Resistin confers resistance to doxorubicin-induced apoptosis in human breast cancer cells through autophagy induction.

Clear evidence has linked obesity to a high risk of incidence as well as poor clinical outcome of breast cancer. It has been proven that changes in the levels of adipokines caused by obesity are associated with the initiation and progression of breast cancer. Resistin is a novel adipokine that is upregulated in breast cancer patients and promotes breast cancer cell growth, invasion, and migration. The aim of the study was to investigate whether resistin affected the efficacy of doxorubicin (Dox), one of the most effective anthracycline chemotherapeutic agents in the treatment of breast cancer. Treatment with resistin significantly attenuated Dox-induced apoptosis in a dose- and time-dependent manner, resulting in an increase in breast cancer cells survival. Moreover, resistin significantly induced autophagy flux and inhibition of autophagy abrogated the pro-survival effect of resistin in doxorubicin-treated cells. Furthermore, the AMPK/mTOR/ULK1 and JNK signaling pathways were activated by resistin treatment. Inhibition of these two pathways markedly reduced the ratio of LC3B-II/LC3B-I and increased cell apoptosis induced by Dox. For the first time, our findings indicate that resistin confers resistance to doxorubicin-induced apoptosis through autophagy induction and that this process involves the activation of AMPK/mTOR/ULK1 and JNK signaling pathways. Our findings suggest that resistin antagonism may be a novel strategy to overcome resistance to doxorubicin-based chemotherapy in breast cancer patients.