The expression of gp140TRK-A mRNA correlates with distinct biologic and clinical subsets of neuroblastoma, which suggests a role for the high-affinity nerve growth factor receptors in determining the phenotype of neuroblastoma.
Thus, the restoration of the NGF-induced differentiation pathway by exogenous TRK-A presents a system of NGF-responsive human cultured cells and focuses attention on the trk-A protein and its function or malfunction in neuroblastoma.
A total of 108 tumours were classified as neuroblastoma or ganglioneuroblastoma; 74 expressed TRKA protein, which strongly correlated with low stage, absence of N-MYC amplification, age (<1 year), CD44 expression and favourable clinical outcome.
Northern blotting and nuclear run-on analyses demonstrated that transcription is a primary determinant of both cell-specific and variable expression of the TrkA gene in neuroblastoma cell lines that express it to different degrees.
Expression level of trkA tyrosine kinase receptor for nerve growth factor is a major prognostic determinant of neuroblastoma, suggesting that defective trkA-mediated signaling is responsible for the tumorigenesis of this childhood malignancy.
The MP-N-TS cell line should be useful for clarifying the TRK-A and TRK-B signaling pathways responsible for the different prognoses in patients with NB.
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.
We suggest that the transcriptional program of neuroblastoma cells is modulated by Trk-receptor expression and basal activation rather than by ligand-induced activation.
Because the Shc family proteins (ShcA, ShcB, and ShcC) are adaptors for various receptors, including Trk receptors, and are regulators of neuronal cell development, we speculated that they may play a role in neuroblastoma.
Because another marker of poor prognosis in neuroblastoma tumors is high expression of brain-derived neurotrophic factor (BDNF) and its tyrosine kinase receptor, TrkB, we sought to evaluate the involvement of BDNF and TrkB in the regulation of VEGF expression.
Furthermore, MIZ-1 expression was positively correlated with the expression of favorable neuroblastoma genes (EFNB2, EFNB3, EPHB6, and NTRK1) in the human neuroblastoma xenograft therapeutic models.
Here, we used the SH-SY5Y human neuroblastoma cell line ectopically expressing either TrkA or TrkB as a model system to analyze the impact of Trk receptor expression on NHEJ-mediated DSB repair.
Expression of Trk receptors has been implicated in the pathogenesis and prognosis of embryonal tumors, including neuroblastoma, nephroblastoma, and medulloblastoma.
NTRK1 c.1810C>T polymorphism appears to be a new independent prognostic factor of poor outcome in neuroblastoma, especially in children under 18 months of age with no MYCN amplification.