Bufalin engages in RIP1-dependent and ROS-dependent programmed necroptosis in breast cancer cells by targeting the RIP1/RIP3/PGAM5 pathway

Breast cancer causes high mortality among females worldwide. Bufalin has recently been shown to trigger tumor cell death, although the mechanism of cytotoxicity remains unclear. The cytotoxicity of bufalin in breast cancer cells was examined using an MTT assay. The modes of death and intracellular reactive oxygen species production were measured by flow cytometry. We also observed cellular morphologic changes by Hoechst 33342 and propidium iodide staining and transmission electron microscopy. Western blotting was performed to determine the expression levels of related proteins. Our results showed that bufalin reduced cellular viability and promoted reactive oxygen species production, which could be inhibited by Nec-1 and N-acetylcysteine. Necroptosis was detected by Hoechst 33342 and propidium iodide staining and transmission electron microscopy. Western blot analysis showed that bufalin induced necroptosis by upregulating the necroptosis mediator RIP1 and the RIP1/RIP3/PGAM5 pathway. Taken together, these findings indicated that bufalin induces breast cancer cell necroptosis by targeting the RIP1/RIP3/PGAM5 pathway. Copyright (C) 2019 Wolters Kluwer Health, Inc. All rights reserved.