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Poxvirus systems have been extensively used as vaccine vectors. Herein a RNA-Seq analysis of intramuscular injection sites provided detailed insights into host innate immune responses, as well as expression of vector and recombinant immunogen genes, after vaccination with a new multiplication defective, vaccinia-based vector, Sementis Copenhagen Vector. Chikungunya and Zika virus immunogen mRNA and protein expression was associated with necrosing skeletal muscle cells surrounded by mixed cellular infiltrates. The multiple adjuvant signatures at 12 hours post-vaccination were dominated by TLR3, 4 and 9, STING, MAVS, PKR and the inflammasome. Th1 cytokine signatures were dominated by IFNγ, TNF and IL1ß, and chemokine signatures by CCL5 and CXCL12. Multiple signatures associated with dendritic cell stimulation were evident. By day seven, vaccine transcripts were absent, and cell death, neutrophil, macrophage and inflammation annotations had abated. No compelling arthritis signatures were identified. Such injection site vaccinology approaches should inform refinements in poxvirus-based vector design.
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Vetores Genéticos/administração & dosagem , Imunidade Inata/imunologia , Reação no Local da Injeção/imunologia , Vacinação/métodos , Vacinas Sintéticas/administração & dosagem , Vacínia/imunologia , Infecção por Zika virus/imunologia , Animais , Feminino , Vetores Genéticos/genética , Genoma Viral , Camundongos , Camundongos Endogâmicos C57BL , RNA-Seq , Vacinas Sintéticas/imunologia , Vacínia/genética , Vacínia/metabolismo , Vacínia/virologia , Vaccinia virus/isolamento & purificação , Vacinologia , Zika virus/isolamento & purificação , Infecção por Zika virus/genética , Infecção por Zika virus/metabolismo , Infecção por Zika virus/virologiaRESUMO
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
Melanoma of the skin is a common cancer only in Europeans, whereas it arises in internal body surfaces (mucosal sites) and on the hands and feet (acral sites) in people throughout the world. Here we report analysis of whole-genome sequences from cutaneous, acral and mucosal subtypes of melanoma. The heavily mutated landscape of coding and non-coding mutations in cutaneous melanoma resolved novel signatures of mutagenesis attributable to ultraviolet radiation. However, acral and mucosal melanomas were dominated by structural changes and mutation signatures of unknown aetiology, not previously identified in melanoma. The number of genes affected by recurrent mutations disrupting non-coding sequences was similar to that affected by recurrent mutations to coding sequences. Significantly mutated genes included BRAF, CDKN2A, NRAS and TP53 in cutaneous melanoma, BRAF, NRAS and NF1 in acral melanoma and SF3B1 in mucosal melanoma. Mutations affecting the TERT promoter were the most frequent of all; however, neither they nor ATRX mutations, which correlate with alternative telomere lengthening, were associated with greater telomere length. Most melanomas had potentially actionable mutations, most in components of the mitogen-activated protein kinase and phosphoinositol kinase pathways. The whole-genome mutation landscape of melanoma reveals diverse carcinogenic processes across its subtypes, some unrelated to sun exposure, and extends potential involvement of the non-coding genome in its pathogenesis.
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Genoma Humano/genética , Melanoma/genética , Mutação/genética , DNA Helicases/genética , GTP Fosfo-Hidrolases/genética , Genes p16 , Humanos , Melanoma/classificação , Proteínas de Membrana/genética , Proteínas Quinases Ativadas por Mitógeno/genética , Neurofibromatose 1/genética , Proteínas Nucleares/genética , Fosfoproteínas/genética , Proteínas Proto-Oncogênicas B-raf/genética , Fatores de Processamento de RNA/genética , Transdução de Sinais/efeitos dos fármacos , Telomerase/genética , Telômero/genética , Proteína Supressora de Tumor p53/genética , Raios Ultravioleta/efeitos adversos , Proteína Nuclear Ligada ao XRESUMO
This corrects the article DOI: 10.1038/nature21063.
