and gene promoters for cancer gene therapy: A comparative study.

Human telomerase reverse transcriptase () and survivin () gene promoters are frequently used for transcriptional targeting of tumor cells, yet there is no comprehensive comparative analysis allowing rational choice of a promoter for a particular therapy. In the current study, the transcriptional activity of , human and mouse Birc5 promoters and their modifications were compared in 10 human cancer cell lines using the luciferase reporter gene activity assay. The results revealed that - and -based promoters had strikingly different cell specificities with comparable activities in only 40% of cell lines. Importantly, relative and transcript abundance cannot be used to predict the most potent promoter. Among the -based promoters that were assessed, modification with the minimal cytomegalovirus promoter generally resulted in the most potent activity. Mouse and modified human promoters were superior to the unmodified human survivin promoter; however, their tumor specificities must be investigated further. In summary, the present results emphasize the desirability for construction of more universal tumor-specific promoters to efficiently target a wide spectrum of tumor cells.