Search Results - EGA European Genome-phenome Archive

Overexpression of the miR-17-92 cluster in colorectal adenoma organoids induces a carcinoma-like genotype

Study EGAS00001005949

Comprehensive analysis of atypical teratoid rhabdoid tumour (ATRT) using genomic, epigenomic and transcriptomic techniques.

ATRTs (Atypical teratoid rhabdoid tumours) represent one of the most aggressive pediatric brain cancers, but intriguingly exhibit few other recurrently mutated loci except for SMARCB1/hSNF5. We integrated whole genome (n=15), exome, copy number, gene expression and methylation analyses to comprehensively interrogate 64 ATRTs and observed that structural events were relatively frequent in the ATRT genome (~3 tumour). In addition to SMARCB1, which was targeted by structural events in a majority (49/64) of tumours, recurrent structural alterations targeting the LRP1B, CDH13, BCR and MKL1 loci were observed. We observed novel translocation events, including 2 targeting SMARCB1 which were detected only by NGS analyses. Significantly, integration of gene expression and methylation profiles with genomic analyses revealed ATRT comprise two sub-groups with distinct clinical and genetic features. Group 1 tumours were characterized by supra-tentorial brain location, focal intragenic alterations of SMARCB1 and a pro-neural gene expression signature with evidence of NOTCH pathway activation. While Group 2 ATRTs were characterized by infra-tentorial brain location, broad SMARCB1 alterations and an activation of the BMP signalling pathway. Our findings highlight epigenetic mechanisms as important determinants of ATRT tumour phenotypes, and demonstrate for the first time that ATRTs arising in different anatomical compartments comprise distinct molecular and therapeutic sub-groups.

Study EGAS00001000506

Integrative sequencing reveals alterations in untreated and castration resistant prostate cancer

We report the integrative sequencing of genomic, transcriptomic and DNA methylation changes in 28 untreated (PC) and 13 castration resistant prostate cancers (CRPC). AR, TGF-β and WNT signaling pathways were altered in CRPCs. We identified two new fusion genes, TMPRSS2-SKIL and DOT1L-HES6. Fusion analysis in an independent cohort validated SKIL as a recurrent 3’ fusion partner and oncogene in prostate cancer. The HES6 fusion was found in an AR-negative CRPC, and HES6 overexpression in vitro led to androgen independent growth. A distinct DNA methylation signature was found for CRPC. Transcriptome assembly uncovered 128 previously unannotated prostate cancer associated transcripts, including the ERG regulated transcript TPCAT-10-36067 whose knockdown had a dramatic effect on the growth, invasiveness, and rate of apoptosis of prostate cancer cells.

Study EGAS00001000526

Analysis of DNA methylation in normal B cells and chronic lymphocytic leukemia

Charting differences between tumors and normal tissue is a mainstay of cancer research. However, clonal tumor expansion from complex normal tissue architectures potentially obscures cancer-specific events, including divergent epigenetic patterns. Using whole-genome bisulfite sequencing of normal B cell subsets, we observed broad epigenetic programming of selective transcription factor binding sites coincident with the degree of B cell maturation. By comparing normal B cells to malignant B cells from 268 patients with chronic lymphocytic leukemia (CLL), we showed that tumors derive largely from a continuum of maturation states reflected in normal developmental stages. Epigenetic maturation in CLL was associated with an indolent gene expression pattern and increasingly favorable clinical outcomes.As second study using these samples focued on evolution and resulting intra-tumor heterogeneity in CLL. We used 450k bead-chip arrays to study DNA methylomes in 68 chronic lymphocytic leukemia (CLL) cases, including 28 serial cases. The result establishs linked evolution of epigenetic and genetic alterations in progressive disease, revealing an important aspect of the biology of epigenetics in cancer.

Study EGAS00001000534

DNA from colon cancer samples and matched normal samples was hybridized on Human 660W-Quad SNP arrays and sequenced in Illumina HiScanSQ.

DNA from colon cancer samples and matched normal samples was hybridized on Human 660W-Quad SNP arrays and sequenced in Illumina HiScanSQ. The objective of the study was to introduce methodology for the detection of genomic copy number alterations (CNAs) using high-throughput sequencing data. The samples in this study allow the comparison of the results from the seqCNA R package with those from other methods that detect copy number alterations (CNAs) in tumoural samples, either using SNP-array data or high-throughput sequencing data.

Study EGAS00001000558

Tumor suppressor miR-133a modulates the prostate cancer epigenome by repressing BAZ2A

Our study revealed a new subgroup of prostate tumors defined by the expression of a novel prognostic marker, BAZ2A, and the first time to show the establishment of CIMP via an microRNA-epigenetic interaction in prostate tumors.

