Early induction of binucleated cells by ultraviolet A (UVA) radiation: a possible role of microfilaments.
The effects of UVA (365 nm) radiation on the cellular distribution of F-actin and formation of binucleated cells have been studied using 3T3 Swiss albino mouse fibroblasts and V79 Chinese hamster fibroblasts. Ultraviolet A at biologically relevant fluences was found to disintegrate the actin filaments in the cells shortly (5 min) after irradiation, concomitant with the formation of cells with two nuclei. In 76-100% of the bi- and multinucleated cells the distribution of F-actin was clearly altered. Cells in GI phase of the cell cycle were most probably involved in the formation of binucleated cells. The disintegration of F-actin was presumably not due to depolymerization of F-actin to G-actin, as the amount of F-actin in the cells was unaltered after UVA exposure but rather due to direct breakage of the actin filaments. Ultraviolet B (297/302 nm) had no effect on the cellular distribution of microfilaments, not even at highly lethal fluences.
Bånrud
H
H
Department of Biophysics, Institute for Cancer Research, Montebello, Oslo, Norway.
Moan
J
J
Berg
K
K
D016475:3T3 Cells; D008841:Actin Cytoskeleton / Q000528:radiation effects; D000199:Actins / Q000528:radiation effects; D000818:Animals; D002460:Cell Line; D002467:Cell Nucleus / Q000528:radiation effects*; D006224:Cricetinae; D051379:Mice; D018462:Photobiology; D014466:Ultraviolet Rays / Q000009:adverse effects*
D000199:Actins