Both Rac1 and Cdc42 regulate VEGF expression in non-hypoxic and hypoxic conditions. All cell strains were serum starved for 24 hours prior to exposure to the indicated agent. Conditioned media were collected after 24 hr and ELISA analyses were completed. The data is presented as either percent of control, or fold induction as indicated in the figure. Error bars represent the SD from triplicate experiments. (a) PH3MT cell strains expressing a vector control (PH3MT-VC-C2), Rac1N17 (PH3MT- Rac1N17-C1), Cdc42N17 (PH3MT-Cdc42N17-C2), or both (PH3MT-Rac1N17/Cdc42N17), were stimulated with either medium containing 10% SCS, 100 μM DFO, 100 μM CoCl2 or Hypoxia (1% O2). (b) MSU-1.1 cells expressing GFP alone (MSU-1.1-GFP-VC-C2), or GFP-tagged Rac1V12 (MSU-1.1-GFP-Rac1V12), or GFP-tagged Cdc42V12 (MSU-1.1-GFP-Cdc42V12). Cells were stimulated with medium containing 10% SCS. * denotes a significant difference (p < 0.01).