Project description:Genome-wide DNA methylation profiling of 30 low-grade neuroepithelial tumors with FGFR1 alterations including rosette-forming glioneuronal tumor, pilocytic astrocytoma, dysembryoplastic neuroepithelial tumor, and extraventricular neurocytoma. The Illumina Infinium EPIC 850k Human DNA Methylation Beadchip was used to obtain DNA methylation profiles across approximately 850,000 CpG sites of genomic DNA extracted from formalin-fixed, paraffin-embedded tumor tissue of 30 low-grade neuroepithelial tumors with FGFR1 alterations including kinase domain tandem duplication, in-frame fusion with TACC1, and hotspot missense mutation within the intracellular tyrosine kinase domain.
Project description:Genome-wide DNA methylation profiling of 8 low-grade neuroepithelial tumors (LGNET) with FGFR2 fusions with various histologic diagnoses including ganglioglioma, multinodular and vacuolating neuronal tumor (MVNT), low-grade glioneuronal tumor NOS, and polymorphous low-grade neuroepithelial tumor of the young (PLNTY). The Illumina Infinium EPIC 850k Human DNA Methylation Beadchip was used to obtain DNA methylation profiles across approximately 850,000 CpG sites of genomic DNA extracted from formalin-fixed, paraffin-embedded tumor tissue of 8 low-grade neuroepithelial tumors with FGFR2 fusions.
Project description:Low grade neuroepithelial tumor is the major cause of epilepsy Low-grade neuroepithelial tumors are major causes of drug-resistant focal epilepsy. The BRAF V600E mutation is frequently observed in low grade neuroepithelial tumor and linked to poor seizure outcomes. However, its molecular role in epileptogenicity remains elusive. To understand the molecular mechanism underlying the epileptogenicity in LEAT with the BRAF V600E genetic mutation (BRAF V600E-LEAT), we conducted RNA sequencing (RNA-seq) analysis using surgical specimens of BRAF V600E-LEAT obtained and stored at a single institute. bioinformatics analysis using this dataset identified 2,134 differentially expressed genes between BRAF V600E-LEAT and control. Additionally, gene set enrichment analysis provided novel insights into the association between estrogen response-related pathways and the epileptogenicity of BRAF V600E-LEAT patients.
Project description:Pediatric neoplasms in the central nervous system show an extensive clinical and molecular heterogeneity. Molecular genetic testing contributes to accurate diagnosis and enables an optimal clinical management of affected children. Unsupervised visualization of genome-wide DNA methylation array data revealed a molecularly distinct type of pediatric high-grade neuroepithelial tumor with fusions involving the capicua transcriptional repressor (CIC) gene, with the most common fusion being CIC::LEUTX. Histopathological review demonstrated a morphologically heterogeneous group of high-grade neuroepithelial tumors with positive immunostaining for markers of glial differentiation in combination with weak and focal expression of synaptophysin, CD56 and CD99. In summary, we expand the spectrum of pediatric-type tumors of the CNS by reporting a previously uncharacterized group of rare high-grade neuroepithelial tumors that share a common DNA methylation signature and recurrent gene fusions involving the transcriptional repressor CIC.
Project description:The discovery of fibroblast growth factor receptor (FGFR) gene family alterations as drivers of primary brain tumors has generated significant excitement, both as potential therapeutic targets as well as defining hallmarks of histologic entities. However, FGFR alterations among neuroepithelial lesions are not restricted to high or low grade, nor to adult vs. pediatric-type tumors. While it may be tempting to consider FGFR-altered tumors as a unified group, this underlying heterogeneity poses diagnostic and interpretive challenges. Therefore, understanding the underlying biology of tumors harboring specific FGFR alterations is critical. In this review, recent evidence for recurrent FGFR alterations in histologically and biologically low-grade neuroepithelial tumors (LGNTs) is examined (namely FGFR1 tyrosine kinase domain duplication in low grade glioma, FGFR1-TACC1 fusions in extraventricular neurocytoma [EVN], and FGFR2-CTNNA3 fusions in polymorphous low-grade neuroepithelial tumor of the young [PLNTY]). Additionally, FGFR alterations with less well-defined prognostic implications are considered (FGFR3-TACC3 fusions, FGFR1 hotspot mutations). Finally, a framework for practical interpretation of FGFR alterations in low grade glial/glioneuronal tumors is proposed.
Project description:Alterations in Fibroblast growth factor receptor proteins frequently occur as oncogenes in many cancers. FGFR alterations have been reported in a subset of pediatric gliomas, representing a therapeutic target for precision medicine approaches. We performed a genomic analysis of 13,659 gliomas and found that 4.5% harbor FGFR alterations including structural variants and single nucleotide variants. FGFR family members are differentially enriched by age, tumor grade, and histological subtype. FGFR1 alterations are most frequent in pediatric gliomas, particularly pediatric low-grade gliomas, while FGFR3 drivers were associated with adult gliomas. In vitro and in vivo functional studies confirm FGFR1 alterations to be sufficient to activate MAPK and mTOR signaling, drive gliomagenesis and activate neuronal transcriptional programs. FGFR1-driven models showed sensitivity to MAPK pathway inhibitors, including panFGFR inhibitors that are FDA approved for use in other cancers. While early FGFR inhibition was sufficient to prolong survival of mice bearing FGFR-driven xenografts, this was insufficient to induce cures. Similarly, review of patients treated with currently available MAPK pathway or FGFR inhibitors revealed modest responses. This study provides key insights into the biology of FGFR1-altered gliomas and potential strategies to therapeutically target them.
