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Aims To evaluate the impact of Allura Clarity technology on radiation exposure in patients undergoing diagnostic coronary angiography. Methods A retrospective analysis was undertaken of invasive coronary angiograms performed by a single experienced operator in Cork University Hospital (CUH) (Allura Xper FD10 angiography system). In order to reduce operator variability, we also analysed cases performed by the same operator in the Bon Secours Hospital Cork (BSHC) (Allura Clarity FD10 angiography system). Cases were selected consecutively, having excluded those involving percutaneous coronary intervention, graft studies, aortography, ventriculography, right heart studies or fractional flow reserve studies. Results A total of 178 patients were included, equally distributed between the CUH arm (n=89) and the BSHC arm (n=89). Cohorts were very well matched in terms of age, gender, Body Mass Index, and procedural approach. The median radiation dose in CUH was a Dose Area Product (DAP) of 10,460 mGy.cm2 vs. median DAP of 12,795 mGy.cm2 in BSHC (p=0.148). The median fluoroscopy time in CUH was 2.25mins vs. median fluoroscopy time of 2.17mins in BSHC (p=0.675). Conclusion The use of the Allura Clarity system for diagnostic coronary angiography did not result in a significant difference in radiation dose or fluoroscopy time when compared to the reference Allura Xper system. Further research is needed to investigate the benefit of this new image noise reduction technology in diagnostic coronary angiography.
Assuntos
Redução da Medicação , Reserva Fracionada de Fluxo Miocárdico , Angiografia Coronária/efeitos adversos , Fluoroscopia/efeitos adversos , Humanos , Doses de Radiação , Estudos RetrospectivosRESUMO
Anaplastic meningioma is a rare and aggressive brain tumor characterised by intractable recurrences and dismal outcomes. Here, we present an integrated analysis of the whole genome, transcriptome and methylation profiles of primary and recurrent anaplastic meningioma. A key finding was the delineation of distinct molecular subgroups that were associated with diametrically opposed survival outcomes. Relative to lower grade meningiomas, anaplastic tumors harbored frequent driver mutations in SWI/SNF complex genes, which were confined to the poor prognosis subgroup. Aggressive disease was further characterised by transcriptional evidence of increased PRC2 activity, stemness and epithelial-to-mesenchymal transition. Our analyses discern biologically distinct variants of anaplastic meningioma with prognostic and therapeutic significance.
Assuntos
Regulação Neoplásica da Expressão Gênica , Neoplasias Meníngeas/genética , Meningioma/genética , Recidiva Local de Neoplasia/genética , Transcriptoma/genética , Idoso , Metilação de DNA/genética , Progressão da Doença , Feminino , Perfilação da Expressão Gênica , Genômica/métodos , Humanos , Masculino , Neoplasias Meníngeas/mortalidade , Neoplasias Meníngeas/patologia , Neoplasias Meníngeas/cirurgia , Meningioma/mortalidade , Meningioma/patologia , Meningioma/cirurgia , Pessoa de Meia-Idade , Gradação de Tumores , Recidiva Local de Neoplasia/mortalidade , Recidiva Local de Neoplasia/patologia , Prognóstico , Análise de Sobrevida , Sequenciamento Completo do GenomaRESUMO
BRAF is a cytoplasmic protein kinase, which activates the MEK-ERK signalling pathway. Deregulation of the pathway is associated with the presence of BRAF mutations in human cancer, the most common being V600E BRAF, although structural rearrangements, which remove N-terminal regulatory sequences, have also been reported. RAF-MEK-ERK signalling is normally thought to occur in the cytoplasm of the cell. However, in an investigation of BRAF localisation using fluorescence microscopy combined with subcellular fractionation of Green Fluorescent Protein (GFP)-tagged proteins expressed in NIH3T3 cells, surprisingly, we detected N-terminally truncated BRAF (ΔBRAF) in both nuclear and cytoplasmic compartments. In contrast, ΔCRAF and full-length, wild-type BRAF (WTBRAF) were detected at lower levels in the nucleus while full-length V600EBRAF was virtually excluded from this compartment. Similar results were obtained using ΔBRAF tagged with the hormone-binding domain of the oestrogen receptor (hbER) and with the KIAA1549-ΔBRAF translocation mutant found in human pilocytic astrocytomas. Here we show that GFP-ΔBRAF nuclear translocation does not involve a canonical Nuclear Localisation Signal (NLS), but is suppressed by N-terminal sequences. Nuclear GFP-ΔBRAF retains MEK/ERK activating potential and is associated with the accumulation of phosphorylated MEK and ERK in the nucleus. In contrast, full-length GFP-WTBRAF and GFP-V600EBRAF are associated with the accumulation of phosphorylated ERK but not phosphorylated MEK in the nucleus. These data have implications for cancers bearing single nucleotide variants or N-terminal deleted structural variants of BRAF.
