Reactive oxygen metabolites, antioxidants and head and neck cancer

Seidman, Michael D.; Quirk, Wayne S.; Shirwany, Najeeb A.

doi:10.1002/(sici)1097-0347(199908)21:5<467::aid-hed14>3.0.co;2-c

Cited by 30 publications

(20 citation statements)

References 153 publications

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“…in cigarette smoke or air pollutants. In order to protect against the deleterious effects of ROS, a well-developed antioxidant system exists in the lung, which includes superoxide dismutases (SODs), catalase, and glutathione-dependent enzymes like glutathione peroxidase (GPx) [3]. SOD enzymes include the intracellular manganese (Mn) SOD and copper-zinc (CuZn) SOD, and an extracellular SOD that exists in epithelial lining fluid and blood vessels [4].…”

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confidence: 99%

Disturbance of systemic antioxidant profile in nonsmall cell lung carcinoma

Chan‐Yeung²,

Ho³

et al. 2006

European Respiratory Journal

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The present study aimed to determine the alterations of antioxidant activities in erythrocytes from patients with nonsmall cell lung carcinoma (NSCLC).A comparative study of the systemic antioxidant activities in red blood cell lysate from subjects with NSCLC and healthy control subjects was conducted. The antioxidants catalase, superoxide dismutase (SOD) and glutathione peroxidase (GPx) were measured using chemical kinetic reactions under spectrophotometry.In total, 189 cases of mostly advanced-stage IIIB or stage IV NSCLC and 202 healthy controls were studied. In subjects with lung cancer, there was similar catalase activity, lower SOD activity (median (interquartile range) 13.4 (9.0-27.2) versus 48. ) compared with controls. The antioxidant activities in lung cancer subjects were not associated with age, sex, smoking status, or tumour cell types. However, more advanced disease (stage IV compared with stage IIIB) was associated with lower SOD activity. Using multivariable analysis, the presence of lung cancer independently predicted SOD and GPx activities.In conclusion, nonsmall cell lung carcinoma in Chinese subjects is associated with alterations in systemic antioxidant activities, which may play an important role in carcinogenesis.

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confidence: 99%

Disturbance of systemic antioxidant profile in nonsmall cell lung carcinoma

Chan‐Yeung²,

Ho³

et al. 2006

European Respiratory Journal

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“…One form of DNA damage, oxidation, can be caused by exposure to reactive oxygen species, routinely generated as byproducts of the respiratory chain, during inflammation, by the exposure to ionizing radiation, or other oxidative stress conditions. Oxidation of DNA causes a wide variety of damage including strand breaks, abasic (Apurinic/Apyrimidinic) sites and oxidized bases that have been implicated in mutagenesis, carcinogenesis, and aging, among others (1,2). One the most abundant and mutagenic base lesions induced by oxidative stress is 7,8-dihydro-8-oxoguanine (8-oxoG) 1 (3).…”

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confidence: 99%

“…Construction of SW480/vector and SW480/AS-mutY (SW480 transfected with vector alone or antisense mutY cDNA) will be described elsewhere. 2 Both transfected cell lines were maintained as described above in regular growth medium containing 600 g/ml G418 sulfate (Invitrogen). Cells were harvested as reported previously (12).…”

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confidence: 99%

Defective Human MutY Phosphorylation Exists in Colorectal Cancer Cell Lines with Wild-type MutY Alleles

Parker¹,

O’Meally²,

Şahin³

et al. 2003

Journal of Biological Chemistry

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Oxidative DNA damage can generate a variety of cytotoxic DNA lesions such as 8-oxoguanine (8-oxoG), which is one of the most mutagenic bases formed from oxidation of genomic DNA because 8-oxoG can readily mispair with either cytosine or adenine. If unrepaired, further replication of A⅐8-oxoG mispairs results in C:G to A:T transversions, a form of genomic instability. We reported previously that repair of A⅐8-oxoG mispairs was defective and that 8-oxoG levels were elevated in several microsatellite stable human colorectal cancer cell lines lacking MutY mutations (human MutY homolog gene, hmyh, MYH MutY homolog protein). In this report, we provide biochemical evidence that the defective repair of A⅐8-oxoG may be due, at least in part, to defective phosphorylation of the MutY protein in these cell lines. In MutY-defective cell extracts, but not extracts with functional MutY, A⅐8-oxoG repair was increased by incubation with protein kinases A and C (PKA and PKC) and caesin kinase II. Treatment of these defective cells, but not cells with functional MutY, with phorbol-12-myristate-13-acetate also increased the cellular A⅐8-oxoG repair activity and decreased the elevated 8-oxoG levels. We show that MutY is serine-phosphorylated in vitro by the action of PKC and in the MutY-defective cells by phorbol-12-myristate-13-acetate but that MutY is already phosphorylated at baseline in proficient cell lines. Finally, using antibody-isolated MutY protein, we show that MutY can be directly phosphorylated by PKC that directly increases the level of MutY catalyzed A⅐8-oxoG repair.

