13313 results for ""pdc"+"heritage+language"+census+study"

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• A genomic approach towards an understanding of clonal evolution and disease progression in multiple myeloma

  Multiple Myeloma (MM) is a largely incurable haematological malignancy defined by the clonal proliferation of malignant plasma cells within the bone marrow. Clonal heterogeneity has recently been established as a feature in MM, however, the subclonal evolution associated with disease progression has not been described. We used whole exome sequencing to analyse 10 paired patient samples, providing new insights into the progression from Monoclonal Gammopathy of Undetermined Significance (MGUS) and Smouldering MM (SMM), to symptomatic MM. We confirm that clonal heterogeneity is a common feature at diagnosis and that the driving events involved in disease progression are more complex than previously reported. While we observe some previously identified known “drivers” of MM, we find that the driving events involved in progression are complex and not limited to the known SNVs or CNVs. The RAS/MAPK pathway was found to be the most frequently deregulated pathway, with recurrent mutations in KRAS and NRAS observed in patients at both MGUS/SMM and MM stages. We reveal that MM evolution is mainly characterised by the phenomenon of clonal stability, where the subclonal plasma cell populations identified at MM progression are already present in the asymptomatic MGUS/SMM stages. These subclonal populations could be amenable to therapeutic intervention to arrest transformation to MM.

  Study EGAS00001002850

• 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

• The neo-open reading frame peptides that comprise the tumor framome are a rich source of neoantigens for cancer immunotherapy

  Identification of immunogenic cancer neoantigens as targets for therapy is challenging. Here, we integrate whole genome and long-read transcript sequencing of cancers to identify the collection of neo-open reading frame peptides (NOPs) expressed in tumors. We termed this collection of NOPs the tumor framome. NOPs represent tumor-specific peptides that are different from wild-type proteins and may be strongly immunogenic. We describe a class of hidden NOPs that derive from structural genomic variants involving an upstream protein coding gene driving expression and translation of non-coding regions of the genome downstream of a rearrangement breakpoint, i.e. where no gene annotation or evidence for transcription exists. The entire collection of NOPs represents a vast number of possible neoantigens particularly in tumors with many structural genomic variants and a low number of missense mutations. We show that NOPs are immunogenic and epitopes derived from NOPs can bind to MHC class I molecules. Finally, we provide evidence for the presence of memory T cells specific for hidden NOPs in peripheral blood from a patient with lung cancer. This work highlights NOPs as a major source of possible neoantigens for personalized cancer immunotherapy and provides a rationale for analyzing the complete cancer genome and transcriptome as a basis for detection of NOPs.

  Study EGAS00001006021

• Hyperhaploid Multiple Myeloma

  Hyperhaploid multiple myeloma is a rare numerical aberration group defined by a range of 24-34 chromosomes which is associated with a poor prognosis. Hyperhaploid samples were sequenced by either exome or targeted panel sequencing. Samples had a median of 13 monosomies (range 12-14), which in general were those not associated with trisomies in hyperdiploid samples. The chromosomes traditionally trisomic in hyperdiploid myeloma were disomic in hyperhaploid myeloma with retention of heterodisomy. We examined the hyperhaploid samples for frequently mutated genes and found that 9/9 (100%) hyperhaploid samples had a mutation in TP53, exceeding the overall rate of mutation in newly diagnosed patients (5.5%), indicating an oncogenic dependency in this group. All samples with TP53 mutation also had monosomy of chromosome 17, indicating bi-allelic inactivation of TP53. As such, this high risk group is part of Double-Hit myeloma. DNA was obtained from either CD138+ cells from the bone marrow of multiple myeloma patients (tumor) or from stem cell harvests from the same patient (control). 100 ng of DNA was fragmented, end-repaired, and adapters ligated using the HyperPlus kit (KAPA Biosystems). After PCR amplification the libraries were hybridized with probes against either the entire exome (MedExome, Nimblegen) or a targeted panel of 140 genes using SeqCap reagents (Nimblegen). Hybridized libraries underwent further amplification before being sequenced on a NextSeq500 (Illumina) using 75 bp paired end reads.

  Study EGAS00001003203

• PAX5 biallelic genomic alterations define a novel subgroup of B cell precursor acute lymphoblastic leukemia

  Chromosomal rearrangements and specific aneuploidy patterns are initiating events and define subgroups in B cell precursor acute lymphoblastic leukemia (BCP-ALL). Here we analyzed 250 BCP-ALL cases and identified a novel subgroup (‘PAX5-plus’, n=19) by distinct DNA methylation and gene expression profiles. All patients in this subgroup harbored mutations in the B-lineage transcription factor PAX5, with p.P80R as hotspot. Mutations either affected two independent codons, consistent with compound heterozygosity, or suffered LOH predominantly through chromosome 9p aberrations. These biallelic events resulted in disruption of PAX5 transcriptional programs regulating B cell differentiation and tumor suppressor functions. Homozygous CDKN2A/B deletions and RAS activating hotspot mutations were highly enriched as cooperating events in the genomic profile of PAX5-plus ALL. Together this defined a specific pattern of triple alterations, exclusive to the novel subgroup. PAX5-plus ALL was observed in pediatric and adult patients. Although restricted by the limited sample size, a tendency for more favorable clinical outcome was observed with 10 of 12 adult PAX5-plus patients achieving long-term survival. PAX5-plus represents the first BCP-ALL subgroup defined by sequence alterations in contrast to gross chromosomal events and exemplifies how deregulated differentiation (PAX5), impaired cell cycle control (CDKN2A/B) together with sustained proliferative signaling (RAS) cooperatively drives leukemogenesis.

