MIIP基因对人胶质瘤细胞U87增殖能力与放疗敏感性影响

目的探讨过表达迁移侵袭抑制蛋白(MIIP)基因对人胶质母细胞瘤细胞系U87放疗敏感性的影响。方法采用过表达MIIP基因慢病毒转染U87细胞,通过Western blot实验检测转染效率;MTT实验检测MIIP基因对U87细胞活力的影响;应用平板克隆形成实验,评价放射线照射对MIIP过表达组与对照组克隆形成能力的影响;进一步应用Western blot实验检测RAD51蛋白与BCL2蛋白的表达情况。结果 MIIP基因过表达可以抑制神经胶质瘤细胞U87的增殖能力。上调MIIP基因,抑制U87细胞的克隆形成能力,并提高放疗敏感性。放疗前与放疗后,MIIP基因均抑制RAD51蛋白与BCL2蛋白的表达。结论过表达MIIP基因抑制U87细胞的增殖能力与克隆形成能力;MIIP基因可提高U87细胞放疗敏感性,其机制与RAD51、BCL2信号转导通路相关。     

光动力疗法抑制NHE1表达协同替莫唑胺抗C6胶质瘤的研究

目的:探讨光动力疗法(Photodynamictherapy,PDT)通过抑制钠-氢交换体(NHE1),逆转药替莫唑胺(Temozolomide,TMZ)耐药,以及联合TMZ治疗C6胶质瘤的作用。方法:Western blot检测C6细胞NHE1、迁移和侵袭相关蛋白以及细胞凋亡相关蛋白的表达改变;Fluorometric Intracellular pH试剂盒检测胞内pH的变化;Transwell技术检测细胞迁移和侵袭能力;流式细胞术检测细胞凋亡和活性氧(reactive oxygen species,ROS)水平。动物实验对肿瘤生长进行测量,并使用HE染色观察肿瘤细胞形态学改变;免疫组化分析肿瘤组织增殖和凋亡。结果:PDT及PDT联合TMZ治疗诱导NHE1、Ezrin、Vimentin表达下降,以及细胞内pH值明显降低,胞内ROS水平升高及Bax、Bcl-2的明显改变。C6细胞迁移和侵袭能力受到明显抑制,细胞凋亡显著增加。体内实验显示PDT组及PDT联合TMZ组肿瘤组织内出现坏死改变,Ki-67显著降低及caspase-3明显升高。结论:PDT及PDT联合TMZ治疗能够有效地抑制C6胶质瘤细胞,并能够逆转胶质瘤对TMZ耐药性。     

阿帕替尼对脑胶质瘤细胞放射敏感性的影响

目的 研究小分子酪氨酸激酶抑制剂甲磺酸阿帕替尼对脑胶质瘤细胞U87MG放射敏感性的影响,并初步探讨其作用机制。方法 将胶质瘤细胞U87MG分为空白对照组、阿帕替尼组、单纯照射组、阿帕替尼联合照射组。CCK-8法检测不同浓度阿帕替尼（5、10、20、40、80 μmol/L）对细胞增殖的影响;创伤愈合实验和侵袭实验检测阿帕替尼对胶质瘤细胞的迁移及侵袭能力的影响;平板克隆实验检测阿帕替尼对脑胶质瘤细胞的放射敏感性的影响;流式细胞术检测细胞凋亡情况;采用Western blot检测Bax、Bcl-2蛋白表达。结果 阿帕替尼对胶质瘤细胞U87MG的增殖具有明显抑制作用,且存在时间-剂量的依赖性。与单纯照射组比较,阿帕替尼联合照射组能明显抑制细胞的增殖、迁移和侵袭,差异有统计学意义（t=9.857、18.704、4.167,P<0.05）。与单纯照射组比较,阿帕替尼联合照射组的D₀、D_q和SF₂均下降,放射增敏比（SER_D0）为1.3。与单纯照射组比较,阿帕替尼联合照射组的细胞凋亡率增加,Bcl-2蛋白表达降低,Bax蛋白表达升高,差异有统计学意义（t=16.187、8.890、5.222,P<0.05）。结论 阿帕替尼能够抑制胶质瘤细胞增殖、迁移和侵袭,并促进细胞凋亡,增加胶质瘤细胞的放射敏感性。     

