Pro-metastatic intracellular signaling of the elaidic trans fatty acid

Trans fatty acids (TFAs) are risk factors of cardiovascular disorders, and a few studies have reported the cancer-promoting effects of TFAs. In the present study, we examined the effects and signaling of elaidic acid (EA), a TFA, in colorectal cancer (CRC) cells. Oral intake of EA increased the metastasis of CT26 mouse CRC cells by inducing the expression of stemness markers nucleostemin (NS) and CD133. Mechanisms underlying EA-induced signaling were confirmed by determining the binding of EA to G-protein coupled receptor 40 (GPR40) and GPR120 by performing surface protein internalization assay. We found that c-SRC mediated EGFR transactivation was induced by the binding of EA to GPR40 and GPR120. Moreover, EGFR signaling upregulated NS and Snail expression and downregulated E-cadherin expression in wild-type APC-containing CT26 cells, and upregulated NS, Wnt5a and CD44 expression in APC-null HT29 cells. These results indicate that EA enhances the stemness and epithelial-mesenchymal transition of CRC cells. These results also indicate the prominent metastatic potential of EA-treated cancer cells and highlight the important implications of EA on public health.