miR-206靶向MAPK-1通路增强胶质瘤细胞放射敏感性

目的 研究miR-206对胶质瘤细胞放射敏感可能作用的信号通路,为深入研究其调控机理奠定基础。方法 将miR-206模拟剂或miR-206抑制剂转染到胶质瘤U87细胞中,使用抑制剂PD98059抑制MAPK通路活性并照射处理细胞,MTT和克隆形成实验检测细胞放射敏感性变化。分别用qRT-PCR和蛋白印迹法检测miR-206和MAPK1的表达变化,TargetScan软件预测和双荧光素酶报告实验验证miR-206和MAPK1的相互作用。结果 胶质瘤细胞放射处理后miR-206表达下调,MAPK1表达上调。miR-206模拟剂过表达miR-206,细胞增殖和克隆形成能力下降,放射敏感性增高;转染抑制剂抑制miR-206表达,细胞增殖和克隆形成能力加强,放射敏感性降低。使用TargetScan软件查找发现MAPK1可能是miR-206的靶基因,双荧光素酶报告实验进一步验证了miR-206和MAPK1具有相互作用。过表达或降低miR-206表达,MAPK1与miR-206呈相反变化趋势。使用抑制剂抑制MAPK信号通路,胶质瘤细胞放射敏感性升高。结论 miR-206可能靶向MAPK1,通过抑制MAPK信号通路活性调节胶质瘤细胞的放射敏感性。     

miR-205-5p/E2F1信号抑制经典Wnt/β蛋白通路调控脑胶质瘤细胞放射敏感性

目的 探索miR-205-5p/E2F1信号轴在脑胶质瘤U251、U87细胞放射耐受中的调控机制。方法 利用X射线逐步递增递间歇诱导方法照射U251、U87细胞,建立放射耐受的U251/TR、U87/TR细胞。对两种细胞进行形态学、细胞运动、侵袭及增殖能力分析。通过荧光素酶基因检测系统及点突变技术分析E2F1基因对U251/TR、U87/TR细胞的调控机制。结果 放射耐受的U251/TR、U87/TR细胞分别比251、U87细胞的增殖活力增强,运动、侵袭能力增强,X射线照射下细胞凋亡下降。miR-205-5p mimics转染能够下调U251/TR细胞E2F1因子表达,抑制细胞增殖、侵袭及运动,增加放射敏感性。miR-205-5p mimics转染协同E2F1下调是通过抑制细胞Wnt/β-catenin信号通路活性发挥抑制肿瘤作用,并降低细胞耐受。结论 逐步递增递间歇诱导方法能较好地建立U251/TR、U87/TR细胞。miR-205-5p/E2F1信号轴通过经典Wnt/β-catenin信号通路发挥抑癌作用,可以作为提高胶质瘤放射敏感性的治疗靶点。     

下调lncRNA LINC00263靶向miR-4458调控乳腺癌SK-BR-3细胞放射敏感性

目的 研究下调lncRNA LINC00263靶向miR-4458对乳腺癌SK-BR-3细胞增殖、运动、侵袭及放射敏感性影响。方法 qRT-PCR方法分别检测乳腺癌组织、癌旁组织、正常乳腺上皮细胞和乳腺癌细胞中LINC00263表达差异。SK-BR-3细胞中转染LINC00263shRNA下调LINC00263表达,克隆实验检测放射敏感性。SK-BR-3细胞给予6Gy照射处理,CCK-8检测细胞增殖,流式细胞术检测凋亡,Transwell小室检测细胞运动和侵袭,蛋白印迹法检测C-Caspase-3、C-Caspase-9、MMP-2、MMP-9蛋白表达。生物信息学软件预测LINC00263和miR-4458有互补结合位点,荧光素酶报告系统测定二者的靶向关系。在SK-BR-3细胞中共转染LINC00263shRNA和miR-4458 inhibitor,给予6Gy照射处理,检测细胞增殖、运动、侵袭和凋亡变化。结果 乳腺癌组织中LINC00263表达水平高于癌旁组织。乳腺癌细胞中LINC00263表达水平高于正常乳腺上皮细胞。转染LINC00263shRNA以后的SK-BR-3细胞放射敏感性增加。转染LINC00263shRNA和放射联合具有协同作用,共同抑制细胞增殖、运动、侵袭,促进细胞凋亡,提高细胞中C-Caspase-3、C-Caspase-9蛋白表达水平,降低细胞中MMP-2、MMP-9蛋白表达水平。下调LINC00263靶向促进miR-4458表达。miR-4458 inhibitor逆转LINC00263shRNA联合放射对SK-BR-3细胞增殖、运动、侵袭的抑制作用和凋亡促进作用。结论 下调lncRNA LINC00263靶向miR-4458抑制SK-BR-3细胞增殖、运动、侵袭,提高细胞放射敏感性。     

