Wavelength dependence of ultraviolet-induced DNA damage distribution: Involvement of direct or indirect mechanisms and possible artefacts

DNA damage, death receptor activation and reactive oxygen species contribute to ultraviolet radiation-induced apoptosis in an essential and independent way

“…PDTC did not affect the formation of CPD, the major DNA photoproduct induced by UVB. This observation is in accordance with previous findings that UVB-induced DNA damage is mostly independent of ROS formation (Kuluncsics et al, 1999). In contrast, addition of the repair enzyme photolyase, as a positive control, significantly reduced CPD, confirming previous observations (Kulms et al, 1999;Stege et al, 2000).…”

Why Cockayne syndrome patients do not get cancer despite their DNA repair deficiency

“…Indeed, we found that the majority of UV-induced mutations in CS-B cells were G:C→T:A mutations, a signature of 8-oxo-dG-induced mutagenesis (Fig. 3F), which can be caused by direct oxidation of DNA by UV and, more indirectly, by singlet oxygen formation in cells following UV irradiation (24)(25)(26). This result is consistent with increased mutagenesis resulting from deficient oxidative DNA-damage repair in CS cells.…”

Distribution and repair of bipyrimidine photoproducts in solar UV-irradiated mammalian cells. Possible role of Dewar photoproducts in solar mutagenesis

“…When only the UV portion (6.8% of the total emitted energy) is taken into account in the determination of the yield of CPD, SSL was a 100 times less efficient than UVB in producing CPD. Such yields of CPD in the DNA of irradiated cells were very similar to those obtained on isolated plasmid DNA irradiated under the same conditions (16). In addition, the maximal SSL and UVA doses used in these experiments correspond to a sunlight exposure of 3.5-4 h in summer at zenith in Paris, in terms of production of CPD (16).…”

“…Since the formation of CPD by UVA radiation has been a matter of debate for over twenty years, we calculated the relative efficiency of different regions of the UV spectrum for the production of this damage using the action spectrum reported by Kielbassa et al (14) and the spectral distributions of our UV sources (16). by UVA2 wavelengths (320-345 nm).…”

“…Thus, compared to UVC, 10 5 higher doses of UVA are necessary to produce the same amount of CPD. Despite this difference, these UVA doses are still biologically relevant since they correspond to a few hours sunlight exposure at zenith in summer (16). Similarly, (6-4)PP and DewarPP can also be produced by UVA radiation and detected at trace levels (Perdiz and Sage, unpublished data).…”