Study EGAS00001000568

To determine the genomic profiles of Triple Negative Breast Cancers (COH cohort)

Specific BRCA and immune configurations determine optimal response to platinum-based chemotherapy in triple negative breast and ovarian carcinomas (COH_TNBC_WGS)

Study EGAS00001006085

Whole genome sequencing and whole exome sequencing of DIPG tumors and matched normal tissue

Diffuse Intrinsic Pontine Glioma (DIPG) is a fatal brain cancer that arises in the brainstem of children with no effective treatment. To understand what drives DIPGs we integrated whole-genome-sequencing with methylation, expression and copy-number profiling.

Study EGAS00001000575

Mutational analysis reveals the origin and therapy-driven evolution of recurrent glioma

Tumor recurrence is a leading cause of cancer mortality. Therapies for recurrent disease may fail, at least in part, because the genomic alterations driving the growth of recurrences are distinct from those in the initial tumor. To explore this hypothesis, we sequenced the exomes of 23 initial low-grade gliomas and recurrent tumors resected from the same patients. In 43% of cases, at least half of the mutations in the initial tumor were undetected at recurrence, including driver mutations inTP53, ATRX, SMARCA4, and BRAF; this suggests that recurrent tumors are often seeded by cells derived from the initial tumor at a very early stage of their evolution. Notably, tumors from 6 of 10 patients treated with the chemotherapeutic drug temozolomide (TMZ) followed an alternative evolutionary path to high-grade glioma. At recurrence, these tumors were hypermutated and harbored driver mutations in the RB (retinoblastoma) and Akt-mTOR (mammalian target of rapamycin) pathways that bore the signature of TMZ-induced mutagenesis.

Study EGAS00001000579

Mesenchymal inflammation drives genotoxic stress in hematopoietic stem cells and predicts disease evolution in human pre-leukemia

Mesenchymal niche cells may drive tissue failure and malignant transformation in the hematopoietic system but the molecular mechanisms and their relevance to human disease remain poorly defined. We demonstrated that perturbation of mesenchymal cells in a mouse model of the preleukemic disorder Shwachman-Diamond syndrome induces mitochondrial dysfunction, oxidative stress and activation of DNA damage responses in hematopoietic stem and progenitor cells. In this study we demonstrate, through massive parallel RNA sequencing of highly purified mesenchymal cells in a range of human preleukemic syndromes, TP53-S100A8/9-TLR4 inflammatory signaling as a common driving mechanism of genotoxic stress, which could be attenuated by TLR4 blockade. S100A8/9 expression in mesenchymal cells predicted outcome in myelodysplastic syndromes, the principal human preleukemic condition, independent of known prognostic variables. Collectively, findings reveal a concept of mesenchymal niche-induced genotoxic stress in heterotypic stem and progenitor cells through inflammatory signaling as an actionable determinant of disease outcome in human preleukemia. The data further provide novel conceptual and mechanistic insights into the intimate link between inflammation and cancer.

Study EGAS00001001926

Resistance to anti-EGFR therapy in colorectal cancer

Monoclonal antibodies targeting the Epidermal Growth Factor Receptor (EGFR), such as cetuximab and panitumumab, have evolved to important therapeutic options in metastatic colorectal cancer (CRC). However, almost all patients with clinical response to anti-EGFR therapies show disease progression within a few months and little is known about mechanism and timing of resistance evolution. Here we performed whole genome sequencing of plasma DNA (plasma-Seq) from patients treated with anti-EGFR therapy. We demonstrate that development of resistance to anti-EGFR therapies is frequently associated with focal amplifications of KRAS, MET, and ERBB2. However, we also show that focal KRAS amplifications can be acquired in tumor genomes of patients under cytotoxic chemotherapy. Furthermore, we provide evidence that specific chromosomal polysomies, such as overrepresentations of 12p and 7p, harboring KRAS and EGFR, respectively, determine responsiveness to anti-EGFR therapy. In contrast, employing ultra-sensitive deep sequencing of genes associated with anti-EGFR resistance, such as KRAS, BRAF, PIK3CA, and EGFR, we did not observe the occurrence of novel, acquired mutations. Overall, whole-genome plasma DNA sequencing represents a non-invasive blood-based surrogate measure of changes in tumors. As such, plasma-Seq enables the identification of novel mutant clones and may therefore facilitate early adjustments of therapies that may delay or prevent disease progression.

Study EGAS00001000582

Assessment of genomic copy number alterations in breast cancer

The aim of this study was to assess genomic copy number alterations in a panel of breast cancer cell lines. These data were used to identify common aberrations associated with breast cancer, and also to identify aberrations associated with response to therapeutic compounds.

