Objective Recombinant plasmid vector pcDNA3.1-CMV-Egr-1-CDTK was constructed by fusing of early growth respons-1(Egr-1) promoter to the double suicide gene CDTK gene; To transfer human cervical cancer cell lines (Hela) with recombinant plasmid vector pcDNA3.1-CMV-Egr-1-CDTK,after irradiated by ~(60)Co-γ rays ,the CDTK mRNA expression in the transfected cell line and the killing effects and the by-stander killing effects in vitro of double suicide genes on the cell lines were observed; The animal model of Ba...