Expression of GRPR in LNCaP cells confers BBS-stimulated COX-2 expression and PGE
synthesis. A) Northern blot confirming the expression of GRPR in transfected LNCaP cells (n = 1). B) Time-dependent change in intracellular Ca2+ concentration measured with Fura-2; comparison of GRPR transfected (LNCaP/GRPR) to control vector-transfected LNCaP cells (LNCaP/Vector) (tracing represents the average change in [Ca2+]i from 40 cells). C) Immunoblot showing effects of BBS treatment on COX-2 protein expression in LNCaP/Vector and LNCaP/GRPR cells. PC-3 cells were used as a positive control. Blots were reprobed for β-actin to ensure the equivalent loading and transfer of protein samples. D) Effects of SB203580 and LY294002 on BBS-stimulated PGE2 elaboration form LNCaP/GRPR cells. Cells were pretreated for 30 min with the inhibitors and then stimulated with BBS for 6 h. PGE2 levels in the culture media were determined as described (Material and Methods) [† BBS vs. vehicle, p < 0.01; * BBS+SB203580 or LY294002 vs. BBS alone, p < 0.01].