Detection and partial purification of glial growth inhibitory factor(GGIF) in the conditioned medium of neuroblastoma cells.
Glial growth inhibitory factor (GGIF) was detected in the culture medium of mouse neuroblastoma cells. The partial purification and characterization of GGIF revealed that it was an acidic and heat-unstable protein and separated into two molecular weight forms (GGIF1: 33.0 to 40.5 K Mr; and GGIF2: 31.0 to 34.0 K Mr) on DEAE. Sephacel column chromatography. GGIF inhibited the growth of neoplastic glial cells as well as normal glioblasts in monolayer culture. The inhibitory effect of GGIF on proliferation of glioblasts appeared even after the incubation for less than 1 h, and retained thereafter unless the factor was removed. Immobilized GGIF exposed to glioblasts was reusable, suggesting the existence of a certain component or receptor mediating GGIF action in the plasma membrane.
Ito
J
J
Departments of Biochemistry and Surgery, Nagoya City University Medical School, Mizuho-Ku, Nagoya 467, Japan.
Kato
T
T
Hara
F
F
Kano-Tanaka
K
K
Tanaka
R
R