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Integrated genomic analysis of 456 pancreatic ductal adenocarcinomas identified 32 recurrently mutated genes that aggregate into 10 pathways: KRAS, TGF-ß, WNT, NOTCH, ROBO/SLIT signalling, G1/S transition, SWI-SNF, chromatin modification, DNA repair and RNA processing. Expression analysis defined 4 subtypes: (1) squamous; (2) pancreatic progenitor; (3) immunogenic; and (4) aberrantly differentiated endocrine exocrine (ADEX) that correlate with histopathological characteristics. Squamous tumours are enriched for TP53 and KDM6A mutations, upregulation of the TP63∆N transcriptional network, hypermethylation of pancreatic endodermal cell-fate determining genes and have a poor prognosis. Pancreatic progenitor tumours preferentially express genes involved in early pancreatic development (FOXA2/3, PDX1 and MNX1). ADEX tumours displayed upregulation of genes that regulate networks involved in KRAS activation, exocrine (NR5A2 and RBPJL), and endocrine differentiation (NEUROD1 and NKX2-2). Immunogenic tumours contained upregulated immune networks including pathways involved in acquired immune suppression. These data infer differences in the molecular evolution of pancreatic cancer subtypes and identify opportunities for therapeutic development.
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Genes Neoplásicos/genética , Genoma Humano/genética , Genômica , Mutação/genética , Neoplasias Pancreáticas/classificação , Neoplasias Pancreáticas/genética , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Carcinoma Ductal Pancreático/classificação , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/imunologia , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Metilação de DNA , Proteínas de Ligação a DNA/genética , Regulação Neoplásica da Expressão Gênica , Redes Reguladoras de Genes , Fator 3-beta Nuclear de Hepatócito/genética , Fator 3-gama Nuclear de Hepatócito/genética , Histona Desmetilases/genética , Proteína Homeobox Nkx-2.2 , Proteínas de Homeodomínio/genética , Humanos , Camundongos , Proteínas Nucleares/genética , Neoplasias Pancreáticas/imunologia , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Prognóstico , Receptores Citoplasmáticos e Nucleares/genética , Análise de Sobrevida , Transativadores/genética , Fatores de Transcrição/genética , Transcrição Gênica , Transcriptoma , Proteína Supressora de Tumor p53/genética , Proteínas Supressoras de Tumor/genética , Proteínas de Peixe-ZebraRESUMO
Patients with high-grade serous ovarian cancer (HGSC) have experienced little improvement in overall survival, and standard treatment has not advanced beyond platinum-based combination chemotherapy, during the past 30 years. To understand the drivers of clinical phenotypes better, here we use whole-genome sequencing of tumour and germline DNA samples from 92 patients with primary refractory, resistant, sensitive and matched acquired resistant disease. We show that gene breakage commonly inactivates the tumour suppressors RB1, NF1, RAD51B and PTEN in HGSC, and contributes to acquired chemotherapy resistance. CCNE1 amplification was common in primary resistant and refractory disease. We observed several molecular events associated with acquired resistance, including multiple independent reversions of germline BRCA1 or BRCA2 mutations in individual patients, loss of BRCA1 promoter methylation, an alteration in molecular subtype, and recurrent promoter fusion associated with overexpression of the drug efflux pump MDR1.
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Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Genoma Humano/genética , Neoplasias Ovarianas/genética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Estudos de Coortes , Ciclina E/genética , Cistadenocarcinoma Seroso/tratamento farmacológico , Cistadenocarcinoma Seroso/genética , Metilação de DNA , Análise Mutacional de DNA , Proteínas de Ligação a DNA/genética , Feminino , Genes BRCA1 , Genes BRCA2 , Genes da Neurofibromatose 1 , Mutação em Linhagem Germinativa/genética , Humanos , Mutagênese/genética , Proteínas Oncogênicas/genética , Neoplasias Ovarianas/tratamento farmacológico , PTEN Fosfo-Hidrolase/genética , Regiões Promotoras Genéticas/genética , Proteína do Retinoblastoma/genéticaRESUMO
Pancreatic cancer remains one of the most lethal of malignancies and a major health burden. We performed whole-genome sequencing and copy number variation (CNV) analysis of 100 pancreatic ductal adenocarcinomas (PDACs). Chromosomal rearrangements leading to gene disruption were prevalent, affecting genes known to be important in pancreatic cancer (TP53, SMAD4, CDKN2A, ARID1A and ROBO2) and new candidate drivers of pancreatic carcinogenesis (KDM6A and PREX2). Patterns of structural variation (variation in chromosomal structure) classified PDACs into 4 subtypes with potential clinical utility: the subtypes were termed stable, locally rearranged, scattered and unstable. A significant proportion harboured focal amplifications, many of which contained druggable oncogenes (ERBB2, MET, FGFR1, CDK6, PIK3R3 and PIK3CA), but at low individual patient prevalence. Genomic instability co-segregated with inactivation of DNA maintenance genes (BRCA1, BRCA2 or PALB2) and a mutational signature of DNA damage repair deficiency. Of 8 patients who received platinum therapy, 4 of 5 individuals with these measures of defective DNA maintenance responded.
