Fig. 7.

PRG contributes to Cox-2 expression downstream of GRPR. (A,B) Time course of Cox-2 expression. Caco-2 (A) or HT-29 (B) cells were stimulated with GRP for the indicated time(s). Cox-2 expression was determined by Western blot utilizing Cox-2-specific antibody. Beta-actin and GAPDH used as loading control. (C,D) Cox-2 expression in Caco-2 (C) or HT-29 (D) cells transfected with scrambled or PRG siRNA. The cells were incubated with GRP for 8 hours. Cox-2 expression and PRG knock down was verified by Western Blot. (E,F) Statistical densitometric analysis of Cox-2 expression from n = 3 for Caco-2 (E) and HT-29 (F) cells. Shown are mean values ± S.E.M.; ***P < 0.001. (G,H) PGE₂ production in Caco-2 cells transfected with scrambled or PRG siRNA. (G) PRG knock down was confirmed with Western blot. (H) Caco2 cells serum-starved overnight and stimulated with GRP for 24 hours. Cell media for each condition was harvested and analyzed for PGE₂ concentration by enzyme-linked immunosorbent assay (ELISA) (see Materials and Methods). Statistical analysis of n = 4. Shown are mean values ± S.E.M.; **P < 0.01.