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  • 1
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    German Medical Science; Düsseldorf, Köln
    In:  27. Deutscher Krebskongress; 20060322-20060326; Berlin; DOCIS012 /20060320/
    Publication Date: 2006-04-21
    Keywords: ddc: 610
    Language: English
    Type: conferenceObject
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  • 2
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    German Medical Science GMS Publishing House; Düsseldorf
    In:  62. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit der Polnischen Gesellschaft für Neurochirurgen (PNCH); 20110507-20110511; Hamburg; DOCDI.07.05 /20110428/
    Publication Date: 2011-04-28
    Keywords: ddc: 610
    Language: English
    Type: conferenceObject
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  • 3
    Keywords: CANCER ; EXPRESSION ; tumor ; COMMON ; RISK ; CDNA ; GENE ; HYBRIDIZATION ; microarray ; SAMPLE ; SAMPLES ; TUMORS ; DNA ; CELL-LINES ; chromosome ; ELEMENT ; STAGE ; PROGRESSION ; AMPLIFICATION ; chromosome 2 ; COPY NUMBER ; COPY-NUMBER ; PATTERNS ; microarrays ; SINGLE-COPY ; ELEMENTS ; NUMBER ; REQUIRES ; EFFICIENT ; REGION ; PHENOTYPE ; FREQUENT ; RECURRENT ; gene amplification ; IMBALANCES ; CDNA MICROARRAYS ; GENOMIC HYBRIDIZATION ; COPY NUMBER CHANGES ; MYCN ; CDNA MICROARRAY ; neuroblastoma ; N-MYC ; CHROMOSOMES ; AMPLIFICATIONS ; TUMORIGENESIS ; 17Q GAIN
    Abstract: Background: Recurrent non-random genomic alterations are the hallmarks of cancer and the characterization of these imbalances is critical to our understanding of tumorigenesis and cancer progression. Results: We performed array-comparative genomic hybridization (A-CGH) on cDNA microarrays containing 42,000 elements in neuroblastoma ( NB). We found that only two chromosomes (2p and 12q) had gene amplifications and all were in the MYCN amplified samples. There were 6 independent non-contiguous amplicons (10.4 - 69.4 Mb) on chromosome 2, and the largest contiguous region was 1.7 Mb bounded by NAG and an EST ( clone: 757451); the smallest region was 27 Kb including an EST ( clone: 241343), NCYM, and MYCN. Using a probabilistic approach to identify single copy number changes, we systemically investigated the genomic alterations occurring in Stage 1 and Stage 4 NBs with and without MYCN amplification ( stage 1-, 4-, and 4+). We have not found genomic alterations universally present in all (100%) three subgroups of NBs. However we identified both common and unique patterns of genomic imbalance in NB including gain of 7q32, 17q21, 17q23-24 and loss of 3p21 were common to all three categories. Finally we confirm that the most frequent specific changes in Stage 4+ tumors were the loss of 1p36 with gain of 2p24-25 and they had fewer genomic alterations compared to either stage 1 or 4-, indicating that for this subgroup of poor risk NB requires a smaller number of genomic changes are required to develop the malignant phenotype. Conclusions: cDNA A-CGH analysis is an efficient method for the detection and characterization of amplicons. Furthermore we were able to detect single copy number changes using our probabilistic approach and identified genomic alterations specific to stage and MYCN amplification
    Type of Publication: Journal article published
    PubMed ID: 15380028
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  • 4
    Keywords: EXPRESSION ; SURVIVAL ; tumor ; Germany ; MODEL ; CLASSIFICATION ; DIAGNOSIS ; SYSTEM ; SYSTEMS ; COHORT ; DISEASE ; RISK ; DISTINCT ; GENE ; GENE-EXPRESSION ; microarray ; ACCURACY ; validation ; PATIENT ; BREAST-CANCER ; STAGE ; TRIAL ; TRIALS ; gene expression ; microarrays ; DELETIONS ; HIGH-RISK ; PROBES ; UNITED-STATES ; PREDICTION ; pathology ; CHILDREN ; DIFFERENTIAL EXPRESSION ; neuroblastoma ; INTEGRATION ; REGRESSION ; SIGNATURE ; PREDICTOR ; SPECIMENS ; SUBGROUPS ; PREDICTS ; SET ; CLINICAL COURSE ; 11Q
