Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04179 (MnSOD)
2,777 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Bleomycin (BLM) is an anticancer drug that generates reactive oxygen species (ROS) after interacting with iron and oxygen. We hypothesized that BLM could cause a different status of oxidative stress in normal versus tumor cells due to possible altered redox status and gene expression in cells following transformation. In this study, the extent of cytotoxicity, levels of ROS, and activities of antioxidant enzymes were compared between normal WI38 cells and SV40-transformed WI38 (VA13) cells following BLM treatment. Basal activities of MnSOD and catalase were lower in VA13 cells and basal ROS levels were higher in VA13 cells. Although BLM caused greater growth inhibition and apoptosis in VA13 cells, it increased ROS levels at an earlier time point in WI38 cells. Moreover, BLM treatment (100 microg/ml) had no effect on the activities of MnSOD, CuZnSOD, and catalase, but increased the activities of glutathione peroxidase (GPX) in WI38 cells after a 48-h treatment and in VA13 cells after a 24- and 48-h treatment. Northern blot analysis indicated that the increase in GPX activities was due to increased transcript levels of GPX1 but not GPX4 in both cells. Our results indicate selective induction of the GPX1 gene by BLM and different redox responses to BLM between WI38 and VA13 cells.
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PMID:Levels of reactive oxygen species and primary antioxidant enzymes in WI38 versus transformed WI38 cells following bleomcyin treatment. 1574 91

Solid tumors are often placed under stress conditions, such as glucose starvation which may result in topoisomerase II drug resistance. In this study, we investigated whether glucose deprivation or substitution by fructose regulates tumor cell apoptosis induced by 2-acetyl furanonaphthoquinone (FNQ). We now show that FNQ exerts much greater antitumor activity than either 7-methoxy 2-ethyl FNQ or 2-ethyl FNQ. Whereas 0.8 microM FNQ induces apoptosis after 16 hours in glucose-supplemented conditions irrespective of bcl-2 overexpression in K1735 melanoma, 0.5 microM FNQ is also effective within 12 hours in low glucose or in fructose-supplemented medium. Under the latter conditions, apoptosis-associated PARP cleavage and cytosolic cytochrome C are increased, together with induction and partial translocation to mitochondria of phosphorylated Jun-N-terminal kinase and massive upregulation of mitochondrial Mn superoxide dismutase. We propose that mitochondrial colocalization of these activities is important in this synergistic anti-tumor effect of FNQ and glucose depletion. Since glucose limitation slows proliferation and decreases efficacy of some genotoxic drugs that trigger apoptosis in rapidly dividing cells, we propose evaluating FNQ as a novel therapeutic anti-cancer adjuvant against slowly proliferating tumors.
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PMID:Decreased glycolytic metabolism accelerates apoptosis in response to 2-acetyl furanonaphthoquinone in K1735 melanoma irrespective of bcl-2 overexpression. 1584 99

Calorie restriction (CR) extends the life span of various species through mechanisms that are as yet unclear. Recently, we have reported that mitochondrion-mediated apoptosis was enhanced in alphaMUPA transgenic mice that spontaneously eat less and live longer compared with their wild-type (WT) control mice. To understand the molecular mechanisms underlying the increased apoptosis, we compared alphaMUPA and WT mice for parameters associated with SOD2 (MnSOD), a mitochondrial antioxidant enzyme that converts superoxide radicals into H(2)O(2) and is also known to inhibit apoptosis. The SOD2-related parameters included the levels of SOD2 mRNA, immunoreactivity and enzymatic activity in the liver, lipid oxidation and aconitase activity in isolated liver mitochondria, and the sensitivity of the mice to paraquat, an agent that elicits oxidative stress. In addition, we compared the mice for the levels of SOD2 mRNA after treatment with bacterial lipopolysaccharides (LPS), and for the DNA binding activity of NFkappaB as a marker for the inflammatory state. We extended SOD2 determination to the colon, where we also examined the formation of pre-neoplastic aberrant crypt foci (ACF) following treatment with dimethylhydrazine (DMH), a colonic organotypic carcinogen. Overall, alphaMUPA mice showed reduced basal levels of SOD2 gene expression and activity concomitantly with reduced lipid oxidation, increased aconitase activity and enhanced paraquat sensitivity, while maintaining the capacity to produce high levels of SOD2 in response to the inflammatory stimulus. alphaMUPA mice also showed increased resistance to DMH-induced pre-neoplasia. Collectively, these data are consistent with a model, in which an optimal fine-tuning of SOD2 throughout a long-term regimen of reduced eating could contribute to longevity, at least in the alphaMUPA mice.
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PMID:Long-lived alphaMUPA transgenic mice show reduced SOD2 expression, enhanced apoptosis and reduced susceptibility to the carcinogen dimethylhydrazine. 1613 68