RESUMO
Chromosomal rearrangements occur constitutionally in the general population and somatically in the majority of cancers. Detection of balanced rearrangements, such as reciprocal translocations and inversions, is troublesome, which is particularly detrimental in oncology where rearrangements play diagnostic and prognostic roles. Here we describe the use of Hi-C as a tool for detection of both balanced and unbalanced chromosomal rearrangements in primary human tumour samples, with the potential to define chromosome breakpoints to bp resolution. In addition, we show copy number profiles can also be obtained from the same data, all at a significantly lower cost than standard sequencing approaches.
Assuntos
Variações do Número de Cópias de DNA/genética , Neoplasias/genética , Translocação Genética , Aberrações Cromossômicas , Pontos de Quebra do Cromossomo , Inversão Cromossômica/genética , Humanos , Hibridização in Situ FluorescenteRESUMO
BACKGROUND: The WHO classification of brain tumours describes 15 subtypes of meningioma. Nine of these subtypes are allotted to WHO grade I, and three each to grade II and grade III. Grading is based solely on histology, with an absence of molecular markers. Although the existing classification and grading approach is of prognostic value, it harbours shortcomings such as ill-defined parameters for subtypes and grading criteria prone to arbitrary judgment. In this study, we aimed for a comprehensive characterisation of the entire molecular genetic landscape of meningioma to identify biologically and clinically relevant subgroups. METHODS: In this multicentre, retrospective analysis, we investigated genome-wide DNA methylation patterns of meningiomas from ten European academic neuro-oncology centres to identify distinct methylation classes of meningiomas. The methylation classes were further characterised by DNA copy number analysis, mutational profiling, and RNA sequencing. Methylation classes were analysed for progression-free survival outcomes by the Kaplan-Meier method. The DNA methylation-based and WHO classification schema were compared using the Brier prediction score, analysed in an independent cohort with WHO grading, progression-free survival, and disease-specific survival data available, collected at the Medical University Vienna (Vienna, Austria), assessing methylation patterns with an alternative methylation chip. FINDINGS: We retrospectively collected 497 meningiomas along with 309 samples of other extra-axial skull tumours that might histologically mimic meningioma variants. Unsupervised clustering of DNA methylation data clearly segregated all meningiomas from other skull tumours. We generated genome-wide DNA methylation profiles from all 497 meningioma samples. DNA methylation profiling distinguished six distinct clinically relevant methylation classes associated with typical mutational, cytogenetic, and gene expression patterns. Compared with WHO grading, classification by individual and combined methylation classes more accurately identifies patients at high risk of disease progression in tumours with WHO grade I histology, and patients at lower risk of recurrence among WHO grade II tumours (p=0·0096) from the Brier prediction test). We validated this finding in our independent cohort of 140 patients with meningioma. INTERPRETATION: DNA methylation-based meningioma classification captures clinically more homogenous groups and has a higher power for predicting tumour recurrence and prognosis than the WHO classification. The approach presented here is potentially very useful for stratifying meningioma patients to observation-only or adjuvant treatment groups. We consider methylation-based tumour classification highly relevant for the future diagnosis and treatment of meningioma. FUNDING: German Cancer Aid, Else Kröner-Fresenius Foundation, and DKFZ/Heidelberg Institute of Personalized Oncology/Precision Oncology Program.
