Construction of recombinant adenovirus with Egr-1 promoter and Smad7

Purpose:To construct replication-defective adenovirus which was recombinated with Egr-1 promoter and to Smad7, and to study whether it can express exogenous Smad7 protein in cytoplasm.Methods:Based on Adeno-X~(TM) expression system, the CMV promoter of the pShuttle vector was replaced by Egr-1 promoter, and the Smad7 cDNA was subcloned into the MCS(multiple cloning site) of pShuttle. The recombinant pShuttle was then subcloned into the Adeno-X~(TM) genome, which was transformed into E.coli to get recombinant Adeno-X~(TM) plasmid DNA. The recombinant adenovirus was made and amplified in the transfected HEK 293 cells before it was purified and tested for viral titer. Then the Smad7’s location in cells was determined by immunocytochemistry.Results:Identified by restriction endonuclease analysis and PCR, recombinant adenovirus with Egr-1 promoter and Smad7 cDNA was constructed successfully, with a viral titer of 1.0×10~(11) TCID50/ml. Both endogenous and exogenous Smad7 protein was found to be located in cytoplasm of fibroblast cells.Conclusions:With Adeno-X~(TM) expression system, utilizing the techniques of molecular cloning, recombinant adenoviral vector could be quickly and efficiently constructed which could be packaged into replication-defective Adenovirus and amplified in HEK293 cells. The recombinant adenovirus could express exogenous Smad7 protein in fibroblast cells.[