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Análise Mutacional de DNA , Genoma Humano/genética , Genômica , Mutação/genética , Neoplasias Pancreáticas/genética , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/genética , Animais , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/genética , Reparo do DNA/genética , Feminino , Genes BRCA1 , Genes BRCA2 , Marcadores Genéticos/genética , Instabilidade Genômica/genética , Genótipo , Humanos , Camundongos , Neoplasias Pancreáticas/classificação , Neoplasias Pancreáticas/tratamento farmacológico , Platina/farmacologia , Mutação Puntual/genética , Inibidores de Poli(ADP-Ribose) Polimerases , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Breast cancer risk is strongly associated with an intergenic region on 11q13. We have previously shown that the strongest risk-associated SNPs fall within a distal enhancer that regulates CCND1. Here, we report that, in addition to regulating CCND1, this enhancer regulates two estrogen-regulated long noncoding RNAs, CUPID1 and CUPID2. We provide evidence that the risk-associated SNPs are associated with reduced chromatin looping between the enhancer and the CUPID1 and CUPID2 bidirectional promoter. We further show that CUPID1 and CUPID2 are predominantly expressed in hormone-receptor-positive breast tumors and play a role in modulating pathway choice for the repair of double-strand breaks. These data reveal a mechanism for the involvement of this region in breast cancer.
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Neoplasias da Mama/genética , Cromossomos Humanos Par 11/genética , Ciclina D1/genética , Reparo do DNA/genética , RNA Longo não Codificante/genética , Linhagem Celular Tumoral , Cromatina/metabolismo , Quebras de DNA de Cadeia Dupla , Dano ao DNA/genética , Elementos Facilitadores Genéticos/genética , Estrogênios/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Predisposição Genética para Doença/genética , Humanos , Células MCF-7 , Polimorfismo de Nucleotídeo Único/genética , Regiões Promotoras Genéticas/genética , Interferência de RNA , RNA Guia de Cinetoplastídeos/genética , RNA Interferente Pequeno/genéticaRESUMO
The replicative immortality of human cancer cells is achieved by activation of a telomere maintenance mechanism (TMM). To achieve this, cancer cells utilise either the enzyme telomerase, or the Alternative Lengthening of Telomeres (ALT) pathway. These distinct molecular pathways are incompletely understood with respect to activation and propagation, as well as their associations with clinical outcomes. We have identified significant differences in the telomere repeat composition of tumours that use ALT compared to tumours that do not. We then employed a machine learning approach to stratify tumours according to telomere repeat content with an accuracy of 91.6%. Importantly, this classification approach is applicable across all tumour types. Analysis of pathway mutations that were under-represented in ALT tumours, across 1,075 tumour samples, revealed that the autophagy, cell cycle control of chromosomal replication, and transcriptional regulatory network in embryonic stem cells pathways are involved in the survival of ALT tumours. Overall, our approach demonstrates that telomere sequence content can be used to stratify ALT activity in cancers, and begin to define the molecular pathways involved in ALT activation.
