title: Cross-talk between nucleotide excision and homologous recombination DNA repair pathways in the mechanism of action of antitumor trabectedin.
abstract: Trabectedin (Yondelis) is a potent antitumor drug that has the unique characteristic of killing cells by poisoning the DNA nucleotide excision repair (NER) machinery. The basis for the NER-dependent toxicity has not yet been elucidated but it has been proposed as the major determinant for the drug's cytotoxicity. To study the in vivo mode of action of trabectedin and to explore the role of NER in its cytotoxicity, we used the fission yeast Schizosaccharomyces pombe as a model system. Treatment of S. pombe wild-type cells with trabectedin led to cell cycle delay and activation of the DNA damage checkpoint, indicating that the drug causes DNA damage in vivo. DNA damage induced by the drug is mostly caused by the NER protein, Rad13 (the fission yeast orthologue to human XPG), and is mainly repaired by homologous recombination. By constructing different rad13 mutants, we show that the DNA damage induced by trabectedin depends on a 46-amino acid region of Rad13 that is homologous to a DNA-binding region of human nuclease FEN-1. More specifically, an arginine residue in Rad13 (Arg961), conserved in FEN1 (Arg314), was found to be crucial for the drug's cytotoxicity. These results lead us to propose a model for the action of trabectedin in eukaryotic cells in which the formation of a Rad13/DNA-trabectedin ternary complex, stabilized by Arg961, results in cell death.
authors.affiliation: Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Cientificas/Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain.
authors.forename: Ana B
authors.initials: AB
authors.lastname: Herrero
authors.forename: Cristina
authors.initials: C
authors.lastname: Martín-Castellanos
authors.forename: Esther
authors.initials: E
authors.lastname: Marco
authors.forename: Federico
authors.initials: F
authors.lastname: Gago
authors.forename: Sergio
authors.initials: S
authors.lastname: Moreno
mesh_terms: D018906:Antineoplastic Agents, Alkylating / Q000494:pharmacology*; D002453:Cell Cycle / Q000187:drug effects; D002467:Cell Nucleus / Q000187:drug effects; D004249:DNA Damage; D004260:DNA Repair / Q000187:drug effects*; D004273:DNA, Neoplasm / Q000187:drug effects; D004149:Dioxoles / Q000494:pharmacology*; D005434:Flow Cytometry; D006801:Humans; D007399:Interphase / Q000187:drug effects; D008741:Methyl Methanesulfonate / Q000494:pharmacology; D011995:Recombination, Genetic / Q000187:drug effects*; D016196:S Phase / Q000187:drug effects*; D012568:Schizosaccharomyces / Q000166:cytology / Q000187:drug effects; D044005:Tetrahydroisoquinolines / Q000494:pharmacology*; D000077606:Trabectedin
chemical_list: D018906:Antineoplastic Agents, Alkylating; D004273:DNA, Neoplasm; D004149:Dioxoles; D044005:Tetrahydroisoquinolines; D008741:Methyl Methanesulfonate; D000077606:Trabectedin