2型转谷氨酰胺酶对人胶质母细胞瘤细胞U251放射敏感性的影响  

Effects of transglutaminase 2 on radiosensitivity of humanglioblastoma cell line U251

作　　者：蓝瑞隆[1] 伍兵 王锃[1] LAN Ruilong;WU Bing;WANG Zeng(Central Lab of The First Affiliated Hospital of Fujian Medical University,Key Laboratory of Radiation Biology of Fujian Province,Fujian Provincial Key Laboratory of Precision Medicine for Cancer Universities,National Regional Medical Center,Binhai Campus of the First Affiliated Hospital,Fujian Medical University,Fuzhou 350005)

机构地区：[1]福建医科大学附属第一医院中心实验室,放射生物福建省高等学校重点实验室,福建省肿瘤精准诊疗重点实验室,福建医科大学附属第一医院滨海院区国家区域医疗中心,福州350005

出　　处：《辐射防护》2024年第5期537-545,共9页Radiation Protection

基　　金：福建省自然科学基金项目(2022J01676);福建省科技创新联合资金项目(2021Y9110);福建省卫生健康中青年骨干人才培养项目(2021GGA027)。

摘　　要：为探讨2型转谷氨酰胺酶(transglutaminase 2,TG2)对胶质母细胞瘤(glioblastoma,GBM)放射敏感性的影响。通过生信分析TG2表达与胶质瘤病人预后的关系,并分析了其在GBM放射抵抗细胞株U251中的水平;瞬时转染得到TG2过表达细胞(U251-TG2)或空载细胞(U251-EV);CCK8法绘制生长曲线;transwell检测细胞迁移能力;不同剂量X射线照射后,检测细胞克隆形成能力、ROS水平;并通过免疫荧光检测γ-H2AX水平;Western blot检测自噬关键分子Beclin-1、LC3及mTOR磷酸化水平。结果显示,TG2高表达胶质瘤患者具有更差的无进展间隔期及总生存期,TG2在放射抵抗型U251中的表达显著高于野生型U251;U251-TG2细胞增殖能力高于U251-EV,且前者迁移能力高于后者;经X射线照射后,U251-TG2细胞克隆形成率高于U251-EV,前者ROS水平及γ-H2AX荧光焦点数均低于后者;自噬关键蛋白Beclin-1及自噬活性指标LC3-Ⅱ/Ⅰ比值在U251-TG2的水平均高于U251-EV,且前者mTOR磷酸化水平低于后者。实验结果证明,X射线照射后,TG2可能通过抑制mTOR磷酸化的方式促进自噬,进而降低GBM细胞U251的放射敏感性。To investigate the effect of transglutaminase 2(TG2)on radiosensitivity of glioblastoma,bioinformatic analysis was adopted to analyze the relationship between TG2 expression and the prognosis of glioma patients and TG2 level in GBM radioresistant cell line U251;TG2-overexpression cells(U251-TG2)or control cells(U251-EV)were obtained by transient transfection;cell growth curve was drawn by CCK8 method,and cell migration ability was measured by transwell;colony formation ability,ROS level andγ-H2AX foci were measured after X-ray treatment;Beclin-1,LC3 and mTOR phosphorylation levels were detected by Western blot.The results showed that glioma patients with high TG2 expression had worse progression-free interval and overall survival,and TG2 expression in radioresistant U251 was significantly higher than that in wild type U251;the cell proliferation and migration ability of U251-TG2 were higher than that of U251-EV;after X-ray treatment,compared with U251-EV,U251-TG2 showed higher colony-forming ratio,lower ROS level andγ-H2AX foci number;the levels of Beclin-1 and LC3-II/I in U251-TG2 were higher than those in U251-EV;mTOR phosphorylation level in U251-TG2 was lower than that in U251-EV.The results indicated that TG2 could promote autophagy by inhibiting mTOR phosphorylation,and then decrease the radiosensitivity of U251 cells.

关 键 词：胶质母细胞瘤 2型转谷氨酰胺酶 放射敏感性 

分 类 号：Q274[生物学—细胞生物学]