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Biologia Computacional/métodos , Neoplasias/genética , Homeostase do Telômero/genética , Telômero/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Correpressoras , Bases de Dados Genéticas , Feminino , Humanos , Aprendizado de Máquina , Melanoma/genética , Melanoma/mortalidade , Chaperonas Moleculares , Mutação , Neoplasias/mortalidade , Proteínas Nucleares/genética , Regiões Promotoras Genéticas , Análise de Sobrevida , Telomerase/genética , Sequenciamento do Exoma , Proteína Nuclear Ligada ao X/genéticaRESUMO
Cutaneous melanoma accounts for at least >10% of all cancers in adolescents and young adults (AYA, 15-30 years of age) in Western countries. To date, little is known about the correlations between germline variants and somatic mutations and mutation signatures in AYA melanoma patients that might explain why they have developed a cancer predominantly affecting those over 65 years of age. We performed genomic analysis of 50 AYA melanoma patients (onset 10-30 years, median 20); 25 underwent whole genome sequencing (WGS) of both tumor and germline DNA, exome data were retrieved from 12 TCGA AYA cases, and targeted DNA sequencing was conducted on 13 cases. The AYA cases were compared with WGS data from 121 adult cutaneous melanomas. Similar to mature adult cutaneous melanomas, AYA melanomas showed a high mutation burden and mutation signatures of ultraviolet radiation (UVR) damage. The frequencies of somatic mutations in BRAF (96%) and PTEN (36%) in the AYA WGS cohort were double the rates observed in adult melanomas (Q < 6.0 × 10-6 and 0.028, respectively). Furthermore, AYA melanomas contained a higher proportion of non-UVR-related mutation signatures than mature adult melanomas as a proportion of total mutation burden (p = 2.0 × 10-4 ). Interestingly, these non-UVR mutation signatures relate to APOBEC or mismatch repair pathways, and germline variants in related genes were observed in some of these cases. We conclude that AYA melanomas harbor some of the same molecular aberrations and mutagenic insults occurring in older adults, but in different proportions. Germline variants that may have conferred disease susceptibility correlated with somatic mutation signatures in a subset of AYA melanomas.
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Predisposição Genética para Doença/genética , Células Germinativas/fisiologia , Melanoma/genética , Mutação/genética , Adolescente , Adulto , Estudos de Coortes , Feminino , Humanos , Masculino , PTEN Fosfo-Hidrolase/genética , Proteínas Proto-Oncogênicas B-raf/genética , Sequenciamento Completo do Genoma/métodos , Adulto JovemRESUMO
The original version of this Article contained an error in the top left of Figure 2: the number 1 on the y-axis had been changed to 0 during the typesetting process. This has now been corrected in both the PDF and HTML versions of the Article.
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PURPOSE: One of the greatest challenges currently facing those studying Mendelian disease is identifying the pathogenic variant from the long list produced by a next-generation sequencing test. We investigate the predictive ability of homozygosity mapping for identifying the regions likely to contain the causative variant. METHODS: We use 179 homozygous pathogenic variants from three independent cohorts to investigate the predictive power of homozygosity mapping. RESULTS: We demonstrate that homozygous pathogenic variants in our cohorts are disproportionately likely to be found within one of the largest regions of homozygosity: 80% of pathogenic variants are found in a homozygous region that is in the ten largest regions in a sample. The maximal predictive power is achieved in patients with <8% homozygosity and variants >3 Mb from a telomere; this gives an area under the curve (AUC) of 0.735 and results in 92% of the causative variants being in one of the ten largest homozygous regions. CONCLUSION: This predictive power can be used to prioritize the list of candidate variants in gene discovery studies. When classifying a homozygous variant the size and rank of the region of homozygosity in which the candidate variant is located can also be considered as supporting evidence for pathogenicity.
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Mapeamento Cromossômico/métodos , Doenças Genéticas Inatas/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Feminino , Doenças Genéticas Inatas/diagnóstico , Doenças Genéticas Inatas/patologia , Homozigoto , Humanos , Masculino , Linhagem , Polimorfismo de Nucleotídeo Único/genética , Análise de Sequência de DNARESUMO
Pancreatic cancer is molecularly diverse, with few effective therapies. Increased mutation burden and defective DNA repair are associated with response to immune checkpoint inhibitors in several other cancer types. We interrogated 385 pancreatic cancer genomes to define hypermutation and its causes. Mutational signatures inferring defects in DNA repair were enriched in those with the highest mutation burdens. Mismatch repair deficiency was identified in 1% of tumors harboring different mechanisms of somatic inactivation of MLH1 and MSH2. Defining mutation load in individual pancreatic cancers and the optimal assay for patient selection may inform clinical trial design for immunotherapy in pancreatic cancer.
