Effects of saturated and polyunsaturated fatty acids on human tumor-cell proliferation.

1. Fatty acids of varying chain length and degree of unsaturation were found to inhibit the proliferation of T24/83, Hep2 and LLC-WRC256 tumor cell lines. 2. There was a strong correlation (r2= -0.956 to -0.995) between the degree of inhibition of proliferation and the degree of unsaturation of 18-carbon fatty acids for all the cell lines studied. No correlation existed in this respect for the 20-carbon fatty acids. 3. Tumor cells can differentiate between the degree of unsaturation of the 18-carbon fatty acids, and this ability is ultimately manifested in the rate of proliferation; however, the mechanisms remain to be identified.