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: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: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: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:Translocations involving FGFR2 gene fusions are common in cholangiocarcinoma and predict response to FGFR kinase inhibitors. However, response rates and durability of are limited due to the emergence of resistance, typically involving FGFR2 kinase domain mutations, and to sub-optimal dosing, relating to drug adverse effects. Here, we develop biparatopic antibodies targeting the FGFR2 extracellular domain (ECD), as candidate therapeutics. Biparatopic antibodies can overcome drawbacks of bivalent monospecific antibodies, which often show poor inhibitory or even agonist activity against oncogenic receptors. We show that oncogenic transformation by FGFR2 fusions requires an intact ECD. Moreover, by systematically generating biparatopic antibodies targeting distinct epitope pairs in FGFR2 ECD, we identified antibodies that effectively block signaling and malignant growth driven by FGFR2-fusions. Importantly, these antibodies demonstrate efficacy in vivo, synergy with FGFR inhibitors, and activity against FGFR2 fusions harboring kinase domain mutations. Thus, biparatopic antibodies may serve as new treatment options for patients with FGFR2-altered cholangiocarcinoma.
Project description:Somatic hotspot mutations and structural amplifications and fusions affecting fibroblast growth factor receptor 2 (FGFR2) occur in multiple cancer types. However, clinical responses to FGFR inhibitors (FGFRi) have remained variable, emphasizing a need to better understand which FGFR2 alterations are oncogenic and targetable. Here we applied transposon-based screening and tumor modelling in mice to uncover truncation of exon (E) 18 of Fgfr2 as a potent driver mutation. Human oncogenomic datasets revealed a diverse set of FGFR2 alterations, including rearrangements (REs), E1-E17 partial amplifications, and E18 nonsense and frameshift mutations, each causing transcription of E18-truncated FGFR2 (FGFR2deltaE18). Somatic modelling in mice and human tumor cell lines using a compendium of FGFR2deltaE18 and full-length variants identified FGFR2deltaE18-truncation as potent single-driver alteration in cancer. Here we show the phosphoproteomic landscape of FGFR2 variants in murine epithelial cell (MEC) lines and mouse tumors. Global (STY) phosphoproteomics using IMAC and phosphotyrosine phosphoproteomics using pTyr IP’s are combined with DIA protein expression data to uncover oncogenic signaling of clinically-relevant FGFR2 variants.
Project description:Dysregulated FGF/FGFR signaling leads to a variety of pathologies. These include cancer as well as congenital syndromes that affect skeleton development, impair the response to injury, and/or result in metabolic disorders. In human cancers, the FGFR genes can be affected by hotspot missense mutations or structural alterations, such as amplifications and fusions/rearrangements. Missense mutations affecting the FGFR extracellular domains (e.g., FGFR3S249C) typically facilitate receptor dimerization and ligand-independent activation whereas kinase domain missense mutations frequently facilitate transition to (e.g., FGFR2N549K) or stabilization of (e.g., FGFR3K650E) an active kinase state. FGFR amplifications result in receptor overexpression. Notably, focal FGFR2 amplifications can also produce C-terminally truncated isoforms owing to genomic breakpoints that perturb intron or the FGFR2 C-terminus-encoding exon 18. FGFR2 and FGFR3 fusion/rearrangement breakpoints typically occur in the I17/E18 hotspot, thus also producing C-terminally truncated receptors. E18-truncated FGFR2 variants (FGFR2E18) indeed act as tumor driver genes. Hence, loss of the C-terminus is vital to render FGFR2 and potentially other FGFRs oncogenic.However, it has remained unclear, which motifs or amino acid residues within the C-terminal tail are most critical to suppress oncogenic FGFR2 signaling. Here we made us of a compendium of Fgfr2E18 and Fgfr2 C-terminal variants to functionally dissect FGFR2E18 signaling and the tumor suppressive nature of the FGFR2 C-terminus.