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It has been demonstrated that survivin, a novel member of the inhibitor of apoptosis (IAP) protein family, is expressed in human cancers but is undetectable in normal differentiated tissues. We employed a recombinant adenoviral vector (reAdGL3BSurvivin) in which a tumor-specific survivin promoter and a luciferase reporter gene were inserted into the E1-deleted region of adenovirus vector. Luciferase activity was measured in both multiple tumor cell lines and two primary melanoma cells infected with reAdGL3BSurvivin. Human fibroblast and mammary epithelial cell lines were used as negative controls. A reAdGL3CMV, containing the CMV promoter and luciferase gene, was used as a positive control to normalize the luciferase activity generated by the survivin promoter. Our data revealed that the survivin promoter showed high activity in both established tumor cell lines and the primary melanoma cells. In contrast, the in vivo studies indicated that the activities of survivin promoter were extremely low in the major mouse organs. The survivin promoter appears to be a promising tumor-specific promoter exhibiting a “tumor on” and “liver off” profile, and therefore, it may prove to be a good candidate for transcriptional targeting of cancer gene therapy in a wide variety of tumors.Cancer Gene Therapy (2004) 11, 256-262. doi:10.1038/sj.cgt.7700679 Published online 12 March 2004 [ABSTRACT FROM AUTHOR]

Replication competent viruses hold promise for treatment of advanced cancers resistant to available therapeutic modalities. Although preliminary clinical results have substantiated their efficacy, preclinical development of these novel approaches is limited by assay substrates. The evaluation of candidate agents could be confounded by differences between primary tumor cells and tumor cell lines, as discordance in the levels of surface receptors relevant for viral entry has been reported. Since primary tumor cells are difficult to analyze ex vivo for longitudinal observation of virus replication, we developed three-dimensional aggregates or spheroids of unpassaged and purified ovarian cancer cells as a means for prolonging primary tumor cell viability and as a three-dimensional in vitro model for replicative viral infection. Ovarian cancer cells purified from ascites samples were sustained for 30 days while retaining the infection profile with tropism modified and unmodified adenoviruses (Ads). Cell line and primary cell spheroids were used to quantitate the replication and oncolytic potency of replicative Ads in preclinical testing for human ovarian cancer trials. Therefore, spheroids provide a method to sustain purified unpassaged primary ovarian cancer cells for extended periods and to allow evaluation of replicative viruses in a three-dimensional model.Cancer Gene Therapy (2003) 10, 377-387. doi:10.1038/sj.cgt.7700578 [ABSTRACT FROM AUTHOR]