AEG-1表达下调对脑胶质瘤U373细胞的放射增敏效应

目的:探讨AEG-1基因表达下调对人脑胶质瘤细胞U373放射敏感性的影响。方法:以人MTDH/AEG-1（NM-178812）为靶标设计shRNA序列,慢病毒介导将AEG-1 shRNA转染至胶质瘤U373细胞中。荧光定量PCR及Western blot测定转染前后AEG-1 mRNA及蛋白的表达;克隆形成实验评估AEG-1基因下调后U373细胞放射敏感性;流式细胞术检测AEG-1下调后U373细胞凋亡及细胞周期分布。结果:通过慢病毒介导的shRNA转染,构建了AEG-1表达稳定下调的U373-shAEG-1细胞系,有效抑制了胶质瘤U373细胞中AEG-1的表达(抑制率84%,P<0.05),增加了凋亡细胞的比例（13.07%±0.28%,P<0.05）,并提高细胞周期中S期细胞比例（58.18％,P<0.01）,且AEG-1基因表达下调后U373细胞的D0值 （1.60Gy） 和Dq值 （1.06Gy）均明显低于空白对照组及阴性对照组细胞（P<0.05）。结论:下调AEG-1可以增强人脑胶质瘤U373细胞的放射敏感性,其机制与诱导细胞凋亡及干预细胞周期分布有关。     

不同类型恶性胶质瘤离体细胞系放射敏感性的比较

利用集落形成法测绘5个恶性胶质瘤离体细胞系的剂量存活曲线,计算与肿瘤细胞固有放射敏感性有关的参数。结果表明胶质母细胞瘤的放射敏感性较低,髓母细胞瘤的放射敏感性较高,复发恶性星形细胞的放射敏感性明显低于初发瘤。进一步证实肿瘤的组织病理学类型与放射敏感性有关。     

miR-21靶向抑制RECK对宫颈癌Hela细胞增殖、侵袭和放射敏感性作用

目的:探究miR-21对宫颈癌Hela细胞增殖、凋亡、侵袭以及放射敏感性的影响和潜在作用机制。方法:利用RT-qPCR方法检测宫颈癌组织和相邻非肿瘤组织、正常宫颈上皮细胞(H8)以及宫颈癌细胞系(HeLa、SiHa、ME180)中miR-21表达水平。通过CCK-8检测、Caspase3/7活细胞凋亡检测、伤口愈合试验...     

shRNA沉默Sp1对胶质瘤细胞放射敏感性的影响

目的 探讨下调Sp1基因表达对胶质瘤细胞放射敏感性的影响。方法 设计并合成编码shRNA的寡核苷酸序列,克隆入LV3（H1/GFP&Puro）载体中构建重组体。然后重组慢病毒分别感染U251和U87细胞,嘌呤霉素筛选得到稳定转染细胞株。荧光定量RT-PCR和蛋白质印迹法分别检测细胞中Sp1 mRNA和蛋白表达水平;克隆存活法检测细胞存活;流式法检测细胞周期;免疫荧光法检测DNA损伤程度。结果 两株胶质瘤细胞在感染72 h后荧光显微镜观察Sp1慢病毒载体均高表达,RT-PCR和蛋白质印迹法结果显示转染后shRNA-U87和shRNA-U251细胞Sp1 mRMA和蛋白表达量均明显降低（P<0.01）,Sp1敲除率达90%以上。shRNA-U251和shRNA-U87细胞在10%细胞存活水平下的放射增敏比（SER）分别为1.39和1.18;两株Sp1敲除组细胞经辐照后G₂/M期比率及γ-H2AX foci数目与对照组相比均极显著增大。结论 shRNA沉默Sp1增大了X线诱导的G₂/M期阻滞,加重了DNA双链断裂程度,提高了胶质瘤细胞的放射敏感性。     