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“…Metabolic activation of carcinogens may also be directly promoted by oxidative stress, i.e., sustained generation of ROS. 3 Oxidative stress is deactivated by the involvement of multiple enzymes, including catalase (CAT), superoxid dismutase (SOD) and glutathione peroxidase (GPX) activities. Excess ROS or non-functionality of these enzymes may induce toxicity, mutations and ultimately cancer in various human tissues.…”

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confidence: 99%

“…Excess ROS or non-functionality of these enzymes may induce toxicity, mutations and ultimately cancer in various human tissues. 3,4 Detoxification enzymes play variable roles in oral cancer development as implied from several studies. Expression of mRNA for various CYPs 5,6 and metabolism of the polycyclic aromatic hydrocarbon benzo(a)pyrene to DNA binding intermediates 7 in cultured human NOK indicate existence of oxidative metabolism.…”

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confidence: 99%

Transcript profiling of enzymes involved in detoxification of xenobiotics and reactive oxygen in human normal and simian virus 40 T antigen‐immortalized oral keratinocytes

Vondracek

Weaver

Sarang

et al. 2002

Intl Journal of Cancer

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The metabolic detoxification capacity may critically regulate the susceptibility of human tissues to cancer development. We used standardized and quantitative, reverse transcription-polymerase chain reaction (StaRT-PCR) and microarray chip techniques to analyze transcript levels of multiple detoxification enzymes in cultured normal human oral keratinocytes (NOK) and the Siman virus 40 T antigenimmortalized oral keratinocyte line SVpgC2a, viewing the latter as a model of a benign tumor state. With good agreement between the 2 methodologies, NOK and SVpgC2a were found to express transcripts for cytochrome P450 enzymes (CYPs), factors related to CYP induction and enzymes involved in conjugation reactions or detoxification of reactive oxygen. The cell types expressed similar levels of CYP 2B6/7, CYP 2E1, P450 oxidoreductase, the aryl hydrocarbon receptor nuclear translocator, sulfotransferase 1A1, sulfotransferase 1A3, epoxide hydrolase, glutathione S-transferase M3, glutathione S-transferase pi and catalase, superoxide dismutase 1, glutathione peroxidase 1 and glutathione peroxidase 3. In contrast, SVpgC2a exhibited comparatively higher levels of CYP1A1, 1B1, aryl hydrocarbon receptor, glutathione S-transferase M1, 2, 4, 5, glutathione S-transferase theta 1 and superoxide dismutase 2 and comparatively lower levels of UDP glycosyltransferase 2 and microsomal glutathione S-transferase 1. Some transcripts, e.g., CYP 2A6/7, were not detected by either standard, non quantitative RT-PCR or the above methods, whereas others were barely quantifiable by StaRT-PCR, i.e., were present at 1-10 molecules/10 6 molecules of actin. Overall, the expression analysis demonstrated presence of mRNA for multiple enzymes involved in foreign compound metabolism and detoxification pathways, including several enzymes not previously reported for oral epithelium. Generally, the comparison of NOK from 2 individuals indicated relatively similar transcript levels of these enzymes. In contrast, differences between NOK and SVpgC2a, e.g., for CYP1B1, may reflect alteration caused by immortalization and aid identification of early stage tumor markers in oral epithelium. © 2002 Wiley-Liss, Inc. Key words: oral epithelium; biotransformation; phase I and II metabolizing enzymes; mRNA expressionSeveral enzyme systems including cytochrome P450s (CYPs), conjugation enzymes and enzymes involved in detoxification of reactive oxygen species (ROS) cooperate to protect the organism against reactive agents that are potentially carcinogenic and stress inducing. 1 Oxidative metabolism (so called phase I metabolism), carried out by the CYP family of enzymes, initiate biotransformation of compounds, which do not possess functional groups suitable for conjugation and can thereby generate toxic and mutagenic/ carcinogenic intermediates. 2 Following CYP dependent oxidative activation, conjugation enzymes (involved in so called phase II metabolism) including transferases for glutathione, sulfate, acetyl moieties and glucuronic acid generally decrease the reactivity of ...

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Reactive oxygen metabolites, antioxidants and head and neck cancer

Cited by 30 publications

References 153 publications

Disturbance of systemic antioxidant profile in nonsmall cell lung carcinoma

Disturbance of systemic antioxidant profile in nonsmall cell lung carcinoma

Defective Human MutY Phosphorylation Exists in Colorectal Cancer Cell Lines with Wild-type MutY Alleles

Transcript profiling of enzymes involved in detoxification of xenobiotics and reactive oxygen in human normal and simian virus 40 T antigen‐immortalized oral keratinocytes

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