Benzo[a]pyrene Enhances the Formation of 8-Hydroxy-2'-deoxyguanosine by Ultraviolet A Radiation in Calf Thymus DNA and Human Epidermoid Carcinoma Cells
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- 作者：Zhisong Liu ; Yuhun Lu ; Barry Rosenstein ; Mark Lebwohl ; and Huachen Wei
- 刊名：Biochemistry
- 出版年：1998
- 出版时间：July 14, 1998
- 年：1998
- 卷：37
- 期：28
- 页码：10307 - 10312
- 全文大小：126K
- 年卷期：v.37,no.28(July 14, 1998)
- ISSN：1520-4995
文摘
The objective of this study is to investigate if benzo[a]pyrene (BaP) and ultraviolet (UV)radiation synergistically induce oxidative DNA damage. Calf thymus DNA was incubated with BaP andirradiated with UVB (280-320 nm) and UVA (335-400 nm). BaP substantially enhanced the formationof 8-hydroxy-2'-deoxyguanosine (8-OHdG) by UVA, but only moderately increased the level of 8-OHdGby UVB. Formation of 8-OHdG proportionally correlated with both UV dose and BaP concentration.Human epidermoid carcinoma cells were incubated with 10 
g of BaP/mL for 24 h and then exposed to10 kJ/m2 UVB and 25 kJ/m2 UVA. UVB plus BaP did not affect the level of 8-OHdG in cultured cells,whereas UVA plus BaP substantially increased 8-OHdG by over 4-fold compared to BaP and UVA controls.To confirm what reactive oxygen species (ROS) are involved in BaP plus UVA-induced oxidative DNAdamage, less or more specific ROS quenchers were added to DNA solution. The results showed thatonly superoxide dismutase and genistein significantly quenched BaP plus UVA-induced 8-OHdG, whereascatalase, sodium azide, and mannitol exhibited no effect. Our studies suggest that BaP enhances theformation of 8-OHdG in purified DNA and cultured cells by UVA, but not by UVB, and that superoxideanion plays an important role in the synergistic induction of oxidative DNA damage.
g of BaP/mL for 24 h and then exposed to10 kJ/m2 UVB and 25 kJ/m2 UVA. UVB plus BaP did not affect the level of 8-OHdG in cultured cells,whereas UVA plus BaP substantially increased 8-OHdG by over 4-fold compared to BaP and UVA controls.To confirm what reactive oxygen species (ROS) are involved in BaP plus UVA-induced oxidative DNAdamage, less or more specific ROS quenchers were added to DNA solution. The results showed thatonly superoxide dismutase and genistein significantly quenched BaP plus UVA-induced 8-OHdG, whereascatalase, sodium azide, and mannitol exhibited no effect. Our studies suggest that BaP enhances theformation of 8-OHdG in purified DNA and cultured cells by UVA, but not by UVB, and that superoxideanion plays an important role in the synergistic induction of oxidative DNA damage.