Effect of Astragalus Polysaccharide on Radiosensitivity and Epithelial-mesenchymal Transition of Human Nasopharyngeal Carcinoma CNE-1 Cells / 中国实验方剂学杂志

ABSTRACT

Objective:Astragalus polysaccharide (APS) was used in combination with ionizing radiation (IR) to investigate the mechanism of APS on the radiosensitivity of human nasopharyngeal narcinoma CNE-1 cells and the epithelial-mesenchymal transition (EMT). Method:Cell counting kit-8 (CCK-8) was used to detect the cytotoxicity of different concentrations of APS (0，6.25，12.5，25，50，100，200 g·L-1) on CNE-1 cells. Colony formation assay was used to calculate the survival fraction (survival fraction, SF) of CNE-1 cells treated with 12.5 g·L-1 APS combined with different radiation doses (0，2，4，6 Gy). The linear quadratic equation mathematical model (LQ) was used to draw the radiosensitivity curve according to SF value. Cell scratch and transwell chamber test were used to detect the migration and invasion ability of cells in each group. The apoptosis of cells in each group was detected by flow cytometry, Western blot was used to detect the expressions of EMT markers, apoptosis markers and protein kinase B/extracellular regulated protein kinases (Akt/ERK) pathway proteins in each group. Result:The results of colony formation assay and radiosensitivity curve showed that the combination of non-toxic dose of 12.5 g·L-1 APS and radiation dose of 4 Gy could significantly increase the radiosensitivity of CNE-1 cells. Compared with blank group and IR group, APS combined with IR could significantly inhibit the migration and invasion of CNE-1 cells (P<0.05), and increase the rate of apoptosis (P<0.05). In addition, compared with the blank group and the IR group, APS combined with IR could significantly down-regulate the expressions of N-cadherin, p-Akt and p-ERK, and significantly up-regulate the expressions of E-cadherin, Bax and Caspase-3 (P<0.05). Conclusion:APS combined with IR can inhibit the migration and invasion of CNE-1 cells, and increase the apoptosis induced by radiotherapy, which may be related to the inhibition of EMT and Akt/ERK pathway.