Influence of conjugated linoleic acid isomers on the metastasis of colon cancer cells in vitro and in vivo

This study investigated the isomer-specific effects of cis-9, trans-11 ( c9, t11) and trans-10, cis-12 ( t10, c12) conjugated linoleic acid (CLA) on the metastasis of colon cancer cells in vitro and in vivo. Cell migration was examined by a Boyden chamber assay in SW480 cells. MMP-9 activity was monitored by gelatin zymography, and MMP-9 protein and mRNA levels were determined by Western blot and RT-PCR analysis, respectively, in SW480 cells. For the experimental metastasis, BALB/c mice were injected intravenously with CT-26 cells in the tail vein. Mice were fed a diet containing either no CLA or 0.1% c9, t11 or t10, c12 CLA for 4 weeks. In experimental metastasis, the numbers of pulmonary nodules were significantly lower in mice fed CLA isomers than in mice fed a control diet ( P