Saberi Alihossein, Shahbazi-Gahrouei Daryoush, Abbasian Mahdi, Fesharaki Mehrafarin, Baharlouei Azam, Arab-Bafrani Zahra
a Department of Medical Genetics, Faculty of Medicine , Ahvaz Jundishapur University of Medical Sciences , Ahvaz , Iran.
b Department of Medical Physics , School of Medicine, Isfahan University of Medical Sciences , Isfahan , Iran.
Int J Radiat Biol. 2017 Mar;93(3):315-323. doi: 10.1080/09553002.2017.1242816. Epub 2016 Nov 2.
Gold nanoparticles (GNP) act as a radiosensitizer in radiation therapy. However, recent studies have shown contradictory evidence in terms of radiosensitization in the presence of GNP combined with X-ray megavoltage energy (MV) on different cell types. In this study, the effect of GNP on radiosensitization enhancement of HT-29 human colorectal cancer cells at MV X-ray energy was evaluated.
The cytotoxicity and radiosensitization of GNP were evaluated in HT-29 human colorectal cancer cells by MTS-assay and multiple MTS-assay, respectively. Cellular uptake was assayed using graphite furnace atomic absorption spectrometry (GFAAS). Apoptosis and cell cycle progression were determined by an Annexin V-FITC/propidium iodide (PI) kit and PI/RNase solution with flow cytometry, respectively.
Results showed that the cell viability of the HT-29 cells was not influenced by exposure to different concentrations of GNP (10-100 μM). GNP alone did not affect the cell cycle progression and apoptosis. In contrast, GNP, in combination with radiation (9 MV), induced more apoptosis. The interaction of GNP with MV energy resulted in a significant radiosensitization enhancement compared with irradiation alone.
It was concluded that GNP may work as bio-inert material on HT-29 cancer cells and their enhancement of radiosensitization may be due to increase in the absorbed irradiation dose.
金纳米颗粒（GNP）在放射治疗中作为一种放射增敏剂。然而，最近的研究表明，在不同细胞类型中，当GNP与兆伏级X射线能量（MV）联合存在时，关于放射增敏作用存在相互矛盾的证据。在本研究中，评估了GNP对HT-29人结肠癌细胞在MV X射线能量下放射增敏增强的影响。
分别通过MTS法和多重MTS法评估GNP在HT-29人结肠癌细胞中的细胞毒性和放射增敏作用。使用石墨炉原子吸收光谱法（GFAAS）检测细胞摄取情况。分别通过Annexin V-FITC/碘化丙啶（PI）试剂盒和PI/RNase溶液结合流式细胞术测定细胞凋亡和细胞周期进程。
结果显示，HT-29细胞的细胞活力不受暴露于不同浓度GNP（10 - 100 μM）的影响。单独的GNP不影响细胞周期进程和细胞凋亡。相反，GNP与辐射（9 MV）联合可诱导更多细胞凋亡。与单独照射相比，GNP与MV能量的相互作用导致显著的放射增敏增强。
得出的结论是，GNP对HT-29癌细胞可能起到生物惰性材料的作用，其放射增敏增强可能归因于吸收辐射剂量的增加。
