16599 results for "sec+and+unspecified+malignant+neoplasm"

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• ATRX mutant neuroblastoma is sensitive to EZH2 inhibition via modulation of neuronal differentiation.

  Mutations and structural alterations of the SWI/SNF-like chromatin remodeler ATRX have been reported at high frequency in a number of adult and pediatric tumors1. However, the consequences of ATRX (Alpha Thalassemia/Mental Retardation, X-linked) mutations in cancer and their underlying epigenetic sensitivities remain ill defined. Particularly intriguing are the large N-terminal deletions of ATRX in neuroblastoma that generate in-frame fusion (IFF) proteins1–3 devoid of key chromatin interaction domains. Here we demonstrate that neuroblastoma cells harbouring ATRX IFFs have distinct gene expression programs compared to neuroblastoma cells that are wild type for ATRX. This is due in part to H3K27me3-mediated silencing of REST (RE1 Silencing Transcription Factor) target genes involved in neuronal differentiation. In turn, we find that ATRX IFF cells display exquisite sensitivity to EZH2 inhibition in both adherent and tumorsphere conditions, due in part to derepression of neurogenesis genes, including REST targets. Examination of the epigenomic landscape of a pediatric neuroblastoma tumor harboring an ATRX IFF revealed that H3K27me3 occupies a subset of REST target genes that are transcriptionally silenced, and are sensitive to EZH2 inhibition in our cell-based assays. Thus, our study greatly advances our understanding of indolent neuroblastoma and identifies EZH2 inhibition as a potential therapy for patients with ATRX mutant disease. Further, these studies may be applicable to other ATRX mutant pediatric malignancies, particularly those carrying similar structural alterations of ATRX.

  Study EGAS00001002507

• Predictive value of chromosome 18q11.2-q12.1 loss for benefit from bevacizumab in metastatic colorectal cancer; a post-hoc analysis of the randomized controlled trial AGITG-MAX

  Patients and methods: We analyzed tumor samples of 256 patients enrolled in the AGITG-MAX 3-arm randomized controlled trial (RCT) who were randomly assigned to receive either capecitabine, or capecitabine and bevacizumab with- or without mitomycin. Chromosome 18q11.2-q12.1 copy number status was measured and correlated with PFS according to a predefined analysis plan with marker-treatment interaction as the primary end-point.Results: Chromosome 18q11.2-q12.1 losses were detected in 71% of patients (181/256) characteristic for mCRC. Consistent with the non-randomized study, significant PFS benefit of bevacizumab was observed in chromosome 18q11.2-q12.1 loss patients (P=0.009), and not in 18q no-loss patients (P=0.67). Although significance for marker-treatment interaction was not reached (Pinteraction = 0.28), hazard ratio and 95% confidence interval (HRinteraction 0.72, CI 0.39 - 1.32) show striking overlap with the non-randomized study cohorts (HRinteraction 0.41, CI 0.32 - 0.8) supported by a non-significant Cochrane chi-squared (P=0.11) for heterogeneity. Conclusions: PFS characteristics for marker positive- and negative patients randomized for treatment with- or without bevacizumab were consistent with those of the non-randomized discovery study, though the number of AGITG-MAX samples fell short to reach significance for marker-treatment interaction. Post-hoc analysis of the AGITG-MAX RCT provides supportive evidence for chromosome 18q11.2-q12.1 as a clinically relevant predictive marker for mCRC patients.

  Study EGAS00001005453

• Whole transcriptome profiling of liquid biopsies from tumour xenografted mouse models: validation cohort