The tissue distribution of Cu/Zn- and Mn-superoxide dismutases (SOD) in adrenal tumors was studied by an immunohistochemical technique, and the concentrations of both SODs were measured by a sensitive sandwich enzyme immunoassay technique. In the normal adrenal gland, both Cu/Zn- and Mn-SODs were localized predominantly in the reticular zone of the cortex. Cu/Zn-SOD was stained clearly in the inner fascicular zone of the cortex, but not in the medulla, whereas Mn-SOD was stained weakly in the medulla. In different adrenal tumors, the localization of both stained SODs reflected the origin of the tumor cell. Thus, in one section of a pheochromocytoma only Mn-SOD was stained clearly. The concentrations of both SODs in the tissues of medullary tumors were lower than those in the normal adrenal gland and adrenocortical adenomas. The concentration of Cu/Zn-SOD in the tumor tissue of Cushing's syndrome adenoma was higher, and that of Mn-SOD was lower than the concentrations in the normal adrenal gland. The ratio of the tissue concentrations of Mn-SOD to Cu/Zn-SOD was lower in adrenal medullary tumors and Cushing's syndrome adenomas than in the normal adrenal gland and primary aldosteronism adenomas, indicating the predominance of Cu/Zn-SOD in the former, and Mn-SOD in the latter. These data suggest that the localization of Cu/Zn- and Mn-SODs in adrenal tissues reflects the specificity of the adrenal cells that produce the tissue-specific hormones. An investigation of changes in these enzymes in adrenal tumors may also provide useful information on adrenal tumor cell differentiation.
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PMID:Cu/Zn- and Mn-superoxide dismutase distribution and concentration in adrenal tumors. 1678 Aug 79

Cellular antioxidant enzymes protect against damage caused by exposure to endogenous or exogenous prooxidants. Singlet oxygen ((1)O(2)) is a reactive form of oxygen that can be produced in vivo either in normal and pathophysiologic conditions or by photosensitizing chemicals, as during photodynamic treatment. We hypothesized that photodynamically generated (1)O(2) would decrease the enzymatic activities of cellular antioxidants. To test this hypothesis, we treated cultured mouse epidermal keratinocytes with the photosensitizer Photofrin plus visible light to produce (1)O(2), and then measured CuZnSOD, MnSOD, and catalase activities with both ingel and spectrophotometric enzyme activity assays. Our results demonstrated that the enzymatic activities of cellular CuZnSOD, MnSOD, and catalase were significantly decreased after keratinocytes were treated with Photofrin plus visible light. By contrast, the enzymatic activities of cellular CuZnSOD, MnSOD, and catalase were unaffected in control cells treated with Photofrin only or visible light only. Despite the decreased levels of enzymatic activities, the protein levels of all three primary antioxidant enzymes remained constant after photodynamic treatment, as determined by Western blotting. L-Histidine, a (1)O(2) quencher, protected against the inactivation of cellular CuZnSOD, MnSOD, and catalase enzymes induced by photodynamically generated (1)O(2). The conclusion from these experiments is that the primary cellular antioxidant enzymes CuZnSOD, MnSOD, and catalase can be inactivated by photodynamically generated (1)O(2) in nucleated mammalian cells. These findings may be useful in the future development of antineoplastic adjuvant therapies that use photodynamic generation of (1)O(2) to inactivate antioxidant defenses with a goal of sensitizing tumor cells to prooxidant-generating drugs.
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PMID:Inactivation of primary antioxidant enzymes in mouse keratinocytes by photodynamically generated singlet oxygen. 1691 Jul 78