Assuntos
Metilação de DNA , Neoplasias Meníngeas/classificação , Neoplasias Meníngeas/genética , Meningioma/classificação , Meningioma/genética , Recidiva Local de Neoplasia/genética , Variações do Número de Cópias de DNA , Análise Mutacional de DNA , Proteínas de Ligação a DNA/genética , Progressão da Doença , Intervalo Livre de Doença , Feminino , Genoma , Humanos , Fator 4 Semelhante a Kruppel , Fatores de Transcrição Kruppel-Like/genética , Masculino , Neoplasias Meníngeas/patologia , Meningioma/patologia , Gradação de Tumores , Recidiva Local de Neoplasia/patologia , Neurofibromina 2/genética , Proteínas Nucleares/genética , Proteínas Proto-Oncogênicas c-akt/genética , Estudos Retrospectivos , Análise de Sequência de RNA , Receptor Smoothened/genética , Taxa de Sobrevida , Fatores de Transcrição/genética , Transcriptoma , Peptídeos e Proteínas Associados a Receptores de Fatores de Necrose Tumoral/genéticaRESUMO
Ependymomas in children can arise throughout all compartments of the central nervous system (CNS). Highly malignant paediatric ependymoma subtypes are Group A tumours of the posterior fossa (PF-EPN-A) and RELA-fusion positive (ST-EPN-RELA) tumours in the supratentorial compartment. It was repeatedly reported in smaller series that accumulation of p53 is frequently observed in ependymomas and that immunohistochemical staining correlates with poor clinical outcome, while TP53 mutations are rare. Our TP53 mutation analysis of 130 primary ependymomas identified a mutation rate of only 3%. Immunohistochemical analysis of 398 ependymomas confirmed previous results correlating the accumulation of p53 with inferior outcome. Among the p53-positive ependymomas, the vast majority exhibited a RELA fusion leading to the hypothesis that p53 inactivation might be linked to RELA positivity.In order to assess the potential of p53 reactivation through MDM2 inhibition in ependymoma, we evaluated the effects of Actinomycin-D and Nutlin-3 treatment in two preclinical ependymoma models representing the high-risk subtypes PF-EPN-A and ST-EPN-RELA. The IC-50 of the agent as determined by metabolic activity assays was in the lower nano-molar range (0.2-0.7 nM). Transcriptome analyses of high-dose (100 nM), low-dose (5 nM) and non-treated cells revealed re-expression of p53 dependent genes including p53 upregulated modulator of apoptosis (PUMA) after low-dose treatment. At the protein level, we validated the Actinomycin-D induced upregulation of PUMA, and of p53 interaction partners MDM2 and p21. Proapoptotic effects of low-dose application of the agent were confirmed by flow cytometry. Thus, Actinomycin-D could constitute a promising therapeutic option for ST-EPN-RELA ependymoma patients, whose tumours frequently exhibit p53 inactivation.
Assuntos
Dactinomicina/uso terapêutico , Ependimoma/tratamento farmacológico , Fator de Transcrição RelA/genética , Proteína Supressora de Tumor p53/genética , Animais , Apoptose , Linhagem Celular Tumoral , Inibidor de Quinase Dependente de Ciclina p21/genética , Análise Mutacional de DNA , Ependimoma/metabolismo , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Imidazóis/metabolismo , Imuno-Histoquímica , Meduloblastoma/metabolismo , Camundongos , Neurônios/metabolismo , Piperazinas/metabolismo , Inibidores da Síntese de Proteínas/uso terapêutico , Proteínas Proto-Oncogênicas c-mdm2/genética , Células-Tronco/metabolismo , Resultado do TratamentoRESUMO
Low-grade neuroepithelial tumors (LGNTs) are diverse CNS tumors presenting in children and young adults, often with a history of epilepsy. While the genetic profiles of common LGNTs, such as the pilocytic astrocytoma and 'adult-type' diffuse gliomas, are largely established, those of uncommon LGNTs remain to be defined. In this study, we have used massively parallel sequencing and various targeted molecular genetic approaches to study alterations in 91 LGNTs, mostly from children but including young adult patients. These tumors comprise dysembryoplastic neuroepithelial tumors (DNETs; n = 22), diffuse oligodendroglial tumors (d-OTs; n = 20), diffuse astrocytomas (DAs; n = 17), angiocentric gliomas (n = 15), and gangliogliomas (n = 17). Most LGNTs (84 %) analyzed by whole-genome sequencing (WGS) were characterized by a single driver genetic alteration. Alterations of FGFR1 occurred frequently in LGNTs composed of oligodendrocyte-like cells, being present in 82 % of DNETs and 40 % of d-OTs. In contrast, a MYB-QKI fusion characterized almost all angiocentric gliomas (87 %), and MYB fusion genes were the most common genetic alteration in DAs (41 %). A BRAF:p.V600E mutation was present in 35 % of gangliogliomas and 18 % of DAs. Pathogenic alterations in FGFR1/2/3, BRAF, or MYB/MYBL1 occurred in 78 % of the series. Adult-type d-OTs with an IDH1/2 mutation occurred in four adolescents, the youngest aged 15 years at biopsy. Despite a detailed analysis, novel genetic alterations were limited to two fusion genes, EWSR1-PATZ1 and SLMAP-NTRK2, both in gangliogliomas. Alterations in BRAF, FGFR1, or MYB account for most pathogenic alterations in LGNTs, including pilocytic astrocytomas, and alignment of these genetic alterations and cytologic features across LGNTs has diagnostic implications. Additionally, therapeutic options based upon targeting the effects of these alterations are already in clinical trials.
