Long-Term Tissue Culture of Neuroblastomas. III. In Vitro Studies of a Nerve Growth-Stimulating Factor in Sera of Children With Neuroblastoma2

Abstract

Sera from children with neuroblastomas contained increased amounts of a nerve growth factor that stimulated the outgrowth of axons in explanted 8-day chick-embryo spinal-ganglia cultures. This factor could not be detected in normal human sera. The nerve growth factor was neutralized by an antiserum prepared in goats against purified nerve growth-stimulating protein isolated from mouse submaxillary glands. The cross-reactivity between the human nerve growth factor and the antisera against the mouse protein was low. The data indicate that neutralization of neuroblastoma sera can be markedly increased by an antiserum prepared from nerve growth-stimulating protein isolated from human tissue. The effect of a nerve growth-promoting protein and its antisera on normal human sympathetic nerve cells and human neuroblastoma cells growing in vitro is discussed and is currently being investigated.