Narrow-band UVB induces more carcinogenic skin tumors than broad-band UVB through the formation of cyclobutane pyrimidine dimer.

Abstract

Phototherapy with narrow-band UVB (NB-UVB), with a peak exclusively at 311 nm wavelength, has been found to be more effective in treating a variety of skin diseases than conventional broad-band UVB (BB-UVB). To assess the difference in carcinogenic activity between NB-UVB and BB-UVB, we investigated skin tumor formation by irradiating albino hairless, Ogg1 knockout mice and C57BL/6J wild counterparts with these two UV sources. We found that the ratio of malignant skin tumors induced by NB-UVB was significantly higher than that induced by BB-UVB. There was no significant difference in carcinogenicity of skin tumor induced by NB-UVB between Ogg1 knockout and wild-type mice. To investigate the possible cause of different carcinogenic activity by the different UV sources, we examined three types of DNA damage: cyclobutane pyrimidine dimer (CPD), (6-4) photoproduct, and 8-oxoguanine (8-oxoG) induced by each UV source. We found that CPD formation following a minimum erythema dose (MED) by NB-UVB was significantly higher than that following 1 MED by BB-UVB, whereas the formation of (6-4) photoproducts and 8-oxoG following BB-UVB was significantly higher than those following NB-UVB exposure. These results suggest that CPD formation is closely related to the higher carcinogenic characteristics of NB-UVB. JID JOURNAL CLUB ARTICLE: For questions, answers and open discussion about this article please go to http://network.nature.com/.

• Authors: Makoto Kunisada, Hiroshi Kumimoto, Kanji Ishizaki, Kunihiko Sakumi, Yusaku Nakabeppu, Chikako Nishigori
• Journal: The Journal of investigative dermatology (J Invest Dermatol) Vol. 127 Issue 12 Pg. 2865-71 (Dec 2007) ISSN: 1523-1747 [Electronic] United States
• PMID: 17687389 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Cyclobutanes
• Pyrimidine Dimers
• Guanosine
• 8-hydroxyguanosine
• DNA Glycosylases
• Ogg1 protein, mouse

Topics

• Animals
• Cell Transformation, Neoplastic
• Cyclobutanes (chemistry)
• DNA Glycosylases (genetics)
• Epidermis (drug effects, radiation effects)
• Guanosine (analogs & derivatives, chemistry)
• Humans
• Immunohistochemistry (methods)
• Mice
• Mice, Inbred BALB C
• Mice, Inbred C57BL
• Mice, Knockout
• Photochemistry (methods)
• Pyrimidine Dimers (chemistry)
• Skin Neoplasms (etiology)
• Ultraviolet Rays