Oxidative DNA damage by crystalline silica

Daniel, Lambert N.; Mao, Yan; Saffiotti, Umberto

doi:10.1016/0891-5849(93)90103-2

Cited by 82 publications

(40 citation statements)

References 23 publications

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“…The above results are consistent with a mechanism of-OH generation by the reaction of H202 with metal ions or with the reactive silica surface via a Fenton-like mechanism. As reported earlier H202 is generated by the reaction of the silica surface with water (5,11,19). Because SOD partially inhibited -OH generation from an aqueous suspension of silica particles, we deduced that°-may be involved.…”

Section: Superoxide Radical Generationmentioning

confidence: 88%

“…While our earlier studies (4-7) have demonstrated that freshly fractured silica are capable of generating 'OH radicals upon reaction with aqueous media, recent studies suggest that superoxide radical (0°) may also be generated (8)(9)(10)(11). However, whether silica particles generate°2-upon reaction with aqueous medium has not been firmly established.…”

Section: Introductionmentioning

confidence: 89%

“…Based on the results reported here and those in the literature (4,11) H202 is thought to be generated by reaction of H20 with silicon-based radicals (5,19) and/or by Op-related reactions involving surface metal oxidation (11,23 …”

Section: Discussionmentioning

confidence: 99%

“…Using (11), aged silica containing lower concentration of free radicals was Environmental Health Perspectives used while in the current ESR study freshly fractured silica containing more free radicals was used; (c) the 'OH may be generated site-specifically on the surface of silica particles. These site-specifically generated -OH radicals may efficiently attack DNA.…”

Section: Discussionmentioning

confidence: 99%

“…All ESR measurements were made using a Varian E4 spectrometer and a flat cell assembly. Hyperfine splittings were measured (to 0.1 G) directly from magnetic field separations using potassium tetraperoxochromate (K3CrO8) (15) (11). Briefly, reactions were carried out in 10 mM phosphate buffer, pH 7.4, in 1.5 ml polypropylene tubes at 37°C.…”

Section: Introductionmentioning

confidence: 99%

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Silica Radical-Induced DNA Damage and Lipid Peroxidation

Shi¹,

Mao²,

Daniel³

et al. 1994

Environmental Health Perspectives

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In recent years, more attention has been given to the mechanism of disease induction caused by the surface properties of minerals. In this respect, specific research needs to be focused on the biologic interactions of oxygen radicals generated by mineral particles resulting in cell injury and DNA damage leading to fibrogenesis and carcinogenesis. In this investigation, we used electron spin resonance (ESR) and spin trapping to study oxygen radical generation from aqueous suspensions of freshly fractured crystalline silica. Hydroxyl radical (0OH), superoxide radical (02-) and singlet oxygen (102) were all detected. Superoxide dismutase (SOD) partially inhibited *OH yield, whereas catalase abolished 0OH generation. H202 enhanced 0OH generation while deferoxamine inhibited it, indicating that OH is generated via a Haber-Weiss type reaction. These spin trapping measurements provide the first evidence that aqueous suspensions of silica particles generate O-and 10 Oxygen consumption measurements indicate that freshly fractured silica uses molecular oxygen to generate 02-and 10 . Electrophoretic assays of in vitro DNA strand breakages showed that freshly fractured silica induced DNA strand breakage, which was inhibited by catalase and enhanced by H202. In an argon atmosphere, DNA damage was suppressed, showing that molecular oxygen is required for the silica-induced DNA damage. Incubation of freshly fractured silica with linoleic acid generated linoleic acid-derived free radicals and caused dose-dependent lipid peroxidation as measured by ESR spin trapping and malondialdehyde formation. SOD, catalase, and sodium benzoate inhibited lipid peroxidation by 49, 52, and 75%, respectively, again showing the role of oxygen radicals in silica-induced lipid peroxidation. These results show that in addition to -OH, 0°and 102 may play an important role in the mechanism of silica-induced cellular injury. -Environ Health Perspect 102(Suppl 10):149-154 (1994)

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Section: Superoxide Radical Generationmentioning

confidence: 88%

Section: Introductionmentioning

confidence: 89%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Silica Radical-Induced DNA Damage and Lipid Peroxidation

Shi¹,

Mao²,

Daniel³

et al. 1994

Environmental Health Perspectives

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Transforming growth factor beta expression and transformation of rat lung epithelial cells by crystalline silica (quartz)

Williams¹,

Knapton²,

Ifon³

et al. 1996

Int. J. Cancer

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Crystalline silica (quartz) induces silicosis and associated peripheral lung carcinomas in rats. The role and pattern of expression of transforming growth factor (TGF)-beta1/beta2 mRNA transcripts were investigated in the fetal rat lung epithelial cell line FRLE, its neoplastic transformants and derived tumors in athymic nude mice. FRLE cells, treated with 100 microgram/cm2 of quartz in serum-free medium, gave rise to phenotypically altered, tumorigenic cells. Quartz-treated, transformed and tumorigenic cells, subcultured directly (QTT-C1) or after growth in soft agar (QTT-C2), formed tumors in athymic nude mice (QTT-T1). Cells subcultured from the tumors (QTT-T1C) were also tumorigenic in nude mice (QTT-T2). QTT-T1 and QTT-T2 tumors were poorly differentiated carcinomas with variable amounts of extracellular matrix-associated TGF-beta1 and desmoplasia. For comparison, a tumorigenic cell line derived from FRLE cells transformed with a mutated K-ras plasmid (RT-C1) and cells subcultured from a corresponding nude mouse tumor (RT-T1) and designated RT-T1C were used. Whereas TGF-beta1 and TGF-beta2 inhibited the growth of QTT-T1C and FRLE cells in a dose-dependent fashion, RT-T1C cells, containing an activated ras gene, were relatively unaffected. TGF-beta1 and TGF-beta2 mRNAs were expressed at higher levels in QTT-T1C cells than in FRLE and TR-T1C cells, and there was an increase in TGF-beta type II receptor (TGR-betaR) mRNA expression in QTT-T1C and RT-T1C cells compared to FRLE cells. Carcinomas in nude mice derived from QTT and RT cells and silicosis-associated lung carcinomas induced in rats by intra-tracheal quartz did not express either active or latent forms of TGF-beta1 protein on immunohistochemistry. The disparity between TGF-beta1 mRNA and TGF-beta1 protein expression in QTT tumors may be due to post-transcriptional regulation of TGF-beta1.

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Neoplastic transformation by quartz in the BALB/3T3/A31-1-1 cell line and the effects of associated minerals

Saffiotti¹,

Ahmed²

1996

Teratog. Carcinog. Mutagen.

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Oxidative DNA damage by crystalline silica

Cited by 82 publications

References 23 publications

Silica Radical-Induced DNA Damage and Lipid Peroxidation

Silica Radical-Induced DNA Damage and Lipid Peroxidation

Transforming growth factor beta expression and transformation of rat lung epithelial cells by crystalline silica (quartz)

Neoplastic transformation by quartz in the BALB/3T3/A31-1-1 cell line and the effects of associated minerals

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