title: Increased chromosome exchange frequencies in iodo-deoxyuridine-sensitized human SW-1573 cells after gamma-irradiation.
abstract: The induction of chromosome exchanges was investigated in SW-1573 human lung tumour cells radiosensitized with iododeoxyuridine (IdUrd) and irradiated with gamma-rays. Following treatment chromosome 2 and X were analyzed using fluorescence in situ hybridization (FISH) with chromosome-specific DNA libraries. The yield of chromosome exchanges involving chromosome 2 was higher than those involving chromosome-X. On the basis of the DNA content the relative involvement of the X-chromosome in exchange frequencies after 2 Gy was much higher than of chromosome 2. After 4 Gy the relative involvement of both chromosomes in exchanges is approximately equal. After radiosensitization, increased chromosome exchange frequencies are observed in both studied chromosomes. For the total chromosome exchange frequencies the sensitizer enhancement ratio (SER) at 2 Gy is 1.8 and 1.3 for chromosome 2 and X respectively. The SER at 4 Gy for total exchange frequencies is 1.6 and 1.9 chromosome 2 and X respectively. For reciprocal exchanges at 2 Gy higher SER values and at 4 Gy lower SER values were observed for both chromosomes.
authors.affiliation: Academic Medical Centre, University of Amsterdam, Department of Radiotherapy, 1100 DE Amsterdam, The Netherlands.
authors.forename: N A
authors.initials: NA
authors.lastname: Franken
authors.forename: C
authors.initials: C
authors.lastname: van Bree
authors.forename: M A
authors.initials: MA
authors.lastname: Veltmaat
authors.forename: G
authors.initials: G
authors.lastname: Ludwików
authors.forename: J B
authors.initials: JB
authors.lastname: Kipp
authors.forename: G W
authors.initials: GW
authors.lastname: Barendsen
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000473:pathology*; D002869:Chromosome Aberrations; D002889:Chromosomes, Human, Pair 2 / Q000187:drug effects / Q000528:radiation effects*; D004249:DNA Damage; D004260:DNA Repair; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D006801:Humans; D007065:Idoxuridine / Q000494:pharmacology*; D017404:In Situ Hybridization, Fluorescence; D008175:Lung Neoplasms / Q000473:pathology*; D011838:Radiation-Sensitizing Agents / Q000494:pharmacology*; D014178:Translocation, Genetic / Q000187:drug effects / Q000528:radiation effects*; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000528:radiation effects; D014960:X Chromosome / Q000187:drug effects / Q000528:radiation effects*
chemical_list: D011838:Radiation-Sensitizing Agents; D007065:Idoxuridine