title: DNA polymerase η modulates replication fork progression and DNA damage responses in platinum-treated human cells.
abstract: Human cells lacking DNA polymerase η (polη) are sensitive to platinum-based cancer chemotherapeutic agents. Using DNA combing to directly investigate the role of polη in bypass of platinum-induced DNA lesions in vivo, we demonstrate that nascent DNA strands are up to 39% shorter in human cells lacking polη than in cells expressing polη. This provides the first direct evidence that polη modulates replication fork progression in vivo following cisplatin and carboplatin treatment. Severe replication inhibition in individual platinum-treated polη-deficient cells correlates with enhanced phosphorylation of the RPA2 subunit of replication protein A on serines 4 and 8, as determined using EdU labelling and immunofluorescence, consistent with formation of DNA strand breaks at arrested forks in the absence of polη. Polη-mediated bypass of platinum-induced DNA lesions may therefore represent one mechanism by which cancer cells can tolerate platinum-based chemotherapy.
authors.affiliation: 1] DNA Damage Response Laboratory, Centre for Chromosome Biology, Biochemistry, School of Natural Sciences, National University of Ireland, Galway, Ireland [2].
authors.forename: Anna M
authors.initials: AM
authors.lastname: Sokol
authors.forename: Séverine
authors.initials: S
authors.lastname: Cruet-Hennequart
authors.forename: Philippe
authors.initials: P
authors.lastname: Pasero
authors.forename: Michael P
authors.initials: MP
authors.lastname: Carty
mesh_terms: D016190:Carboplatin / Q000494:pharmacology / Q000633:toxicity; D002453:Cell Cycle / Q000187:drug effects / Q000502:physiology; D002460:Cell Line; D002945:Cisplatin / Q000494:pharmacology / Q000633:toxicity; D004249:DNA Damage / Q000187:drug effects* / Q000502:physiology*; D004261:DNA Replication / Q000187:drug effects* / Q000502:physiology*; D004259:DNA-Directed DNA Polymerase / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D004357:Drug Synergism; D015870:Gene Expression; D006801:Humans; D010766:Phosphorylation; D010984:Platinum / Q000494:pharmacology* / Q000633:toxicity; D051716:Replication Protein A / Q000378:metabolism; D000099270:Y-Family DNA Polymerases
chemical_list: D016190:Carboplatin; D002945:Cisplatin; D004259:DNA-Directed DNA Polymerase; D010984:Platinum; D051716:Replication Protein A; C516794:RPA2 protein, human; C112338:Rad30 protein; D000099270:Y-Family DNA Polymerases