Characterization of platelet-derived growth factor (PDGF) action on a mouse neuroblastoma cell line, NB41, by introduction of an antisense PDGF beta-receptor RNA.

We have shown previously that platelet-derived growth factor (PDGF) has trophic effects on dopaminergic neurons in vitro. We now examined a mouse neuroblastoma cell line, NB41, for its response to PDGF and studied their phenotypic characteristics following introduction of an antisense PDGF beta-receptor RNA. NB41 cells produce both PDGF-AA and -BB; however, they carry only PDGF beta-receptors, responding to BB but not to AA. Culturing the cells with PDGF-BB induced mRNA for c-fos and PDGF-beta receptor as well as that of neuron-specific enzyme, tyrosine hydroxylase. In contrast, mRNA of chromogranin A, which is produced by chromaffin cells, decreased. Introduction of an antisense PDGF beta-receptor RNA in NB41 cells completely suppressed neurite extension and cell growth. We compared the PDGF-beta receptor sense and antisense clones for their survival. Following serum withdrawal, NB41 cells showed a DNA ladder, which by an addition of the neurotoxin, 6-hydroxy dopamine (6-OHDA), resulted in a further enhancement of the DNA ladder. The addition of PDGF-BB prior to 6-OHDA rescued cells from undergoing apoptosis, seen as a reduction of the DNA ladder. The antisense clone, regardless of the presence of PDGF-BB in the culture, showed a pronounced DNA ladder after serum withdrawal, which was further enhanced by the addition of 6-OHDA.