title: Hyperthermic effects on cell killing in Dictyostelium discoideum amoebae treated with DNA-damaging agents.
abstract: Hyperthermic effects on cell killing of amoeboid cells treated with DNA-damaging agents of Dictyostelium (D). discoideum were studied. Though the amoeboid cells are usually cultured at 23 degrees C, heat treatment at 30 degrees C for 15 min immediately after UV irradiation markedly enhanced cell killing, while not observed in the case of heat treatment immediately before UV irradiation. Similar effects were observed in the case of heat treatment after treatment with 4-nitroquinoline 1-oxide, cis-platinum(II) diamminedichloride or 8-methoxypsoralen photoaddition, while not observed when heat was applied before these treatments. On the contrary, little enhancement by heat treatment was observed even after treatment with N-methyl-N'-nitro-N-nitrosoguanidine or methylmethanesulphonate. The hyperthermic mechanisms in D. discoideum are discussed, based on a diverse set of DNA lesions caused by chemicals and DNA repair mechanisms for them.
authors.affiliation: Department of Biology, Nara Medical University, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Iwata
authors.forename: T
authors.initials: T
authors.lastname: Ohnishi
authors.forename: H
authors.initials: H
authors.lastname: Ohishi
authors.forename: K
authors.initials: K
authors.lastname: Nozu
mesh_terms: D015112:4-Nitroquinoline-1-oxide / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D002945:Cisplatin / Q000494:pharmacology; D004249:DNA Damage; D004260:DNA Repair / Q000187:drug effects / Q000528:radiation effects; D004271:DNA, Fungal / Q000187:drug effects* / Q000528:radiation effects; D004023:Dictyostelium / Q000187:drug effects* / Q000528:radiation effects; D006358:Hot Temperature; D008730:Methoxsalen / Q000494:pharmacology; D008741:Methyl Methanesulfonate / Q000494:pharmacology; D008769:Methylnitronitrosoguanidine / Q000494:pharmacology; D014466:Ultraviolet Rays
chemical_list: D004271:DNA, Fungal; D008769:Methylnitronitrosoguanidine; D015112:4-Nitroquinoline-1-oxide; D008741:Methyl Methanesulfonate; D002945:Cisplatin; D008730:Methoxsalen