纳米颗粒对人肝癌HepG2细胞放射增敏效应的实验研究

目的 探讨纳米金、银颗粒对人肝癌HepG₂细胞的放射增敏作用及其机制。方法 选用MTT法、克隆形成法检测纳米金、银颗粒增强X射线杀伤肿瘤细胞的作用,流式细胞仪检测对细胞凋亡及细胞周期分布影响,蛋白印记法检测对细胞Caspase-3、Bax、Bcl-2蛋白表达变化,酶标仪检测对细胞过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、总谷胱甘肽(GSH)水平改变。结果 纳米金、银颗粒对HepG₂细胞的生长抑制作用 IC₅₀分别为6.51、2.47 μg/ml。由 D₀值得到 1/5 IC₅₀纳米金、银颗粒放射增敏比分别为1.37、1.48,1/10 IC₅₀的分别为1.11、1.09。纳米金、银颗粒增加Caspase-3、Bax表达,降低Bcl-2表达,减少CAT、SOD、总GSH水平。结论 纳米金、银颗粒均能增加HepG₂细胞的放射敏感性,其机制可能为激活线粒体凋亡通路和诱导活性氧产生凋亡。

The radiosensitizing effect of nano-gold and nano-silver particles in HepG2 hepatocellular carcinoma cell

Objective To study the radiosensitizing effect of nano-gold nano-silver particles in hepatocellular carcinoma cells (HepG₂) in vitro and the possible mechanisms. Methods MTT assay and clonogenic assay were performed to determine the killing effect of nano-gold and nano-silver particles in HepG₂ cells. Flow-cytometry was used to measure cell apoptosis and cell cycle distribution. Western blotting was used to measure the expression of Caspase-3, Bax and Bcl-2. ELIASA was used to determine the content of catalase (CAT), superoxide dismutase (SOD), and total glutathione (GSH). Results Nano-gold and nano-silver particles inhibited the proliferation of HepG₂ cells with IC₅₀ of 6.51 μg/ml and 2.47 μg/ml, respectively. Nano-gold and nano-silver particles significantly enhanced the radiosensitivity of HepG₂ cells. Obtained by D_q, the SER of 1/5 IC₅₀ nano-gold and nano-silver particles were 1.37 and 1.48, and 1/10 IC₅₀ with 1.11 and 1.09. Nano-gold and nano-silver particles increased the expression of Caspase-3and Bax and reduced the expression of Bcl-2. CAT,SOD and total GSH were significantly reduced. ConclusionsNano-gold and nano-silver particles can enhance the radiation sensitivity of HepG₂ cells. Specific sensitizing mechanism may be the activation of the mitochondrial apoptosis pathway and the induction of reactive oxygen species in apoptotic pathways, which ultimately induces apoptosis.