title: S phase arrest and induction of multinucleated cells after exposure to ultraviolet radiation.
abstract: The effects of UVA (365 nm) and UVB (297/302 nm) radiation on cellular proliferation, cell cycle progression, aneuploidy and multinucleus induction have been studied in two different fibroblast cell lines; V79 Chinese hamster lung fibroblasts and 3T3 Swiss albino mouse fibroblasts. UVA and UVB were found to inhibit proliferation of the cells in a fluence-dependent manner. This inhibition was due to a temporary accumulation of cells in the S phase of the cell cycle, as determined by flow cytometry of UV-irradiated V79 cells. The UVA- and UVB-induced S phase delay was observed a few hours after irradiation and by 48 h post-irradiation the cells had recovered from cell cycle arrest. For UVA, but not for UVB, the elongation of S phase was followed by a small accumulation of cells in the G2 phase. After exposure to UVA and a post-irradiation time long enough for the cells to recover from cell cycle arrest, a large proportion of the cells were polyploid, with two or more nuclei. Multinucleated cells were not, however, induced by UVB irradiation.
authors.affiliation: Department of Biophysics, Institute for Cancer Research, Montebello, Oslo, Norway.
authors.forename: H
authors.initials: H
authors.lastname: Bånrud
authors.forename: T
authors.initials: T
authors.lastname: Stokke
authors.forename: J
authors.initials: J
authors.lastname: Moan
authors.forename: K
authors.initials: K
authors.lastname: Berg
mesh_terms: D016475:3T3 Cells; D000818:Animals; D002453:Cell Cycle / Q000528:radiation effects*; D002455:Cell Division / Q000528:radiation effects*; D002460:Cell Line; D002467:Cell Nucleus / Q000528:radiation effects*; D006224:Cricetinae; D004307:Dose-Response Relationship, Radiation; D007700:Kinetics; D008168:Lung; D051379:Mice; D016196:S Phase / Q000528:radiation effects; D013997:Time Factors; D014466:Ultraviolet Rays