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Carcinoma Ductal Pancreático/genética , Reparo de Erro de Pareamento de DNA/genética , Mutação , Neoplasias Pancreáticas/genética , Transcriptoma , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise Mutacional de DNA , Feminino , Genoma , Humanos , Masculino , Pessoa de Meia-Idade , Proteína 1 Homóloga a MutL/genética , Proteína 2 Homóloga a MutS/genética , Proteínas Proto-Oncogênicas p21(ras)/genéticaRESUMO
Pancreatic cancer is a highly lethal malignancy with few effective therapies. We performed exome sequencing and copy number analysis to define genomic aberrations in a prospectively accrued clinical cohort (n = 142) of early (stage I and II) sporadic pancreatic ductal adenocarcinoma. Detailed analysis of 99 informative tumours identified substantial heterogeneity with 2,016 non-silent mutations and 1,628 copy-number variations. We define 16 significantly mutated genes, reaffirming known mutations (KRAS, TP53, CDKN2A, SMAD4, MLL3, TGFBR2, ARID1A and SF3B1), and uncover novel mutated genes including additional genes involved in chromatin modification (EPC1 and ARID2), DNA damage repair (ATM) and other mechanisms (ZIM2, MAP2K4, NALCN, SLC16A4 and MAGEA6). Integrative analysis with in vitro functional data and animal models provided supportive evidence for potential roles for these genetic aberrations in carcinogenesis. Pathway-based analysis of recurrently mutated genes recapitulated clustering in core signalling pathways in pancreatic ductal adenocarcinoma, and identified new mutated genes in each pathway. We also identified frequent and diverse somatic aberrations in genes described traditionally as embryonic regulators of axon guidance, particularly SLIT/ROBO signalling, which was also evident in murine Sleeping Beauty transposon-mediated somatic mutagenesis models of pancreatic cancer, providing further supportive evidence for the potential involvement of axon guidance genes in pancreatic carcinogenesis.
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Axônios/metabolismo , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patologia , Genoma/genética , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Animais , Dosagem de Genes , Regulação Neoplásica da Expressão Gênica , Humanos , Estimativa de Kaplan-Meier , Camundongos , Mutação , Proteínas/genética , Transdução de SinaisRESUMO
Ultraviolet radiation (UVR) mutagenesis causes nearly all cutaneous melanomas, however, since UVR signatures are largely absent in acral melanoma, as well as melanoma in sun-protected sites, the cause of these melanomas is unknown. Whole-genome sequencing data generated as part of the Australian Melanoma Genome Project was supplemented with a detailed histopathological assessment with the melanomas then classified as UVR or non-UVR related, based on their mutation signatures. The clinicopathological characteristics of melanomas with mutation signatures for their subtype were compared. Three (of 35=8.6%) acral melanomas, all clinically and pathologically verified as arising from acral or subungual locations, had predominant UVR mutation burden, whereas four (of 140=2.9%) cutaneous melanomas showed predominant non-UVR mutations. Among the acral melanomas, the few that were UVR dominant occurred in younger patients, had a higher mutation load and a proportion of mutation burden due to UVR, which was similar to that in melanomas from intermittently UVR-exposed skin. Acral melanomas with a UVR signature occurred most frequently in subungual sites and included tumors harboring BRAF or NF1 mutations. Cutaneous melanomas dominated by non-UVR signatures had lower mutation burdens counts and their primary tumors were thicker and had more mitoses than in other cutaneous melanomas. No histopathological features predicted UVR dominance in acral melanomas or non-UVR dominance in cutaneous melanomas. Our finding of acral/subungual melanomas with predominant UVR mutagenesis suggests that the nail plate and acral skin do not provide complete protection from UVR. Our data also confirm that cutaneous melanomas not caused by UVR are infrequent. Identifying where mutation burden is discordant with primary tumor anatomical site is likely to be clinically significant when determining treatment options for metastatic acral and cutaneous melanoma patients.
