EVALUATION OF THE USE OF THE LUCIFERASE-REPORTER-GENE SYSTEM FOR GENE-REGULATION STUDIES INVOLVING CYCLIC AMP-ELEVATING AGENTS

The effects of cyclic AMP (cAMP)-elevating agents on the activity of c is-acting gene promoter sequences are frequently studied using the luc iferase-reporter-gene system. The aim of the present study was to asse ss whether cAMP-elevating agents induce any changes in the level of lu ciferase activity independently of a transcriptional activation of pro moter elements. Chloramphenicol acteyltransferase (CAT) and luciferase reporter genes under the control of the same promoter elements were t ransiently expressed in primary cultures of human vascular smooth-musc le cells. Transfected cells were treated with a cell-permeable and non -hydrolysable cAMP analogue, 2'-O-monobutyryl-8-bromo cAMP, or with th e cAMP-elevating agents forskolin and prostaglandin E(1) (PGE(1)). For skolin and PGE(1) induced a significant increase in the level of lucif erase activity, but had no effect on CAT activity. Conclusions based s olely on the use of the luciferase-reporter-gene system in studies inv olving promoter activation by cAMP-elevating agents could therefore be misleading.