Pathways of DNA double-strand break repair during the mammalian cell cycle
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Pathways of DNA double-strand break repair during the mammalian cell cycle. / Rothkamm, Kai; Krüger, Ines; Thompson, Larry H; Löbrich, Markus.
in: MOL CELL BIOL, Jahrgang 23, Nr. 16, 08.2003, S. 5706-15.Publikationen: SCORING: Beitrag in Fachzeitschrift/Zeitung › SCORING: Zeitschriftenaufsatz › Forschung › Begutachtung
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TY - JOUR
T1 - Pathways of DNA double-strand break repair during the mammalian cell cycle
AU - Rothkamm, Kai
AU - Krüger, Ines
AU - Thompson, Larry H
AU - Löbrich, Markus
PY - 2003/8
Y1 - 2003/8
N2 - Little is known about the quantitative contributions of nonhomologous end joining (NHEJ) and homologous recombination (HR) to DNA double-strand break (DSB) repair in different cell cycle phases after physiologically relevant doses of ionizing radiation. Using immunofluorescence detection of gamma-H2AX nuclear foci as a novel approach for monitoring the repair of DSBs, we show here that NHEJ-defective hamster cells (CHO mutant V3 cells) have strongly reduced repair in all cell cycle phases after 1 Gy of irradiation. In contrast, HR-defective CHO irs1SF cells have a minor repair defect in G(1), greater impairment in S, and a substantial defect in late S/G(2). Furthermore, the radiosensitivity of irs1SF cells is slight in G(1) but dramatically higher in late S/G(2), while V3 cells show high sensitivity throughout the cell cycle. These findings show that NHEJ is important in all cell cycle phases, while HR is particularly important in late S/G(2), where both pathways contribute to repair and radioresistance. In contrast to DSBs produced by ionizing radiation, DSBs produced by the replication inhibitor aphidicolin are repaired entirely by HR. irs1SF, but not V3, cells show hypersensitivity to aphidicolin treatment. These data provide the first evaluation of the cell cycle-specific contributions of NHEJ and HR to the repair of radiation-induced versus replication-associated DSBs.
AB - Little is known about the quantitative contributions of nonhomologous end joining (NHEJ) and homologous recombination (HR) to DNA double-strand break (DSB) repair in different cell cycle phases after physiologically relevant doses of ionizing radiation. Using immunofluorescence detection of gamma-H2AX nuclear foci as a novel approach for monitoring the repair of DSBs, we show here that NHEJ-defective hamster cells (CHO mutant V3 cells) have strongly reduced repair in all cell cycle phases after 1 Gy of irradiation. In contrast, HR-defective CHO irs1SF cells have a minor repair defect in G(1), greater impairment in S, and a substantial defect in late S/G(2). Furthermore, the radiosensitivity of irs1SF cells is slight in G(1) but dramatically higher in late S/G(2), while V3 cells show high sensitivity throughout the cell cycle. These findings show that NHEJ is important in all cell cycle phases, while HR is particularly important in late S/G(2), where both pathways contribute to repair and radioresistance. In contrast to DSBs produced by ionizing radiation, DSBs produced by the replication inhibitor aphidicolin are repaired entirely by HR. irs1SF, but not V3, cells show hypersensitivity to aphidicolin treatment. These data provide the first evaluation of the cell cycle-specific contributions of NHEJ and HR to the repair of radiation-induced versus replication-associated DSBs.
KW - Animals
KW - Antimetabolites, Antineoplastic/pharmacology
KW - Bromodeoxyuridine/pharmacology
KW - CHO Cells
KW - Cell Cycle
KW - Cell Line
KW - Cell Nucleus/metabolism
KW - Cricetinae
KW - DNA Damage
KW - DNA Repair
KW - Dose-Response Relationship, Radiation
KW - Flow Cytometry
KW - G1 Phase
KW - G2 Phase
KW - Microscopy, Fluorescence
KW - Phenotype
KW - Recombination, Genetic
KW - S Phase
KW - Time Factors
U2 - 10.1128/mcb.23.16.5706-5715.2003
DO - 10.1128/mcb.23.16.5706-5715.2003
M3 - SCORING: Journal article
C2 - 12897142
VL - 23
SP - 5706
EP - 5715
JO - MOL CELL BIOL
JF - MOL CELL BIOL
SN - 0270-7306
IS - 16
ER -