Project description:Alterations in Fibroblast growth factor receptor proteins frequently occur as oncogenes in many cancers. FGFR alterations have been reported in a subset of pediatric gliomas, representing a therapeutic target for precision medicine approaches. We performed a genomic analysis of 13,659 gliomas and found that 4.5% harbor FGFR alterations including structural variants and single nucleotide variants. FGFR family members are differentially enriched by age, tumor grade, and histological subtype. FGFR1 alterations are most frequent in pediatric gliomas, particularly pediatric low-grade gliomas, while FGFR3 drivers were associated with adult gliomas. In vitro and in vivo functional studies confirm FGFR1 alterations to be sufficient to activate MAPK and mTOR signaling, drive gliomagenesis and activate neuronal transcriptional programs. FGFR1-driven models showed sensitivity to MAPK pathway inhibitors, including panFGFR inhibitors that are FDA approved for use in other cancers. While early FGFR inhibition was sufficient to prolong survival of mice bearing FGFR-driven xenografts, this was insufficient to induce cures. Similarly, review of patients treated with currently available MAPK pathway or FGFR inhibitors revealed modest responses. This study provides key insights into the biology of FGFR1-altered gliomas and potential strategies to therapeutically target them.
Project description:Alterations in Fibroblast growth factor receptor proteins frequently occur as oncogenes in many cancers. FGFR alterations have been reported in a subset of pediatric gliomas, representing a therapeutic target for precision medicine approaches. We performed a genomic analysis of 13,659 gliomas and found that 4.5% harbor FGFR alterations including structural variants and single nucleotide variants. FGFR family members are differentially enriched by age, tumor grade, and histological subtype. FGFR1 alterations are most frequent in pediatric gliomas, particularly pediatric low-grade gliomas, while FGFR3 drivers were associated with adult gliomas. In vitro and in vivo functional studies confirm FGFR1 alterations to be sufficient to activate MAPK and mTOR signaling, drive gliomagenesis and activate neuronal transcriptional programs. FGFR1-driven models showed sensitivity to MAPK pathway inhibitors, including panFGFR inhibitors that are FDA approved for use in other cancers. While early FGFR inhibition was sufficient to prolong survival of mice bearing FGFR-driven xenografts, this was insufficient to induce cures. Similarly, review of patients treated with currently available MAPK pathway or FGFR inhibitors revealed modest responses. This study provides key insights into the biology of FGFR1-altered gliomas and potential strategies to therapeutically target them.
Project description:Low-grade neuroepithelial tumors (LGNTs) are diverse CNS tumors presenting in children and young adults, often with a history of epilepsy. While the genetic profiles of common LGNTs, such as the pilocytic astrocytoma and 'adult-type' diffuse gliomas, are largely established, those of uncommon LGNTs remain to be defined. In this study, we have used massively parallel sequencing and various targeted molecular genetic approaches to study alterations in 91 LGNTs, mostly from children but including young adult patients. These tumors comprise dysembryoplastic neuroepithelial tumors (DNETs; n = 22), diffuse oligodendroglial tumors (d-OTs; n = 20), diffuse astrocytomas (DAs; n = 17), angiocentric gliomas (n = 15), and gangliogliomas (n = 17). Most LGNTs (84 %) analyzed by whole-genome sequencing (WGS) were characterized by a single driver genetic alteration. Alterations of FGFR1 occurred frequently in LGNTs composed of oligodendrocyte-like cells, being present in 82 % of DNETs and 40 % of d-OTs. In contrast, a MYB-QKI fusion characterized almost all angiocentric gliomas (87 %), and MYB fusion genes were the most common genetic alteration in DAs (41 %). A BRAF:p.V600E mutation was present in 35 % of gangliogliomas and 18 % of DAs. Pathogenic alterations in FGFR1/2/3, BRAF, or MYB/MYBL1 occurred in 78 % of the series. Adult-type d-OTs with an IDH1/2 mutation occurred in four adolescents, the youngest aged 15 years at biopsy. Despite a detailed analysis, novel genetic alterations were limited to two fusion genes, EWSR1-PATZ1 and SLMAP-NTRK2, both in gangliogliomas. Alterations in BRAF, FGFR1, or MYB account for most pathogenic alterations in LGNTs, including pilocytic astrocytomas, and alignment of these genetic alterations and cytologic features across LGNTs has diagnostic implications. Additionally, therapeutic options based upon targeting the effects of these alterations are already in clinical trials.