V-Ha-Ras overexpression induces superoxide production and alters levels of primary antioxidant enzymes

• Published in: Antioxidants & redox signaling Vol. 3; no. 4; p. 697
• Main Authors: Yang, J Q, Li, S, Huang, Y, Zhang, H J, Domann, F E, Buettner, G R, Oberley, L W
• Format: Journal Article
• Language: English
• Published: United States 01.08.2001
• Subjects: Animals; Antioxidants - metabolism; Catalase - metabolism; Cell Division; Cell Line, Transformed - metabolism; Cell Transformation, Neoplastic - genetics; DNA - metabolism; DNA-Binding Proteins - metabolism; Electrophoretic Mobility Shift Assay; Epithelial Cells - metabolism; Glutathione Peroxidase - metabolism; Kidney - cytology; MAP Kinase Signaling System; Mitogen-Activated Protein Kinases - metabolism; NF-kappa B - metabolism; Oncogene Protein p21(ras) - biosynthesis; Oncogene Protein p21(ras) - genetics; Oncogene Protein p21(ras) - physiology; Oxidation-Reduction; Phosphorylation; Protein Processing, Post-Translational; Rats; Recombinant Fusion Proteins - biosynthesis; Recombinant Fusion Proteins - physiology; Superoxide Dismutase - metabolism; Superoxides - metabolism; Transcription Factor AP-1 - metabolism; Transcription Factor AP-2; Transcription Factors - metabolism; Transcription, Genetic - drug effects; Transfection
• ISSN: 1523-0864
• DOI: 10.1089/15230860152543032

Reactive oxygen species have been shown to play important roles in v-Ha-Ras mitogenic signaling. We hypothesized that v-Ha-Ras overexpression would induce superoxide production, and therefore modify expression of the primary antioxidant enzyme system. We have demonstrated that immortal rat kidney epithelial cells stably transduced with constitutively active v-Ha-ras produced significantly larger amounts of superoxide radical than wild-type or vector-transfected control cells. The levels of the primary antioxidant enzymes copper- and zinc-containing superoxide dismutase, manganese-containing superoxide dismutase, catalase, and glutathione peroxidase were increased in the superoxide-overproducing cells. DNA-binding activities of the transcription factors activator protein-1, activator protein-2, and nuclear factor-kappaB were all enhanced in the superoxide-overproducing cells. These v-Ha-ras transduced cells also had a shortened cell doubling time and higher plating efficiency, and displayed greater constitutive levels of phosphorylated mitogen-activated protein kinases. These data demonstrate that v-Ha-Ras overexpression increases superoxide production and this apparently affects a wide variety of cell signaling and redox systems.