Autophagy mediates free fatty acid effects on MDA-MB-231 cell proliferation, migration and invasion

Epidemiological and animal studies indicate an association between high levels of dietary fat intake and an increased risk of breast cancer. The multifaceted role of autophagy in cancer has been revealed in previous years. However, the mechanism of this role remains unknown. In the present study, the two most common free fatty acids, palmitate acid (PA) and oleic acid (OA), were used to determine the effect on human breast cancer MDA-MB-231 cells, and the possible role of autophagy was investigated by detecting light chain 3 (LC3)-II/I. Bafliomycin A1 was used to detect autophagy flux. High palmitate acid condition-induced MDA-MB-231 cell death and invasion were mitigated by 3-methyladenine pretreatment or transfection with shRNA against autophagy protein 5. By contrast, high oleic acid condition induced MDA-MB-231 cell proliferation, migration and invasion were mitigated using rapamycin. The present results suggest that autophagy has an important role in the effects of PA and OA on breast cancer growth and metastasis in vitro.