Prostaglandin synthesis in human cancer cells: influence of fatty acids and butyrate.

Previous research has suggested that prostaglandins (PGs) may play a role in the development of colon cancer since tumor cells produce more PGs than normal cells. However, the exact mechanism by which PGs play a role in the development of cancer is not known. In addition, factors that influence PG synthesis are not known since they are complicated by the presence of homeostatic mechanisms. To avoid the homeostatic mechanisms, the present research was designed to examine factors that may influence PG synthesis in an in vitro system, i.e., a tissue culture. We have chosen two human colon cancer cell lines that differ in their ability to metabolize long-chain fatty acids (LCFAs), LS174T cells and HT-29 cells. We examined the effect of LCFAs on their membrane fatty acid composition, growth, and ability to release the main PGs (PGE2 and PGI). The LCFAs used were those most common in the colonic lumen [18:0, 18:2 (n-6), and 18:3 (n-3)]. In addition, we examined the effect of butyrate on the above mentioned parameters. Butyrate is produced in the colon through fermentation of dietary fibers. The data obtained suggest that although both of these tumor cell lines are of human colonic origin, they differ in their response to LCFAs and butyrate in some of the characteristics studied, such as growth, composition of membranes, and the relationship between membrane FA composition and PG synthesis. Polyunsaturated fatty acid supplementation stimulated the growth of HT-29 cells but not of LS174T cells when compared with growth in media supplemented with 18:0.(ABSTRACT TRUNCATED AT 250 WORDS)