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Melanoma/genética , Mutação/efeitos da radiação , Neoplasias Cutâneas/genética , Raios Ultravioleta/efeitos adversos , Adulto , Idoso , Idoso de 80 Anos ou mais , Austrália , Extremidades/patologia , Extremidades/efeitos da radiação , Feminino , Frequência do Gene , Genoma Humano/genética , Genótipo , Humanos , Masculino , Melanoma/patologia , Pessoa de Meia-Idade , Neurofibromina 1/genética , Proteínas Proto-Oncogênicas B-raf/genética , Análise de Sequência de DNA/métodos , Pele/metabolismo , Pele/patologia , Pele/efeitos da radiação , Neoplasias Cutâneas/patologiaRESUMO
BACKGROUND: Malignant mesothelioma (MM) is an aggressive cancer of the pleural and peritoneal cavities caused by exposure to asbestos. Asbestos-induced mesotheliomas in wild-type mice have been used extensively as a preclinical model because they are phenotypically identical to their human counterpart. However, it is not known if the genetic lesions in these mice tumours are similar to in the human disease, a prerequisite for any new preclinical studies that target genetic abnormalities. METHODS: We performed whole exome sequencing of fifteen asbestos-induced murine MM tumour cell lines from BALB/c, CBA and C57BL/6 mouse strains and compared the somatic mutations and copy number variations with those recurrently reported in human MM. We then catalogued and characterised the mutational landscape of the wild-type murine MM tumours. Quantitative RT-PCR was used to interrogate the expression of key MM genes of interest in the mRNA. RESULTS: Consistent with human MM tumours, we identified homozygous loss of the tumour suppressor Cdkn2a in 14/15 tumours. One tumour retained the first exon of both of the p16INK4a and p19ARF isoforms though this tumour also contained genetic amplification of Myc resulting in increased expression of the c-Myc proto-oncogene in the mRNA. There were no chromosomal losses in either the Bap1 or Nf2 regions. One tumour harbored homozygous loss of Trp53 in the DNA. Mutation rates were similar in tumours generated in the CBA and C57BL/6 strains when compared to human MM. Interestingly, all BALB/c tumour lines displayed high mutational loads, consistent with the known mutator phenotype of the host strain. The Wnt, MAPK and Jak-STAT signaling pathways were found to be the most commonly affected biological pathways. Mutations and copy number deletions also occurred in the Hedgehog and Hippo pathways. CONCLUSIONS: These data suggest that in the wild-type murine model asbestos causes mesotheliomas in a similar way to in human MM. This further supports the notion that the murine model of MM represents a genuine homologue of the human disease, something uncommon in cancer, and is thus a valuable tool to provide insight into MM tumour development and to aide the search for novel therapeutic strategies.
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Amianto/toxicidade , Sequenciamento do Exoma , Neoplasias Pulmonares/genética , Mesotelioma/genética , Proteínas de Neoplasias/genética , Animais , Variações do Número de Cópias de DNA/genética , Modelos Animais de Doenças , Predisposição Genética para Doença , Humanos , Neoplasias Pulmonares/induzido quimicamente , Neoplasias Pulmonares/patologia , Mesotelioma/induzido quimicamente , Mesotelioma/patologia , Mesotelioma Maligno , Camundongos , Mutação , Proto-Oncogene Mas , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genéticaRESUMO
The incidence of esophageal adenocarcinoma (EAC) has risen significantly over recent decades. Although survival has improved, cure rates remain poor, with <20% of patients surviving 5 years. This is the first study to explore methylome, transcriptome and ENCODE data to characterize the role of methylation in EAC. We investigate the genome-wide methylation profile of 250 samples including 125 EAC, 19 Barrett's esophagus (BE), 85 squamous esophagus and 21 normal stomach. Transcriptome data of 70 samples (48 EAC, 4 BE and 18 squamous esophagus) were used to identify changes in methylation associated with gene expression. BE and EAC showed similar methylation profiles, which differed from squamous tissue. Hypermethylated sites in EAC and BE were mainly located in CpG-rich promoters. A total of 18575 CpG sites associated with 5538 genes were differentially methylated, 63% of these genes showed significant correlation between methylation and mRNA expression levels. Pathways involved in tumorigenesis including cell adhesion, TGF and WNT signaling showed enrichment for genes aberrantly methylated. Genes involved in chromosomal segregation and spindle formation were aberrantly methylated. Given the recent evidence that chromothripsis may be a driver mechanism in EAC, the role of epigenetic perturbation of these pathways should be further investigated. The methylation profiles revealed two EAC subtypes, one associated with widespread CpG island hypermethylation overlapping H3K27me3 marks and binding sites of the Polycomb proteins. These subtypes were supported by an independent set of 89 esophageal cancer samples. The most hypermethylated tumors showed worse patient survival.