Lung cancer is the leading cause of cancer-related deaths in the United States. Despite improvements in radiation, surgery and chemotherapy the 5 year survival statistics of non-small cell lung cancer (NSCLC) have improved little over the past two decades. It has been proposed that NF-kappaB is a participant in the cytoprotection against several redox-mediated therapeutic agents including ionizing radiation. Cyclooxygenase-2 (COX-2) inhibition has become an attractive target for enhancing the efficacy of radiation and chemotherapy. Numerous mechanistic pathways have been proposed as the means through which COX-2 inhibition enhances the efficacy of radiation. We hypothesize that the COX-2 inhibitor, nimesulide, will improve the efficacy of radiation therapy (RT), at least in part, via the suppression of NF-kappaB mediated cytoprotective pathways. In this study we used the COX-2 inhibitor nimesulide to improve the efficacy of RT when measured by tumor regrowth assays in vivo and clonegenic survival in vitro. For the in vivo assay, A549 tumor cells representing NSCLC were subcutaneously injected into the right flanks of female athymic nude mice (n=10/group). Mice were given nimesulide via drinking water at a concentration of 5 microg/g body weight (b.w.) and the water was replenished daily. Tumors were treated with 30 Gy fractionated radiation and measured bi-weekly. For our in vitro study, clonogenic survival assays were evaluated to determine the effect of nimesulide, radiation, and the combination. The NF-kappaB mediated mechanism of nimesulide was measured by Western blot analysis of NF-kappaB target genes, MnSOD and survivin. In vivo, mice that received combined treatments of 5 microg/g b.w. nimesulide and 30 Gy radiation (3 Gy/fraction, 10 daily fractions) had significant reduction in tumor size in comparison to the 30 Gy radiation control group (p<0.05). In vitro, nimesulide alone produced a significant decrease in clonogenic survival at doses from 0-300 microM. Nimesulide demonstrated an additive effect in combination with radiation. Nimesulide alone reduced MnSOD and survivin protein levels in a dose-dependent manner. 6 Gy radiation caused an initial elevation of MnSOD protein levels which was inhibited by prior treatment of nimesulide suggesting an inhibition of radiation induced NF-kappaB target genes. These results support the hypothesis that COX-2 inhibitors such as nimesulide can increase the efficacy of radiation therapy. In vitro, our results suggest that the radiosensitization of A549 tumor cells by nimesulide is mediated by the suppression of NF-kappaB-mediated, radiation-induced cytoprotective genes.
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PMID:Cyclooxygenase-2 inhibitor, nimesulide, improves radiation treatment against non-small cell lung cancer both in vitro and in vivo. 1696 92

The classic association between cancer and mitochondrial dysfunction is actually considered as a role of mitochondria in cellular signalling. It is understood that mitochondria, mitochondrial oxidative damage and NO and H2O2 diffusion are involved in the progression of human colorectal cancer. Mitochondria from human colorectal tumors and adjacent non-tumor colon tissues showed a markedly increased oxidative damage with increased contents of TBARS and protein carbonyls. Mitochondrial protein carbonyls was the most sensitive indicator. Oxidative stress and damage was also observed in adjacent non-tumor cells. Mitochondrial activities, as NADH-cytochrome c reductase and cytochrome oxidase, were observed decreased in tumor and in adjacent non-tumor tissue. Cu,Zn-SOD activity decreased by 42% in tumor tissue in the advanced stage as compared with the initial stage, whereas Mn-SOD activity did not change in tumor progression. An increased mtNOS activity (46%) was observed in tumor and non-tumor tissues in the advanced stage of cancer progression. A direct linear relationship between mtNOS and oxidative damage in tumor and non-tumor tissues supports the concept that mitochondrial NO and H2O2 diffuse from tumor to adjacent non tumor tissue signaling for cell death as the classic toxohormones.
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PMID:Mitochondrial dysfunction in human colorectal cancer progression. 1712 72