  Study EGAS00001003209

• Personalized peptide vaccination among 173 patients with IDH wildtype glioblastoma: a retrospective analysis

  Tumors from 173 GBM patients were analysed for somatic mutations to generate a personalized peptide vaccine targeting tumor-specific neoantigens. Exome libraries for 173 glioblastoma tumors and matched normal DNA were sequenced on Illumina platform, alongside whole transcriptomes from the tumor samples. Paper Abstract: Current treatment outcome of patients with glioblastoma (GBM) remains poor. Following standard therapy, recurrence is universal with limited survival. GBM tumors from 173 patients were analysed for somatic mutations to generate a personalized peptide vaccine targeting tumor-specific neoantigens. Among all patients, including 70 treated prior to progression (primary) and 103 treated after progression (recurrent), the median overall survival from first diagnosis was 31.9 months (95% CI: 25.0-36.5). Side effects were infrequent and were predominantly grade 1 or 2. A vaccine-induced immune response to at least one of the vaccinated peptides was detected in blood samples of 87 of 99 (88%) monitored patients. T-cell responses to vaccinated neoepitope peptides were durable in most patients. Significantly prolonged survival was observed for patients with multiple vaccine-induced immune responses (53 months) compared to those with no/low induced responses (27 months; P=0.03). Altogether, our results highlight that the application of personalized neoantigen-targeting peptide vaccine is feasible and represents a promising potential treatment option for GBM patients.

  Study EGAS50000000449

• 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

• Detection of mutational patterns in cell free DNA (cfDNA) of colorectal cancer by custom amplicon sequencing

  Monitoring the mutational patterns of solid tumors during cancer therapy is a major challenge in oncology. Analysis of mutations in cell free (cf) DNA offers a non-invasive approach to detect mutations that may be prognostic for disease survival or predictive for primary or secondary drug resistance. A main challenge for the application of cfDNA as a diagnostic tool is the diverse mutational landscape of cancer. Here, we developed a flexible end-to-end experimental and bioinformatics workflow to analyze mutations in cfDNA using custom amplicon sequencing. Our approach relies on open software tools to select primers suitable for multiplex PCR using minimal cfDNA as input. In addition, we developed a robust linear model to identify specific genetic alterations from sequencing data of cfDNA. We used our method to design a custom amplicon panel suitable for detection of hotspot mutations relevant for colorectal cancer and analyzed mutations in serial cfDNA samples from 34 patients with advanced colorectal cancer. Our data demonstrates that recurrent and patient-specific mutational patterns can be reliably detected for the majority of patients. Furthermore, we show that the allele frequency of mutations in cfDNA correlates well with disease progression. Finally, we demonstrate that monitoring of cfDNA can outperform the predictive power of currently used tumor markers and reveal mechanisms of resistance to anti-EGFR antibody treatment.

  Study EGAS00001003382

• Organoid BulkRNAseq

  Here, we aim to understand early determinants of brain organoid quality and generated a set of brain organoids from 12 different hPSC lines using an adaptation of the unguided Lancaster protocol (Lancaster & Knoblich, 2014). All cell lines were obtained from healthy donors. 12 donor hPSC lines were differentiated into brain organoids and a set of 72 individual organoids (6 per line) were randomly selected morphologically diverse organoids and subjected to bulk RNA sequencing for gene expression analysis. RNA was extracted using the RNeasy kit (Qiagen, Germany) according to the manufacturer’s instructions. A total of 1000 ng per sample was sent for RNA sequencing to Azenta Life Sciences (Genewiz Leipzig, Germany) for sequencing. Library preparation was performed using the NEBNext Ultra II RNA Library Prep Kit for Illumina following manufacturer’s instructions (NEB, Ipswich, MA, USA). mRNAs were first enriched with Oligo(dT) beads. The samples were sequenced using a 2x150 Pair-End (PE) configuration v1.5 at a depth of >20 million reads in each sample. Raw sequence data (.bcl files) generated from Illumina NovaSeq6000 was converted into fastq files and de-multiplexed using Illumina bcl2fastq program version 2.20. The raw sequence reads were aligned to the human reference genome GRCh38 using the STAR aligner (Dobin et al., 2013). Gene expression levels were quantified using the FeatureCounts tool (Liao et al., 2014).

  Study EGAS50000000659

• A thymic ILC1-like progenitor with differentiation potential towards KIR+NKG2A- NK cells - sc

  KIR+NKG2A- Natural Killer (NK) cells have the unique ability to detect downregulation of single HLA-I allotypes, frequently occurring in malignantly-transformed and virus-infected cells in order to escape T cell recognition. We have recently shown that circulating Innate Lymphoid Cells 1 (cILC1) have the potential to generate such KIR+NKG2A- NK cells but their developmental origin was unknown. Here we demonstrate that the development of cILC1 is thymus-dependent and identify a putative progenitor of cILC1s in the thymus, called thyILC1. Single-cell RNAseq analysis revealed a close relationship of thyILC1s to CD34+ double-negative (DN) thymocytes, but in contrast to DNs, thyILC1s had lost T cell differentiation potential. However, like cILC1s they could be efficiently differentiated into KIR+NKG2A- NK cells. thyILC1s strongly expressed RAG1/2, PTCRA (preTCR, and NOTCH1/3, but lacked expression of TCR chains, suggesting that they failed to pass the -selection checkpoint of thymocyte development. Finally, analyses of patients with FOXN1het deficiency, showing thymic hypoplasia due to lack of mature thymic epithelial cells, exhibited a profound deficiency of cILC1s but not cILC2s and cILC3s, demonstrating thymus dependency of cILC1s. Together, the data suggest that thyILC1s are the source of a novel thymus-dependent NK cell differentiation pathway that promotes generation of KIR+NKG2A- NK cells.

  Study EGAS50000000790