Antitumor effects of lipoxygenase inhibitors on murine bladder cancer cell line (MBT-2).

Arachidonic acid (AA) metabolites derived from both the lipoxygenase (LOX) and cyclooxygenase (COX) pathways transduce a variety of signals related to cell growth. Selective blockade of the different metabolic pathways of AA (using a general LOX inhibitor NDGA, a 5-LOX inhibitor AA861, a 12-LOX inhibitor baicalein and a general COX inhibitor ibuprofen) revealed that murine bladder cancer cell line (MBT-2) cell proliferation was inhibited by the LOX inhibitors concentration-dependently, but not by the COX inhibitor. Among the LOX inhibitors, baicalein showed the strongest inhibition and induced apoptosis of MBT-2. Proliferation of MBT-2 was also significantly inhibited by 12-LOX antisense oligonucleotides. In an in vivo experiment, the antitumor effects of baicalein administration on C3H/HeN mice implanted with MBT-2 were recognized. These results suggested that LOX inhibition may be significant in the treatment of bladder cancer.