R Exploration of the gene fusion landscape of glioblastoma using transcriptome sequencing and copy number data (original) (raw)
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Scientific Reports
RNA-Sequencing (RNA-Seq) can identify gene fusions in tumors, but not all these fusions have functional consequences. Using multiple data bases, we have performed an in silico analysis of fusions detected by RNA-Seq in tumor samples from 139 newly diagnosed glioblastoma patients to identify in-frame fusions with predictable oncogenic potential. Among 61 samples with fusions, there were 103 different fusions, involving 167 different genes, including 20 known oncogenes or tumor suppressor genes (TSGs), 16 associated with cancer but not oncogenes or TSGs, and 32 not associated with cancer but previously shown to be involved in fusions in gliomas. After selecting in-frame fusions able to produce a protein product and running Oncofuse, we identified 30 fusions with predictable oncogenic potential and classified them into four non-overlapping categories: six previously described in cancer; six involving an oncogene or TSG; four predicted by Oncofuse to have oncogenic potential; and 14 oth...
Novel Gene Fusions in Glioblastoma Tumor Tissue and Matched Patient Plasma
Cancers
Sequencing studies have provided novel insights into the heterogeneous molecular landscape of glioblastoma (GBM), unveiling a subset of patients with gene fusions. Tissue biopsy is highly invasive, limited by sampling frequency and incompletely representative of intra-tumor heterogeneity. Extracellular vesicle-based liquid biopsy provides a minimally invasive alternative to diagnose and monitor tumor-specific molecular aberrations in patient biofluids. Here, we used targeted RNA sequencing to screen GBM tissue and the matched plasma of patients (n = 9) for RNA fusion transcripts. We identified two novel fusion transcripts in GBM tissue and five novel fusions in the matched plasma of GBM patients. The fusion transcripts FGFR3-TACC3 and VTI1A-TCF7L2 were detected in both tissue and matched plasma. A longitudinal follow-up of a GBM patient with a FGFR3-TACC3 positive glioma revealed the potential of monitoring RNA fusions in plasma. In summary, we report a sensitive RNA-seq-based liqui...
Validation of a Targeted RNA Sequencing Assay for Kinase Fusion Detection in Solid Tumors
The Journal of molecular diagnostics : JMD, 2017
Kinase gene fusions are important drivers of oncogenic transformation and can be inhibited with targeted therapies. Clinical grade diagnostics using RNA sequencing to detect gene rearrangements in solid tumors are limited, and the few that are available require prior knowledge of fusion break points. To address this, we have analytically validated a targeted RNA sequencing assay (OSU-SpARKFuse) for fusion detection that interrogates complete transcripts from 93 kinase and transcription factor genes. From a total of 74 positive and 36 negative control samples, OSU-SpARKFuse had 93.3% sensitivity and 100% specificity for fusion detection. Assessment of repeatability and reproducibility revealed 96.3% and 94.4% concordance between intrarun and interrun technical replicates, respectively. Application of this assay on prospective patient samples uncovered OLFM4 as a novel RET fusion partner in a small-bowel cancer and led to the discovery of a KLK2-FGFR2 fusion in a patient with prostate...
The landscape of kinase fusions in cancer
Nature Communications, 2014
Human cancer genomes harbour a variety of alterations leading to the deregulation of key pathways in tumour cells. The genomic characterization of tumours has uncovered numerous genes recurrently mutated, deleted or amplified, but gene fusions have not been characterized as extensively. Here we develop heuristics for reliably detecting gene fusion events in RNA-seq data and apply them to nearly 7,000 samples from The Cancer Genome Atlas. We thereby are able to discover several novel and recurrent fusions involving kinases. These findings have immediate clinical implications and expand the therapeutic options for cancer patients, as approved or exploratory drugs exist for many of these kinases.
