GS抑制剂调节自噬影响肝癌细胞放疗敏感性

Glutamine synthetase regulates autophagy toimprove radiotherapy sensitivity in hepatocellular carcinoma cells

为探究人类肝细胞癌细胞的放疗敏感性与谷氨酰胺合成酶(GS)和自噬之间的关系。HepG2细胞经X射线照射后,采用CCK-8、克隆集落形成实验来测量细胞经GS抑制剂(L-蛋氨酸亚磺酰亚胺,MSO)作用后的增殖能力。实时荧光定量PCR以及蛋白免疫印迹实验(Western Blot,WB)用于检测MSO对GS表达的影响,GS活力检测试剂盒用于检测MSO对GS的活力抑制效率。单丹磺酰尸胺(MDC)染色以及WB实验技术用于检测细胞内的自噬情况,以确定IR及MSO对自噬的影响。结果表明,MSO引起细胞内GS表达增加,但是GS的活力被其显著抑制。此外,MSO可以降低放疗后细胞的增殖能力,并且抑制放疗诱导的自噬。结果表明MSO可通过抑制GS活力提高HepG2细胞的放疗敏感性,这与其对自噬流的调节密切相关。

The aim of this study was to investigate the relationship among radiotherapy sensitivity,glutamine synthetase(GS)and autophagy in human hepatocellular carcinoma cells.After X-ray irradiation,CCK-8 and colony formation assay were used to measure the proliferation of HepG2 cells treated with GS inhibitor(L-methionine sulfonimide,MSO).Real-time fluorescence quantitative PCR and protein immunoblotting assays(Western Blot,WB)were used to detect the effect of MSO on GS expression,and GS activity assay kits were used to detect the efficiency of inhibition of GS activity by MSO.Monodansulfonyl cadaverine(MDC)staining as well as WB assay techniques were used to detect intracellular autophagy to determine the effect of IR and MSO on autophagy.The results indicated that MSO caused an increase in intracellular GS expression,but GS activity was significantly inhibited.In addition,MSO reduced the proliferative capacity of cells after radiotherapy and inhibited radiotherapy-induced autophagy.Results suggested that MSO could enhance the sensitivity of HepG2 cells to radiotherapy by inhibiting GS activity,which was closely related to its regulation of autophagic flow.