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: Ana B Herrero, Cristina Martín-Castellanos, Esther Marco, Federico Gago, Sergio Moreno
• Journal: Cancer research (Cancer Res) Vol. 66 Issue 16 Pg. 8155-62 (Aug 15 2006) ISSN: 1538-7445 [Electronic] United States
• PMID: 16912194 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antineoplastic Agents, Alkylating
• DNA, Neoplasm
• Dioxoles
• Tetrahydroisoquinolines
• Methyl Methanesulfonate
• Trabectedin

Topics

• Antineoplastic Agents, Alkylating (pharmacology)
• Cell Cycle (drug effects)
• Cell Nucleus (drug effects)
• DNA Damage
• DNA Repair (drug effects)
• DNA, Neoplasm (drug effects)
• Dioxoles (pharmacology)
• Flow Cytometry
• Humans
• Interphase (drug effects)
• Methyl Methanesulfonate (pharmacology)
• Recombination, Genetic (drug effects)
• S Phase (drug effects)
• Schizosaccharomyces (cytology, drug effects)
• Tetrahydroisoquinolines (pharmacology)
• Trabectedin