Assuntos
Neoplasias Encefálicas/patologia , Genes myb , Predisposição Genética para Doença , Glioma/genética , Mutação/genética , Proteínas Proto-Oncogênicas B-raf/genética , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/genética , Adolescente , Adulto , Astrocitoma/genética , Astrocitoma/patologia , Neoplasias Encefálicas/genética , Criança , Pré-Escolar , Proteínas de Ligação a DNA , Feminino , Ganglioglioma/genética , Ganglioglioma/patologia , Glioma/patologia , Humanos , Lactente , Masculino , Proteínas Nucleares/genética , Proteínas de Transporte Nucleocitoplasmático/genética , Proteínas Proto-Oncogênicas/genética , Proteínas de Ligação a RNA , Transativadores/genética , Fatores de Transcrição , Adulto JovemRESUMO
AIM: Pilocytic astrocytomas represent the most common paediatric tumours of the central nervous system. Dissemination through the ventricular system occurs rarely in patients with pilocytic astrocytomas; however, it is more common in infants with diencephalic tumours, and is associated with a poor outcome. Despite histological similarities with classic pilocytic astrocytomas, it is still unclear whether disseminated pilocytic astrocytomas may have specific molecular features. METHODS: Seventeen disseminated pilocytic astrocytomas were investigated using the molecular inversion probe array and screened for the presence of gene fusions (KIAA1549-BRAF) and mutations (BRAF, RAS and FGFR1). RESULTS: Along with evidence of a constitutive MAPK activation in all cases, the molecular inversion probe array, fluorescence in situ hybridization analysis and mutational study revealed KIAA1549-BRAF fusions in 66% and BRAF(V600E) mutations in 5% of cases. No KRAS, HRAS, NRAS or FGFR1 mutations were found. CONCLUSIONS: disseminated pilocytic astrocytomas showed genetic features similar to classic pilocytic astrocytoma, including a similar incidence of KIAA1549-BRAF fusions, BRAF mutations and a stable genetic profile. Given common activation of the MAPK pathway, the use of specific inhibitors can be hypothesized for the treatment of disseminated pilocytic astrocytomas, along with standard chemo- and/or radiotherapy.
Assuntos
Astrocitoma/genética , Astrocitoma/patologia , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Imuno-Histoquímica , Hibridização in Situ Fluorescente , Lactente , Masculino , Proteínas de Fusão Oncogênica/genética , Proteínas Proto-Oncogênicas B-raf/genéticaRESUMO
Pilocytic astrocytoma (PA) is the most common brain tumor in children but is rare in adults, and hence poorly studied in this age group. We investigated 222 PA and report increased aneuploidy in older patients. Aneuploid genomes were identified in 45% of adult compared with 17% of pediatric PA. Gains were non-random, favoring chromosomes 5, 7, 6 and 11 in order of frequency, and preferentially affecting non-cerebellar PA and tumors with BRAF V600E mutations and not with KIAA1549-BRAF fusions or FGFR1 mutations. Aneuploid PA differentially expressed genes involved in CNS development, the unfolded protein response, and regulators of genomic stability and the cell cycle (MDM2, PLK2),whose correlated programs were overexpressed specifically in aneuploid PA compared to other glial tumors. Thus, convergence of pathways affecting the cell cycle and genomic stability may favor aneuploidy in PA, possibly representing an additional molecular driver in older patients with this brain tumor.
