Figure 5

LPA-mediated transactivation of upregulated EGFR enhances COX-2 expression in colonic myofibroblasts . We have previously demonstrated that TNF-α potentiates LPA-mediated COX-2 expression via PKD [8], and that TNF-α induces upregulation of EGFR expression and signaling in human colonic myofibroblasts [11]. Here, we demonstrate cross talk between these two signaling pathways through LPA-mediated transactivation of upregulated EGFR, leading to enhanced COX-2 expression in colonic myofibroblasts. A summary of the signaling interactions is illustrated in graphical form.