RESUMO
Monoallelic inactivation of CCCTC-binding factor (CTCF) in human cancer drives altered methylated genomic states, altered CTCF occupancy at promoter and enhancer regions, and deregulated global gene expression. In patients with T cell acute lymphoblastic leukemia (T-ALL), we find that acquired monoallelic CTCF-inactivating events drive subtle and local genomic effects in nearly half of t(5; 14) (q35; q32.2) rearranged patients, especially when CTCF-binding sites are preserved in between the BCL11B enhancer and the TLX3 oncogene. These solitary intervening sites insulate TLX3 from the enhancer by inducing competitive looping to multiple binding sites near the TLX3 promoter. Reduced CTCF levels or deletion of the intervening CTCF site abrogates enhancer insulation by weakening competitive looping while favoring TLX3 promoter to BCL11B enhancer looping, which elevates oncogene expression levels and leukemia burden.
Assuntos
Leucemia-Linfoma Linfoblástico de Células T Precursoras , Humanos , Fator de Ligação a CCCTC/genética , Fator de Ligação a CCCTC/metabolismo , Cromatina , Elementos Facilitadores Genéticos/genética , Mutação , Oncogenes , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Fatores de Transcrição/metabolismo , Proteínas Supressoras de Tumor/metabolismoRESUMO
Implementation of next-generation DNA sequencing (NGS) technology into routine diagnostic genome care requires strategic choices. Instead of theoretical discussions on the consequences of such choices, we compared NGS-based diagnostic practices in eight clinical genetic centers in the Netherlands, based on genetic testing of nine pre-selected patients with cardiomyopathy. We highlight critical implementation choices, including the specific contributions of laboratory and medical specialists, bioinformaticians and researchers to diagnostic genome care, and how these affect interpretation and reporting of variants. Reported pathogenic mutations were consistent for all but one patient. Of the two centers that were inconsistent in their diagnosis, one reported to have found 'no causal variant', thereby underdiagnosing this patient. The other provided an alternative diagnosis, identifying another variant as causal than the other centers. Ethical and legal analysis showed that informed consent procedures in all centers were generally adequate for diagnostic NGS applications that target a limited set of genes, but not for exome- and genome-based diagnosis. We propose changes to further improve and align these procedures, taking into account the blurring boundary between diagnostics and research, and specific counseling options for exome- and genome-based diagnostics. We conclude that alternative diagnoses may infer a certain level of 'greediness' to come to a positive diagnosis in interpreting sequencing results. Moreover, there is an increasing interdependence of clinic, diagnostics and research departments for comprehensive diagnostic genome care. Therefore, we invite clinical geneticists, physicians, researchers, bioinformatics experts and patients to reconsider their role and position in future diagnostic genome care.
Assuntos
Cardiomiopatias/diagnóstico , Testes Genéticos/normas , Genoma Humano , Sequenciamento de Nucleotídeos em Larga Escala/normas , Mutação , Proteínas de Ligação ao Cálcio/genética , Miosinas Cardíacas/genética , Cardiomiopatias/genética , Proteínas de Transporte/genética , Exoma , Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala/instrumentação , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Consentimento Livre e Esclarecido/legislação & jurisprudência , Ensaio de Proficiência Laboratorial/estatística & dados numéricos , MAP Quinase Quinase Quinases/genética , Cadeias Pesadas de Miosina/genética , Países Baixos , Proteínas Serina-Treonina QuinasesRESUMO
BACKGROUND: Establishing botanical extracts as globally-accepted polychemical medicines and a new paradigm for disease treatment, requires the development of high-level quality control metrics. Based on comprehensive chemical and biological fingerprints correlated with pharmacology, we propose a general approach called PhytomicsQC to botanical quality control. METHODS: Incorporating the state-of-the-art analytical methodologies, PhytomicsQC was employed in this study and included the use of liquid chromatography/mass spectrometry (LC/MS) for chemical characterization and chemical fingerprinting, differential cellular gene expression for bioresponse fingerprinting and animal pharmacology for in vivo validation. A statistical pattern comparison method, Phytomics Similarity Index (PSI), based on intensities and intensity ratios, was used to determine the similarity of the chemical and bioresponse fingerprints among different manufactured batches. RESULTS: Eighteen batch samples of Huangqin Tang (HQT) and its pharmaceutical grade version (PHY906) were analyzed using the PhytomicsQC platform analysis. Comparative analysis of the batch samples with a clinically tested standardized batch obtained values of PSI similarity between 0.67 and 0.99. CONCLUSION: With rigorous quality control using analytically sensitive and comprehensive chemical and biological fingerprinting, botanical formulations manufactured under standardized manufacturing protocols can produce highly consistent batches of products.
RESUMO
We used cDNA-based genomic microarrays to examine DNA copy number changes in a panel of prostate tumors and found a previously undescribed amplicon on chromosome 17 containing a novel overexpressed gene that we termed prostate cancer gene 17 (PRC17). When overexpressed in 3T3 mouse fibroblast cells, PRC17 induced growth in low serum, loss of contact inhibition, and tumor formation in nude mice. The PRC17 gene product contains a GTPase-activating protein (GAP) catalytic core motif found in various Rab/Ypt GAPs, including RN-Tre. Similar to RN-Tre, we found that PRC17 protein interacts directly with Rab5 and stimulates its GTP hydrolysis. Point mutations that alter conserved amino acid residues within the PRC17 GAP domain abolished its transforming abilities, suggesting that GAP activity is essential for its oncogenic function. Whereas PRC17 is amplified in 15% of prostate cancers, it is highly overexpressed in approximately one-half of metastatic prostate tumors. The potent oncogenic activity of PRC17 is likely to influence the tumorigenic phenotype of these prostate cancers.
Assuntos
Proteínas Ativadoras de GTPase/genética , Proteínas Oncogênicas/genética , Neoplasias da Próstata/genética , Células 3T3 , Sequência de Aminoácidos , Animais , Divisão Celular/genética , Cromossomos Humanos Par 17/genética , Ativação Enzimática , Proteínas Ativadoras de GTPase/metabolismo , Amplificação de Genes , Humanos , Masculino , Camundongos , Camundongos Nus , Dados de Sequência Molecular , Análise de Sequência com Séries de Oligonucleotídeos , Proteínas Oncogênicas/metabolismo , Neoplasias da Próstata/metabolismo , Proteínas Proto-Oncogênicas , Homologia de Sequência de Aminoácidos , Células Tumorais Cultivadas , Proteínas rab5 de Ligação ao GTP/metabolismoRESUMO
We found that PPM1D, encoding a serine/threonine protein phosphatase, lies within an epicenter of the region at 17q23 that is amplified in breast cancer. We show that overexpression of this gene confers two oncogenic phenotypes on cells in culture: attenuation of apoptosis induced by serum starvation and transformation of primary cells in cooperation with RAS.