CD133+ U87人脑胶质瘤干细胞放射敏感性和DNA双链断裂损伤修复的实验研究

目的 探讨CD133+ U87人脑胶质瘤干细胞放射敏感性及DNA双链断裂损伤修复的情况。 方法 选择人脑胶质瘤U87细胞系,采用免疫流式分选技术分选出CD133+、CD133-细胞;采用克隆形成实验研究细胞的放射敏感性;采用中性单细胞凝胶电泳实验检测4 Gy X射线垂直照射后不同时间点的DNA双链断裂;采用间接免疫荧光技术检测不同时间点磷酸化组蛋白H2AX（γ-H2AX）荧光灶、Rad51（一种同源重组修复蛋白）荧光灶的表达。 结果 假照射条件下,CD133+细胞克隆的形成率明显高于CD133-细胞（t=3.66,P < 0.01）;CD133+细胞经4 Gy照射后的克隆形成率无明显变化（t=0.71,P > 0.05）,而CD133-细胞经4 Gy照射后的克隆形成率下降（t=2.91,P < 0.05）。4 Gy照射后0.5 h,CD133+、CD133-细胞间尾力矩差异无统计学意义（t=1.44,P > 0.05）,照射后6、24 h,CD133+细胞尾力距下降程度大于CD133-细胞（t=5.31和8.09,P < 0.01）;照射后0.5、6 h,CD133+、CD133-细胞间γ-H2AX灶的表达率差异均无统计学意义（t=0.12和0.99,P > 0.05）,照射后24 h,CD133+细胞的γ-H2AX灶的表达率下降程度大于CD133-细胞（t=4.99,P < 0.01）;照射后0.5 h,CD133+、CD133-细胞间Rad51灶的表达率差异无统计学意义（t=1.12,P > 0.05）,照射后6、24 h,CD133-细胞的Rad51灶的表达率与CD133+细胞相比明显下降（t=22.88和12.43,P < 0.01）,而CD133+细胞无明显变化。 结论 CD133+ U87人脑胶质瘤干细胞具有放射抵抗性,可能与其照射后DNA双链的断裂修复能力较高有关。     

靶向生存素基因的RNAi对肺腺癌A549细胞放射敏感性的影响

目的 构建靶向生存素(survivin)基因的RNA干扰(RNAi)载体,观察对肺腺癌A549细胞放射敏感性的影响,并探讨其机制.方法 根据survivin的cDNA序列设计干扰序列,构建干扰survivin的重组干扰质粒pGenesil2-survivin.酶切、测序鉴定正确后,经脂质体介导转染肺腺癌A549细胞;应用反转录.聚合酶链式反应(RT-PCR)和Western blot法检测survivin的表达;流式细胞术检测细胞凋亡的变化;克隆形成实验检测细胞的放射敏感性.结果 酶切和测序结果显示,载体构建正确;将质粒pGenesil2-survivin转染肺腺癌A549细胞48 h,survivin蛋白水平及mRNA水平在正常组与pGenesil2组中无明显变化,5 Gy照射组增强,而转染pGenesil2-survivin后明显抑制;pGenesil2-survivin与5 Gy X射线照射都能诱导细胞凋亡增加(t1=10.63,P<0.001;t2=3.75,P<0.05),两者共同作用,凋亡增加更明显(t=4.83,P<0.05);克隆形成实验显示,pGenesil2与正常组D0、Dq无明显变化,而pGenesil2.survivin则明显降低,说明其可以提高A549细胞的放射敏感性.结论 靶向生存素基因的RNAi能够明显抑制survivin mRNA与蛋白的表达,促进凋亡,增强A549细胞的放射敏感性.     