  While cell-free DNA (cfDNA) in liquid biopsies is widely being used and investigated, free circulating RNA (extracellular RNA, exRNA) has the potential to improve therapy response monitoring and cancer detection due to its dynamic nature. A fundamental open question hampering the initiation of large-scale liquid biopsy collections for tumour exRNA analysis is that it remains unclear in which blood subcompartment tumour-derived exRNAs primarily reside. We set out to develop a host-xenograft deconvolution framework, exRNAxeno, with cDNA mapping strategies to either a combined human-mouse reference genome or both species genomes in parallel, that can be applied to exRNA sequencing data from liquid biopsies of human xenograft mouse models, enabling to distinguish (human) tumoural RNA from (murine) host RNA, and as such to specifically analyse tumour-derived exRNA. Subsequently, the preferred exRNAxeno combination pipeline was applied to total exRNA sequencing data from blood platelets and three plasma fractions from a breast cancer patient-derived and neuroblastoma cell line-derived xenograft mouse model. We show that tumoural exRNA concentrations are not determined by plasma platelet levels, while host exRNA concentrations increase with platelet content. Furthermore, a large variability in exRNA levels and gene content across individual mice is observed. In general, the tumoural gene detectability in plasma is correlated with the RNA expression levels in the tumour tissue or cancer cell line. Our results unravel new aspects of tumour-derived exRNA biology in xenograft mouse models.

  Study EGAS00001006582

• Osteosarcoma 3D patient derived cultures to test genome-informed personalized treatment options; a feasibility study

  Background: Improving osteosarcoma treatment beyond conventional (neo)adjuvant chemotherapy and resection remains challenging. An urgent need for novel therapeutic options, particularly personalized and targeted approaches, has emerged due to high inter-patient molecular heterogeneity. A lack of representative in vitro and in vivo models impedes therapeutic development, therefore we aimed to create 3D in vitro long term culture models directly from patient material. Methods: Tumour cells from seven osteosarcoma patients were propagated in monolayer or collagen hydrogels, while whole-exome sequencing of corresponding primary tumour tissue was performed to identify potential drug targets. Established cultures were subsequently used to assess efficacy of the identified personalized treatment options. Results: Three out of seven hydrogel cultures harboured the same genetic alterations as the corresponding primary tumours. Among these, the L6565 patient line exhibited homozygous CDKN2A loss with retained Rb expression, rendering tumour cells sensitive to CDK4/CDK6 inhibition via palbociclib. This patient line was used to evaluate genome-informed therapy and to compare cell culture models of increasing complexity. Our findings demonstrate feasibility of establishing long-term patient-derived osteosarcoma cultures with a success rate of 14%. Tumour heterogeneity was reflected in advanced culture methods producing more variability in treatment response. Conclusion: These results highlight the potential of genome-informed therapies in osteosarcoma and the importance of refining culture techniques to enhance translational research and therapeutic outcomes.

  Study EGAS50000001583

• Genome-wide cell-free DNA termini in patients with cancer

  The structure, fragmentation pattern, length and terminal sequence of cell-free DNA (cfDNA) is under the influence of nucleases present in the blood. We hypothesized that differences in the diversity of bases at the end of cfDNA fragments can be leveraged on a genome-wide scale to enhance the sensitivity for detecting the presence of tumor signals in plasma. We surveyed the cfDNA termini in 72 plasma samples from 319 patients with 18 different cancer types using low-coverage whole genome sequencing. The fragment-end sequence and diversity were altered in all cancer types in comparison to 76 healthy controls. We converted the fragment end sequences into a quantitative metric and observed that this correlates with circulating tumor DNA tumor fraction (R = 0.58, p < 0.001, Spearman). Using these metrics, we were able to classify cancer samples from control at a low tumor content (AUROC of 91% at 1% tumor fraction) and shallow sequencing coverage (mean AUROC = 0.99 at >1M fragments). Combining fragment-end sequences and diversity using machine learning, we classified cancer from healthy controls (mean AUROC = 0.99, SD = 0.01). Using unsupervised clustering we showed that early-stage lung cancer can be classified from control or later stages based on fragment-end sequences. We observed that fragment-end sequences can be used for prognostication (hazard ratio: 0.49) and residual disease detection inresectable esophageal adenocarcinoma patients, moving fragmentomics toward a greater clinical implementation.

