HUMAN NEUROBLASTOMA GROWTH-INHIBITORY FACTOR (H-NGIF), DERIVED FROM HUMAN ASTROCYTOMA CONDITIONED MEDIUM, HAS NEUROTROPHIC PROPERTIES

Investigations on the general characteristics of human astrocytoma cel l line NAC-1 revealed neuroblastoma growth inhibitory activity in cond itioned medium. Neuroblastoma growth inhibitory factor (NGIF) was part ially purified by Econo Q, Econo CM, and Superose 12 column chromatogr aphy. The protein is weakly basic with an estimated M(r) of 120,000, p ossibly having an M(r) 60,000 dimeric structure. NGIF inhibits the gro wth of human neuroblastoma cell lines but has no effect on morphology nor does it produce any change in the growth of human glioblastoma cel l lines. Interestingly, NGIF appears to promote survival and neurite o utgrowth of embryonal rat cortical neurons. These neurotrophic propert ies suggest a role for NGIF in the development of the nervous system.