Elimination of MYCN-Amplified Neuroblastoma Cells by Telomerase-Targeted Oncolytic Virus via MYCN Suppression.
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ABSTRACT:
SUBMITTER: Tanimoto T
PROVIDER: S-EPMC7321810 | biostudies-literature | 2020 Sep
REPOSITORIES: biostudies-literature
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Project description:Polycomb-group complexes are evolutionarily conserved epigenetic machineries that regulate stem cell fate decisions/development and are also implicated in tumorigenesis mainly by histone modification. PRC1 complexes mediates ubiquitylation of histone H2A on lysine 119 and consists of PRC1.1 to PRC1.6 complexes. Here, we studied the functional roles of a PRC1.6 molecule L3MBTL2 in neuroblastoma (NB) cells. L3MBTL2 knockout- and knockdown-experiments elucidated that L3MBTL2 depletion suppressed NB cell proliferation according with cell cycle arrest and gamma-H2A up-regulation. L3MBTL2 knockout profoundly suppressed xenograft tumor formation. Transcriptome analysis detected the suppressed cell cycle-related pathways and the activated the differentiation-related pathways. The remarkable de-repressed genes by the L3MBTL2 knockout were BRME1 and NRIP3. ChIP experiments showed co-localization of the PRC1.6 components PCGF6/E2F6/L3MBTL2 and MYCN at the transcription start sites (TSS) of these genes. L3MBTL2 knockout reduced H2AK119ub marks at the TSS regions but PCGF6 binding was heterogeneously changed. This study clarified the significance of PRC1.6 molecule L3MBTL2 in NB cell homeostasis and the epigenetic mechanism of the L3MBTL2-mediated gene suppression in NB that regulates the PRC1.6 complex localization and H2AK119 mono-ubiquitination in a gene locus-specific manner.
2023-09-26 | GSE201512 | GEO
Project description:Neuroblastomas are the most common extracranial solid tumors in children and have a unique feature of neuronal differentiation. Peroxisome proliferator-activated receptor (PPAR)-γ is reported to have neuroprotective effects in addition to having antitumor effects in various cancers. Thus, we aimed to clarify the role of PPAR-γ agonist and antagonist in malignant neuroblastomas, which also possess neuronal features. In MYCN-amplified neuroblastoma CHP212 cells, treatment with the PPAR-γ antagonist GW9662 induced growth inhibition in a dose-dependent manner. In addition, the PPAR-γ antagonist treatment changed cell morphology with increasing expression of the neuronal differentiation marker tubulin beta 3 (TUBB3) and induced G1 phase arrest and apoptosis in MYCN-amplified neuroblastoma. Notably, the PPAR-γ antagonist treatment significantly decreased expression of NMYC, B-cell lymphoma 2 (BCL2) and bromodomain-containing protein 4 (BRD4). It is implied that BRD4, NMYC, BCL2 suppression by the PPAR-γ antagonist resulted in cell growth inhibition, differentiation, and apoptosis induction. In our in vivo study, the PPAR-γ antagonist treatment induced CHP212 cells differentiation and resultant tumor growth inhibition. Our results provide a deeper understanding of the mechanisms of tumor cell differentiation and suggest that PPAR-γ antagonist is a new therapeutic and prevention option for neuroblastomas.
| S-EPMC10636585 | biostudies-literature
Project description:To investigate genetic predispositions for MYCN-amplified neuroblastoma, we performed a meta-analysis of three genome-wide association studies totaling 615 MYCN-amplified high-risk neuroblastoma cases and 1869 MYCN-nonamplified non-high-risk neuroblastoma cases as controls using a fixed-effects model with inverse variance weighting. All statistical tests were two-sided. We identified a novel locus at 3p21.31 indexed by the single nucleotide polymorphism (SNP) rs80059929 (odds ratio [OR] = 2.95, 95% confidence interval [CI] = 2.17 to 4.02, Pmeta = 6.47?×?10-12) associated with MYCN-amplified neuroblastoma, which was replicated in 127 MYCN-amplified cases and 254 non-high-risk controls (OR?=?2.30, 95% CI?=?1.12 to 4.69, Preplication = .02). To confirm this signal is exclusive to MYCN-amplified tumors, we performed a second meta-analysis comparing 728 MYCN-nonamplified high-risk patients to identical controls. rs80059929 was not statistically significant in MYCN-nonamplified high-risk patients (OR?=?1.24, 95% CI?=?0.90 to 1.71, Pmeta = .19). SNP rs80059929 is within intron 16 in the KIF15 gene. Additionally, the previously reported LMO1 neuroblastoma risk locus was statistically significant only in patients with MYCN-nonamplified high-risk tumors (OR?=?0.63, 95% CI?=?0.53 to 0.75, Pmeta = 1.51?×?10-8; Pmeta = .95). Our results indicate that common genetic variation predisposes to different neuroblastoma genotypes, including the likelihood of somatic MYCN-amplification.