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Aneuploidia , Astrocitoma/classificação , Biomarcadores Tumorais/genética , Neoplasias Encefálicas/classificação , Adulto , Fatores Etários , Astrocitoma/genética , Astrocitoma/patologia , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Criança , Estudos de Coortes , Feminino , Perfilação da Expressão Gênica , Humanos , Masculino , Mutação/genética , Estadiamento de Neoplasias , Prognóstico , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas c-mdm2/genética , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Adulto JovemRESUMO
Ependymal tumors across age groups are currently classified and graded solely by histopathology. It is, however, commonly accepted that this classification scheme has limited clinical utility based on its lack of reproducibility in predicting patients' outcome. We aimed at establishing a uniform molecular classification using DNA methylation profiling. Nine molecular subgroups were identified in a large cohort of 500 tumors, 3 in each anatomical compartment of the CNS, spine, posterior fossa, supratentorial. Two supratentorial subgroups are characterized by prototypic fusion genes involving RELA and YAP1, respectively. Regarding clinical associations, the molecular classification proposed herein outperforms the current histopathological classification and thus might serve as a basis for the next World Health Organization classification of CNS tumors.
Assuntos
Fatores Etários , Neoplasias do Sistema Nervoso Central/patologia , Ependimoma/patologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Adolescente , Adulto , Idoso , Neoplasias do Sistema Nervoso Central/classificação , Neoplasias do Sistema Nervoso Central/genética , Criança , Pré-Escolar , Metilação de DNA , Ependimoma/classificação , Ependimoma/genética , Feminino , Dosagem de Genes , Perfilação da Expressão Gênica , Fusão Gênica , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Fosfoproteínas/genética , Fatores de Transcrição , Transcrição Gênica , Proteínas de Sinalização YAP , Adulto JovemRESUMO
Glioblastoma (GBM) is a devastating tumor and few patients survive beyond 3 years. Defining the molecular determinants underlying long-term survival is essential for insights into tumor biology and biomarker identification. We therefore investigated homogeneously treated, IDH (wt) long-term (LTS, n = 10) and short-term survivors (STS, n = 6) by microarray transcription profiling. While there was no association of clinical parameters and molecular subtypes with long-term survival, STS tumors were characterized by differential polarization of infiltrating microglia with predominance of the M2 phenotype detectable both on the mRNA and protein level. Furthermore, transcriptional signatures of LTS and STS predicted patient outcome in a large, IDH (wt) cohort (n = 468). Interrogation of overlapping genomic alterations identified concurrent gain of chromosomes 19 and 20 as a favorable prognostic marker. The strong association of this co-gain with survival was validated by aCGH in a second, independent cohort (n = 124). Finally, FISH and gene expression data revealed gains to constitute low-amplitude, clonal events with a strong impact on transcription. In conclusion, these findings provide important insights into the manipulation of the innate immune system by particularly aggressive GBM tumors. Furthermore, we genomically characterize a previously unknown, clinically relevant subgroup of glioblastoma, which can easily be identified through modern neuropathological workup.
Assuntos
Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Cromossomos Humanos Par 19 , Cromossomos Humanos Par 20 , Glioblastoma/genética , Glioblastoma/metabolismo , Adulto , Idoso , Encéfalo/metabolismo , Encéfalo/patologia , Encéfalo/cirurgia , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/patologia , Estudos de Coortes , Feminino , Glioblastoma/diagnóstico , Glioblastoma/patologia , Humanos , Isocitrato Desidrogenase/genética , Macrófagos/metabolismo , Macrófagos/patologia , Masculino , Microglia/metabolismo , Microglia/patologia , Pessoa de Meia-Idade , Prognóstico , RNA Mensageiro/metabolismo , Análise de Sobrevida , Sobreviventes , Fatores de Tempo , Transcrição GênicaRESUMO
Pilocytic astrocytomas (PAs) were recognized as a discrete clinical entity over 70 years ago. They are relatively benign (WHO grade I) and have, as a group, a 10-year survival of over 90%. Many require merely surgical removal and only very infrequently do they progress to more malignant gliomas. While most show classical morphology, they may present a spectrum of morphological patterns, and there are difficult cases that show similarities to other gliomas, some of which are malignant and require aggressive treatment. Until recently, almost nothing was known about the molecular mechanisms involved in their development. The use of high-throughput sequencing techniques interrogating the whole genome has shown that single abnormalities of the mitogen-activating protein kinase (MAPK) pathway are exclusively found in almost all cases, indicating that PA represents a one-pathway disease. The most common mechanism is a tandem duplication of a ≈2 Mb-fragment of #7q, giving rise to a fusion between two genes, resulting in a transforming fusion protein, consisting of the N-terminus of KIAA1549 and the kinase domain of BRAF. Additional infrequent fusion partners have been identified, along with other abnormalities of the MAP-K pathway, affecting tyrosine kinase growth factor receptors at the cell surface (e.g., FGFR1) as well as BRAF V600E, KRAS, and NF1 mutations among others. However, while the KIAA1549-BRAF fusion occurs in all areas, the incidence of the various other mutations identified differs in PAs that develop in different regions of the brain. Unfortunately, from a diagnostic standpoint, almost all mutations found have been reported in other brain tumor types, although some retain considerable utility. These molecular abnormalities will be reviewed, and the difficulties in their potential use in supporting a diagnosis of PA, when the histopathological findings are equivocal or in the choice of individualized therapy, will be discussed.