    Abstract: Purpose To develop a gene expression - based classifier for neuroblastoma patients that reliably predicts courses of the disease. Patients and Methods Two hundred fifty-one neuroblastoma specimens were analyzed using a customized oligonucleotide microarray comprising 10,163 probes for transcripts with differential expression in clinical subgroups of the disease. Subsequently, the prediction analysis for microarrays (PAM) was applied to a first set of patients with maximally divergent clinical courses ( n = 77). The classification accuracy was estimated by a complete 10-times-repeated 10-fold cross validation, and a 144-gene predictor was constructed from this set. This classifier's predictive power was evaluated in an independent second set ( n = 174) by comparing results of the gene expression based classification with those of risk stratification systems of current trials from Germany, Japan, and the United States. Results The first set of patients was accurately predicted by PAM (cross-validated accuracy, 99%). Within the second set, the PAM classifier significantly separated cohorts with distinct courses (3-year event-free survival [EFS] 0.86 +/- 0.03 [ favorable; n = 115] v 0.52 +/- 0.07 [ unfavorable; n = 59] and 3-year overall survival 0.99 +/- 0.01 v 0.84 +/- 0.05; both P 〈.0001) and separated risk groups of current neuroblastoma trials into subgroups with divergent outcome (NB2004: low-risk 3-year EFS 0.86 +/- 0.04 v 0.25 +/- 0.15, P 〈.0001; intermediate-risk 1.00 v 0.57 +/- 0.19, P =.018; high-risk 0.81 +/- 0.10 v 0.56 +/- 0.08, P =.06). In a multivariate Cox regression model, the PAM predictor classified patients of the second set more accurately than risk stratification of current trials from Germany, Japan, and the United States ( P 〈.001; hazard ratio, 4.756 [95% CI, 2.544 to 8.893]). Conclusion Integration of gene expression - based class prediction of neuroblastoma patients may improve risk estimation of current neuroblastoma trials
    Type of Publication: Journal article published
    PubMed ID: 17075126
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  • 5
    Keywords: tumor ; Germany ; COHORT ; GENE ; HYBRIDIZATION ; TUMORS ; PATIENT ; MARKER ; SEQUENCE ; DELETION ; STAGE ; AMPLIFICATION ; COMPARATIVE GENOMIC HYBRIDIZATION ; COPY NUMBER ; PATTERNS ; microarrays ; NUMBER ; MARKERS ; REGION ; REGIONS ; PHENOTYPE ; REVEALS ; CHILDREN ; SEGMENTS ; 1p ; neuroblastoma ; CHROMOSOMES ; SUBSET ; CYTOGENETIC ANALYSIS ; BREAKPOINTS ; MYCN-AMPLIFICATION ; function ; LOSSES ; HIGH-RESOLUTION ANALYSIS ; genomic ; GENOMIC ALTERATIONS ; 11Q ; CGH ANALYSIS ; DNA-COPY-NUMBER
    Abstract: The study of genomic alterations in neuroblastoma is of particular importance since several cytogenetic markers proved to be closely associated with the clinical phenotype. To disclose patterns of gains and losses, we performed high-resolution oligonucleotide array-based comparative genomic hybridization (aCGH). A total cohort of 90 patients was classified into 6 subsets according to tumor stage and outcome: Stages 1-3+ (with event), Stage 1-3- (no event), Stage 4+/-, and Stage 4S+/-. The aberration patterns in Stages 1-3- and 4S- tumors differed from all other groups as they were predominantly characterized by losses (3, 4, 14, X) and gains (7, 17) of whole chromosomes. However, 59/65 (91%) tumors of Stages 1-3+ or Stage 4 revealed numerous structural copy number alterations (sCNA). While deletions in chromosomes 1, 3, and I I discriminated outcome in Stage 4, there were no specific sCNA that distinguished tumor stage within the