The developmental and stress-regulated alternative TrkAIII splice variant of the NGF receptor TrkA is expressed by advanced stage human neuroblastomas (NBs), correlates with worse outcome in high TrkA expressing unfavourable tumours and exhibits oncogenic activity in NB models.
The present studies demonstrate that the effects of necdin on the susceptibility of neuroblastoma cells to oxidant stress are dependent on the ratio of p75NTR to TrkA in the cell.
By directly connecting MYCN to the repression of TRKA and p75NTR, our findings establish a key pathway of clinical pathogenicity and aggressiveness in neuroblastoma.
However, the spontaneous regression of neuroblastoma mimics the programmed cell death normally occurring in developing sympathetic cells expressing both TrkA tyrosine kinase A and p75NTR neurotrophin receptor.
Neurotrophins (NTs) bind to two different classes of cell surface receptors, Trk receptor tyrosine kinases and p75NTR, both of which are expressed by neuroblastoma cells.
Here we demonstrate that NGF-but not neurotrophin-3 (NT-3) or brain-derived neurotrophic factor (BDNF)-induced apoptosis in p75NTR-expressing human neuroblastoma SK-N-MC cells.BDNF prevented NGF-induced apoptosis.
In neuroblastoma tumours, the expression of high levels of trk-A mRNA, which encodes the high-affinity nerve growth factor (NGF) receptor, is associated with good prognosis.
It is concluded that neuroblastomas coexpressing mRNA for both NGF receptor subtypes are favorable tumors likely to differentiate or regress spontaneously or respond to conventional therapy.
A tumor with a functional nerve growth factor receptor may be dependent on the neurotrophin nerve growth factor for survival and may regress in its absence, allowing a new approach to the treatment of certain patients with neuroblastoma.
This retrospective study was designed to determine if expression of nerve growth factor receptor messenger RNA (mRNA) was associated with biologic and clinical parameters and with survival in neuroblastoma.
These results, indicating an inverse relationship between N-myc and NGF-r expression, could help in establishing markers for differentiation, and thus prognosis, in neuroblastoma.
These results demonstrate that NGFR is a biological marker for neuroepithelioma and that NGFR expression is heterogeneous for neuroblastoma cell lines.
Several antibodies to melanoma and neuroblastoma associated antigens including two monoclonal antibodies to the nerve growth factor receptor were also found to react with Ewing cells.