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Adenocarcinoma/genética , Segregação de Cromossomos , Metilação de DNA , Neoplasias Esofágicas/genética , Fuso Acromático , Adenocarcinoma/patologia , Neoplasias Esofágicas/patologia , HumanosRESUMO
Treatment options for patients with brain metastases (BMs) have limited efficacy and the mortality rate is virtually 100%. Targeted therapy is critically under-utilized, and our understanding of mechanisms underpinning metastatic outgrowth in the brain is limited. To address these deficiencies, we investigated the genomic and transcriptomic landscapes of 36 BMs from breast, lung, melanoma and oesophageal cancers, using DNA copy-number analysis and exome- and RNA-sequencing. The key findings were as follows. (a) Identification of novel candidates with possible roles in BM development, including the significantly mutated genes DSC2, ST7, PIK3R1 and SMC5, and the DNA repair, ERBB-HER signalling, axon guidance and protein kinase-A signalling pathways. (b) Mutational signature analysis was applied to successfully identify the primary cancer type for two BMs with unknown origins. (c) Actionable genomic alterations were identified in 31/36 BMs (86%); in one case we retrospectively identified ERBB2 amplification representing apparent HER2 status conversion, then confirmed progressive enrichment for HER2-positivity across four consecutive metastatic deposits by IHC and SISH, resulting in the deployment of HER2-targeted therapy for the patient. (d) In the ERBB/HER pathway, ERBB2 expression correlated with ERBB3 (r(2) = 0.496; p < 0.0001) and HER3 and HER4 were frequently activated in an independent cohort of 167 archival BM from seven primary cancer types: 57.6% and 52.6% of cases were phospho-HER3(Y1222) or phospho-HER4(Y1162) membrane-positive, respectively. The HER3 ligands NRG1/2 were barely detectable by RNAseq, with NRG1 (8p12) genomic loss in 63.6% breast cancer-BMs, suggesting a microenvironmental source of ligand. In summary, this is the first study to characterize the genomic landscapes of BM. The data revealed novel candidates, potential clinical applications for genomic profiling of resectable BMs, and highlighted the possibility of therapeutically targeting HER3, which is broadly over-expressed and activated in BMs, independent of primary site and systemic therapy.
Assuntos
Biomarcadores Tumorais/genética , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/secundário , Perfilação da Expressão Gênica/métodos , Genômica/métodos , Biomarcadores Tumorais/metabolismo , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/enzimologia , Análise Mutacional de DNA , Ativação Enzimática , Amplificação de Genes , Dosagem de Genes , Regulação Neoplásica da Expressão Gênica , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Imuno-Histoquímica , Ligantes , Terapia de Alvo Molecular , Mutação , Fenótipo , Fosforilação , Medicina de Precisão , Valor Preditivo dos Testes , Inibidores de Proteínas Quinases/uso terapêutico , Receptor ErbB-2/genética , Receptor ErbB-2/metabolismo , Receptor ErbB-3/genética , Receptor ErbB-3/metabolismo , Receptor ErbB-4/genética , Receptor ErbB-4/metabolismo , Microambiente TumoralRESUMO
Insulin from the beta-cells of the pancreatic islets of Langerhans controls energy homeostasis in vertebrates, and its deficiency causes diabetes mellitus. During embryonic development, the transcription factor neurogenin 3 (Neurog3) initiates the differentiation of the beta-cells and other islet cell types from pancreatic endoderm, but the genetic program that subsequently completes this differentiation remains incompletely understood. Here we show that the transcription factor Rfx6 directs islet cell differentiation downstream of Neurog3. Mice lacking Rfx6 failed to generate any of the normal islet cell types except for pancreatic-polypeptide-producing cells. In human infants with a similar autosomal recessive syndrome of neonatal diabetes, genetic mapping and subsequent sequencing identified mutations in the human RFX6 gene. These studies demonstrate a unique position for Rfx6 in the hierarchy of factors that coordinate pancreatic islet development in both mice and humans. Rfx6 could prove useful in efforts to generate beta-cells for patients with diabetes.