Assuntos
Astrocitoma , Neoplasias do Sistema Nervoso Central , Astrocitoma/genética , Astrocitoma/patologia , Astrocitoma/fisiopatologia , Neoplasias do Sistema Nervoso Central/genética , Neoplasias do Sistema Nervoso Central/patologia , Neoplasias do Sistema Nervoso Central/fisiopatologia , Predisposição Genética para Doença , Humanos , Modelos Moleculares , Biologia Molecular , NeuroimagemRESUMO
AIMS: Glioblastoma (GBM) is the most common and aggressive primary malignant brain tumour in adults, with a poor prognosis. Changing treatment paradigms suggest improved outcome, but whole nation data for England is scarce. The aim of this report is to examine the incidence of patients with glioblastoma in England, and to assess the influence of gender, age, geographical region and treatment on outcome. METHODS: A search strategy encompassing all patients coded with GBM and treated from January 2007 to December 2011 was obtained from data linkage between the National Cancer Registration Service and Hospital Episode Statistics for England. RESULTS: There were 10,743 patients coded with GBM in this 5-year period (6451 male, 4292 female), giving an overall national age standardised incidence of 4.64/100,000/year. Incidence increases with age. Median survival overall was 6.1 months. One, 2 and 5-year survivals, were 28.4%, 11.5% and 3.4% respectively. Age stratified median survivals decreased significantly (p<0.0001) with increasing age from 16.2 months for the 20-44 year age group, to 7.9 months for the 45-69 years, and 3.2 months for 70+years. In the maximal treatment subgroup, patients aged up to 69 years had a median survival of 14.9 months. Patients over 60 years were less likely to receive maximal combination treatment but median survival was better with maximal treatment at all ages. CONCLUSIONS: The overall outcome for patients with GBM remains poor. However, aggressive treatment at every age group is associated with extended survival similar to that described in clinical trials.
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Neoplasias Encefálicas/epidemiologia , Glioblastoma/epidemiologia , Adulto , Idoso , Neoplasias Encefálicas/mortalidade , Inglaterra/epidemiologia , Feminino , Glioblastoma/mortalidade , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Fatores de TempoRESUMO
Recent sequencing studies have extensively explored the somatic alterations present in the nuclear genomes of cancers. Although mitochondria control energy metabolism and apoptosis, the origins and impact of cancer-associated mutations in mtDNA are unclear. In this study, we analyzed somatic alterations in mtDNA from 1675 tumors. We identified 1907 somatic substitutions, which exhibited dramatic replicative strand bias, predominantly C > T and A > G on the mitochondrial heavy strand. This strand-asymmetric signature differs from those found in nuclear cancer genomes but matches the inferred germline process shaping primate mtDNA sequence content. A number of mtDNA mutations showed considerable heterogeneity across tumor types. Missense mutations were selectively neutral and often gradually drifted towards homoplasmy over time. In contrast, mutations resulting in protein truncation undergo negative selection and were almost exclusively heteroplasmic. Our findings indicate that the endogenous mutational mechanism has far greater impact than any other external mutagens in mitochondria and is fundamentally linked to mtDNA replication.
