Modulation of lipoxidase activity by urokinase-type plasminogen activator.
Malignant cells show increased urokinase (UK) activity and decreased peroxidation of essential fatty acids (EFA). In order to explore this phenomenon the effect of UK on the lipoxidase activity was spectrophotometrically investigated. Decreased lipoxidase activity was obtained with increased UK concentrations (r = -1.000, p < 0.0001). This proteolytic effect of UK on lipoxidase was eliminated with the addition of the UK inhibitor leupeptin. These results suggest that the increase in UK activity in malignant cells may decrease the lipoxidase activity and thus peroxidation of EFA. The effectiveness of a given EFA in killing cancer cells would therefore depend on the modulation of the lipoxidase activity by the UK-type plasminogen activator.
van Aswegen
C H
CH
Wolmarans Research Laboratory, Department of Urology, HF Verwoerd Hospital, Pretoria, South Africa.
du Toit
P J
PJ
du Plessis
D J
DJ
D000595:Amino Acid Sequence; D005228:Fatty Acids, Essential / Q000378:metabolism; D006801:Humans; D007668:Kidney / Q000201:enzymology; D007976:Leupeptins / Q000494:pharmacology; D015227:Lipid Peroxidation / Q000187:drug effects; D008084:Lipoxygenase / Q000378:metabolism*; D016859:Lipoxygenase Inhibitors / Q000494:pharmacology*; D008969:Molecular Sequence Data; D009369:Neoplasms / Q000378:metabolism; D010940:Plant Proteins / Q000037:antagonists & inhibitors; D014568:Urokinase-Type Plasminogen Activator / Q000494:pharmacology*
D005228:Fatty Acids, Essential; D007976:Leupeptins; D016859:Lipoxygenase Inhibitors; D010940:Plant Proteins; D008084:Lipoxygenase; D014568:Urokinase-Type Plasminogen Activator; C032854:leupeptin