NEUROTROPHIN RECEPTORS, TUMOR PROGRESSION AND TUMOR MATURATION

The nerve growth factor receptor TrkA was initially isolated as a tran sforming oncogene, trk, in which most of the extracellular receptor pa rt is replaced by the coding sequence for a tropomyosin-encoding gene. The impact that the identification of the first neurotrophin receptor has made on the entire field of developmental neurobiology cannot be overstated, Following a ! brief introduction to the biology of neurotr ophins and their receptors, this review will focus on oncogenic Trk in human malignant disorders, discuss putative tumorigenic involvement o f Trk family members in the childhood malignancy neuroblastoma, and po int out potential neurotrophin-based treatment modalities for this and other neuroendocrine tumors.