Abstract:

Objective   To investigate radiosensitivity enhancement and its mechanism of thio-glucose bound gold nanoparticles (Glu-GNPs) on the lung adenocarcinoma cell line A549. Methods   MTT assay was used to determine the effect of Glu-GNPs in low concentrations(≤20nmol/L) combined with radiotherapy on the survival of A549 cells. The radiosensitivity enhancement effect of Glu-GNPs on A549 cells was measured by clonal formation. The cell cycle and apoptosis were assayed by the flow cytometric method(FCM). Results   Survival of A549 cells was not obviously restrained by Glu-GNPs in low concentrations. But it was inhibited by GluGNPs combined with X-ray, and the inhibition was enhanced with the increase of concentrations within 15nmol/L. According to Dq and Do, sensitization enhancement ratios(SER) of A549 cells were 1.93 and 1.10, respectively. Radiation and Glu-GNPs could both induce apoptosis, and their apoptosis rates were (13.46±1.99)% and (7.64±1.43)%，respectively, which were enhanced to (21.43±1.04)% by combined treatment(P<0.01). Glu-GNPs decreased A549 cells at the phase S and increased those at G2/M(P<0.05). Conclusion   GluGNPs could induce radiosensitivity enhancement on the lung adenocarcinoma cell line A549, and the mechanism may be related to restraining repair of sublethal damage, blocking cells at G2/M and inducing apoptosis.

Key words: Gold nanoparticles； A549 cells； Radiosensitivity； Apoptosis