Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Although the selective tyrosine kinase inhibitor imatinib is successfully used in the treatment of chronic myeloid leukemia (CML), inherent mechanisms confer primary resistance to leukemic patients. In order to search for potentially useful genes in predicting cytogenetic response, a retrospective gene expression study was performed. Leukocyte RNA isolated before imatinib from interferon-alpha-pretreated chronic phase CML patients (n=34) with or without major cytogenetic remission (< or =35% Philadelphia (Ph)+ metaphases) during the first year of treatment was comparatively analyzed using Affymetrix U133A chips. Using support vector machines for gene classification, an outcome-specific gene expression signature consisting of 128 genes was identified. Comparative expression data of specific genes point to changes in apoptosis (e.g. casp9, tumor necrosis factor receptor-associated protein 1, hras), DNA repair (msh3, ddb2), oxidative stress protection (glutathione synthetase, paraoxonase 2, vanin 1) and centrosomes (inhibitor of differentiation-1) within primary resistant patients. Independent statistical approaches and quantitative real-time reverse transcriptase-polymerase chain reaction studies support the clinical relevance of gene profiling. In conclusion, this study establishes a candidate predictor of imatinib resistance in interferon-alpha-pretreated CML patients to be subjected to future investigation in a larger independent patient cohort. The resulting expression signature point to involvement of BCR-ABL-independent mechanisms of resistance.
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PMID:Gene expression signature of primary imatinib-resistant chronic myeloid leukemia patients. 1672 81

Retinoids play important roles in many diverse biological functions such as cell growth, morphogenesis, differentiation, and reproduction. Previous studies demonstrated that retinol administration to ewes, followed by natural service, resulted in embryos with improved competence to develop under standard in vitro conditions (5% CO(2) in air). Additional studies provided evidence that retinol may have some antioxidant effect by improving blastocyst development in cattle under atmospheric conditions (5% CO(2) in air). Glutathione is an important non-protein, sulphydryl compound found in oocytes and embryos, which acts to decrease oxidative stress. The purpose of the present study was to evaluate the effects of retinol administration to ewes on the content of glutathione and glutathione-related and antioxidant enzymes in in vivo matured sheep oocytes. Briefly, ewes were administered retinol or vehicle during superovulation, and after 60h the oviducts were removed and mature oocytes collected. Glutathione content did not differ significantly between oocytes collected from retinol-treated ewes (6.78+/-3.81pmol/oocyte) and control ewes (6.38+/-1.58pmol/oocyte). Transcripts encoding for manganese superoxide dismutase (Mn-SOD), copper zinc superoxide dismutase (Cu-Zn SOD), glutathione synthetase (GS), and glutathione transferase pi (GSTp) were detected in single ovine oocytes; however, semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) analysis did not reveal any significant differences in transcripts between oocytes from retinol-treated ewes and those from control ewes.
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PMID:Glutathione content and antioxidant enzyme expression of in vivo matured sheep oocytes. 1927 97

T-2 toxin is one of the most potent trichothecenes, and on exposure causes severe human and animal diseases. We investigated the dose- and time-dependent effect of T-2 toxin on certain biochemical variables, oxidative damage in terms of antioxidant enzyme activity, and gene expression profile in mice. Mice treated intraperitoneally with either 1 LD50 or 2 LD50 dose (5.61 and 11.22 mg/kg body weight, respectively) of T-2 toxin showed significant alterations in hepatic alanine amino transferase, aspartate amino transferase, and lactate dehydrogenase. Significant changes in hepatic lipid peroxidation, depletion of glutathione (GSH), and expression of heat shock protein-70 indicated oxidative damage. We also evaluated the activity of antioxidant enzymes and compared the gene expression profile by quantitative real-time reverse transcriptase-polymerase chain reaction. Except for glutathione reductase (GR), there was a significant increase in activity of glutathione-S-transferase (GST), glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase at 1 LD50 dose. At 2 LD50 dose, SOD showed decrease in activity, whereas GST, GPx, and catalase showed significant increase. In contrast, gene expression profile showed downregulation in GR, GPx, GST, and catalase at 1 LD50 dose. At 2 LD50 dose except GSH synthetase, all other genes were downregulated. The results clearly show oxidative stress as one of the mechanisms of T-2 toxin-mediated toxicity.
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PMID:Oxidative damage and gene expression profile of antioxidant enzymes after T-2 toxin exposure in mice. 1952 62