Transfection of p27~(kip1) enhances radiosensitivity induced by ~(60)Co γ-irradiation in hepatocellular carcinoma HepG_2 cell line

摘要

AIM: To study the cell cycle alterations of human hepatoma cell line HepG_2 in vitro after ~(60)Co γ-irradiation and further to examine the mechanisms underlying the enhancement of radiosensitivity to γ-irradiation in HepG_2 transiently transfected with wild type p27~(kip1). METHODS: The proliferation of HepG_2 cells was evaluated with MTT assay, and the cell cycle profile and apoptosis were assessed by cell morphology, DNA fragmentation analysis and flow cytometry. HepG_2 cells were transfected with p27~(kip1) wild type by using Lipofectamine (LF2000), and the expression and subcellular localization of p27~(kip1) in HepG_2 were detected by immunocytochemistry. RESULTS: ~(60)Co γ-irradiation inhibited the growth of HepG_2 cells in a dose-dependent manner. Apoptosis of HepG_2 cells was induced 48 h after γ ray exposure. Furthermore research was carried out to induce exogenous expression of p27~(kip1) in HepG_2. The expression of p27~(kip1) induced G_0/G_1 phase arrest in HepG_2cells. The overexpression of p27~(kip1) enhanced ~(60)Co γ-irradiation-induced radiosensitivity in HepG_2 cells. CONCLUSION: Overexpression of p27~(kip1) is a rational approach to improve conventional radiotherapy outcomes, which may be a possible strategy for human hepatoma therapy.