title: Small-molecule RA-9 inhibits proteasome-associated DUBs and ovarian cancer in vitro and in vivo via exacerbating unfolded protein responses.
abstract: OBJECTIVE
  Ovarian cancer is the deadliest of the gynecologic malignancies. Carcinogenic progression is accompanied by upregulation of ubiquitin-dependent protein degradation machinery as a mechanism to compensate with elevated endogenous proteotoxic stress. Recent studies support the notion that deubiquitinating enzymes (DUB) are essential factors in proteolytic degradation and that their aberrant activity is linked to cancer progression and chemoresistance. Thus, DUBs are an attractive therapeutic target for ovarian cancer.
  
  
  METHODS
  The potency and selectivity of RA-9 inhibitor for proteasome-associated DUBs was determined in ovarian cancer cell lines and primary cells. The anticancer activity of RA-9 and its mechanism of action were evaluated in multiple cancer cell lines in vitro and in vivo in immunodeficient mice bearing an intraperitoneal ES-2 xenograft model of human ovarian cancer.
  
  
  RESULTS
  Here, we report the characterization of RA-9 as a small-molecule inhibitor of proteasome-associated DUBs. Treatment with RA-9 selectively induces onset of apoptosis in ovarian cancer cell lines and primary cultures derived from donors. Loss of cell viability following RA-9 exposure is associated with an unfolded protein response as mechanism to compensate for unsustainable levels of proteotoxic stress. In vivo treatment with RA-9 retards tumor growth, increases overall survival, and was well tolerated by the host.
  
