The involvement of
prostaglandins (PGs) and other
eicosanoids in the development of human
cancer has been known for over two decades. Importantly, an increase in PG synthesis may influence
tumor growth in human beings and experimental animals, and numerous studies have illustrated the effect of PG synthesis on
carcinogen metabolism,
tumor cell proliferation and metastatic potential. PGs produced by
cyclooxygenases (COXs) are represented by a large series of compounds that mainly enhance
cancer development and progression, acting as
carcinogens or
tumor promoters, with profound effects on
carcinogenesis. Further investigations suggest that
arachidonic acid (AA) metabolites derived from
lipoxygenase (LOX) pathways play an important role in growth-related signal transduction, implying that intervention through these pathways should be useful for arresting
cancer progression. We discuss here the implications of COX and LOX in colon, pancreatic, breast, prostate, lung, skin, urinary bladder and
liver cancers. Select inhibitors of COX and LOX are described, including nonsteroidal antiinflammatory drugs (
NSAIDs), selective
COX-2 inhibitors,
curcumin,
tea,
silymarin and
resveratrol, as well as a method useful for evaluating inhibitors of COX. Although a substantial amount of additional work is required to yield a better understanding of the role of COX and LOX in
cancer chemoprevention, it is clear that beneficial
therapeutic effects can be realized through
drug-mediated modulation of these metabolic pathways.