Bufadienolides induce apoptosis and autophagy by inhibiting the AKT signaling pathway in melanoma A-375 cells

Abstract

The purpose of the present study was to investigate the effect of bufadienolides on the A-375 melanoma cell line, and to delineate the underlying mechanism. A Cell Counting Kit-8 assay was used to determine the viability of the cells, and flow cytometry was used to evaluate apoptosis. Western blot analysis was used to evaluate the expression levels of proteins involved in the AKT pathway that are associated with apoptosis and autophagy. The results demonstrated that bufadienolides reduced the viability of A-375 cells in a dose- and a time-dependent manner. Following treatment with bufadienolides, A-375 cells exhibited clear properties that were characteristic of apoptosis and autophagy. The expression levels of the pro-apoptotic proteins Bax and p53 were upregulated, whereas those of the anti-apoptotic proteins, Bcl-2 and caspase-3 were downregulated. In addition, the level of a protein known to be associated with autophagy, microtubule-associated proteins 1A/1B light chain 3-II, was increased, whereas that of p62 protein was reduced. Finally, the AKT signaling pathway was blocked in the bufadienolide-treated A-375 cells. In conclusion, these results revealed that bufadienolides effectively induced apoptosis and autophagy in A-375 cells via the AKT pathway, and therefore may be one of the candidate targets for the future development of targeted drugs to treat melanoma.