Low doses of UVB or UVA induce chromosomal aberrations in cultured human skin cells
article
Chromosomal defects are frequently present in malignant and premalignant skin disorders; however, it is not known whether ultraviolet radiation from sunlight plays a role in their induction. To obtain information on the ability of ultraviolet A and ultraviolet B to induce chromosomal aberrations, cultured melanocytes and fibroblasts were exposed to physiologic doses of ultraviolet A or ultraviolet B and, for comparison, to γ rays. As a measure of chromosomal aberrations, the formation of micronuclei was determined. To obtain sufficient statistical data on induced micronuclei and cell kinetics, a flow cytometry method has been modified and applied. The flow cytometry method analysis is based on staining the DNA with ethidium bromide and the cell membranes with 1,6-diphenyl-1,3,5,-hexatriene. We observed dose-dependent micronuclei formation after γ or ultraviolet B irradiation in both cell types and also for ultraviolet A in fibroblasts. The yield of micronuclei induced in fibroblasts by ultraviolet A was only a factor 15 smaller than that induced by ultraviolet B (313 nm). The results indicate that 10 kJ per m2 (equivalent to 1 minimal erythema dose) of ultraviolet B and 150 kJ per m2 of ultraviolet A (0.2 minimal erythema dose) can induce 1% of micronuclei in fibroblasts, equivalent to the induction due to 0.6 Gy of γ radiation. In conclusion, physiologic doses of sunlight can induce chromosomal aberrations at a level comparable with that observed after exposure to approximately 1 Gy of ionizing radiation. Therefore, sunlight can be considered a potential inducer of chromosomal aberrations in skin cells, which may contribute to skin carcinogenesis.
Topics
Human fibroblastsHuman melanocytesMicronucleiSkin cancer1,6 diphenyl 1,3,5 hexatrieneEthidium bromideCell kineticsChromosome aberrationFibroblastFlow cytometryHumanHuman cellIonizing radiationPriority journalSkin carcinogenesisSkin diseaseUltraviolet radiationCell CycleCells, CulturedChromosome AberrationsDose-Response Relationship, RadiationFibroblastsFlow CytometryGamma RaysHumansLasersMelanocytesMicronuclei, Chromosome-DefectiveRadiation DosageSkinSunlightTime FactorsUltraviolet Rays
TNO Identifier
87321
ISSN
0022202X
Source
The Journal of Investigative Dermatology, 115(3), pp. 35-440.
Pages
35-440
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