Study EGAS00001000585

These are from Korean HCC samples with exome sequencing

Hepatic resection is the most curative treatment option for early-stage hepatocellular carcinoma, but is associated with a high recurrence rate, which exceeds 50% at 5 years after surgery. Understanding the genetic basis of hepatocellular carcinoma at surgically curable stages may enable the identification of new molecular biomarkers that accurately identify patients in need of additional early therapeutic interventions. Whole exome sequencing and copy number analysis was performed on 231 hepatocellular carcinomas (72% with hepatitis B viral infection) that were classified as early-stage hepatocellular carcinomas, candidates for surgical resection. Recurrent mutations were validated by Sanger sequencing. Unsupervised genomic analyses identified an association between specific genetic aberrations and postoperative clinical outcomes. Recurrent somatic mutations were identified in 9 genes, including TP53, CTNNB1, AXIN1, RPS6KA3, and RB1. Recurrent homozygous deletions in FAM123A, RB1, and CDKN2A, and high-copy amplifications in MYC, RSPO2, CCND1, and FGF19 were detected. Pathway analyses of these genes revealed aberrations in the p53, Wnt, PIK3/Ras, cell cycle, and chromatin remodelling pathways. RB1 mutations were significantly associated with cancer-specific and recurrence-free survival after resection (p = 0.016 and p = 0.001, respectively). FGF19 amplifications, known to activate Wnt signalling, were mutually exclusive with CTNNB1 and AXIN1 mutations, and significantly associated with cirrhosis (p = 0.017). RB1 mutations can be used as a prognostic molecular biomarker for resectable hepatocellular carcinoma. Further study is required to investigate the potential role of FGF19 amplification in driving hepatocarcinogenesis in patients with liver cirrhosis and to investigate the potential of anti-FGF19 treatment in these patients.

Study EGAS00001000604

WGS of gastric cancer in the Japanese population (81 gastric cancers of NCC)

As a contribution to The International Cancer Genome Consortium Accelerating Research in Genomic Oncology (ICGC ARGO), whole-genome sequencing of 81 cases from Japanese gastric cancer with various histological subtypes has been conducted. This study aims to reveal the landscape of structural variants (SV) in gastric cancer and analyze mutational and rearrangement signatures simultaneously

Study EGAS00001006051

Multisite_Breast_Cancer_Whole_Genome

DNA extracted from multiple biopsies taken from different areas of primary breast tumours will be subjected to whole genome sequencing and analysed in order to assess intra-tumour heterogeneity with respect to mutations.

Study EGAS00001000890

Whole Genome Sequencing of Asian Lung Cancers: Second Hand Smoke is Not Responsible for Higher Incidence of Lung Cancer Among Asian Never-Smokers

Background Asian nonsmoking populations have a higher incidence of lung cancer compared to their European counterparts. There is a long-standing hypothesis that the increase of lung cancer in Asian never-smokers is due to environmental factors such as second-hand smoke. Results We analyzed whole-genome sequencing of 30 Asian lung cancers. Unsupervised clustering of mutational signatures separated the patients into two categories: i) all of the never-smokers, and ii) only smokers or ex-smokers. Half of the ex-smokers / smokers were in the never-smoker-like cluster. The overall somatic variant profiles of Asian lung cancers were similar to that of European origin with G.C>T.A being predominant in smokers. We found EGFR and TP53 are the most frequently mutated genes with mutations in 50% and 27% of individuals, respectively. Among these Asian never-smokers, 71% had an EGFR mutation compared to 20% of the smokers in the smoking cluster. Other frequently mutated genes include RYR2, SATB2, C1orf88, FERMT1 and CTNNB1. Somatic alterations occurred in WNT signaling pathway genes, suggesting this pathway plays a role in both Western and Asian lung cancers. Conclusions Asian never-smokers have lung cancer signatures distinct from the smoker signature and their mutation profiles are similar to that of European never-smokers. The profiles of Asian and European smokers are also similar. This suggests that the same mutational mechanisms underlie the etiology for both ethnic groups, and the high incidence of lung cancer in Asian never-smokers might not be due to second hand smoke or other carcinogens that cause oxidative DNA damage. Half of the ex-smokers/smokers have a molecular phenotype similar to never-smokers; of which, 50% had EGFR mutations. This suggests that routine EGFR testing is warranted in the Asian population, regardless of smoking status.

