Regulated gene expression in glioma cells: a comparison of three inducible systems.

Transcription control systems enable experimental regulation of transgene expression in eukaryotic cells by application of specific repressors or inducers. Currently used inducible systems include tetracycline (tet-off), dimerizer and ecdysone systems. While numerous studies have utilized a single system, their comparative performance under identical conditions remains unclear. We therefore compared the efficiency of these three systems in C6 glioma cells by using transient transfection and the lacZ reporter gene. Highest induced activity was found with the ecdysone system, followed by tet-off and dimerizer systems. Both lowest repressed activity and highest regulation were revealed with the dimerizer system, followed by ecdysone and tet-off systems. Our data suggest that the most appropriate system depends on the experimental procedures, the application and the gene to be regulated.