Studies On The Preparation,Anticancer Effect And Safety Of Double-Tareting Replicative Adenovirus With Plaminogen Kringle 5 And IL-24 In Vitro

Oncolytic viruses are a class of promising anticancer agents, which replicate selectively in cancer cells and result in cancer-specific cytotoxicity. Two strategies have been employed to construct oncolytic virus. One is to use tumor-specific promoters to control the expression of viral genes essential for replication, such as adenoviral E1A gene. Our Lab constructed a novel oncolytic adenovirus Ad.TERT by replacing the normal El A promoter with hTERT promoter. The other strategy to construct oncolytic adenovirus is to delete function genes that are necessary for efficient viral replication in normal cells, but not in tumor cells. Our Lab also constructed an oncolytic adenovirus--ZD55-gene by deleting adenoviral E1B 55kDa gene. Both constructed cancer-specific oncolytic adenoviruses demonstrate potent antitumoral efficacy in vivo animal experiments.To further improve the anticancer efficacy of oncolytic virus, a new strategy named gene-virus therapy of cancer was put forward. Briefly, antitumoral gene is cloned to the oncolytic virus. With the replication of virus, the expression of antitumoral gene is greatly increased. At the same time, the oncolytic virus itself has potent antitumoral efficacy. In order to improve the safety and anticancer effect of oncolytic virus, we constructed another novel oncolytic adenovirus--TD55 by replacing the normal E1A promoter with hTERT promoter and deleting adenoviral E1B 55kDa gene.Tumor angiogenesis plays important roles in tumor development and metastasis. In the present study, human plasminogen kringle 5 and Mda-7/IL-24 were inserted into TD55, resulting in series of recombinant adenoviruses, such as TD55-K5, TD55-IL-24 and TD55-IL-24-K5. Because K5 can inhibit the angiogenesis, and IL-24 can specifically induce the tumor cells apoptosis and inhibit angiogenesis. So theoretically, the therapy result of the TD55 system with these recombinant adenoviruses should be better than that of gene therapy or oncolytic therapy, and can provide a good platform for the specific gene-virus therapy of cancer. The experiments with tumor cells suggested that the dual-targeting gene virus therapy is safer and more effective than other therapys: TD55 was 1.5 times safer than Onyx015 in impairing the normal cell—HMCS; the ability of TD55-IL-24 to kill Bcap37 was at...