subgroup of unfavorable tumors. sCNA in 1p, 3p, 11q, 17q, or MYCN amplification (MNA) was seen among 22/24 patients who died, 10/12 with metastatic relapses, and 5/9 with local recurrences. Detailed breakpoint analyses on chromosomes 1, 3, 11, and 17 disclosed preferred breaking areas, although breakpoints were not identical. Amplifications were found in 18 patients and involved 2p24 (MYCN) and other segments of chromosome 2, as well as regions on chromosome arms 6q, 12q, and 17q. One single feature in 21q21.1 (BU678720, without known function yet) attracted particular attention since five patients showed a homozygous loss of this sequence. This article contains Supplementary Material available at http://www.interscience.wiley.com/jpages/1045-2257/suppmat. (c) 2006 Wiley-Liss, Inc
    Type of Publication: Journal article published
    PubMed ID: 16958102
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  • 6
    Keywords: EXPRESSION ; tumor ; evaluation ; Germany ; THERAPY ; DIAGNOSIS ; SYSTEM ; SYSTEMS ; DISEASE ; RISK ; DISTINCT ; GENE ; GENE-EXPRESSION ; PATIENT ; DNA ; MARKER ; TRIAL ; TRIALS ; PROGRESSION ; COMPARATIVE GENOMIC HYBRIDIZATION ; PATTERNS ; gene expression ; NUMBER ; AGE ; ABERRATIONS ; MARKERS ; ONCOGENE ; PHENOTYPE ; PROGNOSTIC-SIGNIFICANCE ; PREDICTION ; CHILDREN ; neuroblastoma ; N-MYC ; molecular ; REGRESSION ; review ; PATTERN ; THERAPIES ; PROTOCOL ; PROGNOSTIC MARKER ; PROFILES ; EXPRESSION PROFILES ; LOSSES ; PEDIATRIC-ONCOLOGY-GROUP ; VARIABLES ; PREDICT ; pediatric ; STAGE NEUROBLASTOMA ; PROFILE ; pediatrics ; neoplasm ; MICRORNA EXPRESSION ; CHROMOSOME ARM 17Q ; CLINICAL RELEVANCE ; genomic aberration ; MYC GENE AMPLIFICATION ; risk estimation ; TUMOR-CELL PLOIDY
    Abstract: The pediatric tumor neuroblastoma is a heterogeneous disease: Patients' clinical courses can range from spontaneous regression to fatal progression of the disease. Accordingly, treatment protocols vary from "wait and see" approaches to intensive multimodal therapies. Accurate risk estimation of the patients is therefore mandatory to choose the most adequate therapy. Current trials stratify by a limited number of clinical variables, such as stage of the disease and age of the patient at diagnosis, as well as molecular markers, such as amplification of the oncogene MYCN and loss of the short arm of chromosome 1. However, misclassifications of patients still occur, and thus, a precise prediction of the clinical courses remains a challenge of neuroblastoma research. In recent years, genomic alterations and gene expression profiles of this neoplasm have been characterized thoroughly. It has been shown that the diverse clinical phenotypes are reflected by both specific cytogenetic aberrations and distinct gene expression patterns. Moreover, a variety of DNA copy number changes and gene expression-based classifiers have been described that could predict the outcome of neuroblastoma patients more precisely than established prognostic variables. In this review, the recent advances in the detection and evaluation of molecular prognostic markers for neuroblastoma patients are summarized, and their current and potential contribution to risk stratification systems is discussed
    Type of Publication: Journal article published
    PubMed ID: 18478485
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  • 7
    Keywords: CANCER ; EXPRESSION ; Germany ; RISK ; GENE ; GENE-EXPRESSION ; GENES ; TUMORS ; PROGRESSION ; PATTERNS ; gene expression ; genetics ; DELETIONS ; REGION ; PHENOTYPE ; MICROARRAY ANALYSIS ; METHYLATION ; neuroblastoma ; ONCOLOGY ; PATTERN ; CANDIDATE GENES ; DNA COPY NUMBER ; SUBTYPES ; EXPRESSION PROFILES ; HIGH-RESOLUTION ANALYSIS ; SUBGROUPS ; outcome ; CELL BIOLOGY ; Genetic ; 4S NEUROBLASTOMA ; integrative genomics ; loss of 11q
