尼拉帕利通过DDX21增强胶质母细胞瘤放射敏感性  

Niraparib enhances radiosensitivity of glioblastoma with DDX21

作　　者：罗佳 肖何 彭杨 耿明英 LUO Jia;XIAO He;PENG Yang;GENG Mingying(Cancer Center,Daping Hospital,Army Medical University,Chongqing 400042,China)

机构地区：[1]陆军军医大学大坪医院肿瘤科,重庆400042

出　　处：《江苏大学学报（医学版）》2024年第5期395-406,共12页Journal of Jiangsu University：Medicine Edition

基　　金：国家重点研发计划课题(2018YFC0114402)。

摘　　要：目的:探究多聚腺苷二磷酸核糖聚合酶[poly(ADP-ribose)polymerase,PARP]抑制剂尼拉帕利作为胶质母细胞瘤(glioblastoma,GBM)放疗增敏剂的可行性及作用机制。方法:生物信息学分析PARP抑制剂奥拉帕利和他拉唑帕利在胶质瘤中的作用机制及其与放疗的相关性;CCK-8测定尼拉帕利在GBM细胞(A172、U251和U87)中的最适作用浓度和最适作用时间;克隆形成实验检测尼拉帕利对GBM细胞放疗敏感性的影响;流式细胞术检测尼拉帕利联合放疗对GBM细胞周期的影响,蛋白质印迹检测尼拉帕利联合放疗对DExD-box解旋酶(DExD-box helicase,DDX21)蛋白表达的影响,免疫荧光法研究尼拉帕利联合放疗对DDX21在GBM中细胞核定位的影响,以探讨尼拉帕利在GBM中放疗增敏的作用机制。结果:生物信息学分析表明,在519个肿瘤细胞系中,PARP抑制剂在胶质瘤中发挥作用的途径主要与核糖体生物合成和功能相关;在44个实体肿瘤细胞系中,同源重组修复能力与核糖体生物合成能力高度正相关。尼拉帕利在A172和U87细胞系中的IC50值分别为(10.77±3.31)μmol/L和(32.37±2.84)μmol/L;在尼拉帕利浓度为348 nmol/L和1044 nmol/L时A172细胞的辐射剂量增强因子(DEF37)分别为1.99和2.17,在1056 nmol/L和3169 nmol/L时U87细胞的DEF37分别为1.10和1.44,尼拉帕利对p53野生型的A172细胞和U87细胞具有放疗增敏作用,但对p53突变型的U251细胞无放疗增敏作用;在A172细胞和U87细胞中尼拉帕利联合放疗组的G2/M期细胞均明显多于对照组,尼拉帕利联合放疗可以使A172和U87细胞阻滞在对射线敏感的G2/M期,从而实现放疗增敏。最后,尼拉帕利联合放疗处理U87细胞后,DDX21蛋白表达无显著变化(P>0.05),免疫荧光结果提示尼拉帕利联合放疗处理U87细胞后,DDX21从核仁到核质重新定位;敲低DDX21会引起U87细胞产生放疗抵抗,尼拉帕利对DDX21敲低后的U87细胞仍有放疗增敏作用。结论:尼拉帕利通过使DObjective:To explore the feasibility and mechanism of the poly(ADP-ribose)polymerase(PARP)inhibitor niraparib as a radiosensitizer for glioblastoma(GBM).Methods:Bioinformatics analysis was used to reveal the mechanism of PARP inhibitors in glioma and its correlation with radiotherapy.CCK-8 was used to determine the optimal concentration and treatment time of niraparib in GBM cells(A172,U251 and U87).A clonogenic assay was used to detect the radiosensitivity of GBM cells to niraparib.Flow cytometry was used to detect the effect of niraparb combined with radiotherapy on GBM cell cycle.Western blotting was used to detect the impact of niraparib combined with radiotherapy on the expression of DExD-box RNA helicase(DDX21)protein.Immunofluorescence was used to detect the effect of niraparib combined with radiotherapy on the localization of DDX21 in the nucleus of GBM cells.Results:Pathways relevant to ribosome biosynthesis and functions was found to be responsible for cytotoxicity of niraparib in 519 tumor cell lines.Homologous recombination repair ability was highly positively correlated with ribosomal biosynthesis ability in 44 solid tumor cell lines.Moreover,the IC50 of niraparib in A172 and U87 cell lines were(10.77±3.31)μmol/L and(32.37±2.84)μmol/L respectively.The dose enhancement factor(DEF37)of A172 cells was 1.99 and 2.17 at the concentrations of niraparib at 348 nmol/L and 1044 nmol/L,respectively,and the DEF37 of U87 cells was 1.10 and 1.44 at concentrations of 1056 nmol/L and 3169 nmol/L,respectively.Niraparib exerted radiosensization effects on A172 and U87 cells of p53 wild-type,but not on U251 cell of p53 mutant.Niraparib increased radiosensitivity through G2/M phase arrest in A172 and U87 cellls.Finally,in U87 cells,niraparib combined with irradiation didn′t affect the protein expression of DDX21,but it could lead to the translocation of DDX21 from the nucleolus to the nucleoplasm.Knockdown of DDX21 in U87 cells with high expression of DDX21 resulted radiotherapy resistance,and niraparib still has

关 键 词：胶质母细胞瘤 尼拉帕利 DDX21 放疗敏感性 核糖体生物合成 

分 类 号：R739.41[医药卫生—肿瘤]