靶向生存素基因的RNAi对肺腺癌A549细胞放射敏感性的影响

目的 构建靶向生存素(survivin)基因的RNA干扰(RNAi)载体,观察对肺腺癌A549细胞放射敏感性的影响,并探讨其机制.方法 根据survivin的cDNA序列设计干扰序列,构建干扰survivin的重组干扰质粒pGenesil2-survivin.酶切、测序鉴定正确后,经脂质体介导转染肺腺癌A549细胞;应用反转录.聚合酶链式反应(RT-PCR)和Western blot法检测survivin的表达;流式细胞术检测细胞凋亡的变化;克隆形成实验检测细胞的放射敏感性.结果 酶切和测序结果显示,载体构建正确;将质粒pGenesil2-survivin转染肺腺癌A549细胞48 h,survivin蛋白水平及mRNA水平在正常组与pGenesil2组中无明显变化,5 Gy照射组增强,而转染pGenesil2-survivin后明显抑制;pGenesil2-survivin与5 Gy X射线照射都能诱导细胞凋亡增加(t1=10.63,P<0.001;t2=3.75,P<0.05),两者共同作用,凋亡增加更明显(t=4.83,P<0.05);克隆形成实验显示,pGenesil2与正常组D0、Dq无明显变化,而pGenesil2.survivin则明显降低,说明其可以提高A549细胞的放射敏感性.结论 靶向生存素基因的RNAi能够明显抑制survivin mRNA与蛋白的表达,促进凋亡,增强A549细胞的放射敏感性.     

靶向生存素基因的RNAi对肺腺癌A549细胞放射敏感性的影响

目的 构建靶向生存素(survivin)基因的RNA干扰(RNAi)载体,观察对肺腺癌A549细胞放射敏感性的影响,并探讨其机制.方法 根据survivin的cDNA序列设计干扰序列,构建干扰survivin的重组干扰质粒pGenesil2-survivin.酶切、测序鉴定正确后,经脂质体介导转染肺腺癌A549细胞;应用反转录.聚合酶链式反应(RT-PCR)和Western blot法检测survivin的表达;流式细胞术检测细胞凋亡的变化;克隆形成实验检测细胞的放射敏感性.结果 酶切和测序结果显示,载体构建正确;将质粒pGenesil2-survivin转染肺腺癌A549细胞48 h,survivin蛋白水平及mRNA水平在正常组与pGenesil2组中无明显变化,5 Gy照射组增强,而转染pGenesil2-survivin后明显抑制;pGenesil2-survivin与5 Gy X射线照射都能诱导细胞凋亡增加(t1=10.63,P<0.001;t2=3.75,P<0.05),两者共同作用,凋亡增加更明显(t=4.83,P<0.05);克隆形成实验显示,pGenesil2与正常组D0、Dq无明显变化,而pGenesil2.survivin则明显降低,说明其可以提高A549细胞的放射敏感性.结论 靶向生存素基因的RNAi能够明显抑制survivin mRNA与蛋白的表达,促进凋亡,增强A549细胞的放射敏感性.     

