Effects of C18 fatty acids on breast carcinoma cells in culture.

The relative cytotoxic potential of C18 carbon fatty acids on human breast tumor cells was determined. The saturated (18:0) and monounsaturated (cis C18:1n-9) fatty acids exhibited no cytotoxic effects, while cis polyunsaturated fatty acids (C18:2n-6, C18:3n-6, C18:3n-3, C20:4n-6, C20:5n-3 and C22:6n-3) were cytotoxic dose-dependently. Fatty acids with 3, 4 and 5 double bonds were more effective than those with 2 and 6 double bonds. Cis, but not trans, isomers of C18:2n-6 were cytotoxic. The cells did not demonstrate resistance to the cytotoxic effects induced by the fatty acids at any concentrations. It is concluded that in these cells the cytotoxic potential of the fatty acids depended on the number, the position and the geometric form of the double bond in the fatty acid carbon chain.