Activated Rac1 and Cdc42 independently regulate uPA expression. The indicated cell strains were serum starved for 24 hours then stimulated with medium containing 10% SCS. (a) Grown in the absence of tetracycline, PH3MT cell strains expressing a vector control (PH3MT-VC-C2), Rac1N17(PH3MT- Rac1N17-C1), Cdc42N17 (PH3MT-Cdc42N17-C2) or both Rac1N17 and Cdc42N17 (PH3MT-Rac1N17/Cdc42N17) were tested for uPA expression levels using ELISA. Data is presented as percent of control. Error bars indicate the SD from triplicate experiments. * indicates significant difference, p < 0.05. ** indicates a significant difference compared to PH3MT-Rac1N17-C1 and PH3MT-Cdc42N17-C2, p < 0.05. (b) conditioned medium was collected from MSU-1.1 cells expressing GFP alone (MSU-1.1-GFP-VC), GFP-tagged Rac1V12 (MSU-1.1-GFP-Rac1V12) or GFP-tagged Cdc42V12 (MSU-1.1-GFP-Cdc42V12), and uPA expression was analyzed. Data is presented as fold-induction of uPA expression. Error bars represent the SD from triplicate experiments. * indicates significant difference, p < 0.05.