沉默lncRNA GIHCG通过上调miR-146a-3p增加胶质瘤细胞放射敏感性

目的 探讨lncRNA GIHCG对胶质瘤细胞放射敏感性的影响及作用机制。方法 qRT-PCR实验检测人脑正常胶质细胞HEB和胶质瘤细胞系U251、A172、SHG139、U87中GIHCG和miR-146a-3p表达水平。以U251和SHG139细胞为研究对象,沉默GIHCG表达或过表达miR-146a-3p后,MTT检测细胞增殖,流式细胞仪检测细胞凋亡,克隆形成实验检测细胞放射敏感性,蛋白印迹法检测CDK1、CyclinD1、Bcl-2和Bax蛋白表达水平。生物信息学软件预测GIHCG与miR-146a-3p存在结合位点,双荧光素酶报告基因实验和qRT-PCR实验验证GIHCG与miR-146a-3p的靶向关系。结果 与HEB细胞比较,胶质瘤U87、U251、A172和SHG139细胞中GIHCG表达升高(P<0.05),miR-146a-3p表达降低(P<0.05)。沉默GIHCG表达或过表达miR-146a-3p,U251和SHG139细胞存活率、存活分数、CDK1、CyclinD1和Bcl-2蛋白表达降低(P<0.05),凋亡率和Bax蛋白表达升高(P<0.05)。GIHCG在U251和SHG139细胞中靶向负调控miR-146a-3p表达,抑制miR-146a-3p表达逆转了沉默GIHCG对胶质瘤细胞增殖、凋亡及放射敏感性的影响。结论 沉默GIHCG表达可促进miR-146a-3p表达,从而增强胶质瘤细胞的放射敏感性。     

沉默lncRNA GIHCG通过上调miR-146a-3p增加胶质瘤细胞放射敏感性

目的 探讨lncRNA GIHCG对胶质瘤细胞放射敏感性的影响及作用机制。方法 qRT-PCR实验检测人脑正常胶质细胞HEB和胶质瘤细胞系U251、A172、SHG139、U87中GIHCG和miR-146a-3p表达水平。以U251和SHG139细胞为研究对象,沉默GIHCG表达或过表达miR-146a-3p后,MTT检测细胞增殖,流式细胞仪检测细胞凋亡,克隆形成实验检测细胞放射敏感性,蛋白印迹法检测CDK1、CyclinD1、Bcl-2和Bax蛋白表达水平。生物信息学软件预测GIHCG与miR-146a-3p存在结合位点,双荧光素酶报告基因实验和qRT-PCR实验验证GIHCG与miR-146a-3p的靶向关系。结果 与HEB细胞比较,胶质瘤U87、U251、A172和SHG139细胞中GIHCG表达升高(P<0.05),miR-146a-3p表达降低(P<0.05)。沉默GIHCG表达或过表达miR-146a-3p,U251和SHG139细胞存活率、存活分数、CDK1、CyclinD1和Bcl-2蛋白表达降低(P<0.05),凋亡率和Bax蛋白表达升高(P<0.05)。GIHCG在U251和SHG139细胞中靶向负调控miR-146a-3p表达,抑制miR-146a-3p表达逆转了沉默GIHCG对胶质瘤细胞增殖、凋亡及放射敏感性的影响。结论 沉默GIHCG表达可促进miR-146a-3p表达,从而增强胶质瘤细胞的放射敏感性。     

circ_0001955靶向miR-149对前列腺癌DU145细胞系放射敏感性的实验研究

目的:探讨circ_0001955对前列腺癌DU145细胞系放射敏感性的影响及分子机制。方法:将si-con、si-circ_0001955、miR-con、miR-149转染至DU145细胞中,分别记为si-con、si-circ_0001955、miR-con、miR-149组;将miR-149与pc-circ_0...     

Centrosome amplification induced by survivin suppression enhances both chromosome instability and radiosensitivity in glioma cells

Glioblastoma is characterised by invasive growth and a high degree of radioresistance. Survivin, a regulator of chromosome segregation, is highly expressed and known to induce radioresistance in human gliomas. In this study, we examined the effect of survivin suppression on radiosensitivity in malignant glioma cells, while focusing on centrosome aberration and chromosome instability (CIN). We suppressed survivin by small interfering RNA transfection, and examined the radiosensitivity using a clonogenic assay and a trypan blue exclusion assay in U251MG (p53 mutant) and D54MG (p53 wild type) cells. To assess the CIN status, we determined the number of centrosomes using an immunofluorescence analysis, and the centromeric copy number by fluorescence in situ hybridisation. As a result, the radiosensitisation differed regarding the p53 status as U251MG cells quickly developed extreme centrosome amplification (=CIN) and enhanced the radiosensitivity, while centrosome amplification and radiosensitivity increased more gradually in D54MG cells. TUNEL assay showed that survivin inhibition did not lead to apoptosis after irradiation. This cell death was accompanied by an increased degree of aneuploidy, suggesting mitotic cell death. Therefore, survivin inhibition may be an attractive therapeutic target to overcome the radioresistance while, in addition, proper attention to CIN (centrosome number) is considered important for improving radiosensitivity in human glioma.     