靶向生存素基因的RNAi对肺腺癌A549细胞放射敏感性的影响

目的 构建靶向生存素(survivin)基因的RNA干扰(RNAi)载体,观察对肺腺癌A549细胞放射敏感性的影响,并探讨其机制.方法 根据survivin的cDNA序列设计干扰序列,构建干扰survivin的重组干扰质粒pGenesil2-survivin.酶切、测序鉴定正确后,经脂质体介导转染肺腺癌A549细胞;应用反转录.聚合酶链式反应(RT-PCR)和Western blot法检测survivin的表达;流式细胞术检测细胞凋亡的变化;克隆形成实验检测细胞的放射敏感性.结果 酶切和测序结果显示,载体构建正确;将质粒pGenesil2-survivin转染肺腺癌A549细胞48 h,survivin蛋白水平及mRNA水平在正常组与pGenesil2组中无明显变化,5 Gy照射组增强,而转染pGenesil2-survivin后明显抑制;pGenesil2-survivin与5 Gy X射线照射都能诱导细胞凋亡增加(t1=10.63,P<0.001;t2=3.75,P<0.05),两者共同作用,凋亡增加更明显(t=4.83,P<0.05);克隆形成实验显示,pGenesil2与正常组D0、Dq无明显变化,而pGenesil2.survivin则明显降低,说明其可以提高A549细胞的放射敏感性.结论 靶向生存素基因的RNAi能够明显抑制survivin mRNA与蛋白的表达,促进凋亡,增强A549细胞的放射敏感性.     

靶向生存素基因的RNAi对肺腺癌A549细胞放射敏感性的影响

目的 构建靶向生存素(survivin)基因的RNA干扰(RNAi)载体,观察对肺腺癌A549细胞放射敏感性的影响,并探讨其机制.方法 根据survivin的cDNA序列设计干扰序列,构建干扰survivin的重组干扰质粒pGenesil2-survivin.酶切、测序鉴定正确后,经脂质体介导转染肺腺癌A549细胞;应用反转录.聚合酶链式反应(RT-PCR)和Western blot法检测survivin的表达;流式细胞术检测细胞凋亡的变化;克隆形成实验检测细胞的放射敏感性.结果 酶切和测序结果显示,载体构建正确;将质粒pGenesil2-survivin转染肺腺癌A549细胞48 h,survivin蛋白水平及mRNA水平在正常组与pGenesil2组中无明显变化,5 Gy照射组增强,而转染pGenesil2-survivin后明显抑制;pGenesil2-survivin与5 Gy X射线照射都能诱导细胞凋亡增加(t1=10.63,P<0.001;t2=3.75,P<0.05),两者共同作用,凋亡增加更明显(t=4.83,P<0.05);克隆形成实验显示,pGenesil2与正常组D0、Dq无明显变化,而pGenesil2.survivin则明显降低,说明其可以提高A549细胞的放射敏感性.结论 靶向生存素基因的RNAi能够明显抑制survivin mRNA与蛋白的表达,促进凋亡,增强A549细胞的放射敏感性.     

靶向生存素基因的RNAi对肺腺癌A549细胞放射敏感性的影响

目的 构建靶向生存素(survivin)基因的RNA干扰(RNAi)载体,观察对肺腺癌A549细胞放射敏感性的影响,并探讨其机制.方法 根据survivin的cDNA序列设计干扰序列,构建干扰survivin的重组干扰质粒pGenesil2-survivin.酶切、测序鉴定正确后,经脂质体介导转染肺腺癌A549细胞;应用反转录.聚合酶链式反应(RT-PCR)和Western blot法检测survivin的表达;流式细胞术检测细胞凋亡的变化;克隆形成实验检测细胞的放射敏感性.结果 酶切和测序结果显示,载体构建正确;将质粒pGenesil2-survivin转染肺腺癌A549细胞48 h,survivin蛋白水平及mRNA水平在正常组与pGenesil2组中无明显变化,5 Gy照射组增强,而转染pGenesil2-survivin后明显抑制;pGenesil2-survivin与5 Gy X射线照射都能诱导细胞凋亡增加(t1=10.63,P<0.001;t2=3.75,P<0.05),两者共同作用,凋亡增加更明显(t=4.83,P<0.05);克隆形成实验显示,pGenesil2与正常组D0、Dq无明显变化,而pGenesil2.survivin则明显降低,说明其可以提高A549细胞的放射敏感性.结论 靶向生存素基因的RNAi能够明显抑制survivin mRNA与蛋白的表达,促进凋亡,增强A549细胞的放射敏感性.     

