The effect of three lipid emulsions differing in fatty acid composition on growth, apoptosis and cell cycle arrest in the HT-29 colorectal cancer cell line

Background & aims: An in vitro study showed that a lipid emulsion containing fish oil (FO) slows the growth of colon cancer cells and enhances their sensitivity to 5-fluorouracil (FU). The aim was to confirm this finding and to compare such an emulsion with an alternative to lowered n-6 fatty acid exposure. Methods: We determined the number of viable cells, apoptosis and cell cycle distribution of HT-29 cells after exposure to one of three lipid emulsions. Cell cycle distribution was also assessed after treatment with lipid emulsions and FU. Results: The lipid emulsion containing FO induced a significant growth inhibitory effect without changing the percentage of apoptotic cells. Exposure to the other lipid emulsions had no effect on growth and decreased apoptosis. Each lipid emulsion potentiated the S phase-halting effect of 1 and 10 mu M FU. This effect also occurred at 0.1 mu M FU when the cells were exposed to the FO containing lipid emulsion. Conclusions: A lipid emulsion containing FO has a growth inhibitory effect on a human colon adenocarcinoma cell line, an effect not due to the induction of apoptosis, and potentiated the S phase-halting effect of FU. Thus, an FO lipid emulsion may be of benefit in colorectal cancer. (C) 2009 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.