| S-EPMC6279278 | biostudies-literature
Project description:Neuroblastoma (NB), a childhood cancer arising from the neural crest, poses significant clinical challenges, particularly in cases featuring amplification of the MYCN oncogene. Epigenetic factors play a pivotal role in normal neural crest and NB development, influencing gene expression patterns critical for tumorigenesis. This review delves into the multifaceted interplay between MYCN and known epigenetic modifications during NB genesis, shedding light on the intricate regulatory networks underlying the disease. We provide an extensive survey of known epigenetic mechanisms, encompassing DNA methylation, histone modifications, non-coding RNAs, super-enhancers (SEs), bromodomains (BET), and chromatin modifiers in MYCN-amplified (MNA) NB. These epigenetic changes collectively contribute to the dysregulated gene expression landscape observed in MNA NB. Furthermore, we review emerging therapeutic strategies targeting epigenetic regulators, including histone deacetylase inhibitors (HDACi), histone methyltransferase inhibitors (HMTi), and DNA methyltransferase inhibitors (DNMTi). We also discuss and summarize current drugs in preclinical and clinical trials, offering insights into their potential for improving outcomes for MNA NB patients.
| S-EPMC10707345 | biostudies-literature
Project description:The MYC oncogenes and p53 have opposing yet interrelated roles in normal development and tumorigenesis. How MYCN expression alters the biology and clinical responsiveness of pediatric neuroblastoma remains poorly defined. Neuroblastoma is p53 wild type at diagnosis and repression of p53 signaling is required for tumorigenesis. Here, we tested the hypothesis that MYCN amplification alters p53 transcriptional activity in neuroblastoma. Interestingly, we found that MYCN directly binds to the tetrameric form of p53 at its C-terminal domain, and this interaction is independent of MYCN/MAX heterodimer formation. Chromatin analysis of MYCN and p53 targets reveals dramatic changes in binding, as well as co-localization of the MYCN-p53 complex at p53-REs and E-boxes of genes critical to DNA damage responses and cell cycle progression. RNA sequencing studies show that MYCN-p53 co-localization significantly modulated the expression of p53 target genes. Furthermore, MYCN-p53 interaction leads to regulation of alternative p53 targets not regulated in the presence of low MYCN levels. These novel targets include a number of genes involved in lipid metabolism, DNA repair, and apoptosis. Taken together, our findings demonstrate a novel oncogenic role of MYCN as a transcriptional co-regulator of p53 in high-risk MYCN amplified neuroblastoma. Targeting this novel oncogenic function of MYCN may enhance p53-mediated responses and sensitize MYCN amplified tumors to chemotherapy.
| S-EPMC5945521 | biostudies-literature
Project description:Neuroblastoma is a pediatric malignancy that arises from the neural crest, and patients with high-risk neuroblastoma, which typically harbor amplifications of MYCN, have an extremely poor prognosis. The tyrosine hydroxylase (TH) promoter-driven TH-MYCN transgenic mouse model faithfully recapitulates many hallmarks of human MYCN-amplified neuroblastoma. A key downstream target of Myc oncoproteins in tumorigenesis is ornithine decarboxylase (Odc), the rate-limiting enzyme of polyamine biosynthesis. Indeed, sustained treatment with the Odc suicide inhibitor alpha-difluoromethylornithine (DFMO) or Odc heterozygosity markedly impairs lymphoma development in Emicro-Myc transgenic mice, and these effects are linked to the induction of the cyclin-dependent kinase (Cdk) inhibitor p27(Kip1), which is normally repressed by Myc. Here, we report that DFMO treatment, but not Odc heterozygosity, impairs MYCN-induced neuroblastoma and that, in this malignancy, transient DFMO treatment is sufficient to confer protection. The selective anticancer effects of DFMO on mouse and human MYCN-amplified neuroblastoma also rely on its ability to disable the proliferative response of Myc, yet in this tumor context, DFMO targets the expression of the p21(Cip1) Cdk inhibitor, which is also suppressed by Myc oncoproteins. These findings suggest that agents, such as DFMO, that target the polyamine pathway may show efficacy in high-risk, MYCN-amplified neuroblastoma.
| S-EPMC2749594 | biostudies-literature
Project description:Neuroblastoma is the most common pediatric cancer, arising from the neural crest cells of the sympathetic nervous system. Its most aggressive subtype, characterized by the amplification of the MYCN oncogene, has a dismal prognosis and no effective treatment is available. Understanding the alterations induced by the tumor on the various layers of gene expression is therefore important for a complete characterization of this neuroblastoma subtype and for the discovery of new therapeutic opportunities. Here we describe the profiling of 13 MYCN-amplified neuroblastoma cell lines at the genome (copy number), transcriptome, translatome and miRome levels (GEO series GSE56654, GSE56552 and GSE56655). We provide detailed experimental and data analysis procedures by means of which we derived the results described in [1].
| S-EPMC4664780 | biostudies-literature
Project description:To evaluate the expression of genes associated with MYCN in NB, 10 tumors with MYCN amplification and 10 with normal MYCN copy number were subjected to oligonucleotide microarray using Agilent oligo microarray chips. Two-condition experiment, MYCN normal vs. MYCN amplified 10 NB patient tissues for each group.