环指蛋白187过表达后对人脑胶质瘤细胞U87的影响

 目的 探究环指蛋白187(ring finger protein 187,RNF187)过表达后对人脑胶质瘤细胞U87的影响及其可能机制。方法 体外培养胶质瘤细胞系U87,转染过表达RNF187入U87细胞,对比分析RNF187 过表达对肿瘤细胞生长增殖能力、细胞干性和体外侵袭及转移能力;最后通过检测RNF187及焦亡标志物,即炎性小体3(inflammasome3,NLRP3)、凋亡相关斑点样蛋白(apoptosis-associated speck-like protein,ASC)、GSDMD和GSDME的表达,明确RNF187与焦亡的关系。结果 CCK-8、细胞克隆和Transwell 实验证实,RNF187过表达后U87细胞形态上肿胀肿大,且细胞增殖和侵袭能力较对照组增强,RNF187过表达组细胞增殖率(2.24±0.16)高于其他两组;RT-PCR和Western blot实验表明,RNF187过表达后焦亡相关标志物(NLRP3、ASC、GSDMD、GSDME)表达水平较对照组升高(P＜0.05)。结论 RNF187在胶质瘤细胞表达增多,增加胶质瘤细胞的增殖和侵袭能力,可能是通过促进焦亡实现的。     

白藜芦醇诱导人宫颈癌Hela细胞凋亡及其机制

目的探讨白藜芦醇诱导人宫颈癌Hela细胞的凋亡作用及其分子机制。方法应用不同浓度的白藜芦醇作用于人宫颈癌Hela细胞,采用四甲基偶氮唑蓝（MTT）法检测药物对细胞的增殖抑制率;流式细胞术（FCM）检测细胞凋亡、细胞周期分布：免疫组化法检测Survivin及Caspase-3的表达。结果白藜芦醇能明显抑制Hela细胞的增殖,并呈剂量和时间依赖性。经白藜芦醇处理Hela细胞后,FCM分析发现各实验组S期细胞比例增高,G2／M期细胞比例减少,凋亡率明显高于对照组,并呈剂量依赖性（P〈0．01）;各实验组Heal细胞Survivin的表达均低于对照组,而Caspase-3的表达均高于对照组（P〈0．01）。结论白藜芦醇能明显抑制人宫颈癌Hela细胞的增殖,诱导其凋亡,其机制可能与抑制Survivin的表达、上调Caspase-3的表达有关。     

Photodynamic therapy enhances the cytotoxicity of temozolomide against glioblastoma via reprogramming anaerobic glycolysis

The successful application of photodynamic therapy in the treatment of glioma (CNS WHO grade 4) depends in large part to the effect of killing cells in the infiltrating area after tumor had been removed, when combined with radiotherapy, chemotherapy, and targeted drug therapy. The purpose of this study was to investigate the potential mechanism of TMZ's involvement in the glioma's glycolytic metabolic pathway during photodynamic therapy. The low dose of photodynamic therapy treatment on the cell viability of gliomas was investigated by CCK8. Alterations in reactive oxygen species were detected by flow cytometer. The differentially expressed proteins related to glucose transporter 1 (GLUT-1), matrix metalloproteinase-2 (MMP-2)/actively MMP-2 and apoptosis-associated caspase-3/cleaved caspase-3 were evaluated by Western Blot experiment. Additionally, transmission electron microscopy observed apoptosis, necrosis and the changes of the ultrastructure in U251 cells. In addition, antitumor effects in vivo were tested using orthotopic BALB/c mice with the glioma U87 model. The findings showed that low dose PDT affected mitochondrial function by inducing radical oxygen, hindered cellular glucose transport and metabolism, and induced apoptosis. The results also showed that cell viability considerably decreased and increased cell apoptosis under the PDT therapy. The HIF-1/GLUT-1 axis enhanced the cytotoxicity of temozolomide in gliomas as a result of PDT treatment, which was influenced by ROS. As a result, this study presents PDT as a potential therapeutic approach for treating malignant glioma, and enhanced antitumor effect of TMZ by inhibiting glycolytic pathway.     

