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Induction and Analysis of Oxidative Stress in Sleeping Beauty Transposon-Transfected Human Retinal Pigment Epithelial Cells
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Induction and Analysis of Oxidative Stress in Sleeping Beauty Transposon-Transfected Human Retinal Pigment Epithelial Cells

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Possible protective effects of alpha-tocopherol on enhanced induction of reactive oxygen species by

Oliver Thews, Christine Lambert, Debra K Kelleher

    Advances in Experimental Medicine and Biology
    |April 6, 2006
    PubMed

    Insights

    Inhibiting superoxide dismutase (SOD) with 2-methoxyestradiol enhances oxidative stress and improves tumor control during hyperthermia treatment. Alpha-tocopherol (vitamin E) did not show significant effects on tumor control in this study.

    Area of Science:

    • Oncology
    • Biochemistry
    • Cell Biology

    Background:

    • Non-surgical cancer treatments often rely on generating reactive oxygen species (ROS) to kill tumor cells.
    • Antioxidative enzymes like superoxide dismutase (SOD) and external antioxidants can potentially reduce the effectiveness of these ROS-generating therapies.

    Purpose of the Study:

    • To investigate how inhibiting SOD with 2-methoxyestradiol (2-ME) or administering alpha-tocopherol affects hyperthermia (HT)-induced cellular damage and tumor control.
    • To determine the impact of modulating oxidative stress on the efficacy of ROS-generating hyperthermia in experimental tumors.

    Main Methods:

    • DS-sarcoma cells were studied in vitro and in vivo (subcutaneous tumors in rats).
    • In vitro: Cells were treated with 2-ME to assess proliferation, ROS formation, lipid peroxidation, and apoptosis.
    • In vivo: Tumors were treated with ROS-generating HT, with or without 2-ME or alpha-tocopherol.

    Main Results:

    • Inhibition of SOD by 2-ME in vitro led to significant oxidative injury and reduced cell proliferation.
    • ROS-generating HT achieved local tumor control in 23% of rats.
    • Combining HT with 2-ME significantly increased tumor control rates by approximately 50% compared to HT alone.
    • Alpha-tocopherol administration had no discernible impact on local tumor control, even when combined with HT and/or 2-ME.

    Conclusions:

    • Inhibiting SOD during ROS-generating hyperthermia enhances cellular damage and improves local tumor control.
    • Exogenous alpha-tocopherol (vitamin E) does not appear to mitigate oxidative stress or improve tumor control in this experimental model.
    • Targeting antioxidant defense mechanisms presents a potential strategy to augment the efficacy of oxidative stress-based cancer therapies.

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