Assuntos
DNA Mitocondrial/genética , DNA de Neoplasias/genética , DNA/genética , Genoma Mitocondrial , Mutação , Neoplasias/genética , Animais , Composição de Bases , Replicação do DNA , Mineração de Dados , Evolução Molecular , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Mitocôndrias/genética , Mitocôndrias/patologia , Neoplasias/classificação , Neoplasias/patologia , Polimorfismo de Nucleotídeo ÚnicoRESUMO
Major discoveries in the biology of nervous system tumors have raised the question of how non-histological data such as molecular information can be incorporated into the next World Health Organization (WHO) classification of central nervous system tumors. To address this question, a meeting of neuropathologists with expertise in molecular diagnosis was held in Haarlem, the Netherlands, under the sponsorship of the International Society of Neuropathology (ISN). Prior to the meeting, participants solicited input from clinical colleagues in diverse neuro-oncological specialties. The present "white paper" catalogs the recommendations of the meeting, at which a consensus was reached that incorporation of molecular information into the next WHO classification should follow a set of provided "ISN-Haarlem" guidelines. Salient recommendations include that (i) diagnostic entities should be defined as narrowly as possible to optimize interobserver reproducibility, clinicopathological predictions and therapeutic planning; (ii) diagnoses should be "layered" with histologic classification, WHO grade and molecular information listed below an "integrated diagnosis"; (iii) determinations should be made for each tumor entity as to whether molecular information is required, suggested or not needed for its definition; (iv) some pediatric entities should be separated from their adult counterparts; (v) input for guiding decisions regarding tumor classification should be solicited from experts in complementary disciplines of neuro-oncology; and (iv) entity-specific molecular testing and reporting formats should be followed in diagnostic reports. It is hoped that these guidelines will facilitate the forthcoming update of the fourth edition of the WHO classification of central nervous system tumors.
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Neoplasias do Sistema Nervoso/classificação , Neoplasias do Sistema Nervoso/diagnóstico , Humanos , Técnicas de Diagnóstico Molecular , Índice de Gravidade de DoençaRESUMO
Advances in technology are allowing a molecular characterisation of human brain tumours that is providing a wealth of new information. In this short overview, a summary of the histopathology of the common gliomas is integrated with some molecular data. In some instances, the data are proving clinically relevant with conventional therapies. Some single histological entities are being found to contain a number of molecular subtypes, whereas in others, different histological entities are found to be molecularly similar. The introduction of targeted therapies will necessitate a complete reassessment of the way we characterise tumours, and particularly the adequacy of our pathology reports in a new clinical environment.
Assuntos
Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Glioma/genética , Glioma/patologia , Terapia de Alvo Molecular/métodos , Neoplasias Encefálicas/classificação , Glioma/classificação , Humanos , Terapia de Alvo Molecular/tendênciasRESUMO
Amplification of the C19MC oncogenic miRNA cluster and high LIN28 expression has been linked to a distinctly aggressive group of cerebral CNS-PNETs (group 1 CNS-PNETs) arising in young children. In this study, we sought to evaluate the diagnostic specificity of C19MC and LIN28, and the clinical and biological spectra of C19MC amplified and/or LIN28+ CNS-PNETs. We interrogated 450 pediatric brain tumors using FISH and IHC analyses and demonstrate that C19MC alteration is restricted to a sub-group of CNS-PNETs with high LIN28 expression; however, LIN28 immunopositivity was not exclusive to CNS-PNETs but was also detected in a proportion of other malignant pediatric brain tumors including rhabdoid brain tumors and malignant gliomas. C19MC amplified/LIN28+ group 1 CNS-PNETs arose predominantly in children <4 years old; a majority arose in the cerebrum but 24 % (13/54) of tumors had extra-cerebral origins. Notably, group 1 CNS-PNETs encompassed several histologic classes including embryonal tumor with abundant neuropil and true rosettes (ETANTR), medulloepithelioma, ependymoblastoma and CNS-PNETs with variable differentiation. Strikingly, gene expression and methylation profiling analyses revealed a common molecular signature enriched for primitive neural features, high LIN28/LIN28B and DNMT3B expression for all group 1 CNS-PNETs regardless of location or tumor histology. Our collective findings suggest that current known histologic categories of CNS-PNETs which include ETANTRs, medulloepitheliomas, ependymoblastomas in various CNS locations, comprise a common molecular and diagnostic entity and identify inhibitors of the LIN28/let7/PI3K/mTOR axis and DNMT3B as promising therapeutics for this distinct histogenetic entity.