EMMPRIN基因表达对胶质瘤U251细胞增殖、凋亡的影响

目的探讨特异性小分子干扰（small interference,siRNA）抑制人脑胶质瘤U251细胞株内细胞外基质金属蛋白酶诱导因子（extracellular matrix metalloproteinase inducer,EMMPRIN）基因的表达后,对U251细胞株增殖、凋亡的影响。方法构建EMMPRIN基因小干扰RNA,转染人胶质瘤U251细胞株,运用半定量RT-PCR及Western blot的方法验证转染组及对照组的胶质瘤细胞EMMPRIN基因mRNA及蛋白的表达水平,通过MTT法观察转染48 h后对U251细胞增殖的变化,流式细胞术观察转染48 h后U251细胞周期及凋亡的改变。结果 EMMPRIN基因的特异性siRNA转染U251细胞后,EMM-PRIN基因的mRNA和蛋白表达水平明显降低,细胞增殖明显受到抑制,细胞凋亡增加。结论 EMMPRIN基因的特异性siR-NA能抑制胶质瘤U251细胞株的增殖,促进细胞凋亡。     

异丙酚对胶质瘤U87细胞增殖、侵袭、迁移及JAK2/STAT3通路的影响

 目的 探讨异丙酚对胶质瘤U87细胞增殖、侵袭、迁移及Janus激酶2/信号转导子和转录激活子3(JAK2/STAT3)通路的影响。方法 采用MTT法测定不同浓度的异丙酚对胶质瘤U87细胞和人正常星型胶质细胞HEB生长抑制作用,Transwell侵袭实验测定2、5、10 μM异丙酚对胶质瘤U87细胞体外侵袭能力的影响,划痕实验测定2、5、10 μM异丙酚对胶质瘤U87细胞体外迁移能力的影响,蛋白印迹法(WB)测定10 μM异丙酚对胶质瘤U87细胞JAK2/STAT3通路的影响。结果 与对照组相比,5、10、25、50、100 μM异丙酚均能显著抑制胶质瘤U87细胞增殖,差异有统计学意义(P<0.05),后续选择2、5、10 μM异丙酚进行实验。与对照组相比,胶质瘤U87细胞经2、5、10 μM异丙酚处理后,侵袭能力显著降低,差异有统计学意义(P<0.05)。细胞划痕实验说明,胶质瘤U87细胞经2、5、10 μM异丙酚处理48 h后,迁移能力分别降低了(19.69±2.67)%、(41.41±3.28)%、(59.75±2.91)%,与对照组相比差异有统计学意义(P<0.05)。且胶质瘤U87细胞中JAK2蛋白磷酸化水平、STAT3蛋白磷酸化水平明显下调,与对照组相比差异有统计学意义(P<0.05)。结论 异丙酚可能通过下调JAK2/STAT3信号传导通路相关蛋白表达,抑制胶质瘤U87细胞增殖、侵袭、迁移能力。     

Anti-tumour effects by a trimodal combination of temozolomide,meloxicam and X-rays in cultures of human glioma cells

Purpose:?To investigate the possible cytotoxic interactions between the chemotherapeutic drug temozolomide (TMZ) and the cyclooxygenase-2 inhibitor meloxicam (MLC) or of both drugs combined with X-rays in three human glioma cell lines (D384, Hs 683 and U251).

Materials and methods:?Cells were exposed to TMZ (96 hours) and MLC was co-incubated during the last 24?h. Thereafter, cells were irradiated with X-rays and plated for a clonogenic assay. Total cell numbers and the numbers of surviving cells were determined to study the recovery of the cell populations (up until 19 days) following different combinations of TMZ, MLC and X-rays.

