Amplification of the MYCN oncogene, a member of the MYC family of transcriptional regulators, is one of the most powerful prognostic markers identified for poor outcome in neuroblastoma, the most common extracranial solid cancer in childhood.
Translocation (e.g., c-myc in Burkitt's lymphoma), or amplification (e.g., N-myc in neuroblastoma) of myc genes has been causally linked to tumor formation.
Here, we review the potential clinical application of these and additional polyamine depletion agents to neuroblastoma and other advanced cancers in which MYC is operative.
MYC coordinately regulates polyamine homeostasis as these essential cations support MYC functions, and drugs that antagonize polyamine sufficiency have synthetic-lethal interactions with MYCNeuroblastoma is a lethal tumor in which the MYC homologue MYCN, and ODC1, the rate-limiting enzyme in polyamine synthesis, are frequently deregulated so we tested optimized polyamine depletion regimens for activity against neuroblastoma.
In MYC-amplified neuroblastoma patient samples, there was a significant correlation between SHMT2 and hypoxia-inducible factor-1 α (HIF1α), and SHMT2 expression correlated with unfavorable patient prognosis.
We found that MYCN/MYC-mediated overactivation of the metaphase-anaphase checkpoint synergizes with loss of p53-p21 function to prevent arrest or apoptosis of tetraploid neuroblastoma cells.
This hypothesis-driven systems bioinformatics work offered novel insights into the PRC2-mediated tumor cell growth and differentiation in neuroblastoma, which may exert oncogenic effects together with MYC regulation.
For in vivo validation we selected CSNK1e, a kinase whose expression correlated with MYCN amplification in neuroblastoma (an established MYC-driven cancer).
The involvement of the MYC-MAX-MXD1 network in the development and progression of neural crest cell tumors is further supported by the lack of functional MAX in rat PCC (PC12) cells and by the amplification of MYCN in neuroblastoma and suggests that loss of MAX function is correlated with metastatic potential.
N-myc is a DNA sequence which shares limited homology to the proto-oncogene c-myc and has been found to be amplified in both primary tissue and cell lines from neuroblastoma, a childhood tumour of neuroectodermal origin.
These data suggest that epigenetic and posttranslational inhibition of MYC/MYCN-driven pathways may have significant clinical efficacy against neuroblastoma.
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.
These data implicate tissue-specific enhancers in defining often highly tumor-specific 'MYC target gene signatures' and identify disruption of the MYCN enhancer regulatory axis as a promising therapeutic strategy in neuroblastoma.
MYC and MYCN control the expression of PD-L1 in neuroblastoma cells both <i>in vitro</i> and <i>in vivo</i> Consistently, abundance of PD-L1 transcript correlates with MYC expression in primary neuroblastoma.<b>Conclusions:</b> The combination of PD-L1 and HLA class I represents a novel prognostic biomarker for neuroblastoma.
TFs like MYC and PTEN having six types of adjacent nodes and other classes of TFs investigated really can help to demonstrate that TFs affect pathways through expressions of significant miRNAs involved in the pathogenesis of NB.
Applying this technique, we followed the metaphase location and interphase position of amplified DNA sequences corresponding to the SAMK, MYC, and MYCN genes in four cell lines derived from human tumors: two gastric carcinoma lines (KATO III and SNU-16), a neuroblastoma (NUB-7), and a neuroepithelioma (NUB-20) line.
Taken together our data suggest that these small molecules may hold potential as effective therapeutic agents for the treatment of neuroblastoma and other MYC-driven cancers.
Significant promoter activity in the presence of abundant Myc protein in amplified neuroblastoma lines indicates that autoregulation is disabled in this subset of tumors.