Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Genes Chromosomes Cancer ; 60(5): 303-313, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-32734664

RESUMO

In vitro assays for clustered DNA lesions will facilitate the analysis of the mechanisms underlying complex genome rearrangements such as chromothripsis, including the recruitment of repair factors to sites of DNA double-strand breaks (DSBs). We present a novel method generating localized DNA DSBs using UV irradiation with photomasks. The size of the damage foci and the spacing between lesions are fully adjustable, making the assay suitable for different cell types and targeted areas. We validated this setup with genomically stable epithelial cells, normal fibroblasts, pluripotent stem cells, and patient-derived primary cultures. Our method does not require a specialized device such as a laser, making it accessible to a broad range of users. Sensitization by 5-bromo-2-deoxyuridine incorporation is not required, which enables analyzing the DNA damage response in post-mitotic cells. Irradiated cells can be cultivated further, followed by time-lapse imaging or used for downstream biochemical analyses, thanks to the high throughput of the system. Importantly, we showed genome rearrangements in the irradiated cells, providing a proof of principle for the induction of structural variants by localized DNA lesions.


Assuntos
Quebras de DNA de Cadeia Dupla , Mutagênese , Linhagem Celular , Células Cultivadas , Células Epiteliais/metabolismo , Células Epiteliais/efeitos da radiação , Fibroblastos/metabolismo , Fibroblastos/efeitos da radiação , Humanos , Células-Tronco Pluripotentes/metabolismo , Células-Tronco Pluripotentes/efeitos da radiação , Raios Ultravioleta
2.
Int J Cancer ; 138(10): 2322-33, 2016 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-26455580

RESUMO

In 2011, a novel form of genome instability was reported by Stephens et al., characterized by tens to hundreds of locally clustered rearrangements affecting one or a few chromosome(s) in cancer cells. This phenomenon, termed chromothripsis, is likely due to a single catastrophic event leading to the simultaneous formation of multiple double-strand breaks, which are repaired by error-prone mechanisms. Since then, the occurrence of chromothripsis was detected in a wide range of tumor entities. In this review, we will discuss potential mechanisms of chromothripsis initiation in cancer and outline the prevalence of chromothripsis across entities. Furthermore, we will examine how chromothriptic events may promote cancer development and how they may affect cancer therapy.


Assuntos
Aberrações Cromossômicas , Instabilidade Genômica , Neoplasias/genética , Animais , Transformação Celular Neoplásica/genética , Humanos , Neoplasias/terapia
3.
Int J Cancer ; 138(12): 2905-14, 2016 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-26856307

RESUMO

Chromothripsis is a recently discovered form of genomic instability, characterized by tens to hundreds of clustered DNA rearrangements resulting from a single dramatic event. Telomere dysfunction has been suggested to play a role in the initiation of this phenomenon, which occurs in a large number of tumor entities. Here, we show that telomere attrition can indeed lead to catastrophic genomic events, and that telomere patterns differ between cells analyzed before and after such genomic catastrophes. Telomere length and telomere stabilization mechanisms diverge between samples with and without chromothripsis in a given tumor subtype. Longitudinal analyses of the evolution of chromothriptic patterns identify either stable patterns between matched primary and relapsed tumors, or loss of the chromothriptic clone in the relapsed specimen. The absence of additional chromothriptic events occurring between the initial tumor and the relapsed tumor sample points to telomere stabilization after the initial chromothriptic event which prevents further shattering of the genome.


Assuntos
Neoplasias Cerebelares/genética , Instabilidade Genômica , Meduloblastoma/genética , Homeostase do Telômero , Estudos de Casos e Controles , Neoplasias Cerebelares/enzimologia , Transtornos Cromossômicos/enzimologia , Transtornos Cromossômicos/genética , Ependimoma/enzimologia , Ependimoma/genética , Expressão Gênica , Humanos , Meduloblastoma/enzimologia , Telomerase/genética , Telomerase/metabolismo
4.
Nat Med ; 29(4): 917-926, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36928815

RESUMO

The large diversity of central nervous system (CNS) tumor types in children and adolescents results in disparate patient outcomes and renders accurate diagnosis challenging. In this study, we prospectively integrated DNA methylation profiling and targeted gene panel sequencing with blinded neuropathological reference diagnostics for a population-based cohort of more than 1,200 newly diagnosed pediatric patients with CNS tumors, to assess their utility in routine neuropathology. We show that the multi-omic integration increased diagnostic accuracy in a substantial proportion of patients through annotation to a refining DNA methylation class (50%), detection of diagnostic or therapeutically relevant genetic alterations (47%) or identification of cancer predisposition syndromes (10%). Discrepant results by neuropathological WHO-based and DNA methylation-based classification (30%) were enriched in histological high-grade gliomas, implicating relevance for current clinical patient management in 5% of all patients. Follow-up (median 2.5 years) suggests improved survival for patients with histological high-grade gliomas displaying lower-grade molecular profiles. These results provide preliminary evidence of the utility of integrating multi-omics in neuropathology for pediatric neuro-oncology.


Assuntos
Neoplasias Encefálicas , Glioma , Adolescente , Humanos , Criança , Multiômica , Glioma/diagnóstico , Glioma/genética , Neuropatologia , Metilação de DNA/genética , Mutação , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/genética
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa