Abstract 1454: Telomerase-specific adenoviral labeling and treatment of hepatocellular carcinoma

Abstract We previously constructed telomerase-specific replication-selective adenoviruses OBP-301 (Telomelysin) and OBP-401 which contains the GFP gene (Telomelysin-GFP, TelomeScan). The replication of these adenoviruses is regulated by a human telomerase transcriptase (hTERT) promoter and allows specific targeting and labeling of tumor cells in vivo (Proc. Natl. Acad. Sci. USA, 1-6, 14514-14517, 2009 and Molecular Cancer Therapeutics 8, 3001-3008, 2009). The aim of this study was to validate systemic injection of these telomerase-specific replicating adenoviruses for in vivo hepatocellular carcinoma (HCC) GFP labeling and tumor-cell killing. We assessed the antitumor efficacy and the tumor labeling ability of the adenoviruses in an orthotopic mouse model using the Hep3B-GFP human HCC cell line. Biweekly i.v. treatment of OBP-301 caused a significant inhibition in liver tumor growth and showed a reduction in the number of liver tumor nodules compared to controls. To assess the GFP tumor labeling ability of OBP-401 for HCC, an orthotopic liver tumor model of unlabeled Hep3B was used. After i.v. injection of OBP-401, the liver tumors were labeled with GFP and visualized by fluorescence imaging. These results suggest that the two viruses, OBP-301 and OBP-401, when administrated systemically, are novel anticancer agents and labeling tools for HCC, respectively, with potential for human use. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1454.