红景天苷调节Nrf2/ROS通路增强U-251MG的放射敏感性

Salidroside enhances radiosensitivity of U-251MG by regulating Nrf2/ROS pathway

目的:探究红景天苷(SD)对人星形胶质瘤细胞U-251MG放疗敏感性的影响及相关的分子机制。方法:将U-251MG细胞随机分成4组:对照组、红景天苷单独处理组(SD)、放疗组和放射+SD组。SD组和放射+SD组加50 nmol/L红景天苷处理,放疗组和放射+SD组给予10 Gy、6 MV X射线照射。细胞增殖试剂盒(CCK8)检测0、1、2、3、4 d细胞增殖。流式细胞术检测细胞凋亡情况。蛋白质印迹检测B淋巴细胞瘤2蛋白(Bcl-2)、Bcl-2相关X蛋白(Bax)、核因子E2相关因子(Nrf2)、血红素加氧酶(HO-1)和还原型辅酶/醌氧化还原酶(NQO-1)的表达。氧化应激相关试剂盒检测活性氧(ROS)和丙二醛(MDA)的含量、超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(Gpx)的活性。脑立体定向注射U-251MG建立原位移植瘤裸鼠模型,接种1周后,将20只雄性裸鼠随机分成4组,每组5只。SD组和放射+SD组裸鼠腹腔注射50 nmol/kg的红景天苷,放疗组和放射+SD组裸鼠给予X射线照射。28 d后检测肿瘤重量,免疫组化检测Ki67和PCNA的表达。结果:与对照组相比,SD组和放疗组细胞增殖速率显著降低;凋亡细胞数目明显增加;Bcl-2表达显著下调,Bax的表达显著上调;ROS和MDA的含量显著升高,SOD和Gpx的活性显著降低;Nrf2和NQO-1的表达变化无显著差异,HO-1的表达显著下调;SD组和放疗组体内实验中肿瘤重量显著降低,Ki67和PCNA的表达显著下调。放射+SD组与SD组和放疗组相比,细胞增殖速率显著降低;凋亡细胞数目明显增加;Bcl-2表达显著下调,Bax的表达显著上调;ROS和MDA的含量显著上升,SOD和Gpx的活性显著降低;Nrf2、HO-1和NQO-1的表达显著下调;放射+SD组体内实验中肿瘤重量显著降低,Ki67和PCNA的表达显著下调。结论:红景天苷可能通过调节Nrf2/ROS通路,增强人星形胶质瘤U-251MG的放射敏感性。

Objective:To explore the effect of salidroside(SD)on the radiosensitivity of U-251 MG and its related mechanisms.Methods:Human astroglioma U-251 MG cells line were randomly divided into 4 groups:the control group,the salidroside solo treatment group(SD),the radiotherapy group and the radiation+SD group.SD group and radiation+SD group were treated with50 nmol/L salidroside,while radiotherapy group and radiation+SD group were given 10 Gy,6 MV X-Ray radiation.CCK8 detected cell proliferation in 0,1,2,3 and 4 days.Cell apoptosis was detected by flow cytometry.The expression of Bcl-2,Bax,Nrf2,HO-1 and NQO-1 was detected by Western blot.The content of ROS and MDA,as well as the activity of SOD and Gpx were detected by relative kits.Nude mouse models of orthotopic transplanted tumor were established by stereotactic injection of U-251 MG.After one week inoculation,20 male nude mice were randomly divided into 4 groups,5 cases in each group.In SD group and radiation+SD group,50 nmol/kg salidroside was injected intraperitoneally,X-ray radiation was given to nude mice in radiotherapy group and radiation.SD group.The weight of tumor was detected after 28 days,and the expression of Ki67 and PCNA was detected by immunohistochemistry.Results:Compared with control group,SD group and radiotherapy group cell proliferation rate decreased significantly decreased,the number of apoptotic cells increased significantly,the expression of Bcl-2 decreased significantly,the expression of Bax was significantly up-regulated,the content of ROS and MDA increased significantly,the activity of SOD and Gpx decreased significantly,the expression level of Nrf2 and NQO-1 was not significantly different,and the expression of HO-1 was significantly down-regulated.In mouse models,the tumor weight reduced and the expression of Ki67 and PCNA decreased significantly.Compared with SD group and radiotheray group,Radiation+SD group cell proliferation rate significantly reduced,the number of apoptotic cells increased significantly,the expression of Bcl-2 was significantly down-regulated,the expression of BAX was significantly up-regulated,the content of ROS and MDA increased significantly,the activity of SOD and Gpx decreased significantly,and the expression of Nrf2,HO-1 and NQO1 significantly decreased.In mouse models,the weight of the tumor significantly reduced,and the expression of Ki67 and PCNA was significantly reduced.Conclusion:Salidroside enhances the radiosensitivity of human astrocytoma U-251 MG by regulating the Nrf2/ROS pathway.