Drug Target Insights

The metabolism of arachidonic acid by either the cyclooxygenase (COX) or lipoxygenase (LOX) pathway generates eicosanoids, which have been implicated in the pathogenesis of a variety of human diseases, including cancer. It is now considered that they play important roles in tumor promotion, progression, and metastasis, also, the involvement of COX and LOX expression and function in tumor growth and metastasis has been reported in human tumor cell lines. In this study, we examined the expression of COX and LOX in human urological tumors (renal cell carcinoma, bladder tumor, prostate cancer, testicular cancer) by immunohistochemistry and RT-PCR, and we also examined the effects of COX and LOX (5- and 12-LOX) inhibitors in those cells by MTT assay, hoechest staining, and flow cytometry. COX-2, 5-LOX and 12-LOX expressions were significantly more extensive and intense in malignant tissues than in normal tissues. Furthermore, 5-LOX inhibitor induced the reduction of malignant cell viability through early apoptosis. These results demonstrated COX-2 and LOX were induced in urological tumors, and 5-LOX inhibitor may mediate potent antiproliferative effects against urological tumors cells. Thus, 5-LOX may become a new target in the treatment of urological tumors.