Abstract
Purpose: :
To evaluate the expression of neurotrophin receptor, Trk A and Trk B in retinoblastoma and to elucidate the potential role in the differentiation of retinoblastoma cells
Methods: :
Y79, SNUOT-Rb1 or -Rb4 retiniblastoma cells were injected into the intravitreal cavity of nude mice, and enucleation was performed 4 weeks later. Immunohistochemistry for TrkA and TrkB was performed which was merged with Ki67, nm23, or TUNEL. With treatment of retinoic acid, TrkA and TrkB expression in retinoblastoma cells was measured by western blotting. With treatment of nerve growth factor (NGF) or brain-derived neurotrophic factor (BDNF), the differentiation of retinoblastoma cells was evaluated.
Results: :
In animal model of retinoblastoma with Y79, SNUOT-RB1, and Rb-4, TrkA was highly expressed in the differentiated area of retinoblastoma, whereas TrkB expression was prominent in the progressive area. With treatment of retinoblastoma cells by retinoic acid, TrkA expression was increased with differentiation being characterized by morphological changes of improved attachment neurite outgrowth. However, TrkB expression was decreased with differentiation of retinoblastoma cells. The differentiation of retinoblastoma cells was induced by NGF, but not by BDNF.
Conclusions: :
Our results suggest that differential expression of TrkA and TrkB may be related to differentiation of retinoblastoma cells. Interestingly, TrkA could contribute to differentiation of retinoblastoma cells.