Results:?The combination of MLC and TMZ caused an enhanced cytotoxic effect in D384 and Hs 683. Various treatment combinations demonstrated significant radiation enhancement in all three cell lines. Long-term observations of D384 cells demonstrated that the repopulation rates of the surviving cells are far less affected by the various treatment protocols than those from the non-surviving cells.

Conclusions:?The present study demonstrates that a combination of TMZ and MLC resulted in a significant potentiation of their cytotoxicity in D384 and Hs683. The combination of these two drugs can also cause considerable enhancement of the radiation response in human glioma cell lines, although only D384 cells benefit from trimodal over bimodal treatment.     

Response to high LET radiation 12C (LET, 295 keV/microm) in M5 cells, a radio resistant cell strain derived from Chinese hamster V79 cells

PURPOSE: To study the effects of 12C-beam of 295 keV/microm (57.24 MeV) on M5 and Chinese hamster V79 cells by using cytogenetic assays like micronuclei (MN) induction, chromosomal aberrations (CA) and apoptosis. Additionally, the relative survival of these two cell lines was tested by the colony forming ability of the cells, with a view to understanding the mechanism of cellular damages that lead to difference in cell survival. MATERIALS AND METHODS: Confluent cells were irradiated with 12C-beam at various doses using 15UD Pelletron accelerator. Cell survival was studied by the colony forming ability of cells. MN assay was done by fluorescent staining. Different types of chromosomal aberrations in metaphase cells were scored at 12 h after irradiation. Apoptosis was measured at different post irradiation times as detected by nuclear fragmentation and DNA ladder was prepared after 48 h of incubation. RESULTS: Dose-dependent decrease in surviving fractions was found in both the cell lines. However, the surviving fractions were higher in M5 cells in comparison to V79 cells when exposed to the same radiation doses. On the other hand, induced MN frequencies, CA frequencies and apoptosis percentages were less in M5 cells than V79 cells. Very good correlations between surviving fractions and induced MN frequencies or induced total CA or induced apoptosis percentages were obtained in this study. CONCLUSIONS: The cell strain M5 showed relatively more radio-resistance to 12C-beam compared to Chinese hamster V79 cells in this study. As the MN formation, CA and apoptosis induction were less in M5 cells as compared to parental V79 cells, the higher cell survival in the former could possibly be attributed to their better repairing ability leading to higher cell survival.     

Survivin, a target to modulate the radiosensitivity of Ewing’s sarcoma

Background and purpose

Radiotherapy constitutes an essential element in the multimodal therapy of Ewing’s sarcoma. Compared to other sarcomas, Ewing tumors normally show a good response to radiotherapy. However, there are consistently tumors with a radioresistant phenotype, and the underlying mechanisms are not known in detail. Here we investigated the association between survivin protein expression and the radiosensitivity of Ewing’s sarcoma in vitro.

Material and methods

An siRNA-based knockdown approach was used to investigate the influence of survivin expression on cell proliferation, double-strand break (DSB) induction and repair, apoptosis and colony-forming ability in four Ewing’s sarcoma cell lines with and without irradiation.

Results

Survivin protein and mRNA were upregulated in all cell lines tested in a dose-dependent manner. As a result of survivin knockdown, STA-ET-1 cells showed reduced cell proliferation, an increased number of radiation-induced DSBs, and reduced repair. Apoptosis was increased by knockdown alone and increased further in combination with irradiation. Colony formation was significantly reduced by survivin knockdown in combination with irradiation.

Conclusion

Survivin is a radiation-inducible protein in Ewing’s sarcoma and its down-regulation sensitizes cells toward irradiation. Survivin knockdown in combination with radiation inhibits cell proliferation, repair, and colony formation significantly and increases apoptosis more than each single treatment alone. This might open new perspectives in the radiation treatment of Ewing’s sarcoma.     