Fusionfinder: A software tool to identify expressed gene fusion candidates from RNA-seq data
PLoS ONE, 2012
The hallmarks of many haematological malignancies and solid tumours are chromosomal translocations, which may lead to gene fusions. Recently, next-generation sequencing techniques at the transcriptome level (RNA-Seq) have been used to verify known and discover novel transcribed gene fusions. We present FusionFinder, a Perl-based software designed to automate the discovery of candidate gene fusion partners from single-end (SE) or paired-end (PE) RNA-Seq read data. FusionFinder was applied to data from a previously published analysis of the K562 chronic myeloid leukaemia (CML) cell line. Using FusionFinder we successfully replicated the findings of this study and detected additional previously unreported fusion genes in their dataset, which were confirmed experimentally. These included two isoforms of a fusion involving the genes BRK1 and VHL, whose co-deletion has previously been associated with the prevalence and severity of renal-cell carcinoma. FusionFinder is made freely available for non-commercial use and can be downloaded from the project website
Diagnostic Pathology: Open Access, 2016
Fusion genes are neoplasia-associated mutations, which play a particularly significant role in tumorgenesis and exhibit great importance for clinical applications in malignant hematological diseases and solid tumors. Simultaneously with copy number variants (CNVs), gene fusions are resulting from balanced and unbalanced chromosomal rearrangements. Thus, understanding the mutagenesis and instability of CNV, as well as the underlying molecular mechanisms of chromosomal rearrangements will improve our comprehension of gene fusions. Recently, next generation sequencing (NGS), especially transcriptome sequencing or RNA-Sequencing (RNA-seq), has become a very useful tool to identify gene alterations in cancer and a powerful approach for investigating the tumorgenesis. However, we are still facing with the challenge of minimizing false positives in results of RNA-seq. Whole-genome sequencing (WGS) is also used for the fusion gene detection, which provides us a more comprehensive and integrative way to detect structural variants. WGS may correct the false-negative results from RNA-seq. Additionally; many computational tools with more sensitivity and specificity have been developed for the detection of fusion transcripts from NGS datas. In the future, multi-omics analysis, third-generation sequencing and liquid-biopsy technique all provide opportunities to comprehensively interpret gene fusions and understand the biology of cancer genomes.
BMC Systems Biology, 2014
The extraordinary success of imatinib in the treatment of BCR-ABL1 associated cancers underscores the need to identify novel functional gene fusions in cancer. RNA sequencing offers a genome-wide view of expressed transcripts, uncovering biologically functional gene fusions. Although several bioinformatics tools are already available for the detection of putative fusion transcripts, candidate event lists are plagued with non-functional read-through events, reverse transcriptase template switching events, incorrect mapping, and other systematic errors. Such lists lack any indication of oncogenic relevance, and they are too large for exhaustive experimental validation. Results: We have designed and implemented a pipeline, Pegasus, for the annotation and prediction of biologically functional gene fusion candidates. Pegasus provides a common interface for various gene fusion detection tools, reconstruction of novel fusion proteins, reading-frame-aware annotation of preserved/lost functional domains, and data-driven classification of oncogenic potential. Pegasus dramatically streamlines the search for oncogenic gene fusions, bridging the gap between raw RNA-Seq data and a final, tractable list of candidates for experimental validation.
Therapeutic Advances in Medical Oncology
Introduction: The research objective was to systematically review evidence on neurotrophic tyrosine receptor kinase ( NTRK) gene fusion frequency in solid tumors. Methods: Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic literature review (SLR) was conducted of studies published from January 1987 to 2 January 2020. Selected studies were appraised for use in meta-analysis, with frequency reported as a point estimate with confidence intervals, to estimate NTRK gene fusion tumor incidence and prevalence. Results: The SLR identified 222 studies from North America ( n = 122), Europe ( n = 33), Asia ( n = 41), Brazil ( n = 5), Australia ( n = 2), and multi-continental ( n = 19) reporting NTRK gene fusion frequencies across 101 histologies. Studies were prospective ( n = 43) and retrospective ( n = 179). Testing methods involved DNA ( n = 93), RNA ( n = 72), combined DNA/RNA ( n = 48), protein [immunohistochemistry (IHC), n = 5], an...
2019
BackgroundGene fusion events are a significant source of somatic variation across adult and pediatric cancers and are some of the most clinically-effective therapeutic targets, yet low consensus of RNA-Seq fusion prediction algorithms makes therapeutic prioritization difficult. In addition, events such as polymerase read-throughs, mis-mapping due to gene homology, and fusions occurring in healthy normal tissue require informed filtering, making it difficult for researchers and clinicians to rapidly discern gene fusions that might be true underlying oncogenic drivers of a tumor and in some cases, appropriate targets for therapy.ResultsWe developed annoFuse, an R package, and shinyFuse, a companion web application, to annotate, prioritize, and explore biologically-relevant expressed gene fusions, downstream of fusion calling. We validated annoFuse using a random cohort of TCGA RNA-Seq samples (N = 160) and achieved a 96% sensitivity for retention of high-confidence fusions (N = 603). ...