  
  CONCLUSIONS
  Our preclinical studies support further evaluation of RA-9 as an ovarian cancer therapeutic.
authors.affiliation: Authors' Affiliations: Masonic Cancer Center and Department of Obstetrics, Gynecology and Women's Heath, Department of Neurosciences, University of Minnesota Twin Cities, Minneapolis, Minnesota; Departments of Pathology, Oncology, and Gynecology and Obstetrics, The Johns Hopkins University, Baltimore, Maryland; and Department of Lymphoma/Myeloma, Division of Cancer Medicine, The University of Texas M.D. Anderson Cancer Center, Houston, Texas.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Coughlin
authors.affiliation: Authors' Affiliations: Masonic Cancer Center and Department of Obstetrics, Gynecology and Women's Heath, Department of Neurosciences, University of Minnesota Twin Cities, Minneapolis, Minnesota; Departments of Pathology, Oncology, and Gynecology and Obstetrics, The Johns Hopkins University, Baltimore, Maryland; and Department of Lymphoma/Myeloma, Division of Cancer Medicine, The University of Texas M.D. Anderson Cancer Center, Houston, TexasAuthors' Affiliations: Masonic Cancer Center and Department of Obstetrics, Gynecology and Women's Heath, Department of Neurosciences, University of Minnesota Twin Cities, Minneapolis, Minnesota; Departments of Pathology, Oncology, and Gynecology and Obstetrics, The Johns Hopkins University, Baltimore, Maryland; and Department of Lymphoma/Myeloma, Division of Cancer Medicine, The University of Texas M.D. Anderson Cancer Center, Houston, Texas.
authors.forename: Ravi
authors.initials: R
authors.lastname: Anchoori
authors.affiliation: Authors' Affiliations: Masonic Cancer Center and Department of Obstetrics, Gynecology and Women's Heath, Department of Neurosciences, University of Minnesota Twin Cities, Minneapolis, Minnesota; Departments of Pathology, Oncology, and Gynecology and Obstetrics, The Johns Hopkins University, Baltimore, Maryland; and Department of Lymphoma/Myeloma, Division of Cancer Medicine, The University of Texas M.D. Anderson Cancer Center, Houston, Texas.
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Iizuka
authors.affiliation: Authors' Affiliations: Masonic Cancer Center and Department of Obstetrics, Gynecology and Women's Heath, Department of Neurosciences, University of Minnesota Twin Cities, Minneapolis, Minnesota; Departments of Pathology, Oncology, and Gynecology and Obstetrics, The Johns Hopkins University, Baltimore, Maryland; and Department of Lymphoma/Myeloma, Division of Cancer Medicine, The University of Texas M.D. Anderson Cancer Center, Houston, Texas.
authors.forename: Joyce
authors.initials: J
authors.lastname: Meints
authors.affiliation: Authors' Affiliations: Masonic Cancer Center and Department of Obstetrics, Gynecology and Women's Heath, Department of Neurosciences, University of Minnesota Twin Cities, Minneapolis, Minnesota; Departments of Pathology, Oncology, and Gynecology and Obstetrics, The Johns Hopkins University, Baltimore, Maryland; and Department of Lymphoma/Myeloma, Division of Cancer Medicine, The University of Texas M.D. Anderson Cancer Center, Houston, Texas.
authors.forename: Lauren
authors.initials: L
authors.lastname: MacNeill
authors.affiliation: Authors' Affiliations: Masonic Cancer Center and Department of Obstetrics, Gynecology and Women's Heath, Department of Neurosciences, University of Minnesota Twin Cities, Minneapolis, Minnesota; Departments of Pathology, Oncology, and Gynecology and Obstetrics, The Johns Hopkins University, Baltimore, Maryland; and Department of Lymphoma/Myeloma, Division of Cancer Medicine, The University of Texas M.D. Anderson Cancer Center, Houston, Texas.
authors.forename: Rachel Isaksson
authors.initials: RI
authors.lastname: Vogel
authors.affiliation: Authors' Affiliations: Masonic Cancer Center and Department of Obstetrics, Gynecology and Women's Heath, Department of Neurosciences, University of Minnesota Twin Cities, Minneapolis, Minnesota; Departments of Pathology, Oncology, and Gynecology and Obstetrics, The Johns Hopkins University, Baltimore, Maryland; and Department of Lymphoma/Myeloma, Division of Cancer Medicine, The University of Texas M.D. Anderson Cancer Center, Houston, Texas.
authors.forename: Robert Z
authors.initials: RZ
authors.lastname: Orlowski
authors.affiliation: Authors' Affiliations: Masonic Cancer Center and Department of Obstetrics, Gynecology and Women's Heath, Department of Neurosciences, University of Minnesota Twin Cities, Minneapolis, Minnesota; Departments of Pathology, Oncology, and Gynecology and Obstetrics, The Johns Hopkins University, Baltimore, Maryland; and Department of Lymphoma/Myeloma, Division of Cancer Medicine, The University of Texas M.D. Anderson Cancer Center, Houston, Texas.
authors.forename: Michael K
authors.initials: MK
authors.lastname: Lee
authors.affiliation: Authors' Affiliations: Masonic Cancer Center and Department of Obstetrics, Gynecology and Women's Heath, Department of Neurosciences, University of Minnesota Twin Cities, Minneapolis, Minnesota; Departments of Pathology, Oncology, and Gynecology and Obstetrics, The Johns Hopkins University, Baltimore, Maryland; and Department of Lymphoma/Myeloma, Division of Cancer Medicine, The University of Texas M.D. Anderson Cancer Center, Houston, TexasAuthors' Affiliations: Masonic Cancer Center and Department of Obstetrics, Gynecology and Women's Heath, Department of Neurosciences, University of Minnesota Twin Cities, Minneapolis, Minnesota; Departments of Pathology, Oncology, and Gynecology and Obstetrics, The Johns Hopkins University, Baltimore, Maryland; and Department of Lymphoma/Myeloma, Division of Cancer Medicine, The University of Texas M.D. Anderson Cancer Center, Houston, TexasAuthors' Affiliations: Masonic Cancer Center and Department of Obstetrics, Gynecology and Women's Heath, Department of Neurosciences, University of Minnesota Twin Cities, Minneapolis, Minnesota; Departments of Pathology, Oncology, and Gynecology and Obstetrics, The Johns Hopkins University, Baltimore, Maryland; and Department of Lymphoma/Myeloma, Division of Cancer Medicine, The University of Texas M.D. Anderson Cancer Center, Houston, Texas.
authors.forename: Richard B S
authors.initials: RB
authors.lastname: Roden
authors.affiliation: Authors' Affiliations: Masonic Cancer Center and Department of Obstetrics, Gynecology and Women's Heath, Department of Neurosciences, University of Minnesota Twin Cities, Minneapolis, Minnesota; Departments of Pathology, Oncology, and Gynecology and Obstetrics, The Johns Hopkins University, Baltimore, Maryland; and Department of Lymphoma/Myeloma, Division of Cancer Medicine, The University of Texas M.D. Anderson Cancer Center, Houston, Texas mbazzaro@umn.edu.
authors.forename: Martina
authors.initials: M
authors.lastname: Bazzaro
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001597:Benzylidene Compounds / Q000494:pharmacology*; D015153:Blotting, Western; D002453:Cell Cycle / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007124:Immunoenzyme Techniques; D066298:In Vitro Techniques; D051379:Mice; D008819:Mice, Nude; D010051:Ovarian Neoplasms / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D010881:Piperidones / Q000494:pharmacology*; D046988:Proteasome Endopeptidase Complex / Q000737:chemistry*; D061988:Proteasome Inhibitors / Q000494:pharmacology*; D054852:Small Molecule Libraries / Q000494:pharmacology*; D014407:Tumor Cells, Cultured; D025801:Ubiquitin / Q000378:metabolism; D064570:Ubiquitin-Specific Proteases / Q000037:antagonists & inhibitors*; D056811:Unfolded Protein Response / Q000187:drug effects*; D023041:Xenograft Model Antitumor Assays
chemical_list: C000601949:3,5-bis(nitrobenzylidene)piperidin-4-one; D001597:Benzylidene Compounds; D010881:Piperidones; D061988:Proteasome Inhibitors; D054852:Small Molecule Libraries; D025801:Ubiquitin; D064570:Ubiquitin-Specific Proteases; D046988:Proteasome Endopeptidase Complex
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