title: Importance of TP53 and RB in the repair of potentially lethal damage and induction of color junctions after exposure to ionizing radiation.
abstract: Repair of potentially lethal damage (PLD) was investigated in cells with functional G1-phase arrest with wild-type TP53 and wild-type RB and in cells in which G1-phase arrest was abrogated by inactivation of TP53 or RB. Confluent cultures of cells were plated for clonogenic survival assay either immediately or 24 h after irradiation. Induction of color junctions, an exchange between a painted and unpainted chromosome, was studied in chromosomes 18 and 19 after irradiation with 4 Gy gamma rays. Significant repair of PLD was found in cells carrying both wild-type TP53 and wild-type RB. In cells in which TP53 or RB was inactivated, the survival curves from immediately plated and delayed-plated cells were not significantly different. The numbers of radiation-induced color junctions in chromosomes 18 and 19 were similar in all cell lines. From this study we conclude that a functional G1-phase arrest is important for repair of PLD and that TP53 and RB do not affect the frequencies of induction of color junctions in chromosome 18 or 19.
authors.affiliation: Department of Radiotherapy, University of Amsterdam, P.O. Box 22700, 1100 DE Amsterdam, The Netherlands. N.A.Franken@amc.nl
authors.forename: N A P
authors.initials: NA
authors.lastname: Franken
authors.forename: C
authors.initials: C
authors.lastname: van Bree
authors.forename: R
authors.initials: R
authors.lastname: ten Cate
authors.forename: C H
authors.initials: CH
authors.lastname: van Oven
authors.forename: J
authors.initials: J
authors.lastname: Haveman
mesh_terms: D015153:Blotting, Western; D002869:Chromosome Aberrations; D002887:Chromosomes, Human, Pair 18 / Q000528:radiation effects; D002888:Chromosomes, Human, Pair 19 / Q000528:radiation effects; D004247:DNA / Q000528:radiation effects*; D004249:DNA Damage; D004260:DNA Repair; D004307:Dose-Response Relationship, Radiation; D005434:Flow Cytometry; D016193:G1 Phase / Q000528:radiation effects; D005720:Gamma Rays; D016158:Genes, p53 / Q000235:genetics*; D006801:Humans; D008677:Metaphase; D011839:Radiation, Ionizing; D016160:Retinoblastoma Protein / Q000235:genetics*; D014407:Tumor Cells, Cultured
chemical_list: D016160:Retinoblastoma Protein; D004247:DNA