Role of autophagy in the ω-3 long chain polyunsaturated fatty acid-induced death of lung cancer A549 cells

Abstract

The present study identified that ω-3 long chain polyunsaturated fatty acids (ω-3 PUFAs), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) demonstrate anti-proliferative effects in lung cancer A549 cells. MTS and cytotoxicity assays were conducted to confirm that ω-3 PUFAs induced cell death. Autophagy-associated gene and signaling pathways were also detected. Microtubule-associated protein light chain 3 (LC3) expression was found to be increased subsequent to treatment with DHA and EPA, and the expression of LC3-II was particularly increased. mRFP-GFP-LC3 fluorescence staining and p62 expression levels were used to detect autophagic flux. The present results indicate that DHA and EPA block autophagic flux, suggesting autophagosome accumulation. Subsequent to treatment with DHA and EPA, which interfered with autophagosomes, the expression of Beclin 1 was significantly decreased, while the expression of phosphorylated Akt and phosphorylated mammalian target of rapamycin was significantly increased. Therefore, DHA and EPA exert anti-proliferative effects by inhibiting autophagy in A549 cells, which highlights the potential of DHA and EPA for use in the prevention or treatment of lung cancer.