Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Keywords: GENE-EXPRESSION ; DIFFERENTIATION ; TUMORS ; BIOLOGY ; PROGRESSION ; PHENOTYPE ; P-TEFB ; RISK STRATIFICATION ; SUBGROUPS ; MIRNA EXPRESSION
    Abstract: Neuroblastoma, a childhood cancer that originates from neural crest-derived cells, is the most common deadly solid tumor of infancy. Amplification of the MYCN oncogene, which occurs in approximately 20-25% of human neuroblastomas, is the most prominent genetic marker of high-stage disease. The availability of valid preclinical in vivo models is a prerequisite to develop novel targeted therapies. We here report on the generation of transgenic mice with Cre-conditional induction of MYCN in dopamine beta-hydroxylase-expressing cells, termed LSL-MYCN;Dbh-iCre. These mice develop neuroblastic tumors with an incidence of 〉75%, regardless of strain background. Molecular profiling of tumors revealed upregulation of the MYCN-dependent miR-17-92 cluster as well as expression of neuroblastoma marker genes, including tyrosine hydroxylase and the neural cell adhesion molecule 1. Gene set enrichment analyses demonstrated significant correlation with MYC-associated expression patterns. Array comparative genome hybridization showed that chromosomal aberrations in LSL-MYCN;Dbh-iCre tumors were syntenic to those observed in human neuroblastomas. Treatment of a cell line established from a tumor derived from a LSL-MYCN;Dbh-iCre mouse with JQ1 or MLN8237 reduced cell viability and demonstrated oncogene addiction to MYCN. Here we report establishment of the first Cre-conditional human MYCN-driven mouse model for neuroblastoma that closely recapitulates the human disease with respect to tumor localization, histology, marker expression and genomic make up. This mouse model is a valuable tool for further functional studies and to assess the effect of targeted therapies.Oncogene advance online publication, 1 September 2014; doi:10.1038/onc.2014.269.
    Type of Publication: Journal article published
    PubMed ID: 25174395
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    Keywords: CANCER ; EXPRESSION ; GROWTH ; tumor ; CELL ; MODEL ; PATHWAY ; PATHWAYS ; COHORT ; DISEASE ; GENE ; GENE-EXPRESSION ; RNA ; DIFFERENTIATION ; TUMORS ; ACTIVATION ; BINDING ; BIOLOGY ; TARGET ; CHROMATIN ; gene expression ; PROMOTER ; genetics ; MODULATION ; C-MYC ; REPRESSION ; TRANSCRIPTIONAL REPRESSION ; MYCN ; neuroblastoma ; N-MYC ; signaling ; ONCOLOGY ; B-CELL LYMPHOMAS ; miRNA ; outcome ; MICRORNA ; CELL BIOLOGY ; Genetic ; COHORTS ; EXPRESSION SIGNATURES ; PATHWAY DEREGULATION
    Abstract: Increased activity of MYC protein-family members is a common feature in many cancers. Using neuroblastoma as a tumor model, we established a microRNA (miRNA) signature for activated MYCN/c-MYC signaling in two independent primary neuroblastoma tumor cohorts and provide evidence that c-MYC and MYCN have overlapping functions. On the basis of an integrated approach including miRNA and messenger RNA (mRNA) gene expression data we show that miRNA activation contributes to widespread mRNA repression, both in c-MYC- and MYCN-activated tumors. c-MYC/MYCN-induced miRNA activation was shown to be dependent on c-MYC/MYCN promoter binding as evidenced by chromatin immunoprecipitation. Finally, we show that pathways, repressed through c-MYC/MYCN miRNA activation, are highly correlated to tumor aggressiveness and are conserved across different tumor entities suggesting that c-MYC/MYCN activate a core set of miRNAs for cooperative repression of common transcriptional programs related to disease aggressiveness. Our results uncover a widespread correlation between miRNA activation and c-MYC/MYCN-mediated coding gene expression modulation and further substantiate the overlapping functions of c-MYC and MYCN in the process of tumorigenesis. Oncogene (2010) 29, 1394-1404; doi:10.1038/onc.2009.429; published online 30 November 2009
    Type of Publication: Journal article published
    PubMed ID: 19946337
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    Keywords: CANCER ; GENE ; MYCN ; EXPRESSION PROFILES ; receptor tyrosine kinase ; SYMPATHETIC NEURONS ; THERAPEUTIC TARGET ; ACTIVATING MUTATIONS ; MEK INHIBITION ; MUTATED NEUROBLASTOMA
    Abstract: PURPOSE: Activating ALK mutations are present in almost 10% of primary neuroblastomas and mark patients for treatment with small-molecule ALK inhibitors in clinical trials. However, recent studies have shown that multiple mechanisms drive resistance to these molecular therapies. We anticipated that detailed mapping of the oncogenic ALK-driven signaling in neuroblastoma can aid to identify potential fragile nodes as additional targets for combination therapies. EXPERIMENTAL DESIGN: To achieve this goal, transcriptome profiling was performed in neuroblastoma cell lines with the ALK(F1174L) or ALK(R1275Q) hotspot mutations, ALK amplification, or wild-type ALK following pharmacologic inhibition of ALK using four different compounds. Next, we performed cross-species genomic analyses to identify commonly transcriptionally perturbed genes in MYCN/ALK(F1174L) double transgenic versus MYCN transgenic mouse tumors as compared with the mutant ALK-driven transcriptome in human neuroblastomas. RESULTS: A 77-gene ALK signature was established and successfully validated in primary neuroblastoma samples, in a neuroblastoma cell line with ALK(F1174L) and ALK(R1275Q) regulable overexpression constructs and in other ALKomas. In addition to the previously established PI3K/AKT/mTOR, MAPK/ERK, and MYC/MYCN signaling branches, we identified that mutant ALK drives a strong upregulation of MAPK negative feedback regulators and upregulates RET and RET-driven sympathetic neuronal markers of the cholinergic lineage. CONCLUSIONS: We provide important novel insights into the transcriptional consequences and the complexity of mutant ALK signaling in this aggressive pediatric tumor. The negative feedback loop of MAPK pathway inhibitors may affect novel ALK inhibition therapies, whereas mutant ALK induced RET signaling can offer novel opportunities for testing ALK-RET oriented molecular combination therapies. Clin Cancer Res; 21(14); 3327-39. (c)2015 AACR.