选择性环氧合酶-2抑制剂增强光动力学疗法杀伤胶质瘤细胞效应的研究

目的探讨选择性环氧合酶-2抑制剂塞来昔布(celecoxib)增强光动力学疗法(photodynamic therapy,PDT)杀伤C6胶质瘤细胞的效应.方法应用细胞存活曲线、透射电镜及流式细胞仪(FCM)方法检测光动力联合治疗组(塞米昔布 PDT)、PDT组、塞米昔布组及空白对照组杀伤C6胶质细胞的效应.结果存活曲线显示联合组对C6胶质瘤细胞的抑制作用优于PDT组,增敏比为1.34.电镜检查联合组的细胞凋亡明显多于其他组.FCM检测细胞凋亡联合组为64.3%,PDT组为4.5%,塞米昔布组为15.3%,联合治疗组细胞凋亡明显增加.结论塞米昔布联合光动力学疗法对C6胶质瘤细胞的抑制及诱导凋亡的作用明显地高平PDT组及塞米昔布组,塞米昔布具有增强光动力学疗法杀伤胶质瘤细胞的作用.     

99Tc m标记lncRNA HOTAIR反义寡核苷酸探针的制备及其对人脑胶质瘤U87细胞活性的影响

目的 制备新型的靶向长链非编码RNA（lncRNA）同源异型盒基因转录的反义基因间RNA（HOTAIR）的反义寡核苷酸（ASON）探针99Tcm-HYNIC-ASON（HYNIC为联肼尼克酰胺）,探讨其对人脑胶质瘤U87细胞增殖和迁移能力的影响。 方法 设计并通过化学修饰合成HOTAIR的ASON,使用双功能螯合剂HYNIC偶联99Tcm并进行纯化。采用快速薄层层析(ITLC)法和琼脂糖凝胶电泳分别检测探针的标记率、放射化学纯度、体外稳定性及完整性。细胞摄取实验分为2组:Lipo-99Tcm-HYNIC-ASON组（转染组）和99Tcm-HYNIC-ASON组（未转染组）,通过脂质体转染探针,测定人脑胶质瘤U87细胞对探针的摄取率;细胞计数试剂盒8（CCK-8）实验和细胞划痕实验分为3组:Lipo-99Tcm-HYNIC-ASON组（转染组）、99Tcm-HYNIC-ASON组（未转染组）、99Tcm-Control组（对照组）,分别检测转染探针后细胞增殖和迁移能力的变化。2组间比较采用Student t检验,多组间比较采用单因素方差分析。 结果 99Tcm-HYNIC-ASON的标记率为（90.0±5.6）%。琼脂糖凝胶电泳结果显示,99Tcm与探针成功标记并且没有明显的降解,探针孵育12 h的放射化学纯度>80%。细胞摄取实验结果显示,转染后5 h,探针Lipo-99Tcm-HYNIC-ASON在人脑胶质瘤U87细胞中的摄取率最大（0.70%）,与未转染组（0.16%）相比,差异有统计学意义（t=17.81,P<0.01）。CCK-8实验结果显示,转染探针Lipo-99Tcm-HYNIC-ASON能抑制人脑胶质瘤U87细胞的增殖能力,与未转染组相比,在各个时间点（1、2、3、4、5 d）的差异均有统计学意义（t=2.336~30.230, 均P<0.05）。细胞划痕实验结果显示,转染探针Lipo-99Tcm-HYNIC-ASON能抑制人脑胶质瘤U87细胞的迁移,3组细胞间隙融合率的差异有统计学意义(F=331.8,P<0.01),与未转染组相比,转染组细胞间隙融合率明显降低,且差异有统计学意义（60.0%对23.6%, t=51.54,P<0.01）。 结论 成功合成了靶向人脑胶质瘤lncRNA HOTAIR的探针99Tcm-HYNIC-ASON,该探针具有良好的体外稳定性和靶向结合能力,能够抑制人脑胶质瘤U87细胞的增殖和迁移。