Regulation of fatty acid synthase (FAS) and apoptosis in estrogen-receptor positive and negative breast cancer cells by conjugated linoleic acids

Abstract Background Conjugated linoleic acids (CLAs) are natural dairy food components that exhibit a unique body of potential health benefits in animals and man, including anti-cardiovascular disease and anti-cancer effects. Several studies have demonstrated that fatty acid synthase (FAS) levels (protein and mRNA) are over expressed in many carcinomas. Sterol regulatory element binding proteins (SREBPs) are transcription factors that regulate genes involved in lipid metabolism, including FAS. Methods Breast cancer cell lines, MCF-7 and MDA-MB-231 were treated with CLAs to investigate the regulation of SREBP-1c and FAS expression. Results In MDA-MB-231 cells, SREBP-1c and FAS were co-ordinately decreased by treatment with 25 μM CLA 9–11 and 10–12. In MCF-7 cells, the decrease in SREBP-1c and FAS expression was dependant on the concentration of CLA used. Conclusions The data suggest a differential effect of CLAs on SREBP-1c and FAS in estrogen receptor-positive (MCF-7) compared to estrogen receptor-negative (MDA-MB-231) breast cancer cells.