%0 Journal Article
%T A Modified Adenovirus Vector¨CMediated Antibody Screening Method Identifies EphA2 as a Cancer Target
%A Hiromi Yamada
%A Kazuo Tamura
%A Masahide Kuroki
%A Shohta Kodama
%A Toshihiro Tanaka
%A Yasushi Takamatsu
%J Archive of "Translational Oncology".
%D 2017
%R 10.1016/j.tranon.2017.04.001
%X BACKGROUND: We constructed a genetically modified adenovirus vector incorporating an IgG Fc-binding motif from staphylococcal protein A, Z33 (Adv-FZ33). Adv-FZ33 allows an antibody to redirect the vector to a target molecule on the cell surface. We attempted to search for target antigen candidates and antibodies that allowed highly selective gene transduction into malignant tumors. METHODS: Hybridoma libraries producing monoclonal antibodies (mAbs) were screened that increased transduction efficiency in cancer cell lines after cross-linking with Adv-FZ33. Target antigens of the mAbs were identified by immunoprecipitation and mass spectrometry. Of these mAbs, we noted a clone, F2-27, that recognized the receptor tyrosine kinase EphA2. Next, we generated an adenovirus vector, Ax3CMTK-FZ33, that expressed a herpes simplex virus thymidine kinase (HSV-TK). The therapeutic efficacy of F2-27¨Cmediated HSV-TK gene transduction, followed by ganciclovir (GCV) administration, was studied in vitro. The inhibitory effect of F2-27 on cancer cell invasion was investigated by a three-dimensional spheroid formation assay. RESULTS: In vitro reporter gene expression after Adv-FZ33 infection via F2-27 was 146 times higher than with control mAb in EphA2-expressing cancer cell lines. F2-27¨Cmediated Ax3CMTK-FZ33 infection induced the HSV-TK gene in an F2-27¨Cdependent manner and had a highly effective cytotoxic effect in a GCV-dependent manner. Additionally, F2-27 independently inhibited migration of EphA2-positive breast cancer cell lines in three-dimensional culture. CONCLUSION: Our modified adenovirus and hybridoma screening system is useful for the development of targeted cancer therapy, and F2-27 has the potential to be an antibody-based therapy for various EphA2-positive cancers
%U https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5430157/