Mosaic BRAF fusions are a recurrent cause of congenital melanocytic naevi targetable by MEK inhibition
Ontology highlight
ABSTRACT:
INSTRUMENT(S): Illumina HiSeq 2500
ORGANISM(S): Homo sapiens
SUBMITTER: Veronica Kinsler
PROVIDER: E-MTAB-13182 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:Mosaic BRAF fusions are a recurrent cause of congenital melanocytic naevi targetable by MEK inhibition
| PRJEB64546 | ENA
Project description:Fusion genes can be oncogenic drivers in a variety of cancer types and represent potential targets for targeted therapy. The BRAF gene is frequently involved in oncogenic fusions, with fusion frequencies of 0.2-3% throughout different cancers. However, BRAF fusions rarely occur in the same gene configuration, potentially challenging personalized therapy design. In particular, the influence that is imposed by the wide variety of fusion partners on the oncogenic role of BRAF during tumor growth and drug response is unknown. Here, we used patient-derived colorectal cancer organoids to functionally characterize and cross-compare previously identified BRAF fusions containing various partner genes (AGAP3, DLG1 and TRIM24) with respect to cellular behaviour, downstream signaling activation and response to targeted therapies. We demonstrate that 5’ partner choice of BRAF fusions affects their subcellular localization and intracellular signaling capacity. In particular the DLG1-BRAF fusion protein showed distinct localization to the plasma membrane and exhibited increased activation of downstream MAPK signaling under unperturbed conditions. Moreover, phosphoproteomics and RNA sequencing identified distinct subsets of affected signaling pathways and altered gene expression of BRAF fusions. The different BRAF fusions exhibited varying sensitivities to simultaneous targeted inhibition of MEK and the EGF receptor family. However, all BRAF fusions conveyed resistance to targeted monotherapy against the EGF receptor family, suggesting that BRAF fusions should be screened alongside other MAPK pathway alterations to identify mCRC patients to exclude from cetuximab treatment
2020-01-16 | PXD013461 | Pride
Project description:RAF kinases play major roles in cancer. BRAFV600E mutants drive ~6% of human cancers. Potent kinase inhibitors exist but show variable effects in different cancer types, sometimes even inducing paradoxical RAF kinase activation. Both paradoxical activation and drug resistance are frequently due to enhanced dimerization between RAF1 and BRAF, which maintains or restores the activity of the downstream MEK-ERK pathway. Here, using quantitative proteomics we mapped the interactomes of RAF1 monomers, RAF1-BRAF and RAF1-BRAFV600E dimers identifying and quantifying >1,000 proteins. In addition, we examined the effects of vemurafenib and sorafenib, two different types of clinically used RAF inhibitors. Using regression analysis to compare different conditions we found a large overlapping core interactome but also distinct condition specific differences. Given that RAF proteins have kinase independent functions such dynamic interactome changes could contribute to their functional diversification. Analysing this dataset may provide a deeper understanding of RAF signalling and mechanisms of resistance to RAF inhibitors.
2023-02-27 | PXD036792 | Pride
Project description:Large and giant congenital melanocytic nevi (CMN) are rare melanocytic lesions mostly caused by post-zygotic acquisition of NRAS alteration. However, large/giant CMN may exhibit phenotypic differences among distinct areas patients and in addition, patients differ in features such as presence of multiple CMN or Spilus-like lesions. Overall, 50 fresh-frozen biopsies corresponding to 37 phenotypically characterized areas of large/giant CMNs, 9 satellite lesions, 1 acquired nevus and 3 healthy skin biopsies were analyzed by a multigene panel and RNA sequencing (RNA-seq). Mutational screening showed mutations in 76.2% of large/giant CMN. NRAS mutation was found in 57.1% of cases, and mutations in other genes such as BRAF, KRAS, APC and MET were detected in 14.3% of patients. RNA-seq revealed the fusion transcript ZEB2-ALK and SOX5-RAF1 in large/giant CMN from two patients without point mutations. Both alterations were not detected in unaffected skin and were detected in different affected skin. These findings suggest that large/giant CMN may result from distinct molecular events in addition to NRAS mutations including point mutations and fusions transcripts.
