Arenobufagin induces MCF-7 cell apoptosis by promoting JNK-mediated multisite phosphorylation of Yes-associated protein

作者：Lijuan Deng, Ming Qi, Qun-Long Peng, Minfeng Chen, Qi Qi, Jiayan Zhang, Nan Yao, Maohua Huang, Xiaobo Li, Yin-Hui Peng, Jun-Shan Liu, Deng-Rui Fu, Jiaxu Chen, Wen‐Cai Ye, Dongmei Zhang · 发表于：Cancer Cell International · 年份：2018 · DOI：10.1186/s12935-018-0706-9 · 被引用次数：27 · 研究领域：Hippo pathway signaling and YAP/TAZ、Cell death mechanisms and regulation、Axon Guidance and Neuronal Signaling

It has been demonstrated that bufadienolides exert potent anti-cancer activity in various tumor types. However, the mechanisms that underlie their anti-cancer properties remain unclear. Yes-associated protein, a key effector of Hippo signaling, functions as a transcription coactivator, plays oncogenic and tumor suppressor roles under different conditions. Here, we report that arenobufagin (ABF), a representative bufadienolide, induced breast cancer MCF-7 cells to undergo apoptosis, which occurred through the JNK-mediated multisite phosphorylation of YAP. Cytotoxicity was examined using an MTT assay. ABF-induced apoptosis was measured with a TUNEL assay and Annexin V-FITC/PI double staining assay. Western blotting, immunofluorescence, qRT-PCR and coimmunoprecipitation were employed to assess the expression levels of the indicated molecules. Lose-of-function experiments were carried out with siRNA transfection and pharmacological inhibitors. ABF-induced phosphopeptides were enriched with Ti4 + -IMAC chromatography and further subjected to reverse-phase nano-LC–MS/MS analysis. ABF significantly reduced the viability of MCF-7 cells and increased the percentage of early and late apoptotic cells in a concentration- and time-dependent manner. Following ABF treatment, YAP accumulated in the nucleus and bound to p73, which enhanced the transcription of the pro-apoptotic genes Bax and p53AIP1 . YAP knock-down significantly attenuated ABF-induced apoptotic cell death. Importantly, we fo...