title: Multidrug Resistance-associated Protein-1 (MRP-1)-dependent Glutathione Disulfide (GSSG) Efflux as a Critical Survival Factor for Oxidant-enriched Tumorigenic Endothelial Cells.
abstract: Endothelial cell tumors are the most common soft tissue tumors in infants. Tumor-forming endothelial (EOMA) cells are able to escape cell death fate despite excessive nuclear oxidant burden. Our previous work recognized perinuclear Nox-4 as a key contributor to EOMA growth. The objective of this work was to characterize the mechanisms by which EOMA cells evade oxidant toxicity and thrive. In EOMA cells, compared with in the cytosol, the nuclear GSSG/GSH ratio was 5-fold higher. Compared to the ratio observed in healthy murine aortic endothelial (MAE) cells, GSSG/GSH was over twice as high in EOMA cells. Multidrug resistance-associated protein-1 (MRP-1), an active GSSG efflux mechanism, showed 2-fold increased activity in EOMA compared with MAE cells. Hyperactive YB-1 and Ape/Ref-1 were responsible for high MRP-1 expression in EOMA. Proximity ligand assay demonstrated MRP-1 and YB-1 binding. Such binding enabled the nuclear targeting of MRP-1 in EOMA in a leptomycin-B-sensitive manner. MRP-1 inhibition as well as knockdown trapped nuclear GSSG, causing cell death of EOMA. Disulfide loading of cells by inhibition of GSSG reductase (bischoloronitrosourea) or thioredoxin reductase (auranofin) was effective in causing EOMA death as well. In sum, EOMA cells survive a heavy oxidant burden by rapid efflux of GSSG, which is lethal if trapped within the cell. A hyperactive MRP-1 system for GSSG efflux acts as a critical survival factor for these cells, making it a potential target for EOMA therapeutics.
authors.affiliation: From the Department of Plastic Surgery, Davis Heart and Lung Research Institute, and gayle.gordillo@osumc.edu.
authors.forename: Gayle M
authors.initials: GM
authors.lastname: Gordillo
authors.affiliation: From the Department of Plastic Surgery, Davis Heart and Lung Research Institute, and.
authors.forename: Ayan
authors.initials: A
authors.lastname: Biswas
authors.affiliation: Davis Heart and Lung Research Institute, and Department of Surgery.
authors.forename: Savita
authors.initials: S
authors.lastname: Khanna
authors.affiliation: Davis Heart and Lung Research Institute, and Department of Surgery.
authors.forename: James M
authors.initials: JM
authors.lastname: Spieldenner
authors.affiliation: Center for Biostatistics, Ohio State University Wexner Medical Center, Columbus, Ohio 43212.
authors.forename: Xueliang
authors.initials: X
authors.lastname: Pan
authors.affiliation: Davis Heart and Lung Research Institute, and Department of Surgery.
authors.forename: Chandan K
authors.initials: CK
authors.lastname: Sen
mesh_terms: D000818:Animals; D001310:Auranofin / Q000494:pharmacology; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase / Q000235:genetics / Q000378:metabolism; D042783:Endothelial Cells / Q000378:metabolism* / Q000473:pathology; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D019803:Glutathione Disulfide / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D019043:Vascular Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism* / Q000473:pathology
chemical_list: D001310:Auranofin; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase; D005231:Fatty Acids, Unsaturated; D019803:Glutathione Disulfide; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D009363:Neoplasm Proteins; D014157:Transcription Factors; C541744:Ybx1 protein, mouse; C486216:Apex1 protein, mouse; C038753:leptomycin B; C421109:multidrug resistance-associated protein 1
keywords: Ape/Ref-1; NADPH oxidase; Nox-4; YB-1; endothelial cell; multidrug transporter; thioredoxin; tumor