title: Interaction between the anticancer drug Cisplatin and the copper chaperone Atox1 in human melanoma cells.
abstract: Cisplatin (CisPt) is one of the most common anticancer drugs used against many severe forms of cancers. However, treatment with this drug causes many side effects and often, it results in the development of cell resistance. A majority of side effects as well as cell resistance are thought to develop due to CisPt interactions with proteins prior to reaching the nucleus and the DNA target. The copper (Cu) transport proteins Ctr1 and ATP7A/B have been implicated in cellular resistance of CisPt, possibly exporting the drug out of the cell. Recent in vitro work demonstrated that CisPt also interacts with the cytoplasmic Cu-chaperone Atox1, binding in or near the Cu-binding site, without expulsion of bound Cu. Whereas Ctr1 and ATP7B interactions with CisPt have been shown in vivo or ex vivo, there is no such information for Atox1-CisPt interactions. To address this, we developed a method to probe if CisPt interacts with Atox1 in human melanoma cells. Atox1-specific antibodies were linked to magnetic beads and used to immune-precipitate Atox1 from melanoma cells that had been pre-exposed to CisPt. Analysis of extracted Atox1 with inductively coupled plasma mass spectrometry demonstrated the presence of Pt in the protein fraction. Thus, CisPt-exposed human melanoma cells contain Atox1 molecules that bind some derivative of CisPt. This study gives the first indication for the intracellular presence of Atox1-CisPt complexes ex vivo.
authors.forename: Maria E
authors.initials: ME
authors.lastname: Palm-Espling
authors.forename: Christina
authors.initials: C
authors.lastname: Lundin
authors.forename: Erik
authors.initials: E
authors.lastname: Björn
authors.forename: Peter
authors.initials: P
authors.lastname: Naredi
authors.affiliation: Department of Chemistry, Umeå University, 90187 Umeå, Sweden. pernilla.wittung@chem.umu.se.
authors.forename: Pernilla
authors.initials: P
authors.lastname: Wittung-Stafshede
mesh_terms: D000906:Antibodies / Q000276:immunology; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001665:Binding Sites / Q000187:drug effects; D045744:Cell Line, Tumor; D002945:Cisplatin / Q000494:pharmacology*; D003300:Copper / Q000737:chemistry; D000079922:Copper Transport Proteins; D006801:Humans; D047468:Immunoprecipitation; D058185:Magnetite Nanoparticles / Q000737:chemistry; D013058:Mass Spectrometry; D008545:Melanoma / Q000188:drug therapy*; D056511:Metallochaperones / Q000737:chemistry* / Q000276:immunology*; D018832:Molecular Chaperones; D011485:Protein Binding
chemical_list: C474500:ATOX1 protein, human; D000906:Antibodies; D000970:Antineoplastic Agents; D000079922:Copper Transport Proteins; D058185:Magnetite Nanoparticles; D056511:Metallochaperones; D018832:Molecular Chaperones; D003300:Copper; D002945:Cisplatin