Conjugated linoleic acid (CLA)-enriched milk fat inhibits growth and modulates CLA-responsive biomarkers in MCF-7 and SW480 human cancer cell lines.
Milk enriched in conjugated linoleic acid (CLA) was obtained from cows on pasture supplemented with full-fat rapeseeds (FFR; 2.26 g cis 9, trans 11 (c9,t11)-CLA/100 g fatty acid methyl esters) and full-fat soyabeans (1.83 g c9,t11-CLA100 g fatty acid methyl esters). A control milk fat (1.69 g c9,t11-CLA/100 g fatty acid methyl esters) was obtained from cows fed on pasture only. The present study assessed the potency of the CLA-enriched milk fats to modulate biomarkers that had previously been observed to respond to c9,t11-CLA in the MCF-7 and SW480 cell lines. Cell numbers decreased (P<0.05) by up to 61 and 58% following the incubation of MCF-7 and SW480 cells, respectively, for 4 d with milk fats (yielding CLA concentrations between 60.2 and 80.6 microM). The FFR milk fat, containing the highest CLA content, increased (P<0.05) [14C]arachidonic acid (AA) uptake into the monoacylglycerol fraction of MCF-7 and SW480 cells while it decreased (P<0.05) uptake into the phospholipid fraction of the latter. This milk fat also decreased (P<0.05) [14C]AA conversion to prostaglandin (PG) E2 while increasing conversion to PGF2alpha in both cell lines. All milk-fat samples increased (P<0.05) lipid peroxidation as measured by 8-epi-PGF2alpha in both cell lines. In SW480 cells the milk-fat samples decreased (P<0.05) bcl-2 and cytosolic glutathione levels while increasing (P<0.05) membrane-associated annexin V levels. All milk-fat samples decreased (P<0.05) the expression of ras in SW480 cells. These data suggest that milk-fat CLA was effective at modulating synthetic CLA-responsive biomarkers.
Miller
Aine
A
School of Biotechnology, Dublin City University, Dublin 9, Republic of Ireland.
Stanton
Catherine
C
Murphy
John
J
Devery
Rosaleen
R
D000818:Animals; D017304:Annexin A5 / Q000032:analysis; D017209:Apoptosis / Q000502:physiology; D016718:Arachidonic Acid / Q000378:metabolism; D015415:Biomarkers; D002452:Cell Count; D002455:Cell Division / Q000502:physiology; D045744:Cell Line, Tumor; D004041:Dietary Fats / Q000378:metabolism*; D015237:Dinoprost / Q000031:analogs & derivatives* / Q000096:biosynthesis; D015777:Eicosanoids / Q000378:metabolism; D015870:Gene Expression / Q000235:genetics; D019254:Genes, bcl-2 / Q000235:genetics; D011905:Genes, ras / Q000235:genetics; D005978:Glutathione / Q000032:analysis; D006801:Humans; D044243:Linoleic Acids, Conjugated / Q000378:metabolism*; D015227:Lipid Peroxidation / Q000502:physiology; D008892:Milk / Q000378:metabolism*
D017304:Annexin A5; D015415:Biomarkers; D004041:Dietary Fats; D015777:Eicosanoids; D044243:Linoleic Acids, Conjugated; C075750:8-epi-prostaglandin F2alpha; D016718:Arachidonic Acid; D015237:Dinoprost; D005978:Glutathione