Belimezi MM, Papanastassiou D, Merkouri E, Baxevanis CN, Mamalaki A. Growth inhibition of breast cancer cell lines overexpressing Her2/neu by a novel internalized fully
human Fab antibody fragment.
Cancer Immunol Immunother 2006;
55:1091-9. [PMID:
16311733 PMCID:
PMC11030719 DOI:
10.1007/s00262-005-0100-z]
[Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2005] [Accepted: 11/01/2005] [Indexed: 12/23/2022]
Abstract
The Her2/neu oncogene is overexpressed in various human cancers of epithelial origin and is associated with increased metastatic potential and poor prognosis. Blocking the Her2/neu signalling has been the focus of most therapeutic approaches. In this paper, the Her2/neu extracellular domain expressed in soluble form in yeast Pichia pastoris was used in order to isolate a fully human Fab fragment from a combinatorial Fab phage display library, derived from invaded lymph nodes of a breast cancer patient. The isolated fully human Fab63 binds specifically the native Her2/neu receptor and competes with Herceptin for binding to soluble Her2/neu receptor. In Her2/neu overexpressing cancer cells, Fab63 is rapidly internalized and has significant antiproliferative effects, where ligand-independent mechanisms dominate signal induction. Moreover, in the presence of the ligand heregulin, growth inhibition was also detected by Fab63. The human Fab63 is a non-immunogenic agent with unique properties that can be applied in diagnosis and cancer therapy, with great potential for further manipulation towards the generation of an effective anticancer molecule.
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