Effect Of PTEN Gene Knock-Out On Reactive Oxygen Species And Radiosensitivity

Objective: PTEN tumor suppressor gene is lack or mutant in many tumors. PTEN negatively controls the PI3K/AKT pathway involved in the regulation of cell proliferation, apoptosis, differentiation and migration. Usually, there are high levels of reactive oxygen species which is related with PTEN in many tumors. The study aims to discuss the effect of PTEN gene knock-out on reactive oxygen species and radiosensitivity to offer original clue for tumor treatment.Methods: The levels of reactive oxygen species was assessed by flow cytometry. The expression of Peroxiredoxins was detected by Western blot. The AKT activity pretreated with diphenyleneiodonium chloride or hydrogen peroxide was detected by Western blot.The radiosensitivity toγ-ray was analyzed by cell cloning efficiency test.Results: The levels of reactive oxygen species of PTEN gene knock-out cells were significantly elevated. The PeroxiredoxinⅠ,Ⅱ,Ⅴ,Ⅵexpression of PTEN gene knock-out cells were down-regulated, PeroxiredoxinⅣexpression up-regulated and PeroxiredoxinⅢexpression no change obviously. Pretreatment with diphenyleneiodonium chloride or hydrogen peroxide influenced the AKT activity of control cell but not PTEN gene knock-out cell. PTEN gene knock-out decreased radiosensitivity.Conclusion: PTEN gene knock-out down-regulate Peroxiredoxins expression and elevate levels of reactive oxygen species. PTEN gene knock-out may block PI3K/AKT signal transduction pathway mediated by reactive oxygen species and make AKT active constitutively which may be the main reason of radiosensitivity down.