Solar UV radiation: differential effectiveness of UVB subcomponents in causing cell death, micronucleus induction and delayed expression of heritabledamage in human hybrid cells

Citation
D. Bettega et al., Solar UV radiation: differential effectiveness of UVB subcomponents in causing cell death, micronucleus induction and delayed expression of heritabledamage in human hybrid cells, INT J RAD B, 77(9), 2001, pp. 963-970
Citations number
25
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Experimental Biology
Journal title
INTERNATIONAL JOURNAL OF RADIATION BIOLOGY
ISSN journal
0955-3002 → ACNP
Volume
77
Issue
9
Year of publication
2001
Pages
963 - 970
Database
ISI
SICI code
0955-3002(200109)77:9<963:SURDEO>2.0.ZU;2-8
Abstract
Purpose: To determine the effectiveness of two UV spectra with different UV B components for cell kill and micronucleus induction in irradiated human H eLa x skin fibroblast (CGL1) hybrid cells and their progeny. To determine t he presence of reactive oxygen species (ROS) in the progeny of the irradiat ed cells at various post-irradiation times and their relationship with indu ced delayed biological effects. Material and methods: A commercial solar ultraviolet simulator was used. Tw o different filters were employed: the first transmitted radiation with lam bda >284 nm and the second radiation with lambda >293 nm. The resulting spe ctra have different UVB components (lambda between 284 and 320 nm, 19 W/m(2 ), and between 293 and 320 nm, 13 W/m(2)) and the same UVA component (lambd a between 320 and 400 nm, 135 W/m(2)). CGL1 cells were irradiated with vari ous doses. Clonogenic survival and micronucleus formation were scored in th e irradiated cells and their progeny. ROS were detected by incubation of cu ltures at various post-irradiation times with dichlorodihydrofluorescein di acetate followed by flow cytometric measurement of the final product, dichl orofluorescein. Results: The biological effectiveness of the lambda >284 nm spectrum was hi gher by a factor of 3 compared to the lambda >293 nm spectrum for cell kill , and by a factor of 5 for micronucleus induction. No delayed cell death or micronucleus formation was found in the progeny of cells exposed to lambda >294 nm, while a large and dose-dependent effect was found in the progeny of cells exposed to lambda >284 nm for both of these endpoints. ROS levels above those in unirradiated controls were found only in the progeny of cell s exposed to the lambda >284 nm spectrum. Conclusions: The spectrum with lambda >284 nm was more effective than that with lambda >293 nm for induction of cell kill and micronucleus formation i n the directly irradiated cells as well as induction of delayed effects in the progeny in the form of delayed reproductive death and micronucleus form ation. The presence of ROS in the progeny of the irradiated cells may be th e cause of the delayed effects.