Figure 3

Effects of GRK5 expression on PGE2-mediated TOPFLASH and CREB reporter activities and cell growth. (A) HCT116 cells were transfected with control or GRK5 expression vector for 24 h, and expression of the GRK5 fusion protein was determined by Western blot analysis using anti-myc or anti-GRK5 antibodies. Actin expression was used as a loading control. (B) TOPFLASH and CREB reporter activities were determined in HCT116 cells after transient expression of indicated expression vectors for 24 h, serum starvation for 16 h and then PGE2 (10 nM) incubation for 24 h. (C) Cell proliferation was determined in HCT116 cells transfected with control or GRK5 expression vector for 24 h, serum starvation for 16 h, and PGE2 stimulation for 48 h. Representative results from triplicate samples were expressed as means ± SD. *, P < 0.05; **, P < 0.01; ***, P < 0.001. Control, Ctrl.