Department of Molecular Medicine, Institute of Medical Biotechnology, National Institute of Genetic Engineering and Biotechnology, P.O. Box: 14965/161, Tehran, Iran; Department of Genetics, Faculty of Advanced Science and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran.
Cancer Biology Research Center, Cancer Institute, Tehran University of Medical Sciences, Tehran, Iran.
Life Sci. 2020 May 1;248:117466. doi: 10.1016/j.lfs.2020.117466. Epub 2020 Feb 24.
Nanoparticles (NPs)-based drugs have been recently introduced to improve the efficacy of current therapeutic strategies for the treatment of cancer; however, the molecular mechanisms by which a NP interacts with cellular systems still need to be delineated. Here, we utilize the autophagic potential of TiO NPs for improving chemotherapeutic effects of 5-fluorouracil (5-FU) in human AGS gastric cells.
Cell growth and viability were determined by trypan blue exclusion test and MTT assay, respectively. Vesicular organelles formation was evaluated by acridine orange staining of cells. Cell cycle and apoptosis were monitored by flow cytometry. Reactive oxygen species (ROS) level were measured by DCHF-DA staining. Autophagy was examined by q-PCR and western blotting. Molecular docking was used for studying NP interaction with autophagic proteins.
TiO NPs increase ROS production, impair lysosomal function and subsequently block autophagy flux in AGS cells. In addition, the autophagy blockade induced by non-toxic concentrations of TiO NPs (1 μg/ml) can promote cytotoxic and apoptotic effects of 5-FU in AGS cells.
These results confirm the beneficial effects of TiO NPs in combination with chemotherapy in in vitro model of gastric cancer, which may pave the way to develop a possible solution to circumvent chemoresistance in cancer.
纳米粒子（NPs）药物最近被引入以提高当前癌症治疗策略的疗效；然而，NP 与细胞系统相互作用的分子机制仍需阐明。在这里，我们利用 TiO2 NPs 的自噬潜力来提高氟尿嘧啶（5-FU）在人 AGS 胃细胞中的化疗效果。
通过台盼蓝排斥试验和 MTT 测定分别确定细胞生长和活力。通过吖啶橙染色评估囊泡细胞器的形成。通过流式细胞术监测细胞周期和细胞凋亡。通过 DCHF-DA 染色测量活性氧（ROS）水平。通过 q-PCR 和 Western blot 检查自噬。分子对接用于研究 NP 与自噬蛋白的相互作用。
TiO2 NPs 增加 ROS 产生，损害溶酶体功能，随后阻断 AGS 细胞中的自噬流。此外，非毒性浓度的 TiO2 NPs（1μg/ml）诱导的自噬阻断可促进 5-FU 在 AGS 细胞中的细胞毒性和细胞凋亡作用。
这些结果证实了 TiO2 NPs 与化疗联合在胃癌体外模型中的有益作用，这可能为开发克服癌症化疗耐药性的可能解决方案铺平道路。
