Both n-6 PUFAs and n-3 PUFAs modulate peroxisome proliferator-activated receptor gamma
(PPARγ) and decrease cell growth in human lung cancer cells (7). PPARγ is a member of the
ligand-inducible nuclear transcription factors that heterodimerize with retinoid X receptors and
bind to peroxisome proliferator response elements (PPRE) located in the promoter region of
PPAR target genes (8). These lipid-sensitive receptors can be activated in a variable isotypespecific
manner by natural/dietary ligands including long chain polyunsaturated fatty acids
which are found in fish oil (e.g. n-3-PUFA, n-6-PUFA), various eicosanoids (e.g. 15d-PGJ2),
lipid hydroperoxides (e.g. 9(s)-HODE and 13(s)-HODE), and in linoleic acid (9,10). The
efficacy of these compounds as anti-cancer agents has been examined in a variety of cancers
including colon, breast and prostate, and they have been found to inhibit cancer cell growth in
vitro and in vivo (11).