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This corrects the article DOI: 10.1038/nature21063.
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The diagnosis of pancreatic neuroendocrine tumours (PanNETs) is increasing owing to more sensitive detection methods, and this increase is creating challenges for clinical management. We performed whole-genome sequencing of 102 primary PanNETs and defined the genomic events that characterize their pathogenesis. Here we describe the mutational signatures they harbour, including a deficiency in G:C > T:A base excision repair due to inactivation of MUTYH, which encodes a DNA glycosylase. Clinically sporadic PanNETs contain a larger-than-expected proportion of germline mutations, including previously unreported mutations in the DNA repair genes MUTYH, CHEK2 and BRCA2. Together with mutations in MEN1 and VHL, these mutations occur in 17% of patients. Somatic mutations, including point mutations and gene fusions, were commonly found in genes involved in four main pathways: chromatin remodelling, DNA damage repair, activation of mTOR signalling (including previously undescribed EWSR1 gene fusions), and telomere maintenance. In addition, our gene expression analyses identified a subgroup of tumours associated with hypoxia and HIF signalling.
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Carcinoma Neuroendócrino/genética , Genoma Humano/genética , Genômica , Neoplasias Pancreáticas/genética , Sequência de Bases , Proteínas de Ligação a Calmodulina/genética , Montagem e Desmontagem da Cromatina/genética , Aberrações Cromossômicas , Variações do Número de Cópias de DNA/genética , DNA Glicosilases/genética , Análise Mutacional de DNA , Reparo do DNA/genética , Feminino , Mutação em Linhagem Germinativa/genética , Humanos , Masculino , Proteína EWS de Ligação a RNA , Proteínas de Ligação a RNA/genética , Serina-Treonina Quinases TOR/metabolismo , Telômero/genética , Telômero/metabolismoRESUMO
Next-generation sequencing (NGS) was applied to 148 lung neuroendocrine tumours (LNETs) comprising the four World Health Organization classification categories: 53 typical carcinoid (TCs), 35 atypical carcinoid (ACs), 27 large-cell neuroendocrine carcinomas, and 33 small-cell lung carcinomas. A discovery screen was conducted on 46 samples by the use of whole-exome sequencing and high-coverage targeted sequencing of 418 genes. Eighty-eight recurrently mutated genes from both the discovery screen and current literature were verified in the 46 cases of the discovery screen, and validated on additional 102 LNETs by targeted NGS; their prevalence was then evaluated on the whole series. Thirteen of these 88 genes were also evaluated for copy number alterations (CNAs). Carcinoids and carcinomas shared most of the altered genes but with different prevalence rates. When mutations and copy number changes were combined, MEN1 alterations were almost exclusive to carcinoids, whereas alterations of TP53 and RB1 cell cycle regulation genes and PI3K/AKT/mTOR pathway genes were significantly enriched in carcinomas. Conversely, mutations in chromatin-remodelling genes, including those encoding histone modifiers and members of SWI-SNF complexes, were found at similar rates in carcinoids (45.5%) and carcinomas (55.0%), suggesting a major role in LNET pathogenesis. One AC and one TC showed a hypermutated profile associated with a POLQ damaging mutation. There were fewer CNAs in carcinoids than in carcinomas; however ACs showed a hybrid pattern, whereby gains of TERT, SDHA, RICTOR, PIK3CA, MYCL and SRC were found at rates similar to those in carcinomas, whereas the MEN1 loss rate mirrored that of TCs. Multivariate survival analysis revealed RB1 mutation (p = 0.0005) and TERT copy gain (p = 0.016) as independent predictors of poorer prognosis. MEN1 mutation was associated with poor prognosis in AC (p = 0.0045), whereas KMT2D mutation correlated with longer survival in SCLC (p = 0.0022). In conclusion, molecular profiling may complement histology for better diagnostic definition and prognostic stratification of LNETs. © 2016 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.
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Tumor Carcinoide/genética , Carcinoma Neuroendócrino/genética , Montagem e Desmontagem da Cromatina/genética , Neoplasias Pulmonares/genética , Tumores Neuroendócrinos/genética , Carcinoma de Pequenas Células do Pulmão/genética , Adulto , Idoso , Tumor Carcinoide/patologia , Carcinoma Neuroendócrino/patologia , Estudos de Coortes , Variações do Número de Cópias de DNA , Proteínas de Ligação a DNA/genética , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Itália , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Mutação , Proteínas de Neoplasias/genética , Tumores Neuroendócrinos/patologia , Prognóstico , Proteínas Proto-Oncogênicas/genética , Proteínas de Ligação a Retinoblastoma/genética , Análise de Sequência de DNA , Carcinoma de Pequenas Células do Pulmão/patologia , Telomerase/genética , Ubiquitina-Proteína Ligases/genéticaRESUMO
BACKGROUND: Detection of molecular tumor heterogeneity has become of paramount importance with the advent of targeted therapies. Analysis for detection should be comprehensive, timely and based on routinely available tumor samples. AIM: To evaluate the diagnostic potential of targeted multigene next-generation sequencing (TM-NGS) in characterizing gastrointestinal cancer molecular heterogeneity. METHODS: 35 gastrointestinal tract tumors, five of each intestinal type gastric carcinomas, pancreatic ductal adenocarcinomas, pancreatic intraductal papillary mucinous neoplasms, ampulla of Vater carcinomas, hepatocellular carcinomas, cholangiocarcinomas, pancreatic solid pseudopapillary tumors were assessed for mutations in 46 cancer-associated genes, using Ion Torrent semiconductor-based TM-NGS. One ampulla of Vater carcinoma cell line and one hepatic carcinosarcoma served to assess assay sensitivity. TP53, PIK3CA, KRAS, and BRAF mutations were validated by conventional Sanger sequencing. RESULTS: TM-NGS yielded overlapping results on matched fresh-frozen and formalin-fixed paraffin-embedded (FFPE) tissues, with a mutation detection limit of 1% for fresh-frozen high molecular weight DNA and 2% for FFPE partially degraded DNA. At least one somatic mutation was observed in all tumors tested; multiple alterations were detected in 20/35 (57%) tumors. Seven cancers displayed significant differences in allelic frequencies for distinct mutations, indicating the presence of intratumor molecular heterogeneity; this was confirmed on selected samples by immunohistochemistry of p53 and Smad4, showing concordance with mutational analysis. CONCLUSIONS: TM-NGS is able to detect and quantitate multiple gene alterations from limited amounts of DNA, moving one step closer to a next-generation histopathologic diagnosis that integrates morphologic, immunophenotypic, and multigene mutational analysis on routinely processed tissues, essential for personalized cancer therapy.