title: Influence of pre-treatment with DNA-damaging agents on hyperthermic potentiation in cell killing of ultraviolet light-irradiated Dictyostelium discoideum.
abstract: Heat treatment at 30 degrees C for 15 min immediately after ultraviolet (UV) irradiation enhanced cell killing of Dictyostelium discoideum. However, when the cells were UV-irradiated and cultured at 23 degrees C for 30 min before giving UV irradiation and heat treatment, the enhancement of cell killing by heat treatment immediately after post-UV irradiation was depressed. Similar depressions in the heat enhancement of cell killing of UV-irradiated cells were also observed in the case of the cells cultured after pretreatment with 4-nitroquinoline 1-oxide, cis-platinum(II) diaminedichloride or 8-methoxypsoralen photoaddition, but not with N-methyl-N'-nitro-N-nitrosoguanidine or methylmethanesulphonate. These results suggest that the depression in heat enhancement in cell killing of UV-irradiated cells may be deeply related with kinds of DNA lesions or DNA repair processes for them.
authors.affiliation: Department of Oncoradiology, Nara Medical University, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Iwata
authors.forename: H
authors.initials: H
authors.lastname: Ohishi
authors.forename: T
authors.initials: T
authors.lastname: Ohnishi
mesh_terms: D015112:4-Nitroquinoline-1-oxide / Q000494:pharmacology; D002945:Cisplatin / Q000494:pharmacology; D004249:DNA Damage; D004260:DNA Repair / Q000187:drug effects / Q000528:radiation effects; D004023:Dictyostelium / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D006358:Hot Temperature; D008730:Methoxsalen / Q000494:pharmacology; D008741:Methyl Methanesulfonate / Q000494:pharmacology; D008769:Methylnitronitrosoguanidine / Q000494:pharmacology; D014466:Ultraviolet Rays
chemical_list: D008769:Methylnitronitrosoguanidine; D015112:4-Nitroquinoline-1-oxide; D008741:Methyl Methanesulfonate; D002945:Cisplatin; D008730:Methoxsalen