Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P30044 (antioxidant enzyme)
 8,037 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chemoresistance and therapeutic selectivity are major obstacles to successful chemotherapy of ovarian cancer. Manganese superoxide disumutase (MnSOD) is an important antioxidant enzyme responsible for the elimination of superoxide radicals. We reported here that MnSOD was significantly elevated in ovarian cancer cells and its overexpression was one of the mechanisms that increased resistance to apoptosis in cancer cells. Knockdown of MnSOD by small-interfering RNA (siRNA) led to an increase in superoxide generation and sensitisation of ovarian cancer cells to the two front-line anti-cancer agents doxorubicin and paclitaxel whose action involved free-radical generation. This synergistic effect was not observed in non-transformed ovarian surface epithelial cells. Furthermore, our results revealed that this combination at the cellular level augmented activation of caspase-3 and caspase-9, but not caspase-8, suggesting involvement of an intrinsic apoptotic pathway. Evaluation of signalling pathways showed that MnSOD siRNA enhanced doxorubicin- and paclitaxel-induced phosphorylation of extracellular signal-regulated kinase 1/2. Akt activation was not affected. These results identify a novel chemoresistance mechanism in ovarian cancer, and show that combination of drugs capable of suppressing MnSOD with conventional chemotherapeutic agents may provide a novel strategy with a superior therapeutic index and advantage for the treatment of refractory ovarian cancer.
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PMID:Chemosensitisation by manganese superoxide dismutase inhibition is caspase-9 dependent and involves extracellular signal-regulated kinase 1/2. 1859 23

Increased levels of reactive oxygen species (ROS) such as superoxide anions and hydrogen peroxide have been reported in many cancer cells and they have been implicated in carcinogenesis and tumor progression. Antioxidant enzymes, such as Manganese Superoxide Dismutase (MnSOD or SOD2) and Glutathione Peroxidase-1 (GPx1), act coordinately to neutralize ROS. These enzymes are also thought to contribute to cancer cell resistance to conventional radio-chemo-therapies. Although some relationships have been reported between psychosocial factors and the regulation of antioxidant enzymes, little is known about these relationships in the context of cancer progression. The current study investigated the levels of MnSOD and GPx1in confirmed serous, high-grade tumor tissue from 60 ovarian cancer patients, and explored the relationship between the activity of these enzymes, the levels of tumor norepinephrine (NE), and patient mood as determined via pre-operative questionnaires. MnSOD activity was positively related to depressed mood (p=0.025) and tumor NE (p=0.023). In contrast, GPx1 activity was inversely related to fatigue (p=0.015) and tumor NE (p=0.009), and was positively associated with vigor (p=0.024). These findings suggest that psychological state and adrenergic signaling are linked with antioxidant enzyme activity in ovarian cancer and may have implications for patient treatments and outcomes.
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PMID:Biobehavioral and neuroendocrine correlates of antioxidant enzyme activity in ovarian carcinoma. 2598 10

Oxidative stress is considered an important factor in the development of endometriosis, including its malignant transformation. Previous studies have found that AT-rich interactive domain 1A (ARID1A), a tumor suppressor gene, is frequently mutated and inactivated in endometriosis-associated ovarian cancer (EAOC), and such a change in this gene is considered an early event in malignant transformation. We observed oxidative stress status by measuring the activity of the antioxidant enzyme manganese superoxide dismutase (MnSOD), malondialdehyde (MDA), and ARID1A gene expression in tissue samples from patients with endometriosis, EAOC, or non-endometriosis-associated ovarian cancer (non-EAOC). We also induced oxidative stress in the cultured cells from patients with primary endometriosis by adding H2O2 and tested for any alteration of ARID1A gene expression based on different H2O2 concentrations. The results showed that MnSOD activity in endometriosis and EAOC was lower than in non-EAOC, but MDA levels were higher. This study also showed that oxidative stress reduced ARID1A gene expression.
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PMID:ARID1A Expression is Down-Regulated by Oxidative Stress in Endometriosis and Endometriosis-Associated Ovarian Cancer. 2846 4