title: Radioresistant Sf9 insect cells display efficient antioxidant defence against high dose γ-radiation.
abstract: OBJECTIVE
  To investigate the effect of gamma radiation-induced alterations in antioxidant defence of radioresistant Sf9 insect cells.
  
  
  METHODS
  Sf9 cells were irradiated at doses ranging from 0.5-200 Gy. Lipid peroxidation and protein carbonylation levels were observed at 4 h post-exposure along with reduced glutathione/oxidized glutathione (GSH/GSSG) profile as well as specific activities of redox active enzymes superoxide dismutase (SOD), catalase, ascorbate peroxidase (APOx), and glutathione reductase (GR). Human brain malignant glioma (BMG-1) cells were used for comparing radiation response of mammalian cells.
  
  
  RESULTS
  Sf9 cells displayed significantly less radiation-induced reactive oxygen/nitrogen species (ROS/RNS) generation, protein carbonylation and growth inhibition as compared to mammalian cells. Sf9 cells have higher basal APOx (∼4-fold), catalase (∼1.7-fold), SOD (∼1.3-fold) activity and GSH level (∼2.2-fold) compared to mammalian cells. A radiation dose-dependent increase in SOD, Catalase and APOx activity was found in Sf9 cells at least up to 100 Gy dose, while maximum activity in mammalian cells was achieved by 10 Gy.
  
  
  CONCLUSIONS
  The present study suggests that Lepidopteran insect cells carry a stronger antioxidant system that protects against radiation-induced macromolecular damage, growth inhibition and cell death.
authors.affiliation: a Natural Radiation Response Mechanisms Group, Division of Radiation Biosciences, Institute of Nuclear Medicine and Allied Sciences , Delhi , India.|b Department of Zoology , University of Delhi , Delhi , India.
authors.forename: Shubhankar
authors.initials: S
authors.lastname: Suman
authors.affiliation: b Department of Zoology , University of Delhi , Delhi , India.
authors.forename: Zubeda
authors.initials: Z
authors.lastname: Khan
authors.affiliation: b Department of Zoology , University of Delhi , Delhi , India.
authors.forename: Mahtab
authors.initials: M
authors.lastname: Zarin
authors.affiliation: a Natural Radiation Response Mechanisms Group, Division of Radiation Biosciences, Institute of Nuclear Medicine and Allied Sciences , Delhi , India.
authors.forename: Sudhir
authors.initials: S
authors.lastname: Chandna
authors.affiliation: b Department of Zoology , University of Delhi , Delhi , India.
authors.forename: Rakesh Kumar
authors.initials: RK
authors.lastname: Seth
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D002460:Cell Line; D049109:Cell Proliferation / Q000528:radiation effects; D005720:Gamma Rays / Q000009:adverse effects*; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D015227:Lipid Peroxidation / Q000528:radiation effects; D018384:Oxidative Stress / Q000528:radiation effects; D050050:Protein Carbonylation / Q000528:radiation effects; D011836:Radiation Tolerance / Q000502:physiology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D061987:Sf9 Cells; D013045:Species Specificity; D018411:Spodoptera / Q000378:metabolism* / Q000528:radiation effects*
chemical_list: D000975:Antioxidants; D017382:Reactive Oxygen Species; D005978:Glutathione
keywords: Radioresistance; Sf9 cells; Spodoptera frugiperda; antioxidant enzymes; lepidoptera; oxidative stress