Increased Neurite Outgrowth Induced by Inhibition of Protein Tyrosine Kinase Activity in PC12 Pheochromocytoma Cells

Abstract

Genistein and other inhibitors of protein tyrosine kinases were examined for effects on neurite elongation and growth cone morphology in the rat PC12 pheochromocytoma cell line. Genistein increased the rate of neurite elongation in PC12 cells grown on a collagen/polylysine substratum after priming with nerve growth factor (NGF), but had no effect on undifferentiated cells. Steady-state levels of phosphotyrosine-modified proteins (105, 59, 52, and 46 kDa) were reduced in NGF-primed cells by genistein treatment. The target of genistein action did not appear to be the NGF receptor/trk tyrosine kinase because the presence of NGF in cultures of NGF-primed cells was not necessary for genistein-stimulated neurite outgrowth. The tyrosine kinase inhibitors tyrphostin RG508964 and herbimycin A also increased the rate of neurite elongation in NGF-primed PC12 cells. Video-enhanced differential interference contrast microscopy revealed that growth cones of genistein-treated cells had less complex morphologies and were less dynamic than untreated cells, with short filopodia restricted to the leading edge, unlike untreated cells whose growth cones exhibited longer, more numerous filopodia and lamellipodia, which remodeled continuously. These results suggest that protein tyrosine kinase activity in PC12 cells negatively regulates neurite outgrowth and directly or indirectly affects growth cone morphology.

Bradykinin-Induced Collapse of Rat Pheochromocytoma (PC12) Cell Growth Cones: A Role for Tyrosine Kinase Activity

“…Our data show that the nonreceptor PTK pp60 c-src that is concentrated in nerve growth cones of developing and regenerating neurons (Maness et al, 1988;Ignelzi et al 1992) can be activated through activation of extracellularly applied bradykinin. Inhibition of pp60 c-src present in PC12 growth cones (Miller et al, 1993) by genistein is also in good agreement with our results. Therefore, the pp60 c-src may be involved in bradykinininduced growth cone collapse.…”

Src Family Kinases Control Neural Development and Function

“…It has also been shown to affect a number of cell surface parameters, leading to reductions in cell adhesion (42) growth factor, and insulin receptor families (26). cells on collagen (27 Studies by over-expression of v-Src and by inhibitors of its family have indicated that Src family may function during the neural cell differentiation, axonal guidance, and synaptic transduction. The mutation analyses in Drosophila have shown that the mutation of D-Src or Abelson (Abl) tyrosine kinase has not disturbed the neural formation, but the double null mutant of Abl and fasciclin I exhibits aberrant growth cone navigation and abnormal neural networks (13).…”

Apoptosis of human primary gastric carcinoma cells induced by genistein

“…It also inhibits microsomal lipid peroxidation [12] and angiogenesis [13] . Genistein exhibits antioxidant properties [14][15][16] and was reported to induce differentiation of numerous cell types [17][18][19] . Moreover, a recent report shows that genistein is a potent cancer chemopreventive agent [20][21][22] .…”