It was found that Hsp90 inhibition in neuroblastoma cell lines resulted in significant growth suppression, a decrease in MYCN and MYC expression, and an increase in the expression of p53.
These results, together with those obtained in human neuroblastoma, suggest that the distal part of the short arm of chromosome 1 harbors an unidentified tumor suppressor gene(s), whose inactivation may be involved in MYC family gene amplification (an example of genetic instability) in tumors of various cellular origins.
Here, we found miR-1303 was upregulated in NB cells and tissues, miR-1303 overexpression promoted the proliferation of SH-SY5Y NB cell investigated by MTT assay, colony formation assay and anchorage-independent growth ability assay, while miR-1303 knockdown reduced this effect. mechanism analysis suggested glycogen synthase kinase 3 beta (GSK3β) and secreted frizzled-related protein 1 (SFRP1) were the target of miR-1303, luciferase assay revealed miR-1303 directly bound to the 3'UTR of GSK3β and SFRP1. miR-1303 increased expression of MYC and CyclinD1, and decreased the expression of p21 and p27, and further demonstrated miR-1303 promotes NB proliferation.
As these results are of potential clinical importance, but not in agreement with our own initial observations, the putative correlation between ID2 and MYC(N) expression in neuroblastoma cell lines and tumors was reinvestigated.
Specific inhibition of hyperactive rRNA synthesis and protein translation was shown to be an effective way to suppress MYC/MYCN protein expression and neuroblastoma growth.
An element in the region responsible for premature termination of transcription mediates repression of c-myc gene expression by thyroid hormone in neuroblastoma cells.
We review the latest approaches envisioned for blockade of ALK activity in neuroblastoma, present a classification of potential approaches for therapeutic targeting of MYCN, and discuss how recent developments in targeting of MYC proteins seem to make therapeutic inhibition of MYCN a reality in the clinic.
The N-myc gene, first detected by its homology to the second exon of the c-myc gene, is amplified and/or expressed in tumours or cell lines derived from neuroblastoma, retinoblastoma and SCLC.
MYCN and MYC play a crucial role in determining the malignancy of unfavorable neuroblastomas, whereas high-level expression of the favorable neuroblastoma genes is associated with a good disease outcome and confers growth suppression of neuroblastoma cells.
Clinical data set analysis of MYCN, MYC and TWIST1 expression permits us to confirm that TWIST1 expression is upregulated in MYCN amplified neuroblastoma but also in a subset of neuroblastoma harboring high expression of MYCN or MYC without gene amplification.
Exposures mimicking conditions of CO (2) pneumoperitoneum lead to significant overexpression of C-MYC and HMGB-1 in neuroblastoma cells with decreased apoptosis.
Amplification of the MYCN is the predominant marker for aggressive NB and correlates with poor prognosis, while c-MYC overexpression is a defining feature of MB subgroups inflected with aggressive biological behavior and increased likelihood of metastasis.
MYC has been shown to associate with DNA methyltransferases, thereby inducing transcriptional repression of target genes, which suggested that MYCN might play a similar mechanistic role in the hypermethylation of tumor suppressor genes in neuroblastoma.