Radiation therapy of tumors of the head and neck region is compromised by dose limiting toxicity of normal tissues including the oral cavity and oropharyngeal mucosa. MnSOD-Plasmid Liposome (MnSOD-PL) intraoral gene therapy has been demonstrated to decrease normal tissue toxicity and also improve survival in mice with orthotopic SCC-VII squamous cell tumors on the floor of the mouth. Furthermore, intravenous administration of MnSOD-PL in mice with orthotopic tumors, or addition of MnSOD-PL to tumor cell lines in vitro produces a radiosensitizing effect attributable to differences in antioxidant pool responses of tumor cells compared to normal tissues following irradiation. To determine whether EGF receptor (EGFR) antagonists Iressa, or Cetuximab provided further improvement of radiation killing of squamous cell tumors, MnSOD-PL transfected or control SCCVII tumor cells were irradiated in vitro, and then the effect of EGFR receptor antagonists was tested. Cells transfected with MnSOD-PL were relatively radiosensitive D0 = 1.244 +/- 0.126 Gy compared to control D0 = 3.246 +/- 0.087 (p < 0.0001). Clonogenic radiation survival curves of SCCVII cells demonstrated radiosensitization by Iressa D0 = 2.770 +/- 0.134 Gy (p = 0.0264), but no significant radiosensitizing effect of Cetuximab D0 = 3.193 +/- 0.309 (p = 0.7338). The combination of MnSOD-PL plus Iressa further increased radiosensitivity of SCC-VII cells in vitro D0 = 0.785 +/- 0.01064 (p < 0.0001). The results suggest some synergy of the effectiveness of the EGFR antagonist Iressa on increasing the radiation killing of SCC-VII cells that supplements MnSOD-PL tumor radiosensitization.
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PMID:Effect of EGFR antagonists gefitinib (Iressa) and C225 (Cetuximab) on MnSOD-plasmid liposome transgene radiosensitization of a murine squamous cell carcinoma cell line. 1720 69

Autoantibodies against tumor antigens are promising means for cancer diagnosis and prognosis. In this study, we applied a proteomic approach to identify proteins that commonly elicit humoral response in lung squamous carcinoma (LSC). Sera from 20 newly diagnosed patients with LSC and 20 matched healthy individuals were analyzed for antibody-based reactivity against LSC proteins separated by two-dimensional electrophoresis. Autoantibodies against triosephosphate isomerase (Tim) and superoxide dismutase [Mn] (MnSOD) were detected in sera from over 20% patients with LSC but none from the normal controls. Furthermore, the occurrence of autoantibodies against Tim and MnSOD was evaluated by ELISA in an additional 40 LSC patients, 30 other types of cancer (OTC) patients, and 50 noncancer controls (NC). Results showed that frequency of autoantibody against Tim (27.5%) in LSC patients was significantly higher than that in OTC patients (6.7%, p = 0.027) and in NC (6%, p = 0.005). Likewise, frequency of autoantibody against MnSOD in LSC (20%) patients was significantly higher than that in NC (4%, p = 0.016), however, there was no significant difference when comparing to that in OTC patients (6.7%, p = 0.115). We also observed significantly increased expression and secretion of Tim and MnSOD in LSC, which possibly account for their autoantibody development. Our results indicate that autoantibody and antigen of Tim and MnSOD may be useful for screening and diagnosis of the lung squamous carcinoma.
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PMID:Identification of tumor antigens in human lung squamous carcinoma by serological proteome analysis. 1726 31

Cells typically die by either apoptosis or necrosis. However, the consequences of apoptosis and necrosis are quite different for a whole organism. In the case of apoptosis, the cell content remains packed in the apoptotic bodies that are removed by macrophages, and thereby inflammation does not occur; during necrosis, the cell membrane is ruptured, and the cytosolic constituents are released into the extracellular space provoking inflammation. Recently, inflammation and necrosis have been suggested to promote tumor growth. We investigated the molecular mechanism underlying cell death in response to glucose depletion (GD), a common characteristic of the tumor microenvironment. GD induced necrosis through production of reactive oxygen species (ROS) in A549 lung carcinoma cells. Inhibition of ROS production by N-acetyl-L-cysteine and catalase prevented necrosis and switched the cell death mode to apoptosis that depends on mitochondrial death pathway involving caspase-9 and caspase-3 activation, indicating a critical role of ROS in determination of GD-induced cell death mode. We demonstrate that protein kinase C-dependent extracellular regulated kinase 1/2 (ERK1/2) activation also switched GD-induced necrosis to apoptosis through inhibition of ROS production possibly by inducing manganese superoxide dismutase (SOD) expression and by preventing GD-induced degradation of copper zinc SOD. Thus, these results suggest that GD-induced cell death mode is determined by the protein kinase C/ERK1/2 signal pathway that regulates MnSOD and CuZnSOD and that these antioxidants may exert their known tumor suppressive activities by inducing necrosis-to-apoptosis switch.
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PMID:Protein kinase C-ERK1/2 signal pathway switches glucose depletion-induced necrosis to apoptosis by regulating superoxide dismutases and suppressing reactive oxygen species production in A549 lung cancer cells. 1730 78


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