title: Activation of DNA damage checkpoints in CHO cells requires a certain level of DNA damage.
abstract: DNA damage activates checkpoint controls in eukaryotic cells. It is not clear, however, whether a certain level of DNA damage is required for the activation of DNA damage checkpoints. We show here that low levels of DNA damage in Chinese hamster ovary (CHO) cells induced by short exposure to hydroxyurea (HU) did not trigger checkpoints, whereas higher levels of DNA damage caused by longer exposure to HU resulted in a cell cycle arrest. Our results argue that a threshold of DNA damage is necessary for activation of DNA damage checkpoints.
authors.affiliation: State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Research Center of Life Science, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai, 200031, China.
authors.forename: M R
authors.initials: MR
authors.lastname: Jiang
authors.forename: Y
authors.initials: Y
authors.lastname: Yang
authors.forename: J R
authors.initials: JR
authors.lastname: Wu
mesh_terms: D000818:Animals; D015153:Blotting, Western; D016466:CHO Cells; D002453:Cell Cycle; D020552:Comet Assay; D006224:Cricetinae; D004249:DNA Damage; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005434:Flow Cytometry; D006918:Hydroxyurea / Q000494:pharmacology; D013997:Time Factors
chemical_list: D004791:Enzyme Inhibitors; D006918:Hydroxyurea