  Study EGAS00001005738

• Genome-wide cell-free DNA termini in patients with cancer

  The structure, fragmentation pattern, length and terminal sequence of cell-free DNA (cfDNA) is under the influence of nucleases present in the blood. We hypothesized that differences in the diversity of bases at the end of cfDNA fragments can be leveraged on a genome-wide scale to enhance the sensitivity for detecting the presence of tumor signals in plasma. We surveyed the cfDNA termini in 72 plasma samples from 319 patients with 18 different cancer types using low-coverage whole genome sequencing. The fragment-end sequence and diversity were altered in all cancer types in comparison to 76 healthy controls. We converted the fragment end sequences into a quantitative metric and observed that this correlates with circulating tumor DNA tumor fraction (R = 0.58, p < 0.001, Spearman). Using these metrics, we were able to classify cancer samples from control at a low tumor content (AUROC of 91% at 1% tumor fraction) and shallow sequencing coverage (mean AUROC = 0.99 at >1M fragments). Combining fragment-end sequences and diversity using machine learning, we classified cancer from healthy controls (mean AUROC = 0.99, SD = 0.01). Using unsupervised clustering we showed that early-stage lung cancer can be classified from control or later stages based on fragment-end sequences. We observed that fragment-end sequences can be used for prognostication (hazard ratio: 0.49) and residual disease detection inresectable esophageal adenocarcinoma patients, moving fragmentomics toward a greater clinical implementation.

  Study EGAS00001005747

• Genome-wide association study identifies common variants associated with breast cancer in South African Black women

  Genome-wide association studies (GWAS) have characterized the contribution of common variants to the development of breast cancer (BC) in populations of European descent, however no GWAS have been reported in resident African populations. This GWAS included 2,485 resident African BC cases and 1,101 population matched controls. Two risk loci were identified, one on chromosome 15, located between UNC13C and RAB27A (rs7181788, p = 1.01x10-08) and a second in an intron of USP22 on chromosome 17 (rs899342, p = 4.62x10-08). RAB27A is a member of the RAS oncogene family associated with invasive growth and metastasis, and UNC13C is involved in tumor progression. The rs899342 SNP is an eQTL for expression of USP22 in a wide range of tissues. Several genome-wide significant signals were detected in a hormone receptor subtype analysis. Comparison of a meta-analysis of other African ancestry BC GWAS datasets predominantly of West African ancestry with our South African data showed limited evidence of shared risk loci, suggesting potential heterogeneity in genetic risk factors for breast cancer in different African populations. A European ancestry derived polygenic risk model for BC was applied to our data, explaining only 0.79% of variance, with an area under the curve of 0.56. This study identified genetic risk factors for BC in a resident African population, but larger studies in this and other African populations are needed to further define the contribution of common variants to BC risk.

  Study EGAS00001008032

• Eribulin efficacy in platinum-resistant and refractory high-grade serous ovarian cancer patient-derived xenograft models

  Objectives: To determine the potential of anti-microtubule agent (AMA) therapy (paclitaxel, vinorelbine and eribulin) in platinum-resistant or refractory (PRR) HGSC by assessing response in patient-derived xenograft (PDX) models of HGSC. Approach:We characterized a cohort of PRR HGSC PDX models generated from treatment naïve or postsystemic therapy specimens, representative of individuals with PRR HGSC in the clinic. Whole-exome sequencing was carried out on five PDX tumours and whole-genome sequencing was carried out on one patient tumour.

  Study EGAS50000000152

• Molecular Signatures of DCIS to Invasive Progression for Basal-Like Breast Cancers: An Integrated Mouse Model and Human Tumor Study

  We studied the genomic signatures of progression in breast ductal carcinoma in situ (DCIS) as it progresses towards triple negative invasive breast cancer (TNBC). Single cell RNA sequencing (scRNAseq) was performed on the C3Tag genetically engineered mouse model that forms human breast-like DCIS and TNBC. Bulk RNA sequencing was performed on RNA harvested from archival formalin-fixed, paraffin embedded (FFPE) pairs comprising of estrogen receptor (ER) positive (ER+) and negative (ER-) subsets of DCIS. 

  Study phs002443

• Pulmonary Fibrosis and Telomerase Dysfunction

  This study was used to perform an exome-limited analysis of whole genome sequencing data of patients with idiopathic pulmonary fibrosis (IPF) or familial pulmonary fibrosis. Case cohorts were derived from local centers at University of Southwestern or Columbia University, and subjects were from the IPFnet cohort of clinical trial. Rare damaging mutations in the coding regions of cases were compared to healthy controls, and gene burden analysis was performed to identify enrichment of novel risk genes in the development of pulmonary fibrosis. 

  Study phs002692