Here we demonstrate that PI3K/Akt pathway is crucial for the upregulation of P2X7R expression in serum-deprived neuroblastoma cells, circumstance that facilitates cell proliferation in the absence of trophic support.
Since detection of PGP9.5 and TH gene transcripts by the "touchdown" PCR was highly specific and sensitive, it might be most informative at present to carry out both PGP9.5 and TH mRNA assays for minimal residual neuroblastoma cells in blood and bone marrow.
This study offers compelling evidence that (a) IGR-N-91 is a human neuroblastoma xenograft model able to induce metastasis in nude mice, (b) an increase in MYCN and MDR1 transcripts levels is associated with the metastatic process, and (c) IGR-N-91 provides a biological tool for the study of gene activations during tumor dissemination in neuroblastoma.
We conditionally activated N-myc in SH-EP neuroblastoma cells subjected to the trophic stress of serum or nutrient deprivation while changing the expression of Bcl-2, survivin and FLIP(L), antiapoptotic molecules often overexpressed in poor prognosis neuroblastomas.
Our results suggest that enhanced MYCN expression in human neuroblastoma cells alters the angiogenic balance by down-regulating endothelial cell growth inhibitors but leaving the expression of the stimulators unaffected.
The potential mechanisms for the inhibition of NB migration and invasion by vandetanib may partly be attributed to the ability of vandetanib to suppress the expression of CXCR4 and MMP14 in human NB cells.
We show that the glial cell line-derived neurotrophic factor (GDNF) activates the PI3K/Akt-signaling pathway in human neuroblastoma cells that express functional Ret-receptor complexes.
In addition, we observed that neuroblastoma is associated to significantly higher levels of cyclin D1 as compared to both ganglioneuroma and ganglioneuroblastoma.
Conversely, overexpression of synapsins in neuroblastoma cells results in corresponding reciprocal changes in raft lipid composition, increased localization of Fyn to rafts and promotion of BDNF-stimulated neurite formation.
Because expression of mdr-1 is increased in neuroblastoma cell lines by differentiating agents, the authors hypothesized a similar correlation with differentiation in vivo in neuroblastomas.
To gain an insight into the distribution of MYCN binding and to identify clinically relevant MYCN target genes, we performed an integrated analysis of MYCN ChIP-chip and mRNA expression using the MYCN repressible SHEP-21N neuroblastoma cell line.
Further, combination of KLF4 overexpression and APG treatment was highly effective in inhibiting migration of both neuroblastoma cell lines and was associated with down regulation of matrix metalloproteinases (MMPs) such as MMP-2 and MMP-9.
The finding that, in neuroblastoma cells, selected signal transduction systems are involved in the insulin-dependent activation of estrogen receptor is of particular interest considering that estrogen receptor might restrict the role played by insulin during the differentiation of neural cells and interfere with its proliferative potential while allowing its regulation of other functions related to cell survival.
Our results revealed that BDE-47 significantly triggered the metastasis of human neuroblastoma SH-SY5Y cells via upregulation of MMP-9 by the GPER/PI3K/Akt signal pathway.
We therefore investigated whether PACAP affected the VIP gene expression and elucidated the molecular mechanisms using the human neuroblastoma cell line NB-1.
Expression of brain-derived neurotrophic factor (BDNF) was stimulated in human neuroblastoma SH-SY5Y cells by a nonprotein extract of inflamed rabbit skin inoculated with vaccinia virus (Neurotropin), an analgesic widely used in Japan for treatment of disorders associated with chronic pain, with the optimal dosage at 10mNU/mL.
An examination of human neuroblastoma tumor tissues for IGF-II gene expression using in situ hybridization histochemistry revealed that IGF-II is expressed by tumor cells in only 5 of 21 neuroblastomas, but is detectable in cells of nonmalignant tissues including adrenal cortical cells, stromal fibroblasts, and eosinophils in all 21 tumors.
The level of tyrosine phosphorylation of the 150 kDa proto-Ret protein was approximately 10-fold higher than that of the 170 kDa proto-Ret protein, although both proteins were expressed at similar levels in neuroblastoma cells.
Given the importance of MRP1 overexpression in neuroblastoma, MRP1 inhibition may be a clinically relevant approach to improving patient outcome in this disease.