2019-10-24 | GSE120597 | GEO
Project description:<p>Most prostate cancer deaths are caused by metastatic, castration resistant disease (mCRPC). To develop a precision medicine framework for mCRPC, we established a multi-institutional, international clinical sequencing infrastructure to enroll and carry out prospective whole exome and transcriptome sequencing of tumors from a cohort of mCRPC patients. We obtained high quality DNA and RNA sequence data from 150 bone or soft tissue biopsies. Central pathology revealed high-grade adenocarcinoma with only four cases (3.6%) showing neuroendocrine differentiation. Aberrations of AR, ETS genes, TP53 and PTEN were frequent (40-60% of cases), with TP53 and AR alterations being the most enriched in mCRPC compared to primary prostate cancer. We identified novel genomic alterations in PIK3CA/B (fusions and mutations); R-spondin, BRAF and RAF1 (fusions); APC (inactivating mutations); delta-catenin (missense mutations); and ZBTB16/PLZF (homozygous deletions). Aberrations of BRCA2, BRCA1 and ATM were observed at substantially higher frequencies (19.3% overall) than seen in primary prostate cancers, with 56% of these being exclusively somatic. Putative driver gene alterations were identified in nearly all patients, and over half also harbored driver gene fusions, homozygous deletions and/or amplifications. Moreover, 89% of patients harbored a clinically actionable aberration including 62.7% with aberrations in AR, 65% in other cancer-related genes, and 8% with actionable pathogenic germline alterations. Overall, integrative clinical sequencing analysis can be safely and efficiently performed in mCRPC, yields findings that may be actionable for enrolling patients in clinical trials of targeted therapies, and may inform the basis of individual clinical responses.</p>
| phs000915 | dbGaP
Project description:Large Congenital Melanocytic Naevi have a higher propensity to malignant transformation compared to acquired naevi. They thus represent a good model for studying initial steps of melanocarcinogenesis. We have performed genotypic (karyotype, FISH and mutational analyses) and differential expression studies on a large cohort of medium (n=3) and large (n=24) congenital melanocytic naevi. Unlike malignant melanoma, chromosomal abnormalities were rare and single, a feature probably reflecting the benignity of these lesions. Mutational screening showed a high frequency of NRAS mutations in our series, while BRAF mutations were less common. Differential expression study between tumoral and normal melanocytes did not show significant alterations of cellular processes such as cell proliferation, cell migration/invasion, angiogenesis, apoptosis, and immune/inflammatory responses. However, significant down-regulation of genes involved in pigmentation and up-regulation of genes playing a role in DNA protection were observed. Lastly, our micro-arrays displayed up-regulation of genes mediating chemoresistance in cancer. As alteration of pigmentation mechanisms can trigger oxidative damage, increased expression of genes involved in maintenance of DNA integrity might reflect the ability of naevocytic cells to self protection against cellular stress. Furthermore, the observed alterations linked to chemoresistance might partially account for the well known inefficacy of chemotherapy in malignant melanoma. Keywords: cell type comparison
2008-07-01 | GSE8525 | GEO
Project description:Purpose: Assessment of the performance characteristics of an RNA-Seq assay designed to detect gene fusions in 573 genes to aid in the management of cancer patients. Methods: Polyadenylated RNA was converted to cDNA which was then used to prepare NGS libraries that were sequenced on a HiSeq 2500 instrument and analyzed with an in-house developed bioinformatic pipeline. Results: The assay identified 38 of 41 (93%) gene fusions previously detected by a different laboratory using FISH, RT-PCR, or RNA-Seq for a sensitivity of 93%. No false positive gene fusions were identified in 15 normal tissue specimens and 10 tumor specimens that were negative for fusions by RNA-Seq in a different laboratory (100% specificity). The assay also identified 22 fusions in 17 tumor specimens that had not been detected by other methods. Nineteen of the 22 fusions had not previously been described. Good intra- and inter-assay reproducibility was observed with complete concordance for the presence or absence of gene fusions in replicates. The analytical sensitivity of the assay was tested by diluting RNA isolated from gene fusion positive cases with fusion negative RNA. Gene fusions were generally detectable down to 12.5% dilutions for most fusions and as little as 3% for some fusions. The assay identified 38 of 41 (93%) gene fusions previously detected by a different laboratory using FISH, RT-PCR, or RNA-Seq for a sensitivity of 93%. No false positive gene fusions were identified in 15 normal tissue specimens and 10 tumor specimens that were negative for fusions by RNA-Seq in a different laboratory (100% specificity). The assay also identified 22 fusions in 17 tumor specimens that had not been detected by other methods. Nineteen of the 22 fusions had not previously been described. Good intra- and inter-assay reproducibility was observed with complete concordance for the presence or absence of gene fusions in replicates. The analytical sensitivity of the assay was tested by diluting RNA isolated from gene fusion positive cases with fusion negative RNA. Gene fusions were generally detectable down to 12.5% dilutions for most fusions and as little as 3% for some fusions. This assay should be useful for identifying cancer patients that may benefit from both FDA-approved and investigational targeted therapies.
2018-04-01 | GSE111320 | GEO
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.
2020-02-26 | GSE142441 | GEO
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.
2020-08-27 | GSE142442 | GEO