Specificity of hydroperoxy fatty acid inhibition of cell growth and the lack of effect on tumour necrosis factor-induced cytotoxicity in WEHI clone 13 cells.
We have examined whether different omega6-hydroperoxy fatty acids affect tumour cell growth or modulate TNF-induced toxicity in a fatty acid specific way in WEHI clone 13 fibrosarcoma cells. The omega6-hydroperoxides were synthesized from 8 different n - 6 and n - 3 PUFAs by soybean lipoxygenase. The omega6-hydroperoxy fatty acids inhibited cell growth in a concentration-dependent way by a mechanism that is related to the hydroperoxy moiety. Intracellular GSH seemed to protect since the GSH synthase inhibitor L-buthionine-S,R-sulfoximine (BSO) increased cell growth inhibition further. The antioxidants butylated hydroxyanisole (BHA), butylated hydroxytoluene and alpha-tocopherol did not affect the toxicity. The extent of growth inhibition varied between the hydroperoxides, but the difference was relatively small. The most toxic was hydroperoxy-alpha-linolenic acid which reduced cell survival by 56% after 44 h incubation at 35 microM, while the least toxic, hydroperoxy-gamma-linolenic acid, reduced cell survival by only 10%. The data also show that there is no correlation between toxicity and degree of unsaturation of the hydroperoxy fatty acids. None of the 8 different hydroperoxy fatty acids potentiated TNF-induced toxicity. This, together with the differential effects of BHA and BSO on TNF- and hydroperoxy fatty acid toxicity, indicate that neither the hydroperoxides nor their metabolites are involved in mediating or modulating the TNF-effect.
Nøding
R
R
Department of Clinical Chemistry, Norwegian University of Science and Technology, Trondheim University Hospital, Norway.
Brekke
O L
OL
Bjerve
K S
KS
D000818:Animals; D016923:Cell Death / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D004347:Drug Interactions; D005227:Fatty Acids / Q000737:chemistry / Q000494:pharmacology*; D005354:Fibrosarcoma / Q000473:pathology*; D006801:Humans; D010084:Oxidation-Reduction; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D005227:Fatty Acids; D014409:Tumor Necrosis Factor-alpha