title: Radioresistant Sf9 insect cells display moderate resistance against cumene hydroperoxide.
abstract: Lepidopteran insect cells serve as excellent model to study stress responses and are known to display resistance against DNA damaging agents including ionizing radiation; however, limited information is available on the effects of membrane damaging agents in these cells. In this study, we investigated the response of Sf9 cells (derived from ovaries of Spodoptera frugiperda; order Lepidoptera) to cumene hydroperoxide (CHPx), compared to human BMG-1 cells. CHPx treatment at doses lethal for human cells also caused typical necrosis in Sf9. Severe necrosis in human BMG-1 cells was observed at 125 μM, whereas similar effect in Sf9 cells was observed at 250 μM. In Sf9 cells, CHPx (250 μM) induced negligible changes in mitochondrial membrane potential and intracellular reactive oxygen species, while moderate effect was observed on intracellular calcium distribution. Reduced DNA damage and lipid (including cardiolipin) oxidation was observed in Sf9 cells that could be due to moderate total antioxidant status and constitutive/induced glutathione S-transferase activity. This study importantly demonstrates that Lepidopteran insect cells having extensive resistance towards DNA damaging agents show only moderately higher resistance to membrane damaging agents. A stronger reducing environment involving efficient antioxidant system seems to contribute significantly in this response.
authors.affiliation: Division of Radiation Biosciences, Institute of Nuclear Medicine & Allied Sciences (INMAS), Timarpur, Delhi, India.
authors.forename: Jyoti Swaroop
authors.initials: JS
authors.lastname: Kumar
authors.forename: Shubhankar
authors.initials: S
authors.lastname: Suman
authors.forename: Vijaypal
authors.initials: V
authors.lastname: Singh
authors.forename: Sudhir
authors.initials: S
authors.lastname: Chandna
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D001555:Benzene Derivatives / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D002460:Cell Line / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism / Q000528:radiation effects*; D002470:Cell Survival / Q000187:drug effects; D004249:DNA Damage; D004351:Drug Resistance; D059585:G1 Phase Cell Cycle Checkpoints / Q000187:drug effects; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D008928:Mitochondria / Q000187:drug effects; D016877:Oxidants / Q000494:pharmacology*; D018384:Oxidative Stress; D011836:Radiation Tolerance; D017382:Reactive Oxygen Species / Q000378:metabolism; D018411:Spodoptera; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
chemical_list: D000975:Antioxidants; D001555:Benzene Derivatives; D016877:Oxidants; D017382:Reactive Oxygen Species; D017392:Thiobarbituric Acid Reactive Substances; D005982:Glutathione Transferase; C007164:cumene hydroperoxide; D002118:Calcium