Dataset Information

Whole genome sequencing with linked reads of pediatric glioblastoma samples

ABSTRACT: Pediatric glioblastoma (pGBM) is a lethal cancer with no effective therapies. To understand mechanisms of tumor evolution in this cancer, we performed whole genome sequencing with linked reads on longitudinally resected pGBM samples. Our analyses showed that all diagnostic and recurrent samples were collections of genetically diverse subclones. Clonal composition rapidly evolved at recurrence, with less than 8% of non-synonymous single nucleotide variants being shared in diagnostic-recurrent pairs. In order to track the origins of the mutational events we observed in pGBM, we generated whole genome datasets for two patients and their parents. These trios showed that genetic variants could be (i) somatic, (ii) inherited from a healthy parent, or (iii) arose de novo in the germlines of pGBM patients. Analysis of variant allele frequencies supported a model of tumor growth involving slow-cycling cancer stem cells that give rise to fast-proliferating progenitor-like cells and to non-dividing cells. Interestingly, radiation and anti-mitotic chemotherapeutics did not increase overall tumor burden upon recurrence. These findings support an important role for slow-cycling stem cell populations in contributing to recurrences, since slow-cycling cell populations are expected to be less prone to genotoxic stress induced by these treatments and to accumulate few mutations. Our results highlight the need for new targeted treatments that account for the complex functional hierarchies and genomic heterogeneity of pGBM.

OTHER RELATED OMICS DATASETS IN: GSE117599

PROVIDER: EGAS00001003432 | EGA |

REPOSITORIES: EGA

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Publications

Intratumoral Genetic and Functional Heterogeneity in Pediatric Glioblastoma.

Hoffman Mary M Gillmor Aaron H AH Kunz Daniel J DJ Johnston Michael J MJ Nikolic Ana A Narta Kiran K Zarrei Mehdi M King Jennifer J Ellestad Katrina K Dang Ngoc Ha NH Cavalli Florence M G FMG Kushida Michelle M MM Coutinho Fiona J FJ Zhu Yuankun Y Luu Betty B Ma Yussanne Y Mungall Andrew J AJ Moore Richard R Marra Marco A MA Taylor Michael D MD Pugh Trevor J TJ Dirks Peter B PB Strother Douglas D Lafay-Cousin Lucie L Resnick Adam C AC Scherer Stephen S Senger Donna L DL Simons Benjamin D BD Chan Jennifer A JA Morrissy A Sorana AS Gallo Marco M

Cancer research 20190315 9

Pediatric glioblastoma (pGBM) is a lethal cancer with no effective therapies. To understand the mechanisms of tumor evolution in this cancer, we performed whole-genome sequencing with linked reads on longitudinally resected pGBM samples. Our analyses showed that all diagnostic and recurrent samples were collections of genetically diverse subclones. Clonal composition rapidly evolved at recurrence, with less than 8% of nonsynonymous single-nucleotide variants being shared in diagnostic-recurrent ...[more]

PMID: 30877103

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Project description:Background and aims: Liver transplantation (LT) is the most radical treatment for hepatocellular carcinoma (HCC) with high rates of long-term survival, but tumor recurrence after LT is an unresolved problem. The aim of our study was to identify predictive markers for tumor recurrence after liver transplantation. Methods: In a retrospective single-center study, we included all patients with LT for HCC in our institution (01/2007-12/2012). Beside demographic data, we analyzed course, bridging therapies, Serum-AFP, time point of tumor recurrence, as well as the correlation of imaging and histopathology of our recipients. Additionally, we performed a microarray analysis to identify different miRNA profiles of patients with and without HCC recurrence after LT. Single assay stem-loop real-time PCR (Q-RT-PCR) was used for validation of the results. Results: During the study period, we performed 92 LT in patients with HCC (22 women, 70 men). Twenty-two (23.9%) patients developed a recurrent HCC after LT. Our subgroup with tumor recurrence after LT, presented with a mean disease-free survival of 10 months (3-55 months) and an overall survival of 25.5 months (4-77 months). Milan criteria, AFP levels and pathologic grading had an influence on the tumor recurrence. Performing miRNA analysis, we could identify significant upregulation of 8 miRNAs and downregulation of another 5 miRNAs in patients with tumor recurrence. Consecutively, array data were successfully validated using Q-RT-PCR. Multivariate Cox regression, ROC analysis and Kaplan-Meier showed that a score consisting of two miRNAs and Milan criteria are an independent predictor for tumor recurrence-free survival. Conclusions: Despite careful selection of patients, an early recurrence of HCC after LT cannot be avoided completely. Reliable prognostic markers related to tumor biology are still missing. Analysis and validation of specific miRNAs combined with radiological parameters might lead to a promising strategy for the prediction of tumor recurrence, but prospective studies have to follow. 8 macrodissected hepatocellular carcinoma (recurrent HCC) and 10 macrodissected hepatocellular carcinoma (non-recurrent HCC).

