title: Binding-induced activation of overexpressed p185HER2 is essential in triggering neuronal differentiation of PC12 cells.
abstract: To determine whether p185HER2 overexpression per se triggers p185HER2 cellular signaling or whether an extracellular signal is required, we transfected PC12 cells with the human erbB-2 proto-oncogene, and established a cell line that overexpresses p185HER2. PC12-HER2 cells, maintained in suspension culture or plated on a collagen layer, showed the same morphology and growth rate as PC12 and PC12 mock-transfected control cells. When treated with monoclonal antibody (MAb) MGr6 or other anti-p185HER2 MAbs, PC12-HER2 cells specifically underwent neuronal differentiation comparable to that induced by nerve growth factor (NGF), and the differentiation-inducing effect of the MAb was dramatically enhanced by the addition of a second anti-mouse IgG. MAb-induced cell differentiation correlated with p185HER2 phosphorylation, recruitment of Shc and Grb-2 transducer molecules into complexes, and MAPK phosphorylation. These data indicate the requirement for a specific binding-induced activation of the overexpressed p185HER2 receptor in inducing PC12 cell differentiation. PC12-HER2 cells represent a suitable system for selection of p185HER2-activating ligands (peptides, phage-displayed peptides or proteins) or specific inhibitors of its tyrosine kinase activity.
authors.affiliation: Division of Experimental Oncology E, Istituto Nazionale per lo Studio e la Cura dei Tumori, Milan, Italy. Orlandi@istitutotumori.mi.it
authors.forename: R
authors.initials: R
authors.lastname: Orlandi
authors.forename: C
authors.initials: C
authors.lastname: Formantici
authors.forename: M I
authors.initials: MI
authors.lastname: Colnaghi
authors.forename: S
authors.initials: S
authors.lastname: Ménard
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000032:analysis; D002454:Cell Differentiation; D015870:Gene Expression; D006801:Humans; D019950:Mitogen-Activated Protein Kinase 1 / Q000032:analysis; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D016501:Neurites; D009474:Neurons / Q000166:cytology*; D016716:PC12 Cells; D019000:Phosphotyrosine / Q000032:analysis; D000090063:Proto-Oncogene Mas; D051381:Rats; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D015398:Signal Transduction; D014162:Transfection
chemical_list: D000911:Antibodies, Monoclonal; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D019000:Phosphotyrosine; D000090063:Proto-Oncogene Mas; D018719:Erb-b2 Receptor Tyrosine Kinases; C000715470:MAS1 protein, human