trans-10,cis-12 Conjugated Linoleic Acid Inhibits the G1–S Cell Cycle Progression in DU145 Human Prostate Carcinoma Cells

Conjugated linoleic acid (CLA) is a group of positional and geometric isomers of linoleic acid, and has evidenced anti-cancer activities in experimental animal cancer models and in vitro studies. The two predominant isomers of CLA are cis-9,trans-11 CLA (c9t11) and trans-10,cis-12 CLA (t10c12). The present study was performed to study the effect of the individual CLA isomers on DU145 cell growth. The cells were incubated in serum-free medium with different concentrations of the fatty acids. Treatment of cells with t10c12 (at 2.5–10 µmol/L) resulted in a dose-dependent reduction in the numbers of viable cells, whereas c9t11 CLA at a concentration of 5 µmol/L slightly increased viable cell numbers at 3 days (P < .05). DNA flow cytometric analysis revealed that the treatment of DU145 cells with t10c12 for 24 hours induced a small but significant increase in the number of cells in the G1 phase, accompanied by a complementary decrease in cells in the S phase. c9t, however, had no effect on cell cycle progressi...