection of TLS signatures was associated with prolonged survival after BrM diagnosis in lung cancer patients. Our findings highlight the cellular diversity of the tumor immune microenvironment in BrM of different cancer types and suggest a role of TLS formation for BrM patient outcome.

Study EGAS50000000563

Longitudinal single-cell transcriptomic study in patient-derived xenografts of pediatric T-ALL

In this study, we conducted single cell full length total RNA sequencing (VASA-seq) on 13 matched pediatric T-ALL PDX samples at initial diagnosis and relapse, along with 5 non-relapsing PDX samples collected at initial diagnosis. We identified a subpopulation of T-ALL cells with stem-like cell features that expands substantially at relapse indicating resistance to first-line therapy. Chemotherapy resistance was further validated through functional testing: Two samples were subjected to in-vitro drug testing, treated with Cytarabine for three days, followed by single-cell transcriptomic analysis using 10x Genomics. Additionally, in-vivo drug testing was conducted on one sample, involving re-engraftment into mice and treatment with a combination of Vincristine, Doxorubicin, and Dexamethasone. Single-cell transcriptomic analysis using 10x Genomics was performed after 0, 15 and 30 days of treatment.

Study EGAS50000000582

Cell-type, allelic and genetic signatures in the human pancreatic beta cell transcriptome

Pancreatic beta cells within the islets of Langerhans are centrally involved in the pathogenesis of both type 1 and type 2 diabetes. Describing the differentiated state of the human beta cell has been hampered so far by technical (low resolution microarrays) and biological limitations (whole islet preparations rather than isolated beta cells). We circumvent these by deep RNA sequencing of purified beta cells from 11 individuals, presenting here the first characterization of the human beta cell transcriptome. Additionally, we perform the first comparison of gene expression profiles between beta cells, whole islets (N=7) and beta cell depleted islet preparations (N=5), revealing thus beta cell specific expression signatures. Finally, we combine this with whole-genome sequencing data for 7 of our donors, describing here the first set of genetic variants controlling inter-individual variability in beta cell gene expression.

Study EGAS00001000442

Whole genome sequencing data from tumor and normal samples

Whole genome sequencing FASTQ files from tumor and normal samples from 202 patients. All experiments reported in this article were performed in the Clinical Laboratory Improvement Amendments (CLIA)-certified and College of American Pathologists (CAP)-accredited laboratories at Personalis Inc., as guided by the Association for Molecular Pathology (AMP) and CAP’s joint recommendations52. Preferred input material consisting of FFPE slides (enabling H&E and macrodissection which is part of the standard NeXT Personal process) was not available for the majority (94%) of tumor samples. Most tumor samples (72%) were processed from FFPE curls, with the remaining processed from pre-extracted DNA and fresh frozen material. Where FFPE material on slide was available, tumor sections were macrodissected to increase tumor content, with a minimum allowable cellularity threshold of 20% determined by pathological review. The tumor cellularity threshold of 20% was chosen based on prior work demonstrating that no significant correlation is observed between tumor purity and assay limit of detection (LOD) at this threshold31. Genomic DNA was isolated from tumor and normal samples and WGS libraries prepared as previously described31. Genomic DNA was isolated from matched tumor and normal samples using the Qiagen AllPrep DNA/RNA FFPE Tissue Kit or the QIAamp DNA Mini Kit (QIAGEN, Germantown, MD, USA) using internally optimized workflows. WGS sequencing libraries were prepared with 120-500 ng of acoustically sheared genomic DNA (Covaris LLC, Woburn, MA, USA) using the KAPA HyperPrep Kit (Roche Sequencing Solutions, Pleasanton, CA, USA) and customized methods. Libraries were cleaned-up using AMPure XP beads and then quantified using the KAPA Library Quantification Kit (Roche Sequencing Solutions, Pleasanton, CA, USA), before being sequenced to 30X depth of coverage using a NovaSeq 6000 instrument (Illumina, San Diego, CA, USA).

