title: Structural and functional evaluation of interaction between mammalian ribosomal RNA with platinum-containing antineoplastic drugs.
abstract: Cisplatin, oxaliplatin, and carboplatin primarily target DNA, but also alter RNA functionality, albeit to different extent. This study determined the in vitro cytotoxicity (IC50 values) of platinum drugs in LS180 cells and compared the rRNA platination patterns following IC50 exposure. Relevance of particular secondary RNA structures for platination susceptibility was evaluated by primer extension methodology using 18S rRNA as a model RNA. Consequences of rRNA platination for translation efficiency were evaluated by monitoring fluorescence of a destabilised green fluorescent protein variant through flow cytometry. Oxaliplatin and cisplatin were most cytotoxic with IC50 values of 1.7 μM±0.8 and 4.1 μM±0.1, respectively. Carboplatin was significantly less efficient (IC50 147.1 μM±19.4). When exposed to equitoxic concentrations (respective IC50), all three compounds caused similar stop signal incidence or intensity. Moreover, the same rRNA sites were targeted without selectivity for particular secondary structures but with a slight preference for guanine-rich regions. Compared to cycloheximide, none of the drugs diminished translation efficiency at typical in vivo concentrations. In conclusion, equitoxic concentrations of platinum drugs target the same sites in cellular rRNA and cause similar platination intensities. At pharmacokinetically relevant concentrations, cisplatin, oxaliplatin or carboplatin do not inhibit translation efficiency.
authors.affiliation: Department of Clinical Pharmacology and Pharmacoepidemiology, University of Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany. Electronic address: dirk.theile@med.uni-heidelberg.de.
authors.forename: Dirk
authors.initials: D
authors.lastname: Theile
authors.affiliation: Biochemistry Center and Cluster of Excellence CellNetworks, University of Heidelberg, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Kos
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D000970:Antineoplastic Agents / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology*; D016190:Carboplatin / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002945:Cisplatin / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology*; D003110:Colonic Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D015972:Gene Expression Regulation, Neoplastic; D049452:Green Fluorescent Proteins / Q000096:biosynthesis / Q000235:genetics; D006801:Humans; D020128:Inhibitory Concentration 50; D015394:Molecular Structure; D009690:Nucleic Acid Conformation; D009944:Organoplatinum Compounds / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology*; D000077150:Oxaliplatin; D014176:Protein Biosynthesis; D012335:RNA, Ribosomal / Q000737:chemistry / Q000378:metabolism*; D013329:Structure-Activity Relationship
chemical_list: D000970:Antineoplastic Agents; D009944:Organoplatinum Compounds; D012335:RNA, Ribosomal; D000077150:Oxaliplatin; D049452:Green Fluorescent Proteins; D016190:Carboplatin; D002945:Cisplatin
keywords: Carboplatin; Cisplatin; Oxaliplatin; Primer extension; Ribosomal RNA; Translation efficiency