    Abstract: Imbalances in chromosome 11q occur in approximately 30% of primary neuroblastoma and are associated with poor outcome. It has been suggested that 11q loss constitutes a distinct clinico-genetic neuroblastoma subgroup by affecting expression levels of corresponding genes. This study analysed the relationship of 11q loss, clinical phenotype and global transcriptomic profiles in four clinico-genetic subgroups (11q alteration/favourable outcome, n = 7; 11q alteration/unfavourable outcome, n 14; no 11q alteration/favourable outcome, n 81; no 11q alteration/unfavourable outcome, n 8; tumours with MYCN amplification and/or 1p loss were excluded). Unsupervised and supervised comparisons of gene expression profiles consistently showed significantly different mRNA patterns between favourable and unfavourable neuroblastomas, both in the subgroups with and without 11q loss. In contrast, favourable tumours with and without 11q loss showed highly similar transcriptomic profiles. Disproportionate downregulation of 11q genes was observed only in unfavourable tumours with 11q loss. The diverging molecular profiles were neither caused by considerable differences in the size of the deleted regions nor by differential methylation patterns of 11q genes. Together, this study shows that neuroblastoma with 11q loss comprises two biological subgroups that differ both in their clinical phenotype and gene expression patterns, indicating that 11q loss is not a primary determinant of neuroblastoma tumour behaviour. Oncogene (2010) 29, 865-875; doi:10.1038/onc.2009.390; published online 9 November 2009
    Type of Publication: Journal article published
    PubMed ID: 19901960
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  • 8
    Keywords: CANCER ; EXPRESSION ; CLASSIFICATION ; QUANTIFICATION ; GENE ; GENE-EXPRESSION ; TUMORS ; PATTERNS ; PATHOGENESIS ; REVEALS ; PREDISPOSITION ; ANAPLASTIC LYMPHOMA KINASE ; ACTIVATING MUTATIONS
    Abstract: Purpose: Genomic alterations of the anaplastic lymphoma kinase (ALK) gene have been postulated to contribute to neuroblastoma pathogenesis. This study aimed to determine the interrelation of ALK mutations, ALK expression levels, and clinical phenotype in primary neuroblastoma. Experimental Design: The genomic ALK status and global gene expression patterns were examined in 263 primary neuroblastomas. Allele-specific ALK expression was determined by cDNA cloning and sequencing. Associations of genomic ALK alterations and ALK expression levels with clinical phenotypes and transcriptomic profiles were compared. Results: Nonsynonymous point mutations of ALK were detected in 21 of 263 neuroblastomas (8%). Tumors with ALK mutations exhibited about 2-fold elevated median ALK mRNA levels in comparison with tumors with wild-type (WT) ALK. Unexpectedly, the WT allele was preferentially expressed in 12 of 21 mutated tumors. Whereas survival of patients with ALK mutated tumors was significantly worse as compared with the entire cohort of WT ALK patients, it was similarly poor in patients with WT ALK tumors in which ALK expression was as high as in ALK mutated neuroblastomas. Global gene expression patterns of tumors with ALK mutations or with high-level WT ALK expression were highly similar, and suggested that ALK may be involved in cellular proliferation in primary neuroblastoma. Conclusions: Primary neuroblastomas with mutated ALK exhibit high ALK expression levels and strongly resemble neuroblastomas with elevated WT ALK expression levels in both their clinical and molecular phenotypes. These data suggest that high levels of mutated and WT ALK mediate similar molecular functions that may contribute to a malignant phenotype in primary neuroblastoma.
