Nerve Growth Factor and Nerve Growth-Stimulating Activity in Sera From Normal and Neuroblastoma Patients2

Abstract

Neuroblastoma, a tumor of early infancy, may regress spontaneously. The relationship between the clinical activity of neuroblastoma and the “nerve growth factor” (NGF) of Levi-Montalcini was investigated. The growth of axons from chick-embryo spinal ganglia occurs in the presence of some human sera. As compared with the effect of mouse NGF, fewer axons are stimulated. The activity in human sera was determined in 78 normal children. No significant differences were found in comparisons of nerve growth-stimulating activity (NGSA) in the sera of patients in various stages of active disease, of patients free of disease for 3 years or more, of patients with tumors other than neuroblastoma, and of normal children. Immunological cross-reactions were not found between mouse NGF or its antiserum and human sera with high or low NGSA. NGSA of some human sera was demonstrated. This seemed to be similar to NGF; yet the identity of the active human agent with mouse NGF could not be shown. No significant relationship between NGSA serum levels and the clinical activity of neuroblastoma was demonstrated.