Identification of small-molecule inhibitors of the cyclin D2 promoter. NIH3T3 cells overexpressing c-maf and the cyclin D2 promoter driving luciferase were plated in 96-well plates (13 000 cells per well) by a robotic liquid handler. After the cells had adhered to the plates, they were treated with aliquots of molecules from the LOPAC and Prestwick libraries of off-patent drugs and chemicals at a final concentration of approximately 5 μmol/L and approximately 0.1% DMSO. As a control, cells were treated with DMSO alone. Cells were incubated with the molecules at 37°C in a humid atmosphere for 20 hours. After incubation, cyclin D2 transactivation was assessed by the luciferase assay. In parallel, we also assessed viability with an MTS assay. The results of the screens are shown. The activity of the compound is expressed as log2((sample luciferase RFU/control luciferase RFU)/(sample MTS OD/control MTS OD)). Compounds with an activity less than −1 were considered inhibitors.