title: A peptide antagonist of the ErbB1 receptor inhibits receptor activation, tumor cell growth and migration in vitro and xenograft tumor growth in vivo.
abstract: The epidermal growth factor family of receptor tyrosine kinases (ErbBs) plays essential roles in tumorigenesis and cancer disease progression, and therefore has become an attractive target for structure-based drug design. ErbB receptors are activated by ligand-induced homo- and heterodimerization. Structural studies have revealed that ErbB receptor dimers are stabilized by receptor-receptor interactions, primarily mediated by a region in the second extracellular domain, termed the "dimerization arm". The present study is the first biological characterization of a peptide, termed Inherbin3, which constitutes part of the dimerization arm of ErbB3. Inherbin3 binds to the extracellular domains of all four ErbB receptors, with the lowest peptide binding affinity for ErbB4. Inherbin3 functions as an antagonist of epidermal growth factor (EGF)-ErbB1 signaling. We show that Inherbin3 inhibits EGF-induced ErbB1 phosphorylation, cell growth, and migration in two human tumor cell lines, A549 and HN5, expressing moderate and high ErbB1 levels, respectively. Furthermore, we show that Inherbin3 inhibits tumor growth in vivo and induces apoptosis in a tumor xenograft model employing the human non-small cell lung cancer cell line A549. The Inherbin3 peptide may be a useful tool for investigating the mechanisms of ErbB receptor homo- and heterodimerization. Moreover, the here described biological effects of Inherbin3 suggest that peptide-based targeting of ErbB receptor dimerization is a promising anti-cancer therapeutic strategy.
authors.affiliation: Protein Laboratory, Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Ruodan
authors.initials: R
authors.lastname: Xu
authors.forename: Gro Klitgaard
authors.initials: GK
authors.lastname: Povlsen
authors.forename: Vladislav
authors.initials: V
authors.lastname: Soroka
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Bock
authors.forename: Vladimir
authors.initials: V
authors.lastname: Berezin
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D048708:Cell Growth Processes / Q000187:drug effects; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D066246:ErbB Receptors / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000235:genetics; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D051379:Mice; D016513:Mice, SCID; D009368:Neoplasm Transplantation; D010446:Peptide Fragments / Q000737:chemistry / Q000494:pharmacology*; D011940:Receptor Aggregation / Q000187:drug effects; D020893:Receptor, ErbB-3 / Q000737:chemistry; D020545:Respiratory Mucosa / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D047368:Tumor Burden / Q000187:drug effects
chemical_list: D010446:Peptide Fragments; D066246:ErbB Receptors; D020893:Receptor, ErbB-3