Dataset EGAD50000001909

Genetic mechanisms of resistance to chemotherapy in breast cancer

Resistance towards chemotherapy is one of the main causes of treatment failure and deathamong breast cancer patients.The main objective of this project is toidentify genetic mechanisms causing some breast cancer patients not torespond to a particluar type of chemotherapy (epirubicin) while otherpatients respond very well to the same treatment. In the project wewill perform genome / exome sequencing of a selection of breast cancerpatients (n=30). These patients are drawn from a cohort where allpatients have recieved treatment with epirubicin monotherapy before surgical removal of alocally advanced breast tumour, and where all patients have beensubjected to objective evaluation of the response to thetherapy. Subsequent to sequencing, we will analyse the data andcompare with the clinical data for each patient (object response totherapy). The main aim being to identify mutations that are associatedwith resistance to epirubicin. Identification of mutations with strongpredictive value, may have a direct impact on cancer treatment sinceit opens the possibility for genetic testing of a tumour, and desicionon which drug is likely to work best, prior to treatment start.

Dataset EGAD00001000264

RNA-seq, WGS and WES of Hepatocellular carcinomas, enriched in fibrolamellar carcinomas

DNAJB1-PRKACA fusion is a specific driver event in fibrolamellar carcinoma (FLC), a rare subtype of hepatocellular carcinoma (HCC) occurring in adolescents and young adults. In older patients, molecular determinants of HCC with mixed histological features of HCC and FLC (mixed-FLC/HCC) remain to be discovered.This study aims to molecularly caracterize mixed fibrolamellar hepatocellular carcinoma (mixed FLC/HCC) within the molecular liver tumors diversity, in respect of pure FLC and different HCC subtypes. This study reunites WGS data (n=3, Tumoral/Non-Tumoral pairs), WES data (n=43, Tumoral/Non-Tumoral pairs) and RNAseq data (n=66, Tumoral only). On a trascriptomic level, most of the mixed-FLC/HCC RNAseq clustered in a robust subgroup of tumors all showing mutation or translocation inactivating BAP1 that codes for the BRCA1 associated protein-1.

Study EGAS00001003837

TRACERx: TRAcking non-small cell lung Cancer Evolution through therapy (Rx). Pilot Study. Multi-region sequencing of early-stage NSCLCs.

Deciphering the complexity of non-small cell lung cancer (NSCLC) evolutionary histories may elucidate the basis for its dismal outcome. We performed multi-region sequencing of early-stage NSCLCs. Spatial dissection revealed branched tumor evolution, with driver mutations occurring before and after subclonal diversification. Intra-tumor heterogeneity in DNA copy number alterations, translocations and endogenous APOBEC mutational processes demonstrates that NSCLC may follow multiple distinct evolutionary trajectories simultaneously. In smokers, despite maintained carcinogen exposure, temporal dissection reveals a relative decrease in smoking-related mutations during tumor progression, accompanied by an increase in APOBEC-related mutations. In the tumors from ex-smokers, genome-doubling occurred before subclonal diversification, suggesting prolonged latency before clinical detection. Multi-region sequencing demonstrates the relentless and heterogeneous nature of genomic instability processes in early-stage NSCLCs.

Study EGAS00001000809

Combination_therapies_for_personalized_cancer_medicine

It is the ambition of the team formed by members of the Netherlands Cancer Institute (NKI) and the Cancer Genome Project at the Wellcome Trust Sanger Institute (WTSI) to unravel the genomic and phenotypic complexity of human cancers in order to identify optimal drug combinations for personalized cancer therapy. Our integrated approach will entail (i) deep sequencing of human tumours and cognate mouse tumours; (ii) drug screens in a 1000+ fully characterized tumour cell line panel; (iii) high-throughput in vitro and in vivo shRNA and cDNA drug resistance and enhancement screens; (iv) computational analysis of the acquired data, leading to significant response predictions; (v) rigorous validation of these predictions in genetically engineered mouse models and patient-derived xenografts. This integrated effort is expected to yield a number of combination therapies and companion-diagnostics biomarkers that will be further explored in our existing clinical trial networks.

Study EGAS00001000655

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