Assuntos
Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , MicroRNAs/genética , Tumores Neuroectodérmicos Primitivos/genética , Tumores Neuroectodérmicos Primitivos/metabolismo , Proteínas de Ligação a RNA/metabolismo , Adolescente , Idade de Início , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/terapia , Linhagem Celular Tumoral , Criança , Pré-Escolar , DNA (Citosina-5-)-Metiltransferases/metabolismo , Metilação de DNA , Diagnóstico Diferencial , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Lactente , Masculino , Família Multigênica , Tumores Neuroectodérmicos Primitivos/diagnóstico , Tumores Neuroectodérmicos Primitivos/terapia , DNA Metiltransferase 3BRESUMO
To outline further genetic mechanisms of transformation from follicular lymphoma (FL) to diffuse large B-cell lymphoma (DLBCL), we have performed whole genome array-CGH in 81 tumors from 60 patients [29 de novo DLBCL (dnDLBCL), 31 transformed DLBCL (tDLBCL), and 21 antecedent FL]. In 15 patients, paired tumor samples (primary FL and a subsequent tDLBCL) were available, among which three possessed more than two subsequent tumors, allowing us to follow specific genetic alterations acquired before, during, and after the transformation. Gain of 2p15-16.1 encompassing, among others, the REL, BCL11A, USP34, COMMD1, and OTX1 genes was found to be more common in the tDLBCL compared with dnDLBCL (P < 0.001). Furthermore, a high-level amplification of 2p15-16.1 was also detected in the FL stage prior to transformation, indicating its importance during the transformation event. Quantitative real-time PCR showed a higher level of amplification of REL, USP34, and COMMD1 (all involved in the NFκΒ-pathway) compared with BCL11A, which indicates that the altered genes disrupting the NFκΒ pathway may be the driver genes of transformation rather than the previously suggested BCL11A. Moreover, a 17q21.33 amplification was exclusively found in tDLBCL, never in FL (P < 0.04) or dnDLBCL, indicating an upregulation of genes of importance during the later phase of transformation. Taken together, our study demonstrates potential genomic markers for disease progression to clinically more aggressive forms. We also confirm the importance of the TP53-, CDKN2A-, and NFκΒ-pathways for the transformation from FL to DLBCL.
Assuntos
Aberrações Cromossômicas , Cromossomos Humanos Par 2/genética , Linfoma Folicular/genética , Linfoma Difuso de Grandes Células B/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Pré-Escolar , Cromossomos Humanos Par 17/genética , Progressão da Doença , Feminino , Marcadores Genéticos , Humanos , Linfoma Folicular/patologia , Linfoma Difuso de Grandes Células B/patologia , Masculino , Pessoa de Meia-Idade , NF-kappa B/metabolismo , Transdução de SinaisRESUMO
The objective of this study was to assess attitudes and opinions of women declining the offer of cystic fibrosis (CF) carrier screening through a population-based programme in Victoria, Australia. Between December 2009 and May 2011, women declining an offer of CF carrier screening were invited to participate in a questionnaire-based study. Recruitment was at two private obstetric ultrasound clinics and two private obstetric practices in Melbourne. Of the participants (n = 54), the majority were well educated (76%), aged 30-34 years (54%), with a household income of >AUD$100,000 (76%). Compared to those who accepted screening (reported in a previous study) (Ioannou et al., Public Health Genomics 13:449-56, 2010), knowledge levels were significantly lower in participants declining screening (t = 3.32, p < 0.01). The main reasons for declining screening were having no family history of CF (58%) and not considering a termination of pregnancy for CF (53%). Providers and consumers should be informed that most children born with autosomal-recessive conditions such as CF have no family history of the condition.
RESUMO
Three histological variants are known within the family of embryonal rosette-forming neuroepithelial brain tumors. These include embryonal tumor with abundant neuropil and true rosettes (ETANTR), ependymoblastoma (EBL), and medulloepithelioma (MEPL). In this study, we performed a comprehensive clinical, pathological, and molecular analysis of 97 cases of these rare brain neoplasms, including genome-wide DNA methylation and copy number profiling of 41 tumors. We identified uniform molecular signatures in all tumors irrespective of histological patterns, indicating that ETANTR, EBL, and MEPL comprise a single biological entity. As such, future WHO classification schemes should consider lumping these variants into a single diagnostic category, such as embryonal tumor with multilayered rosettes (ETMR). We recommend combined LIN28A immunohistochemistry and FISH analysis of the 19q13.42 locus for molecular diagnosis of this tumor category. Recognition of this distinct pediatric brain tumor entity based on the fact that the three histological variants are molecularly and clinically uniform will help to distinguish ETMR from other embryonal CNS tumors and to better understand the biology of these highly aggressive and therapy-resistant pediatric CNS malignancies, possibly leading to alternate treatment strategies.