Project description:Synovial sarcoma (SynSa) is an aggressive mesenchymal tumor, comprising approximately 10% of all soft tissue sarcomas. Over half of SynSa patients develop metastasis or local recurrence, but the underlying molecular mechanisms of the aggressive clinical behavior remain poorly characterized. Sixty four frozen tumor specimens from 54 SynSa patients were subjected to array comparative genomic hybridization (aCGH) and gene expression profiling. The examined set of tumor specimens included 16 primary tumors from untreated patients who did not develop metastasis/local recurrence (SynSa1 group), 26 primary tumors from untreated patients who developed metastases or local recurrence during follow-up (SynSa2 group), and 22 metachronous metastatic/recurrent SynSa tumors (SynSa3 group). AURKA and KIF18A, which play important roles in various mitotic events, were the two most up-regulated genes in SynSa2 and SynSa3 groups compared to the SynSa1 group. Expression profiles of SynSa2 and SynSa3 tumors did not show any significant differences. Analysis of genomic index (GI) based on aCGH profiles demonstrated that the SynSa1 group consisted of tumors with significantly less complex genomes compared to SynSa2 and SynSa3 groups. There was no significant difference in genome complexity between SynSa2 and SynSa3 tumors. Primary SynSa tumors from patients who develop metastases or local recurrence share common molecular features with metastatic/recurrent tumors. Presented data suggest that the aggressive clinical SynSa behavior is determined early in tumorigenesis and might be related to impaired regulation of mitotic mechanisms. Introduction: Synovial sarcoma (SynSa) is an aggressive mesenchymal tumor, comprising approximately 10% of all soft tissue sarcomas. Over half of SynSa patients develop metastasis or local recurrence, but the underlying molecular mechanisms of the aggressive clinical behavior remain poorly characterized. Materials and methods: Sixty four frozen tumor specimens from 54 SynSa patients were subjected to array comparative genomic hybridization (aCGH) and gene expression profiling. The examined set of tumor specimens included 16 primary tumors from untreated patients who did not develop metastasis/local recurrence (SynSa1 group), 26 primary tumors from untreated patients who developed metastases or local recurrence during follow-up (SynSa2 group), and 22 metachronous metastatic/recurrent SynSa tumors (SynSa3 group). Results: AURKA and KIF18A, which play important roles in various mitotic events, were the two most up-regulated genes in SynSa2 and SynSa3 groups compared to the SynSa1 group. Expression profiles of SynSa2 and SynSa3 tumors did not show any significant differences. Analysis of genomic index (GI) based on aCGH profiles demonstrated that the SynSa1 group consisted of tumors with significantly less complex genomes compared to SynSa2 and SynSa3 groups. There was no significant difference in genome complexity between SynSa2 and SynSa3 tumors. Conclusions: Primary SynSa tumors from patients who develop metastases or local recurrence share common molecular features with metastatic/recurrent tumors. Presented data suggest that the aggressive clinical SynSa behavior is determined early in tumorigenesis and might be related to impaired regulation of mitotic mechanisms. Gene expression profiling of 15 primary tumors from untreated patients who did not develop metastasis/local recurrence (SynSa1 group), 21 primary tumors from untreated patients who developed metastases or local recurrence during follow-up (SynSa2 group), and 21 metachronous metastatic/recurrent SynSa tumors (SynSa3 group); Agilent One-Color technology.

Dataset Information

Whole genome sequencing with linked reads of pediatric glioblastoma samples

Publications

Intratumoral Genetic and Functional Heterogeneity in Pediatric Glioblastoma.

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