Direct monitoring of UV-induced free radical generation in HaCaT keratinocytes.
BACKGROUND
Ultraviolet radiation (UVR) is one of the most important aetiological factors in the development of skin cancer, with an estimated 100,000 new cases of nonmelanoma skin cancer (NMSC) diagnosed each year in the UK. To date, little work has been carried out to investigate the role of UVR in the increased production of reactive oxygen species (ROS) and reactive nitrogen species (RNS) following exposure of skin cells to simulated solar UVR.


OBJECTIVE
To monitor directly the effects of simulated solar UVR on ROS and RNS generation in HaCaT keratinocytes.


METHODS
This study reports the use of electrochemical monitoring techniques for the direct, real-time detection of two highly reactive free radical species, superoxide (O2-) and nitric oxide (NO), from HaCaT keratinocyte cells that had been exposed to a source of UVR designed to simulate the doses of UVA and UVB found in solar light.


RESULTS
An increase in both O2- and NO generation was observed in HaCaT cells that had been exposed to UVR. No detectable increase in either species was observed in cells that had not been exposed to UVR. The specificity of the electrochemical methods for O2- or NO was confirmed through the scavenging or inhibition of these species.


CONCLUSIONS
The findings of this study demonstrated that exposure of HaCaT cells to relatively low doses of UVR resulted in the immediate generation of both O2- and NO, therefore potentially leading to the downstream generation of highly damaging metabolites and the development of a number of pathologies, including cancer.
Aitken
G R
GR
Dermatological Sciences, Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, UK.
Henderson
J R
JR
Chang
S-C
SC
McNeil
C J
CJ
Birch-Machin
M A
MA
D002460:Cell Line; D005609:Free Radicals / Q000378:metabolism*; D006801:Humans; D015603:Keratinocytes / Q000378:metabolism* / Q000528:radiation effects*; D009569:Nitric Oxide / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism; D014466:Ultraviolet Rays
D005609:Free Radicals; D013481:Superoxides; D009569:Nitric Oxide