摘要
目的 研究射线照射对人胶质母细胞瘤(U87细胞系)侵袭性的促进和可能机制.方法 U87细胞接受不同剂量的射线照射(0、2、4 Gy),使用实时细胞分析系统检测细胞侵袭性改变,明胶酶谱法检测射线照射前后U87细胞的MMP2、MMP9活性改变,细胞免疫组化观察射线照射后U87细胞内β-catenin含量及分布变化,实时荧光定量PCR测定Wnt/β-catenin通路目标基因mRNA含量.结果 射线照射后U87细胞的侵袭性明显增加(P<0.01),在一定范围内与照射剂量相关.射线照射显著增强U87细胞的MMP2和MMP9活性(分别为P=0.031、0.004).照射后U87细胞内β-catenin含量增加(P<0.01),且从细胞膜和黏附连接向细胞核内转运移位.Wnt/β-catenin通路相关基因FZD7、TCF1的mRNA含量显著增加(P<0.01),且目标基因尤其是侵袭性相关基因如MMP2、MMP7、MMP9和CD44转录均有显著增加(P<0.05).结论 射线照射对U87细胞侵袭性有促进作用,Wnt/β-catenin通路激活和侵袭性相关基因表达的增加是其可能机制.
Objective To study the pro-invasive effect of irradiation on human glioblastoma cell line U87 and its possible mechanism.Methods Cultured U87 cells received different doses of irradiation (0,2,and 4 Gy).The change in cellular invasiveness was measured using the real-time cell analyzer system.The activities of matrix metalloproteinase-2 (MMP2) and matrix metalloproteinase-9 (MMP9) in U87 ceils were measured by gelatin zymography before and after irradiation.The content and distribution of intracellular β-catenin after irradiation were determined by immunohistochemistry.The mRNA levels of Wnt/β-catenin target genes were measured by real-time quantitative PCR.Results After irradiation,the invasiveness of U87 cells increased significantly (P 〈 0.01),which was dose-dependent within a certain dose range; the activities of MMP2 and MMP9 in U87 cells increased significantly (P =0.031 for MMP2 ; P =0.004 for MMP9) ;the content of β-catenin in U87 cells increased significantly (P 〈 0.01),with translocation from the cell membrane and adherens junctions to the nucleus; the mRNA levels of Wnt/β-catenin-related genes (FZD7 and TCF1) increased significantly (P 〈 0.01),and the transcription of Wnt/β-catenin target genes,especially those related to migration and invasion such as MMP2,MMP7,MMP9,and CD44,was significantly enhanced (P 〈 0.05).Conclusions Irradiation can promote the invasion of glioblastoma U87 cells,possibly by activating the Wnt/β-catenin pathway and enhancing the transcription of migration-and invasion-related genes.
出处
《中华放射肿瘤学杂志》
CSCD
北大核心
2014年第3期272-276,共5页
Chinese Journal of Radiation Oncology
基金
国家自然科学基金资助项目(81272780)