    Type of Publication: Journal article published
    PubMed ID: 25805801
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    Keywords: APOPTOSIS ; CANCER ; EXPRESSION ; SITES ; GENE-EXPRESSION ; cell line ; DIFFERENTIATION ; NEUROBLASTOMA-CELLS ; CLEAVAGE ; AMPLIFICATION ; REGIONS ; DNA-DAMAGE ; REVEALS ; TUMOR-SUPPRESSOR ; senescence ; miRNA ; 3p25.3 ; p53 stabilization
    Abstract: Several microRNA (miRNA) loci are found within genomic regions frequently deleted in primary neuroblastoma, including miR-885-5p at 3p25.3. In this study, we demonstrate that miR-885-5p is downregulated on loss of 3p25.3 region in neuroblastoma. Experimentally enforced miR-885-5p expression in neuroblastoma cell lines inhibits proliferation triggering cell cycle arrest, senescence and/or apoptosis. miR-885-5p leads to the accumulation of p53 protein and activates the p53 pathway, resulting in upregulation of p53 targets. Enforced miR-885-5p expression consistently leads to downregulation of cyclin-dependent kinase (CDK2) and mini-chromosome maintenance protein (MCM5). Both genes are targeted by miR-885-5p via predicted binding sites within the 3'-untranslated regions (UTRs) of CDK2 and MCM5. Transcript profiling after miR-885-5p introduction in neuroblastoma cells reveals alterations in expression of multiple genes, including several p53 target genes and a number of factors involved in p53 pathway activity. Taken together, these data provide evidence that miR-885-5p has a tumor suppressive role in neuroblastoma interfering with cell cycle progression and cell survival.
    Type of Publication: Journal article published
    PubMed ID: 21233845
    Signatur Availability
    BibTip Others were also interested in ...
  • 5
    Keywords: RECEPTOR ; CANCER ; EXPRESSION ; N-MYC ; TUMOR-SUPPRESSOR ; MICRORNA ; TRANSCRIPTIONAL TARGET ; THERAPEUTIC TARGET ; ACTIVATING MUTATIONS ; ALK KINASE
    Abstract: Neuroblastoma is an embryonic tumor arising from immature sympathetic nervous system cells. Recurrent genomic alterations include MYCN and ALK amplification as well as recurrent patterns of gains and losses of whole or large partial chromosome segments. A recent whole genome sequencing effort yielded no frequently recurring mutations in genes other than those affecting ALK. However, the study further stresses the importance of DNA copy number alterations in this disease, in particular for genes implicated in neuritogenesis. Here we provide additional evidence for the importance of focal DNA copy number gains and losses, which are predominantly observed in MYCN amplified tumors. A focal 5 kb gain encompassing the MYCN regulated miR-17 approximately 92 cluster as sole gene was detected in a neuroblastoma cell line and further analyses of the array CGH data set demonstrated enrichment for other MYCN target genes in focal gains and amplifications. Next we applied an integrated genomics analysis to prioritize MYCN down regulated genes mediated by MYCN driven miRNAs within regions of focal heterozygous or homozygous deletion. We identified RGS5, a negative regulator of G-protein signaling implicated in vascular normalization, invasion and metastasis, targeted by a focal homozygous deletion, as a new MYCN target gene, down regulated through MYCN activated miRNAs. In addition, we expand the miR-17 approximately 92 regulatory network controlling TGFss signaling in neuroblastoma with the ring finger protein 11 encoding gene RNF11, which was previously shown to be targeted by the miR-17 approximately 92 member miR-19b. Taken together, our data indicate that focal DNA copy number imbalances in neuroblastoma (1) target genes that are implicated in MYCN signaling, possibly selected to reinforce MYCN oncogene addiction and (2) serve as a resource for identifying new molecular targets for treatment.
    Type of Publication: Journal article published
    PubMed ID: 23308108
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...