title: Wedelolactone Acts as Proteasome Inhibitor in Breast Cancer Cells.
abstract: Wedelolactone is a multi-target natural plant coumestan exhibiting cytotoxicity towards cancer cells. Although several molecular targets of wedelolactone have been recognized, the molecular mechanism of its cytotoxicity has not yet been elucidated. In this study, we show that wedelolactone acts as an inhibitor of chymotrypsin-like, trypsin-like, and caspase-like activities of proteasome in breast cancer cells. The proteasome inhibitory effect of wedelolactone was documented by (i) reduced cleavage of fluorogenic proteasome substrates; (ii) accumulation of polyubiquitinated proteins and proteins with rapid turnover in tumor cells; and (iii) molecular docking of wedelolactone into the active sites of proteasome catalytic subunits. Inhibition of proteasome by wedelolactone was independent on its ability to induce reactive oxygen species production by redox cycling with copper ions, suggesting that wedelolactone acts as copper-independent proteasome inhibitor. We conclude that the cytotoxicity of wedelolactone to breast cancer cells is partially mediated by targeting proteasomal protein degradation pathway. Understanding the structural basis for inhibitory mode of wedelolactone might help to open up new avenues for design of novel compounds efficiently inhibiting cancer cells.
authors.affiliation: Laboratory of Cell Differentiation, Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic. 322903@mail.muni.cz.|International Clinical Research Center, Center for Biological and Cellular Engineering, St. Anne's University Hospital, Pekarska 53, 656 91 Brno, Czech Republic. 322903@mail.muni.cz.
authors.forename: Tereza
authors.initials: T
authors.lastname: Nehybová
authors.affiliation: Laboratory of Cell Differentiation, Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic. smarda@sci.muni.cz.
authors.forename: Jan
authors.initials: J
authors.lastname: Šmarda
authors.affiliation: International Clinical Research Center, Center for Biological and Cellular Engineering, St. Anne's University Hospital, Pekarska 53, 656 91 Brno, Czech Republic. 211165@mail.muni.cz.|Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic. 211165@mail.muni.cz.
authors.forename: Lukáš
authors.initials: L
authors.lastname: Daniel
authors.affiliation: Department of Chemistry, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic. 408516@mail.muni.cz.
authors.forename: Marek
authors.initials: M
authors.lastname: Stiborek
authors.affiliation: Department of Chemistry, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic. viktor.kanicky@ceitec.muni.cz.|CEITEC-Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic. viktor.kanicky@ceitec.muni.cz.
authors.forename: Viktor
authors.initials: V
authors.lastname: Kanický
authors.affiliation: Department of Life Sciences, Institute for Multidisciplinary Research, University of Belgrade, 11030 Belgrade, Serbia. redoxsci@gmail.com.
authors.forename: Ivan
authors.initials: I
authors.lastname: Spasojevič
authors.affiliation: Department of Chemistry, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic. preisler@chemi.muni.cz.|CEITEC-Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic. preisler@chemi.muni.cz.
authors.forename: Jan
authors.initials: J
authors.lastname: Preisler
authors.affiliation: International Clinical Research Center, Center for Biological and Cellular Engineering, St. Anne's University Hospital, Pekarska 53, 656 91 Brno, Czech Republic. jiridamborsky0@gmail.com.|Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic. jiridamborsky0@gmail.com.
authors.forename: Jiří
authors.initials: J
authors.lastname: Damborský
authors.affiliation: Laboratory of Cell Differentiation, Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic. pbenes@sci.muni.cz.|International Clinical Research Center, Center for Biological and Cellular Engineering, St. Anne's University Hospital, Pekarska 53, 656 91 Brno, Czech Republic. pbenes@sci.muni.cz.
authors.forename: Petr
authors.initials: P
authors.lastname: Beneš
mesh_terms: D001943:Breast Neoplasms / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D003300:Copper / Q000378:metabolism; D003374:Coumarins / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity; D006801:Humans; D062105:Molecular Docking Simulation; D046988:Proteasome Endopeptidase Complex / Q000737:chemistry / Q000378:metabolism; D061988:Proteasome Inhibitors / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity; D011485:Protein Binding; D059748:Proteolysis; D017382:Reactive Oxygen Species / Q000378:metabolism; D054875:Ubiquitination
chemical_list: D003374:Coumarins; D061988:Proteasome Inhibitors; D017382:Reactive Oxygen Species; C051122:wedelolactone; D003300:Copper; D046988:Proteasome Endopeptidase Complex
keywords: breast cancer; copper; proteasome; reactive oxygen species; wedelolactone