title: The synthetic β-nitrostyrene derivative CYT-Rx20 induces breast cancer cell death and autophagy via ROS-mediated MEK/ERK pathway.
abstract: The β-nitrostyrene family has been shown to suppress cancer cell proliferation and induce programmed cell death. However, mechanisms underlying β-nitrostyrenes remain less evaluated. Here, we synthesized a β-nitrostyrene derivative, CYT-Rx20, and characterized its anticancer effect and involving mechanisms in breast cancer. We found that CYT-Rx20 arrested breast cancer cells at G2/M phase and decreased cell viability by activating the caspase cascade, accompanying with increases of poly (ADP-ribose) polymerase (PARP) cleavage and γ-H2AX expression. On the other hand, up-regulation of Beclin-1, ATG5, and LC-3 was observed in CYT-Rx20-induced autophagy, which was evidently shown by transmission electron microscopy. In addition to these, CYT-Rx20-induced breast cancer cell death, intracellular reactive oxygen species (ROS) formation and expression of phospho-ERK1/2, Beclin-1, and LC-3 were significantly reversed in the presence of N-acetyl-l-cysteine (NAC), a thiol antioxidant. Furthermore, the cytotoxicity of CYT-Rx20 was enhanced by co-treatment with the autophagy inhibitor chloroquine or bafilomycin A1, suggesting that an incomplete autophagy process could deteriorate CYT-Rx20-induced cytotoxicity. In nude mice xenograft study, CYT-Rx20 significantly reduced orthotopic tumor growth. Immunohistochemical analysis revealed elevated expression of phospho-ERK1/2 and LC-3 in tumor tissues of the mice treated with CYT-Rx20. Together, we propose that CYT-Rx20 may have potential to be further developed into a β-nitrostyrene-based anticancer compound for the treatment of breast cancer.
authors.affiliation: Translational Research Center, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Amos C
authors.initials: AC
authors.lastname: Hung
authors.affiliation: Translational Research Center, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Chun-Hao
authors.initials: CH
authors.lastname: Tsai
authors.affiliation: Cancer Center, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Ming-Feng
authors.initials: MF
authors.lastname: Hou
authors.affiliation: Translational Research Center, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Wen-Lin
authors.initials: WL
authors.lastname: Chang
authors.affiliation: Translational Research Center, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Chie-Hong
authors.initials: CH
authors.lastname: Wang
authors.affiliation: Translational Research Center, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Anatomy, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Yi-Chen
authors.initials: YC
authors.lastname: Lee
authors.affiliation: Faculty of Science, University of Western Ontario, London, Ontario, Canada.
authors.forename: Alice
authors.initials: A
authors.lastname: Ko
authors.affiliation: Department of Dermatology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Dermatology, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Stephen Chu-Sung
authors.initials: SC
authors.lastname: Hu
authors.affiliation: Graduate Institute of Natural Products, College of Pharmacy, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Fang-Rong
authors.initials: FR
authors.lastname: Chang
authors.affiliation: Graduate Institute of Natural Products, School of Traditional Chinese Medicine, Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan. Electronic address: pewehs@mail.cgu.edu.tw.
authors.forename: Pei-Wen
authors.initials: PW
authors.lastname: Hsieh
authors.affiliation: Translational Research Center, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Obstetrics and Gynecology, Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Lipid Science and Aging Research Center, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan. Electronic address: 1020005@kmuh.org.tw.
authors.forename: Shyng-Shiou F
authors.initials: SS
authors.lastname: Yuan
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D001343:Autophagy / Q000187:drug effects*; D000071187:Autophagy-Related Protein 5; D000071186:Beclin-1; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000201:enzymology / Q000648:ultrastructure; D020169:Caspases / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D005260:Female; D059565:G2 Phase Cell Cycle Checkpoints / Q000187:drug effects; D006657:Histones / Q000378:metabolism; D006801:Humans; D061986:MCF-7 Cells; D008565:Membrane Proteins / Q000378:metabolism; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects*; D010766:Phosphorylation; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D013343:Styrenes / Q000494:pharmacology*; D023041:Xenograft Model Antitumor Assays
chemical_list: C512238:3-hydroxy-4-methoxy-beta-methyl-beta-nitrostyrene; C502778:ATG5 protein, human; D000970:Antineoplastic Agents; D000975:Antioxidants; D051017:Apoptosis Regulatory Proteins; D000071187:Autophagy-Related Protein 5; C491997:BECN1 protein, human; D000071186:Beclin-1; C468783:H2AX protein, human; D006657:Histones; C477012:MAP1LC3A protein, human; D008565:Membrane Proteins; D008869:Microtubule-Associated Proteins; D017382:Reactive Oxygen Species; D013343:Styrenes; D011065:Poly(ADP-ribose) Polymerases; D048049:Extracellular Signal-Regulated MAP Kinases; D020929:Mitogen-Activated Protein Kinase Kinases; D020169:Caspases
keywords: Breast cancer; MEK/ERK; Reactive oxygen species; β-Nitrostyrene