^(60)Co γ射线对肝癌细胞株HepG_2增殖和细胞周期的影响

Cell cycle alteration and cell growth inhibition induced by ^(60)Co γ-irradiation in HepG_2 cell line

目的 观察6 0 Coγ射线对肝癌细胞株HepG2 增殖、凋亡和细胞周期的影响 ,并探讨γ射线对细胞周期改变与p2 7kip1 蛋白表达和分布之间的关系。方法 以不同剂量的γ射线照射培养的HepG2 细胞 ,观察细胞形态和生长曲线变化 ,同时应用流式细胞计数仪观察细胞周期和凋亡的改变 ,并应用免疫荧光方法观察p2 7kip1 蛋白的表达和分布改变。结果 6 0 Coγ射线照射细胞引起He pG2 细胞株剂量依赖性的生长抑制和凋亡增加。6 0 Coγ射线可引起细胞G2 M期阻滞 ,同时p2 7kip1 表达明显抑制 ,并主要分布于细胞浆。结论 6 0 Coγ射线所导致的肝癌细胞株HepG2 细胞的G2 M阻滞可能与细胞内p2 7kip1 的表达抑制和细胞浆的分布比例增加有关。

Objective To study the cell cycle alterations in cells of human liver cancer cell line HepG_2 in vitro after 60 Co γ-irradiation, in order to investigate further the role of p27 kip1 protein on cell cycle and proliferation. Methods The effect on proliferation of HepG_2 cell line by irradiation with 1.0-6.0 Gy γ-rays was evaluated with MTT assay. The cell cycle profile and apoptosis were analyzed by FACS,and the expression and subcellular localization of p27 kip1 in the cells were detected by laser confocal microscopy. Results 60 Co γ-irradiation inhibited the growth of HepG_2 cell line in a dose-dependent manner. The HepG_2 cell line cells were arrested in G_2/M 48 hours after 3.0 Gy γ-ray exposure. The expression of p27 kip1 was down-regulated as compared to HepG_2 cell line cells without γ- radiation exposure,Furthermore the p27 kip1 was redistributed to cytoplasm after γ-irradiation. Conclusion The low expression and cytoplasmic localization of p27 kip1 might be due to the G_2/M phase arrest induced by gamma- irradiation of HepG_2 cell line cells.