OncoTargets and Therapy (Mar 2020)
Berberine Reverses Doxorubicin Resistance by Inhibiting Autophagy Through the PTEN/Akt/mTOR Signaling Pathway in Breast Cancer
Abstract
Ye Wang,* Yanfang Liu,* Xinyang Du, Hong Ma, Jing Yao Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, People’s Republic of China*These authors contributed equally to this workCorrespondence: Jing YaoCancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Jiefang Road 1277, Wuhan, Hubei Province 430022, People’s Republic of ChinaTel +86-189 8627 1157Email [email protected]: Berberine (BBR), a traditional Chinese medicine, has been shown effects on inhibiting cancer development. Autophagy-mediated resistance plays an important role in cancer progression; therefore, regulation of autophagy is a novel therapeutic strategy for cancer treatment. However, effects of BBR on autophagy-mediated resistance have not been reported.Methods: MCF-7 breast cancer cells and the doxorubicin (ADR)-resistant MCF-7 cells (MCF-7/ADR) were used for analyses. Western blotting was conducted to evaluate protein expression; MTT, colony formation, and EdU assays were conducted to assess cell proliferation; transmission electron microscopy was used to monitor autophagy levels; and a xenograft tumor model was established to assess the effects of BBR on reversing doxorubicin resistance.Results: We confirmed that BBR, recently identified as a suppressor of autophagy, inhibits autophagosome formation in MCF-7/ADR cells. Treatment with BBR blocked the accumulation of the autophagy-associated protein LC3II, resulting in cellular accumulation of p62, reduced cell proliferation, and reversal of doxorubicin resistance. Mechanistically, we found that BBR inhibited autophagy by modulating the PTEN/Akt/mTOR signaling pathway. In vivo, our study showed that BBR exerts clear anti-tumor effects.Conclusion: The results of this study suggest that BBR reverses doxorubicin resistance in breast cancer cells by inhibiting autophagy. This finding highlights the potential clinical application of BBR in the treatment of breast cancer.Keywords: breast cancer, berberine, chemoresistance, PTEN, autophagy, ADR
