Abstract: To reduce the killing effect of oncolytic adenovirus on normal cells and get safe clinical application, oncolytic adenovirus AdCN103, a novel dual-targeting tumor specific proliferating virus,was constructed by replacing the wild type adenovirus E1A promoter with the promoter of human telomerase reverse transonptase (hTERT) and mutant E1A lacking CR2 region.The single-controlled recombinant adenovirus was generated with either 24 bp deleted E1A (AdCN101) or wild-type of E1A driven by hTERT promoter (AdCN102).〖JP〗Killing effects of AdCN103 on several different tumor cells and normal cells were detected by crystal violet dye method and MTT assay.The virus replicating ability was assessed by virus progeny assay.The result shows that AdCN103 can selectively replicate in tumor cells and it has an overt cytopathic effect.Meanwhile, there is a dramatic reduction of cytotoxicity in normal cells infected with AdCN103 compared with its corresponding control vectors.Such protocol may have important applications for cancer gene therapies in the future.

Key words: CR2, oncolytic adenovirus, gene-virotherapy, hTERT, CR2, oncolytic adenovirus, gene-virotherapy