The role of cyclooxygenase-2 and prostaglandins in colon cancer

The temporal association between loss of function of the tumor suppressor adenomatous polyposis coli (APC) and overexpression of cyclooxygenase 2 (COX-2) has been demonstrated in vivo and has led to the hypothesis that APC regulates COX-2 expression. This could potentially occur through a variety of mechanisms including the well-characterized ability of APC to negatively regulate Wnt signaling and decrease expression of target genes. However, recent findings suggest that the products of COX-2 elicit effects that occur upstream of the β-catenin/TCF/LEF pathway. This review will focus on the regulation of COX-2 by APC and the interplay between COX-2 and the Wnt signaling pathway.