Silencing of R-Spondin1 increases radiosensitivity of glioma cells

Although radiation therapy is the most effective postoperative adjuvant treatment, it does not substantially improve the long-term outcomes of glioma patients because of the characteristic radioresistance of glioma. We found that R-Spondin1 (Rspo1) expression was elevated in high-grade gliomas and was associated with worse overall survival and disease-free survival. Rspo1 expression was also associated with reduced survival rates in glioma patients after treatment with radiotherapy and temozolomide (RT-TMZ). Importantly, Rspo1 was dramatically upregulated after radiation treatment in patients with glioma. Rspo1 silencing by shRNA potentiated glioma cell death upon radiation treatment. In a xenograft nude mouse model, combining radiation and silencing of Rspo1 potentiated tumor growth inhibition. Thus, combining radiotherapy with silencing of Rspo1 is a potential therapeutic approach.     

miR-203a-3p靶向AKT2增强骨肉瘤细胞的放射敏感性

目的:研究miR-203a-3p对骨肉瘤MG-63细胞凋亡和放射敏感性的影响及潜在作用机制.方法:qRT-PCR检测AKT2 mRNA的表达水平及不同放射剂量(0、2、4、6、8 Gy)照射后MG-63细胞中miR-203a-3p的表达水平,克隆形成实验检测不同放射剂量处理后细胞存活分数,流式细胞术测定MG-63细胞凋...     

EBV-LMP1 targeted DNAzyme enhances radiosensitivity by inhibiting tumor angiogenesis via the JNKs/HIF-1 pathway in nasopharyngeal carcinoma

LMP1, which is encoded by the Epstein-Barr virus, is proposed to be one of the major oncogenic factors involved in nasopharyngeal carcinoma (NPC). Previous studies demonstrated that down-regulation of LMP1 by LMP1-targeted DNAzyme (DZ1) increases the radiosensitivity of NPC. However, the mechanism by which DZ1 contributes to this radiosensitivity remains unclear. In this study, we determined whether a DZ1 blockade of LMP1 expression has an overall positive effect on the radiotherapy of NPCs by repressing HIF-1/VEGF activity and to investigate the mechanisms underlying LMP1-induced HIF-1 activation in NPC cells. The results showed that DZ1 inhibited the microtubule-forming ability of HUVECs co-cultured with NPC cells, which occurs with the down-regulation of VEGF expression and secretion. Moreover, LMP1 increases phosphorylated JNKs/c-Jun signaling, which is involved in the regulation of HIF-1/VEGF activity. After silencing LMP1 and decreasing phosphorylation of JNKs, NPC cells exhibited an enhanced radiosensitivity. Furthermore, in vivo experiments revealed a significant inhibition of tumor growth and a marked reduction of the K^trans parameter, which reflects the condition of tumor micro-vascular permeability. Taken together, our data suggested that VEGF expression is increased by LMP1 through the JNKs/c-Jun signaling pathway and indicated that DZ1 enhances the radiosensitivity of NPC cells by inhibiting HIF-1/VEGF activity.     

miR-324-5p通过靶向调控DAPK1降低胰腺癌细胞的放射敏感性

目的:探讨死亡相关蛋白激酶1（death-associated protein kinase 1,DAPK1）在胰腺癌（pancreatic cancer,PaC）细胞放射敏感性中的作用,验证miR-324-5p通过靶向调控DAPK1影响胰腺癌细胞放射敏感性的机制。方法:通过生物信息学预测靶向DAPK1的miRNAs,并利用双荧光素酶报告基因检测miR-324-5p对DAPK1的调控作用。在PANC-1和MIA PaCa-2细胞中过表达miR-324-5p和DAPK1或抑制miR-324-5p后,对各细胞株进行放射诱导,检测细胞增殖和凋亡情况,以及凋亡相关分子的表达情况。结果:GEO数据集结果显示,胰腺癌组织中miR-324-5p的表达水平高于正常组织。与正常胰腺导管上皮细胞系（HPDE6-C7）相比,胰腺癌细胞系(Capan-1、Bxpc-3、PANC-1和MIA PaCa-2)中miR-324-5p表达水平更高（P均<0.001）。双荧光素报告基因检测结果表明,miR-324-5p靶向DAPK1的3' UTR,并且可下调DAPK1的表达。细胞实验结果证实,过表达miR-324-5p通过靶向调控DAPK1降低放射诱导的细胞凋亡和DNA的损伤,进而降低了胰腺癌细胞的放射敏感性。结论:miR-324-5p通过负调控DAPK1降低胰腺癌细胞对放射的敏感性,从而影响DNA修复和细胞凋亡。miR-324-5p/DAPK1途径可能为胰腺癌的靶向治疗提供了潜在的治疗靶点。