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Fluoxetine induces autophagic cell death via eEF2K-AMPK-mTOR-ULK complex axis in triple negative breast cancer.

ABSTRACT: OBJECTIVES:Triple negative breast cancer (TNBC) is a complex and intrinsically aggressive tumour with poor prognosis, and the discovery of targeted small-molecule drugs for TNBC treatment still remains in its infancy. In this study, we aimed to discover a small-molecule agent for TNBC treatment and illuminate its potential mechanisms. MATERIALS AND METHODS:Cell viability was detected by using methylthiazoltetrazolium (MTT) assay. Electron microscopy, GFP-LC3 transfection, monodansylcadaverine staining and apoptosis assay were performed to determine Fluoxetine-induced autophagy and apoptosis. Western blotting and siRNA transfection were carried out to investigate the mechanisms of Fluoxetine-induced autophagy. iTRAQ-based proteomics analysis was used to explore the underlying mechanisms. RESULTS:We have demonstrated that Fluoxetine had remarkable anti-proliferative activities and induced autophagic cell death in MDA-MB-231 and MDA-MB-436 cells. The mechanism for Fluoxetine-induced autophagic cell death was associated with inhibition of eEF2K and activation of AMPK-mTOR-ULK complex axis. Further iTRAQ-based proteomics and network analyses revealed that Fluoxetine-induced mechanism was involved in BIRC6, BNIP1, SNAP29 and Bif-1. CONCLUSIONS:These results demonstrate that Fluoxetine induces apoptosis and autophagic cell death in TNBC, which will hold a promise for the future TNBC therapy.

SUBMITTER: Sun D

PROVIDER: S-EPMC6528897 | biostudies-literature | 2018 Apr

REPOSITORIES: biostudies-literature

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Fluoxetine induces autophagic cell death via eEF2K-AMPK-mTOR-ULK complex axis in triple negative breast cancer.

Sun Dejuan D Zhu Lingjuan L Zhao Yuqian Y Jiang Yingnan Y Chen Lixia L Yu Yang Y Ouyang Liang L

Cell proliferation 20171101 2

<h4>Objectives</h4>Triple negative breast cancer (TNBC) is a complex and intrinsically aggressive tumour with poor prognosis, and the discovery of targeted small-molecule drugs for TNBC treatment still remains in its infancy. In this study, we aimed to discover a small-molecule agent for TNBC treatment and illuminate its potential mechanisms.<h4>Materials and methods</h4>Cell viability was detected by using methylthiazoltetrazolium (MTT) assay. Electron microscopy, GFP-LC3 transfection, monodans ...[more]

PMID: 29094413

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Project description:BackgroundBreast cancer is the most prevalent female tumor, of which triple-negative breast cancer (TNBC) accounts for about 15%. Characterized by its aggressive nature and limited treatment options, TNBC currently stands as a significant clinical challenge. This study aimed to investigate the effects of icariin (ICA) on TNBC and explore the underlying molecular mechanism.MethodsCell viability was assessed using CCK-8 assay, whereas the impact of ICA on cell proliferation was determined using colony formation assay and detection of proliferating cell nuclear antigen protein. Wound healing and transwell assays were used to evaluate the effects of ICA on cell migration and invasion, respectively. Flow cytometry was used to analyze cell cycle distribution and apoptosis. Transmission electron microscopy and monodansylcaverine staining were performed to detect the induction of autophagy, whereas molecular docking was conducted to predict the potential targets associated with autophagy. The in vivo anti-tumor effects of ICA were evaluated using a TNBC 4T1 xenograft mouse model. Protein expression levels were examined using immunoblotting and immunohistochemistry.ResultsIn vitro, ICA effectively suppressed the viability, proliferation, migration, and invasion of TNBC cells and induced G0/G1 phase cell cycle arrest, apoptosis, and autophagy in TNBC cells by regulating the adenosine monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR)/Unc-51-like kinase 1 (ULK1) signaling pathway. The knockdown of AMPK and inhibition of autophagy with 3-methyladenine reversed the effects of ICA, highlighting the importance of AMPK and autophagy in the anti-cancer mechanism of ICA. In vivo, ICA significantly inhibited TNBC growth, promoted autophagy, and regulated AMPK/mTOR/ULK1 pathway.ConclusionsOur findings demonstrated that ICA exerts anti-cancer effects against TNBC and the associated molecular mechanisms. This study will help to facilitate further preclinical and clinical investigations for the treatment of TNBC.

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Dataset Information

Fluoxetine induces autophagic cell death via eEF2K-AMPK-mTOR-ULK complex axis in triple negative breast cancer.

Publications

Fluoxetine induces autophagic cell death via eEF2K-AMPK-mTOR-ULK complex axis in triple negative breast cancer.

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