Suppression effect of a dual cancer-specific oncolytic adenovirus on luciferase-labeled human melanoma cells in vitro and in vivo

BACKGROUND: To explore the suppressive effect of Apoptin-loaded oncolytic adenovirus (Ad-VT) on luciferase-labeled human melanoma cells in vitro and in vivo. METHODS: The stable luciferase-expressing human melanoma cells A375-luc or M14-luc were obtained by transfecting the plasmid pGL4.51 and selection with G418, followed by luciferase activity, genetic stability and bioluminescence intensity assays. In vitro, the inhibitory effects of Ad-VT on A375-luc or M14-luc were evaluated using the MTS cell proliferation, FITC-Annexin V apoptosis detection, transwell migration, Matrigel invasion and scratch assays. The inhibition pathway in Ad-VT-infected A375-luc and M14-luc cells were analyzed by JC-1 staining and Western-blot detection of mitochondrial apoptosis-related proteins. In vivo, the suppressive effects of Ad-VT on A375-luc or M14-luc were assessed by living imaging technology, tumor volume, bioluminescence intensity, survival curves and immunohistochemical analysis of the tumors from the xenograft tumor model BALB/c nude mice. RESULTS: The growth and migration of A375-luc and M14-luc were significantly inhibited by Ad-VT in vitro. The evaluations of A375-luc and M14-luc tumor models in BALB/c nude mice were successfully performed using living imaging technology. Ad-VT had an anti-tumor effect by reducing tumor growth and increasing survival in vivo. Ad-VT significantly changed the mitochondrial membrane potential by triggering the the mitochondrial release of apoptosis-related proteins, AIF (apoptosis inducing factor), ARTS (Apoptosis-Related Proteins), and Cyto-c (cytochrome c) from the mitochondria. CONCLUSION: Ad-VT reduced the mitochondrial membrane potential in A375-luc or M14-luc cells and induced the mitochondrial release of AIF, ARTS and Cyto-C. Ad-VT induced apoptosis in A375-luc or M14-luc cells via the mitochondrial apoptotic pathway.