Unique and selective mitogenic effects of vanadate on SV40-transformed cells.
Vanadate and insulin both function as unique complete mitogens for SV40-transformed 3T3T cells, designated CSV3-1, but not for nontransformed 3T3T cells. The mitogenic effects induced by vanadate and insulin in CSV3-1 cells are mediated by different signaling mechanisms. For example, vanadate does not stimulate the tyrosine phosphorylation of the insulin receptor beta-subunit nor the 170 kDa insulin receptor substrate-1. Instead, vanadate induces a marked increase in tyrosine phosphorylation of 55 and 64 kDa proteins that is not observed in insulin-stimulated CSV3-1 cells. Perhaps most interestingly, vandate-induced mitogenesis is associated with the selective induction of c-jun and junB expression without significantly inducing c-fos or c-myc. Furthermore, treatment of CSV3-1 cells with genistein abolishes the effects of vanadate on protein tyrosine phosphorylation and c-jun induction. These and related data suggest that modulation of protein tyrosine phosphorylation and c-jun and junB expression may serve the critical roles in mediating vandate-induced mitogenesis in SV40-transformed cells.
Wang
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Department of Pathology, The University of Tennessee College of Medicine, Memphis, Tennessee 38163, USA.
Scott
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D016475:3T3 Cells; D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002461:Cell Line, Transformed; D002472:Cell Transformation, Viral; D051379:Mice; D013539:Simian virus 40; D014638:Vanadates / Q000494:pharmacology*
D014638:Vanadates