Radiosensitive effect of gold nanoparticles on lung cancer A549 cells / 中华放射医学与防护杂志

ABSTRACT

Objective To study the radiosensitization effect of thio-glucose capped gold nanoparticles (Glu-GNPs) on human lung adenocarcinoma A549 cells in vitro.Methods Human lung adenocarcinoma cell line A549 in logarithmic phase was divided into four groupscontrol group,drug group (Glu-GNPs),irradiation group (irradiation of 6 MV group and irradiation of 160 kV group),Glu-GNPs combined irradiation group (6 MV + Glu-GNPs group,160 kV + Glu-GNPs group).Transmission electron microscopy (TEM) was used to observe the distribution of Glu-GNPs in cells.Toxicity of Glu-GNPs on A549 cells and the inhibitory effect of Glu-GNPs combined with irradiation on cell proliferation were determined using crystal violet assay.Clonogenic assay were performed to evaluate radiosensitization of Glu-GNPs on A549 cells.Immunofluorescence assay of γ-H2AX,a biomarker of DNA damage that underlies cellular response to irradiation was used to evaluate radiation-induced DNA double-strand break (DSB).Results TEM images showed that Glu-GNPs were mainly distributed in the cytoplasm of A549 cells,including endosomes and mitochondria.Glu-GNPs had little cytotoxicity toward A549 cells with a concentration lower than 100 nmol/L.Different concentrations (0-100 nmol/L)of Glu-GNPs combined with different energy of X-rays had significant inhibitory effects on A549 cells.Under 160 kV and 6 MV X-ray conditions,the Glu-GNPs treatment further decreased the survival fraction of irradiation group (P ＜ 0.05),and the sensitizing enhancement ratio (SER) was 1.41 and 1.15,respectively.Moreover,Glu-GNPs significantly increased radiation-induced γ-H2AX foci in A549 cells,and the number of γ-H2AX foci with 160 kV X-ray radiation was higher than that with 6 MV X-ray radiation (t =12.392,14.893,18.947,P ＜ 0.05).Conclusions Uptake of Glu-GNPs by A549 cells could enhance radiation effects,especially for kilovolt X-ray radiation.