THE EFFECT OF ESSENTIAL FATTY-ACIDS ON GROWTH AND UROKINASE-TYPE PLASMINOGEN-ACTIVATOR PRODUCTION IN HUMAN PROSTATE DU-145 CELLS

Urokinase-type plasminogen activator (uPA) is an important protease en zyme in carcinogenesis, and is involved in both invasion and metastasi s of cancer. Increased uPA activity and decreased essential fatty acid (EFA) levels have been reported in cancer. This phenomenon may be exp lained by the fact that certain EFAs, such as gamma-linolenic acid (GL A) and eicosapentaenoic acid (EPA), inhibit uPA activity. The effect o f EFA on human prostate DU-145 cell growth and uPA production is still unknown and was investigated in this study. Data obtained from the di fferent unsaturated fatty acids showed that oleic acid (OA) and EPA en hanced DU-145 cell proliferation at 0.004 and 0.04 mM for up to 4 days . However, alpha-linolenic acid (ALA), linoleic acid (LA), GLA and ara chidonic acid (AA) suppressed cell proliferation under the same condit ions, possibly as a result of inhibition of DNA and protein synthesis as measured using labelled thymidine and glycine incorporation. In con trast to the cell proliferation, uPA production was inhibited by all t he unsaturated fatty acids under investigation. Therefore, the absence of EFAs, as reported, may affect invasion and metastasis of cancer.