Expression and function of Trk-C in favourable human neuroblastomas.

Human neuroblastomas express the neurotrophin receptors trk-A and trk-B. Favourable outcome is associated with expression of trk-A, while unfavourable, MYCN amplified tumours express trk-B. In this study we examined the expression of trk-C in primary neuroblastoma tumour-derived cell lines. We found by Northern blot analysis that trk-C mRNA is expressed in 14 of 55 (25%) primary tumours. Trk-C was expressed in significantly more lower stage tumours (stage 1, 2, 4S) than higher stage tumours (stage 3, 4, P < 0.04). The expression of trk-C was correlated positively with survival and negatively correlated with MYCN amplification. We also studied the function of trk-C in transfected cell lines and found that NT-3 promotes both cell survival and differentiation. Our results suggest that trk-C is involved in the biology of favourable neuroblastomas.