Dataset Information

MiRNA expression profiling of the murine TH-MYCN neuroblastoma model reveals similarities with human tumors and identifies novel candidate miRNAs.

ABSTRACT:

Background

MicroRNAs are small molecules which regulate gene expression post-transcriptionally and aberrant expression of several miRNAs is associated with neuroblastoma, a childhood cancer arising from precursor cells of the sympathetic nervous system. Amplification of the MYCN transcription factor characterizes the most clinically aggressive subtype of this disease, and although alteration of p53 signaling is not commonly found in primary tumors, deregulation of proteins involved in this pathway frequently arise in recurrent disease after pharmacological treatment. TH-MYCN is a well-characterized transgenic model of MYCN-driven neuroblastoma which recapitulates many clinicopathologic features of the human disease. Here, we evaluate the dysregulation of miRNAs in tumors from TH-MYCN mice that are either wild-type (TH-MYCN) or deficient (TH-MYCN/p53ER(TAM)) for the p53 tumor suppressor gene.

Principal findings

We analyzed the expression of 591 miRNAs in control (adrenal) and neuroblastoma tumor tissues derived from either TH-MYCN or TH-MYCN/p53ER(TAM) mice, respectively wild-type or deficient in p53. Comparing miRNA expression in tumor and control samples, we identified 159 differentially expressed miRNAs. Using data previously obtained from human neuroblastoma samples, we performed a comparison of miRNA expression between murine and human tumors to assess the concordance between murine and human expression data. Notably, the miR-17-5p-92 oncogenic polycistronic cluster, which is over-expressed in human MYCN amplified tumors, was over-expressed in mouse tumors. Moreover, analyzing miRNAs expression in a mouse model (TH-MYCN/p53ER(TAM)) possessing a transgenic p53 allele that drives the expression of an inactive protein, we identified miR-125b-3p and miR-676 as directly or indirectly regulated by the level of functional p53.

Significance

Our study represents the first miRNA profiling of an important mouse model of neuroblastoma. Similarities and differences in miRNAs expression between human and murine neuroblastoma were identified, providing important insight into the efficacy of this mouse model for assessing miRNA involvement in neuroblastoma and their potential effectiveness as therapeutic targets.

SUBMITTER: Terrile M

PROVIDER: S-EPMC3229581 | biostudies-literature | 2011

REPOSITORIES: biostudies-literature

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miRNA expression profiling of the murine TH-MYCN neuroblastoma model reveals similarities with human tumors and identifies novel candidate miRNAs.

Terrile Marta M Bryan Kenneth K Vaughan Lynsey L Hallsworth Albert A Webber Hannah H Chesler Louis L Stallings Raymond L RL

PloS one 20111202 12

<h4>Background</h4>MicroRNAs are small molecules which regulate gene expression post-transcriptionally and aberrant expression of several miRNAs is associated with neuroblastoma, a childhood cancer arising from precursor cells of the sympathetic nervous system. Amplification of the MYCN transcription factor characterizes the most clinically aggressive subtype of this disease, and although alteration of p53 signaling is not commonly found in primary tumors, deregulation of proteins involved in th ...[more]

PMID: 22164278

Similar Datasets

Project description:BackgroundThe TH-MYCN transgenic neuroblastoma model, with targeted MYCN expression to the developing neural crest, has been used to study neuroblastoma development and evaluate novel targeted tumor therapies.MethodsWe followed tumor development in 395 TH-MYCN (129X1/SvJ) mice (125 negative, 206 hemizygous and 64 homozygous mice) by abdominal palpations up to 40 weeks of age. DNA sequencing of MYCN in the original plasmid construct and mouse genomic DNA was done to verify the accuracy. Copy number analysis with Affymetrix® Mouse Diversity Genotyping Arrays was used to characterize acquired genetic aberrations.ResultsDNA sequencing confirmed presence of human MYCN cDNA in genomic TH-MYCN DNA corresponding to the original plasmid construct. Tumor incidence and growth correlated significantly to transgene status with event-free survival for hemizygous mice at 50%, and 0% for homozygous mice. Hemizygous mice developed tumors at 5.6-19 weeks (median 9.1) and homozygous mice at 4.0-6.9 weeks (5.4). The mean treatment window, time from palpable tumor to sacrifice, for hemizygous and homozygous mice was 15 and 5.2 days, respectively. Hemizygous mice developing tumors as early as homozygous mice had a longer treatment window. Age at tumor development did not influence treatment window for hemizygous mice, whereas treatment window in homozygous mice decreased significantly with increasing age. Seven out of 10 analysed tumors had a flat DNA profile with neither segmental nor numerical chromosomal aberrations. Only three tumors from hemizygous mice showed acquired genetic features with one or more numerical aberrations. Of these, one event corresponded to gain on the mouse equivalent of human chromosome 17.ConclusionHemizygous and homozygous TH-MYCN mice have significantly different neuroblastoma incidence, tumor growth characteristics and treatment windows but overlap in age at tumor development making correct early genotyping essential to evaluate therapeutic interventions. Contrasting previous studies, our data show that TH-MYCN tumors have few genetic aberrations.