Lee J.-H.Chen P.B.Yang S.-H.Cheng C.-H.Chueh L.-L.Pang V.F.Hsiao M.VICTOR FEI PANGJIH-JONG LEECHUNG-TIEN LIN2020-01-072020-01-0720070002-9645https://scholars.lib.ntu.edu.tw/handle/123456789/446413Objective - To investigate the antitumor effect of the chicken anemia virus (CAV) VP3 gene in canine mammary tumor (CMT) cells. Sample populations - Established primary canine cell lines that originated from epithelial cells of resected CMTs and nonneoplastic mammary gland epithelial (MGE) cells. Procedures - Expression vectors and lentiviral vectors encoding the VP3gene from a Taiwan-Ilan isolate of CAV were used to deliver the VP3 gene into CMT cells and nonneoplastic MGE cells. Ectopic gene expression and the pro-apoptotic effect of the VP3 gene on CMT and nonneoplastic MGE cells by either transfection or viral infection were evaluated via immunofluorescence microscopy, western blot analysis, and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling analysis. Results - Overexpression of the enhanced green fluorescent protein-VP3 fusion protein was detected predominantly in the nuclei of CMT cells. In contrast, the VP3 protein was localized to the cytoplasm of nonneoplastic MGE cells. Among the fusion protein-expressing CMT cells, most underwent characteristic changes of apoptosis, whereas apoptosis was not detected in fusion protein-expressing, nonneoplastic MGE cells. Induction of apoptosis by VP3 gene overexpression in CMT cells was associated with the caspase-9-, but not the caspase-8-, mediated apoptosis pathway. Conclusions and clinical relevance - These data indicate that the VP3 gene of the CAV induces apoptosis in malignant CMT cells, but not in nonneoplastic canine MGE cells. On the basis of such tumor cell-specific killing, the VP3 gene may be a promising agent for the treatment of malignant mammary gland tumors in dogs.[SDGs]SDG3caspase 8; caspase 9; green fluorescent protein; hybrid protein; lentivirus vector; protein VP3; apoptosis; article; breast epithelium; breast tumor; cell killing; cell line; cell nucleus; Circoviridae; controlled study; cytoplasm; data analysis; dog; epithelium cell; expression vector; gene expression; genetic transfection; human; human cell; immunofluorescence microscopy; nick end labeling; nonhuman; protein expression; protein localization; tumor cell; virus gene; virus infection; virus isolation; Western blotting; Animals; Apoptosis; Blotting, Western; Capsid Proteins; Cell Line, Tumor; Chicken anemia virus; Dog Diseases; Dogs; Gene Expression Regulation, Neoplastic; Gene Therapy; Genetic Vectors; In Situ Nick-End Labeling; Lentivirus; Mammary Neoplasms, Animal; Microscopy, Fluorescence; Canis familiaris; Chicken anemia virusjournal article10.2460/ajvr.68.4.4112-s2.0-34247500365https://www2.scopus.com/inward/record.uri?eid=2-s2.0-34247500365&doi=10.2460%2fajvr.68.4.411&partnerID=40&md5=c85b49ae575c106635a72c5b45533a18