Project description:We analyzed the copy number profiles of clinical samples of diagnostically difficult melanocytic tumors. Of 1202 cases, 22 cases demonstrated relative gain of the 5' portion of NTRK3. We further performed DNA or RNA sequencing on 12 of these cases and identified ETV6-NTRK3, MYO5A-NTRK3 and MYH9-NTRK3 fusions in the 8 cases in this cohort. Analysis of genomic copy number of melanocytic tumors versus commericial pooled normal control.
Project description:In our clinical practice, we perform genome-wide high-resolution SNP-array analysis as an adjunct to the histopathologic diagnosis for diagnostically challenging melanocytic tumors. The concept of using array-based DNA copy number analysis to screen for gene fusions associated with unbalanced genomic aberrations flanking the fusion points was applied in the diagnostic setting, and intragenic copy number changes involving common receptor kinase genes are typically further analyzed and, if necessary, studied by alternative methods. Here we present the discovery of recurrent NTRK3 gene rearrangements in childhood melanocytic neoplasms based on genome-wide high-resolution SNP-array analysis.
Project description:Oncogenic gene fusions have been identified in many cancers and many serve as biomarkers or targets for therapy. Here we identify six different melanocytic tumors with genomic rearrangements of MET fusing the kinase domain of MET in-frame to six different N-terminal partners. These tumors lack activating mutations in other established melanoma oncogenes. We functionally characterize two of the identified fusion proteins (TRIM4-MET and ZKSCAN1-MET) and find that they constitutively activate the mitogen-activated protein kinase (MAPK), phosphoinositol-3 kinase (PI3K), and phospholipase C gamma 1 (PLCγ1) pathways. The MET inhibitors cabozantinib (FDA-approved for progressive medullary thyroid cancer) and PF-04217903 block their activity at nanomolar concentrations. MET fusion kinases thus provide a potential therapeutic target for a rare subset of melanoma for which currently no targeted therapeutic options currently exist.
Project description:The newest WHO classification suggests eliminating cases with BRAF and NRAS mutations from the categories of Spitz tumors (ST) and Spitz melanoma (SM). We aimed to better characterize the genomics of Spitz neoplasms and assess whether integrating genomic data with morphologic diagnosis improves classification and prognostication. We performed DNA and RNA sequencing on 80 STs, 26 SMs, and 22 melanomas with Spitzoid features (MSF). NGS data was used to reclassify tumors by moving BRAF/NRAS-mutated cases to MSF. Eighty-one percent of STs harbored kinase fusions/truncations. Of SMs, 77% had fusions/truncations, 8 involving MAP3K8. Novel fusions identified were MYO5A-FGFR1, MYO5A-ERBB4, and PRKDC-CTNNB1. The majority of MSFs (84%) had BRAF, NRAS, or NF1 mutations, and 62% had TERT promoter mutations. Only after reclassification, the following was observed: 1) mRNA expression showed distinct clustering of MSF; 2) 6/7 cases with recurrence and all distant metastases were MSFs; 3) RFS was worse in MSF than ST and SM groups (p=0.0073); 4) classification incorporating genomic data was highly predictive of recurrence (OR 13.20, p=0.0197). The majority of STs and SMs have kinase fusions as primary initiating genomic events. Eliminating BRAF/NRAS-mutated neoplasms from these categories results in improved classification and prognostication of melanocytic neoplasms with Spitzoid cytomorphology.
Project description:In this study, we characterize the fusion protein produced by the EPC1-PHF1 translocation in Low Grade Endometrial Stromal Sarcoma (LG-ESS) and Ossifying FibroMyxoid Tumors (OFMT). We express the fusion protein and necessary controls in K562 Cells. The fusion protein assembles a mega-complex harboring both NuA4/TIP60 and PRC2 subunits and enzymatic activities and leads to mislocalization of chromatin marks in the genome, linked to aberrant gene expression.
Project description:The newest WHO classification suggests eliminating cases with BRAF and NRAS mutations from the categories of Spitz tumors (ST) and Spitz melanoma (SM). We aimed to better characterize the genomics of Spitz neoplasms and assess whether integrating genomic data with morphologic diagnosis improves classification and prognostication. We performed DNA and RNA sequencing on 80 STs, 26 SMs, and 22 melanomas with Spitzoid features (MSF). NGS data was used to reclassify tumors by moving BRAF/NRAS-mutated cases to MSF. Eighty-one percent of STs harbored kinase fusions/truncations. Of SMs, 77% had fusions/truncations, 8 involving MAP3K8. Novel fusions identified were MYO5A-FGFR1, MYO5A-ERBB4, and PRKDC-CTNNB1. The majority of MSFs (84%) had BRAF, NRAS, or NF1 mutations, and 62% had TERT promoter mutations. Only after reclassification, the following was observed: 1) mRNA expression showed distinct clustering of MSF; 2) 6/7 cases with recurrence and all distant metastases were MSFs; 3) RFS was worse in MSF than ST and SM groups (p=0.0073); 4) classification incorporating genomic data was highly predictive of recurrence (OR 13.20, p=0.0197). The majority of STs and SMs have kinase fusions as primary initiating genomic events. Eliminating BRAF/NRAS-mutated neoplasms from these categories results in improved classification and prognostication of melanocytic neoplasms with Spitzoid cytomorphology.