Our results indicate that the disruption of the PTEN/MMAC1 gene is not a frequent event in neuroblastoma, and suggest that this disruption may be responsible for malignant progression in only a limited proportion of cases of neuroblastoma.
From our work, we can conclude that PTEN and DMBT1 seem to contribute to the development of a small fraction of neuroblastomas, and that promoter hypermethylation might have a role in DMBT1 gene silencing.
Gastrin-releasing peptide-induced down-regulation of tumor suppressor protein PTEN (phosphatase and tensin homolog deleted on chromosome ten) in neuroblastomas.
Furthermore, PICT-1 was aberrantly expressed in 18 (41%) of 44 human neuroblastoma specimens, and the PICT-1 loss was associated with reduced PTEN protein expression in spite of the existence of PTEN mRNA.
Our analysis of melanoma cell lines suggests that activating mutations in BRAF can occur simultaneously with inactivation of phosphatase and tensin homolog (PTEN), but neuroblastoma RAS (NRAS) mutations are not coincident.
For example, miR-15 and miR-16 induce apoptosis by targeting Bcl2. miRNAs from the miR-17-92 cluster modulate tumor formation and function as oncogenes by influencing the translation of E2F1 mRNA. miR-21 modulates gemcitabine-induced apoptosis by phosphatase and tensin homolog deleted on chromosome 10-dependent activation of PI 3-kinase signaling. miR-34a acts as a suppressor of neuroblastoma tumorigenesis by targeting the mRNA encoding E2F3 and reducing E2F3 protein levels.
This is the first report that combination of 4-HPR and GST mediated reactivation of multiple tumor suppressors (p53, p21, Rb, and PTEN) for early cell cycle exit (due to G1/S phase arrest) in neuroblastoma cells.
The expression of the miRNAs and phosphatase and tensin homolog (PTEN) messenger RNA in the neuroblastoma cells was studied by real-time polymerase chain reaction.
Interestingly, PTEN overexpression decreased GRP-mediated migration and angiogenesis; a novel role for this, otherwise, understated tumor suppressor in 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.
In addition, AZD8055 suppressed the mTOR pathway and increased the expression of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) in the neuroblastoma cells.
In a MYCN transgenic mouse model, loss of one allele of PTEN promoted tumor growth, illustrating the potential role of PTEN in neuroblastoma pathogenesis.