The gastric hormone gastrin regulates the expression of a variety of genes involved in control of of acid secretion and also in the growth and organisation of the gastric mucosa. One putative target is plasminogen activator inhibitor-2 (PAI-2) which is a component of the urokinase activator system that acts extracellularly to inhibit urokinase plasminogen activator (uPA) and intracellularly to suppress apoptosis. Previous studies have demonstrated that gastrin induces PAI-2 both in gastric epithelial cells expressing the gastrin (CCK-2) receptor and, via activation of paracrine networks in adjacent cells that do not express the receptor. We have now sought to identify the response element(s) in the PAI-2 promoter targeted by paracrine mediators initiated by gastrin. Mutational analysis identified two putative response elements in the PAI-2 promoter that were downstream of gastrin-activated paracrine signals. One was identified as a putative MAZ site, mutation of which dramatically reduced both basal and gastrin-stimulated responses of the PAI-2 promoter by a mechanism involving PGE2 and the small GTP-ase, RhoA. Yeast-1-hybrid screening identified the other as binding the activating signal cointegrator-1 (ASC-1) complex which was shown to be the target of IL-8 released by gastrin. RNAi knockdown of two subunits of the ASC-1 complex (p50 & p65) inhibited induction of PAI-2 expression by gastrin. The data reveal previously unsuspected transcriptional mechanisms activated as a consequence of gastrin-triggered paracrine networks and emphasise the elaborate and complex cellular control mechanisms required for a key component of tissue responses to damage and infection.