Cancer targeting Gene-Viro-Therapy of liver carcinoma by dual-regulated oncolytic adenovirus armed with TRAIL gene

Abstract

Liver cancer is a common and aggressive malignancy, but available treatment approaches remain suboptimal. Cancer targeting Gene-Viro-Therapy (CTGVT) has shown excellent anti-tumor effects in a preclinical study. CTGVT takes advantage of both gene therapy and virotherapy by incorporating an anti-tumor gene into an oncolytic virus vector. Potent anti-tumor activity is achieved by virus replication and exogenous expression of the anti-tumor gene. A dual-regulated oncolytic adenoviral vector designated AdÁAFPÁE1AÁE1B (D55) (AdÁAFPÁD55 for short thereafter) was constructed by replacing the native viral E1A promoter with the simian virus 40 enhancer/a-fetoprotein (AFP) composite promoter (AFPep) based on an E1B-55K-deleted construct, ZD55. AdÁAFPÁD55 showed specific replication and cytotoxicity in AFP-positive hepatoma cells. It also showed enhanced safety in normal cells when compared with the mono-regulated vector ZD55. To improve the anti-hepatoma activities of the virus, the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) gene was introduced into AdÁAFPÁD55. AdÁAFPÁD55-TRAIL exhibited remarkable anti-tumor activities in vitro and in vivo. Treatment with AdÁAFPÁD55-TRAIL can induce both autophagy owing to the AdÁAFPÁD55 vector and caspase-dependent apoptosis owing to the TRAIL protein. Therefore, AdÁAFPÁD55-TRAIL could be a potential anti-hepatoma agent with anti-tumor activities due to AFP-specific replication and TRAIL-induced apoptosis.

Gene-viro-therapy targeting liver cancer by a dual-regulated oncolytic adenoviral vector harboring IL-24 and TRAIL

“…Characterization of Ad Á AFP Á D55-IL-24 and Ad Á AFP Á D55-TRAIL We have previously confirmed the selective transcriptional activity of the AFP promoter in human AFPpositive HCC cells, 10 suggesting Ad Á AFP Á D55 could be an ideal HCC-targeting vector system. In this work, we inserted antitumor gene IL-24 or TRAIL into the OV Ad Á AFP Á D55 to enhance its curative effect (Figure 1a).…”

“…10 Generation, identification, production, purification and titration of recombinant adenovirus The recombinant adenoviruses (rec-Ads) were generated by respective homologous recombination between the shuttle plasmids and the packaging plasmid pBHGE3 in HEK293 cells. Detailed procedures on the generation, identification, production, purification and titration of the recombinant adenovirus can be found in our previous report.…”

“…Detailed procedures on the generation, identification, production, purification and titration of the recombinant adenovirus can be found in our previous report. 10 Cytotoxicity assays Tumor cells and normal cells were seeded in 24-well plates, and were infected with adenoviruses at various multiplicity of infections (MOIs) 24 h later. At 96 h after infection, the medium was removed, and the cells were stained with 2% crystal violet in 20% methanol for 20 min.…”

“…8,9 Moreover, we previously reported that the combination of two therapeutic genes mediated by replication-defective vectors can exert synergic or compensatory antitumor activities. 2,4 Based on these studies, we decided to evaluate the effects of combined usage of IL-24 and TRAIL with a newly constructed dual-regulated OV Ad Á AFP Á D55, 10 whose replication was controlled by dual mechanisms (E1B-55KD deletion and E1A regulated by AFP promoter).…”

Tumor suppressor BLU inhibits proliferation of nasopharyngeal carcinoma cells by regulation of cell cycle, c-Jun N-terminal kinase and the cyclin D1 promoter

“…The system could be improved by replacing the ubiquitous promoter derived from murine cytomegalovirus with a regulatory element that has high activity in the malignancies to control the expression of biotherapeutic target genes. Such elements include α-fetoprotein enhancer-promoter for hepatocellular carcinoma cells [21], and origin of plasmid replication (OriP) element [22,23]. …”