    Type of Publication: Journal article published
    PubMed ID: 21632861
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  • 9
    Keywords: INHIBITOR ; CLASSIFICATION ; GENE-EXPRESSION ; transcription ; RECRUITMENT ; HISTONE DEACETYLASE ; N-MYC ; B-CELL LYMPHOMAS ; HIGH-RISK NEUROBLASTOMA ; PEDIATRIC SOLID TUMORS
    Abstract: Neuroblastoma is an embryonic solid tumor of neural crest origin and accounts for 11% of all cancer-related deaths in children. Novel therapeutic strategies are therefore urgently required. MYCN oncogene amplification, which occurs in 20% of neuroblastomas, is a hallmark of high risk. Here we aimed to exploit molecular mechanisms that can be pharmacologically addressed with epigenetically modifying drugs, such as HDAC inhibitors. GRHL1, a gene critical for Drosophila neural development, belonged to the genes most strongly responding to HDAC inhibitor treatment of neuroblastoma cells in a genome-wide screen. An increase in the histone H4 pan-acetylation associated with its promoter preceded transcriptional activation. Physically adjacent, HDAC3 and MYCN co-localized to the GRHL1 promoter and repressed its transcription. High-level GRHL1 expression in primary neuroblastomas correlated on transcriptional and translational levels with favorable patient survival and established clinical and molecular markers for favorable tumor biology, including lack of MYCN amplification. Enforced GRHL1 expression in MYCN-amplified neuroblastoma cells with low endogenous GRHL1 levels abrogated anchorage-independent colony formation, inhibited proliferation and retarded xenograft growth in mice. GRHL1 knock-down in MYCN single-copy cells with high endogenous GRHL1 levels promoted colony formation. GRHL1 regulated 170 genes genome-wide, and most were involved in pathways regulated during neuroblastomagenesis, including nervous system development, proliferation, cell-cell adhesion, cell spreading and cellular differentiation. In summary, the data presented here indicate a significant role of HDAC3 in the MYCN-mediated repression of GRHL1 and suggest drugs that block HDAC3 activity and suppress MYCN expression as promising candidates for novel treatment strategies of high-risk neuroblastoma.
    Type of Publication: Journal article published
    PubMed ID: 24419085
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  • 10
    Keywords: GENE ; neuroblastoma ; ENHANCERS ; LANDSCAPE ; TERT REARRANGEMENTS
    Abstract: Neuroblastoma is a malignant paediatric tumour of the sympathetic nervous system. Roughly half of these tumours regress spontaneously or are cured by limited therapy. By contrast, high-risk neuroblastomas have an unfavourable clinical course despite intensive multimodal treatment, and their molecular basis has remained largely elusive. Here we have performed whole-genome sequencing of 56 neuroblastomas (high-risk, n = 39; low-risk, n = 17) and discovered recurrent genomic rearrangements affecting a chromosomal region at 5p15.33 proximal of the telomerase reverse transcriptase gene (TERT). These rearrangements occurred only in high-risk neuroblastomas (12/39, 31%) in a mutually exclusive fashion with MYCN amplifications and ATRX mutations, which are known genetic events in this tumour type. In an extended case series (n = 217), TERT rearrangements defined a subgroup of high-risk tumours with particularly poor outcome. Despite a large structural diversity of these rearrangements, they all induced massive transcriptional upregulation of TERT. In the remaining high-risk tumours, TERT expression was also elevated in MYCN-amplified tumours, whereas alternative lengthening of telomeres was present in neuroblastomas without TERT or MYCN alterations, suggesting that telomere lengthening represents a central mechanism defining this subtype. The 5p15.33 rearrangements juxtapose the TERT coding sequence to strong enhancer elements, resulting in massive chromatin remodelling and DNA methylation of the affected region. Supporting a functional role of TERT, neuroblastoma cell lines bearing rearrangements or amplified MYCN exhibited both upregulated TERT expression and enzymatic telomerase activity. In summary, our findings show that remodelling of the genomic context abrogates transcriptional silencing of TERT in high-risk neuroblastoma and places telomerase activation in the centre of transformation in a large fraction of these tumours.
    Type of Publication: Journal article published
    PubMed ID: 26466568
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