Effect of nerve growth factor on the expression of colchicine-binding activity and 14-3-2 protein in an established line of human neuroblastoma.

Abstract

Purified nerve growth factor induced the outgrowth of neurites from cultured human neuroblastoma cells (NJB line) and a concomitant increase in colchicine-binding activity in extracts from these cultures. The parallel stimulation of neurite outgrowth from the cells and colchicine-binding activity of the extracts is interpreted to represent de novo synthesis of microtubular subunit protein in response to the challenge by nerve growth factor. The regulation of the expression of 14-3-2 protein, a protein characteristic of differentiated neuronal cells, was not affected in NJB cells by the addition of nerve growth factor to the culture medium. 14-3-2 protein is present in NJB cells at a concentration equal to that present in human brain from subculture to the stationary phase of growth of the tumor cells. It was concluded that these two gene products, characteristic of differentiated neural cells, are not coordinately regulated in NJB human neuroblastoma cells.