title: p53-independent DNA repair and cell cycle arrest in embryonic stem cells.
abstract: The role of p53 in DNA repair and cell cycle checkpoint after ultraviolet irradiation was investigated in an embryonic stem cell line homozygous for a targeted deletion of p53. Results indicate that loss of p53 does not alter the capacity of ES cells to respond to DNA damage. Wild-type and p53-deficient cells showed similar cessation of DNA synthesis after UV damage and similar ultimate capacity to repair a transiently transfected reporter plasmid. Interestingly, in the absence of DNA damaging treatment, the transit of p53-deficient cells through S phase was slower than wild-type cells. We suggest that this may result from the absence of a p53-dependent response to endogenous DNA damage: without p53 sensing endogenous damage leading to immediate repair, such damage may persist and thus delay DNA synthesis.
authors.affiliation: Cancer Research Campaign Laboratories, University Department of Pathology, Medical School, Edinburgh, Scotland, UK.
authors.forename: S
authors.initials: S
authors.lastname: Prost
authors.forename: C O
authors.initials: CO
authors.lastname: Bellamy
authors.forename: A R
authors.initials: AR
authors.lastname: Clarke
authors.forename: A H
authors.initials: AH
authors.lastname: Wyllie
authors.forename: D J
authors.initials: DJ
authors.lastname: Harrison
mesh_terms: D000818:Animals; D002453:Cell Cycle / Q000502:physiology*; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics / Q000378:metabolism; D004249:DNA Damage / Q000235:genetics; D004260:DNA Repair / Q000502:physiology*; D004261:DNA Replication / Q000235:genetics; D005434:Flow Cytometry; D017353:Gene Deletion; D017930:Genes, Reporter / Q000235:genetics; D007399:Interphase / Q000502:physiology; D051379:Mice; D016196:S Phase / Q000502:physiology; D013234:Stem Cells / Q000502:physiology*; D015533:Transcriptional Activation / Q000235:genetics; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000502:physiology*; D014466:Ultraviolet Rays / Q000009:adverse effects
chemical_list: D016159:Tumor Suppressor Protein p53; D015500:Chloramphenicol O-Acetyltransferase