2013-12-17 | E-GEOD-53371 | biostudies-arrayexpress
Project description:Aurora kinases regulate key stages of mitosis including centrosome maturation, spindle assembly, chromosome segregation, and cytokinesis. Aurora A and B kinase overexpression has also been associated with various human cancers, and as such, they have been extensively studied as novel antimitotic drug targets. Here, we characterize the Aurora kinase inhibitor CCT137690, a highly selective, orally bioavailable imidazo[4,5-b]pyridine derivative that inhibits Aurora A and B kinases with low nanomolar IC(50) values in both biochemical and cellular assays and exhibits antiproliferative activity against a wide range of human solid tumor cell lines. CCT137690 efficiently inhibits histone H3 and transforming acidic coiled-coil 3 phosphorylation (Aurora B and Aurora A substrates, respectively) in HCT116 and HeLa cells. Continuous exposure of tumor cells to the inhibitor causes multipolar spindle formation, chromosome misalignment, polyploidy, and apoptosis. This is accompanied by p53/p21/BAX induction, thymidine kinase 1 downregulation, and PARP cleavage. Furthermore, CCT137690 treatment of MYCN-amplified neuroblastoma cell lines inhibits cell proliferation and decreases MYCN protein expression. Importantly, in a transgenic mouse model of neuroblastoma that overexpresses MYCN protein and is predisposed to spontaneous neuroblastoma formation, this compound significantly inhibits tumor growth. The potent preclinical activity of CCT137690 suggests that this inhibitor may benefit patients with MYCN-amplified neuroblastoma.
| S-EPMC4298164 | biostudies-literature
Project description:Neuroblastoma derived from primitive sympathetic neural precursors is a common type of solid tumor in infants. MYCN proto?oncogene bHLH transcription factor (MYCN) amplification and 1p36 deletion are important factors associated with the poor prognosis of neuroblastoma. Expression levels of MYCN and c?MYB proto?oncogene transcription factor (c?myb) decline during the differentiation of neuroblastoma cells; E2F transcription factor 1 (E2F1) activates the MYCN promoter. However, the underlying mechanism of MYCN overexpression and amplification requires further investigation. In the present study, potential c?Myb target genes, and the effect of c?myb RNA interference (RNAi) on MYCN expression and amplification were investigated in MYCN?amplified neuroblastoma cell lines. The mRNA expression levels and MYCN gene copy number in five neuroblastoma cell lines were determined by quantitative polymerase chain reaction. In addition, variations in potential target gene expression and MYCN gene copy number between pre? and post?c?myb RNAi treatment groups in MYCN?amplified Kelly, IMR32, SIMA and MHH?NB?11 cell lines, normalized to those of non?MYCN?amplified SH?SY5Y, were examined. To determine the associations between gene expression levels and chromosomal aberrations, MYCN amplification and 1p36 alterations in interphases/metaphases were analyzed using fluorescence in situ hybridization. Statistical analyses revealed correlations between 1p36 alterations and the expression of c?myb, MYB proto?oncogene like 2 (B?myb) and cyclin dependent kinase inhibitor 1A (p21). Additionally, the results of the present study also demonstrated that c?myb may be associated with E2F1 and L3MBTL1 histone methyl?lysine binding protein (L3MBTL1) expression, and that E2F1 may contribute to MYCN, B?myb, p21 and chromatin licensing and DNA replication factor 1 (hCdt1) expression, but to the repression of geminin (GMNN). On c?myb RNAi treatment, L3MBTL1 expression was silenced, while GMNN was upregulated, indicating G2/M arrest. In addition, MYCN gene copy number increased following treatment with c?myb RNAi. Notably, the present study also reported a 43.545% sequence identity between upstream of MYCN and Drosophila melanogaster amplification control element 3, suggesting that expression and/or amplification mechanisms of developmentally?regulated genes may be evolutionarily conserved. In conclusion, c?myb may be associated with regulating MYCN expression and amplification. c?myb, B?myb and p21 may also serve a role against chromosome 1p aberrations. Together, it was concluded that MYCN gene is amplified during S phase, potentially via a replication?based mechanism.
| S-EPMC6297758 | biostudies-literature