Study EGAS00001000621

Divergence between high metastatic tumor burden and low circulating tumor DNA concentration in metastasized breast cancer

Circulating tumor DNA (ctDNA) was reported to represent a highly sensitive biomarker of metastatic cancer disease directly reflecting tumor burden and dynamics. Here we investigated the role of ctDNA in patients with metastatic breast cancer. In an index patient with more than 100,000 circulating tumor cells (CTCs) in serial blood analyses, whole genome, exome, or targeted deep sequencing of the primary tumor, metastases, and 551 CTCs were consistent with a genetically homogeneous cancer. However, the allele fractions (AFs) of ctDNA were only 2-3% in each analysis, which did neither reflect the tumor burden nor the dynamics of this progressive disease by far. Indeed, plasma analyses of 71 further patients demonstrated highly variable AFs of mutant fragments, which frequently did not correspond to the tumor burden. These results provide insights into mechanisms involved in CTC and ctDNA release into the circulation and have important implications for diagnostic tests based on liquid biopsies.

Study EGAS00001000625

Evolutionary histories of breast cancer and related clones

Study EGAS00001006282

Frequent mutations in chromatin-remodelling genes in pulmonary carcinoids

Pulmonary carcinoids are rare neuroendocrine tumours of the lung. The molecular alterations underlying the pathogenesis of these tumours have not been systematically studied so far. Here we perform gene copy number analysis (n¼54), genome/exome (n¼44) and transcriptome (n¼69) sequencing of pulmonary carcinoids and observe frequent mutations in chromatin-remodelling genes. Covalent histone modifiers and subunits of the SWI/SNF complex are mutated in 40 and 22.2% of the cases, respectively, with MEN1, PSIP1 and ARID1A being recurrently affected. In contrast to small-cell lung cancer and large-cell neuroendocrine tumours, TP53 and RB1 mutations are rare events, suggesting that pulmonary carcinoids are not early progenitor lesions of the highly aggressive lung neuroendocrine tumors but arise through independent cellular mechanisms. These data also suggest that inactivation of chromatinremodelling genes is sufficient to drive transformation in pulmonary carcinoids.

Study EGAS00001000650

A Genomics-Based Classification of Human Lung Tumors

We characterized genome alterations in 1255 clinically annotated lung tumors of all histological subgroups to identify genetically defined and clinically relevant subtypes. More than 55% of all cases had at least one oncogenic genome alteration potentially amenable to specific therapeutic intervention, including several personalized treatment approaches that are already in clinical evaluation. Marked differences in the pattern of genomic alterations existed between and within histological subtypes, thus challenging the original histomorphological diagnosis. Immunohistochemical studies confirmed many of these reassigned subtypes. The reassignment eliminated almost all cases of large cell carcinomas, some of which had therapeutically relevant alterations. Prospective testing of our genomics-based diagnostic algorithm in 5145 lung cancer patients enabled a genome-based diagnosis in 3863 (75%) patients, confirmed the feasibility of rational reassignments of large cell lung cancer, and led to improvement in overall survival in patients with EGFR-mutant or ALK-rearranged cancers. Thus, our findings provide support for broad implementation of genome-based diagnosis of lung cancer.

Study EGAS00001000647

CD74-NRG1 fusions in lung adenocarcinoma

We discovered a novel somatic gene fusion, CD74-NRG1, by transcriptome sequencing of 25 lung adenocarcinomas of never smokers. By screening 102 lung adenocarcinomas negative for known oncogenic alterations we found four additional fusion-positive tumors, all of which were of the invasive mucinous subtype. Mechanistically, CD74-NRG1 leads to extracellular expression of the EGF-like domain of NRG1 III-beta3, thereby providing the ligand for ERBB2-ERBB3 receptor complexes. Accordingly, ERBB2 and ERBB3 expression was high in the index case and expression of phospho-ERBB3 was specifically found in tumors bearing the fusion (p<0.0001). Ectopic expression of CD74-NRG1 in lung cancer cell lines expressing ERBB2 and ERBB3 activated ERBB3 and the PI3K-AKT pathway, and led to increased colony formation in soft agar. Thus, CD74-NRG1 gene fusions are activating genomic alterations in invasive mucinous adenocarcinomas and may offer a therapeutic opportunity for a lung tumor subtype with, so far, no effective treatment.

Study EGAS00001000653

Identification of novel fusion genes in lung cancer using breakpoint assembly of transcriptome sequencing data

Genomic translocation events frequently underlie cancer development through generation of gene fusions with oncogenic properties. Identification of such fusion transcripts by transcriptome sequencing might help to discover new potential therapeutic targets. We developed TRUP (Tumor-specimen suited RNA-seq Unified Pipeline (https://github.com/ruping/TRUP), a computational approach that combines split-read and read-pair analysis with de-novo assembly for the identification of chimeric transcripts in cancer specimens. We apply TRUP to RNA-seq data of different tumor types, and find it to be more sensitive than alternative tools in detecting chimeric transcripts, such as secondaryrearrangements in EML4-ALK-positive lung tumors, or recurrent inactivating rearrangements affecting RASSF8.

Study EGAS00001000659

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