title: The inhibition of EGF-dependent proliferation of keratinocytes by tyrphostin tyrosine kinase blockers.
abstract: Protein tyrosine kinase blockers of the tyrphostin family inhibited the EGF-dependent proliferation of human and guinea pig keratinocytes grown in culture and induced their growth arrest. These blockers also significantly inhibited the growth of epidermal keratinocytes, but not of dermal cells, in whole skin organ culture from both guinea pig and human origin. The antiproliferative activity of these tyrphostins correlated quantitatively with their potency as inhibitors of EGF receptor autophosphorylation and the EGF-dependent protein phosphorylation of intracellular target proteins in the keratinocyte. Furthermore, no significant cell cytotoxicity or reduction in serine and threonine phosphorylation of many intracellular polypeptides were observed upon incubation of the cells with tyrphostins like AG213. The complete growth arrest induced by the tyrphostins is fully reversible and upon their removal the keratinocytes resumed their growth with the original growth rate. Because of the nontoxic nature of these compounds and their growth-arresting properties, we suggest their use as agents to treat hyperproliferative conditions of human skin.
authors.affiliation: Department of Biological Chemistry, Hebrew University of Jerusalem, Israel.
authors.forename: A
authors.initials: A
authors.lastname: Dvir
authors.forename: Y
authors.initials: Y
authors.lastname: Milner
authors.forename: O
authors.initials: O
authors.lastname: Chomsky
authors.forename: C
authors.initials: C
authors.lastname: Gilon
authors.forename: A
authors.initials: A
authors.lastname: Gazit
authors.forename: A
authors.initials: A
authors.lastname: Levitzki
mesh_terms: D000818:Animals; D002396:Catechols / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D066246:ErbB Receptors / Q000037:antagonists & inhibitors / Q000502:physiology*; D006168:Guinea Pigs; D006801:Humans; D066298:In Vitro Techniques; D015603:Keratinocytes / Q000166:cytology*; D008970:Molecular Weight; D009570:Nitriles / Q000494:pharmacology*; D010750:Phosphoproteins / Q000737:chemistry / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D019000:Phosphotyrosine; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors*; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism; D020032:Tyrphostins
chemical_list: D002396:Catechols; D009570:Nitriles; D010750:Phosphoproteins; D020032:Tyrphostins; C060152:tyrphostin 47; D019000:Phosphotyrosine; D014443:Tyrosine; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D011505:Protein-Tyrosine Kinases; C060641:tyrphostin A23