反义miR-30a-5p抑制脑胶质瘤生长的体内实验研究

ObjectiveTo study the inhibitory effect of knocking down miR-30a-5p on the U87 human glioma xenograft growth and its possible mechanism. MethodsNude mice bearing subcutaneous U87 human glioblastoma were established and treated with miR-30a-5p antisense oligonucleotides (AS-miR-30a-5p) subcutaneous injection. Tumor size was measured every other day until the observation period ended. Researchers executed the animals after the treatment, stripped tumor tissues and extracted RNA and protein. Real-time PCR were conducted to detect the expression of miR-30a-5p. The histopathological characteristics and proliferation and apoptosis biological characters (including SEPT7, PCNA, cyclinD1, MMP-2, apoptosis related factor P53, bcl-2 and caspase3)were evaluated by HE and immunohistochemical staining, Western blot analysis respectively, and the cell apoptosis was detected by TUNEL method.ResultsIn AS-miR-30a-5p treated group, the tumor growth was delayed and the final tumor volume was smaller than that in the control and scr-ODN treated group (F=7.167, P＜0.05), and the expression of miR-30a-5p was knocked down. The expression of PCNA、cyclinD1 were significantly down-regulated while P53、SEPT7 and caspase3 up-regulated. Apoptotic index was increased significantly. ConclusionAs-miR-30a-5p suppresses the growth of U87 human gliomas xenografts significantly. Malignant phenotype of tumors are reversed to a considerable degree. Therefore, miR-30a-5p can be a candidate for targeted therapy of human glioma.     

敲低miR-19a、miR-19b抑制人脑胶质瘤细胞生长的体外研究

目的 探究敲低microRNA(miR)-19a和miR-19b表达对人脑胶质瘤细胞系SNB19细胞生物学特征的影响.方法 常规培养SNB19细胞,脂质体介导miR-19a、miR-19b抑制物转染SNB19细胞,同时设未转染组(对照组)、无义序列转染组和miR-19a+miR-19b抑制物转染组.应用RT-PCR检测转染后细胞miR-19a、miR-19b的表达,MTT、流式细胞术分别检测转染后细胞增殖能力和细胞周期的变化,Transwell实验检测转染后细胞的侵袭能力.结果 与对照组和无义序列转染组比较,抑制物转染组细胞miR-19a和miR-19b的表达、增殖和侵袭能力均降低,差异有统计学意义(P＜0.05),而且miR-19a+miR-19b抑制物转染组细胞miR-19a和miR-19b的表达、转染后2、3、4、5 d细胞的增殖能力、侵袭能力均低于miR-19a、miR-19b抑制物转染组,差异有统计学意义(P＜0.05);抑制物转染组较对照组和无义序列转染组细胞周期延迟,且miR-19a+miR-19b抑制物转染组较miR-19a、miR-19b抑制物单独转染组细胞延迟更为明显.结论 miR-19a和miR-19b可能是癌微RNA,有望作为人脑胶质瘤基因治疗的侯选靶点.

Abstract：

objective To investigate the effects of knocking down of miR-19a and miR-19b on the biological characteristics of SNB19 glioblastoma cells. Methods Oligonucleotides inhibitor of miR-19a and miR-19b (miR-19a inhibitor or miR-19b inhibitor) mediated by lipofectamine2000 were transfected to SNB19 cells to knock down miR-19a and miR-19b; control group (without transfection),group D (performing transfection with nonsense sequence) and group E (performing transfection with both miR-19a inhibitor and miR-19b inhibitor) were established. Real time PCR was conducted to detect the expressions ofmiR-19a and miR-19b in these groups after the transfection. The cell proliferation rate and cell cycle kinetics were detected by 3-(4, 5-Dime- -thylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay and flow cytometry, respectively; the cell invasive ability was evaluated by Transwell assay.Results As compared with those in control group and group D, the expressions of miR-19a and miR-19b, proliferation activity and invasive ability of cells in the miR-19a/19b inhibitor transfected cells (group A/B) were significantly reduced (P＜0.05). The expressions of miR-19a and miR-19b and the proliferation activity and invasive ability of cells 2, 3, 4 and 5 d after the transfection in group E were significantly reduced as compared with those in group A/B (P＜0.05). Delayed cell cycle in group A/B and group E was noted as compared with that in control group and group D; and group E enjoyed more obviously delayed eell cycle than group A/B (P＜0.05). Conclusion MiR-19a and miR-19b might be oncomiRs, and may be candidate target miRNAs for gene therapy of glioma.     

Wnt2信号通路重要成员在胶质瘤中的表达及其意义

近来发现Wnt信号通路对个体发育和肿瘤生成具有重要作用[1-2].为进一步探讨Wnt通路在胶质瘤中是否存在表达异常及其在胶质瘤生成中的作用,我们采用RT-PcR、组织芯片免疫组织化学染色以及蛋白印迹法,对人脑胶质瘤Wnt2通路相关因子的表达变化及其意义进行了分析.     

反义miRNA-221/222上调p27kip1抑制胶质瘤细胞生长的体外研究

目的 探讨敲低miRNA-221/222表达上调p27kip1抑制U251人脑胶质瘤细胞株生长的效果及机制.方法 脂质体共转染反义miRNA-221/222下调U251人脑胶质瘤细胞株miRNA-221、miRNA-222的表达.使用Northern blot方法 鉴定转染后U251细胞miRNA-221、miRNA-222表达水平下调;MTT法评价反义miRNA-221/222抑制U251细胞生长效果;流式细胞术检测转染后U251细胞周期分布;Western blot分析p27kip1蛋白的表达变化.结果 Northern blot显示反义miRNA-221/222共转染组使miRNA-221、miRNA-222的表达水平明显下降.反义miRNA-221转染组仅使miRNA-221的表达水平明显下降,反义miRNA-222转染组仅使miRNA-222的表达水平明显下降.转染无意序列组及对照组的miRNA-221、miRNA-222表达水平没有改变.MTT结果 显示反义miRNA-221/222共转染组肿瘤细胞生长速度小于对照组、转染无意序列组、转染反义miRNA-221组、转染反义miRNA-222组.流式细胞术检测可见反义miRNA-221/222共转染组细胞周期存在G0/G1期阻滞且明显高于其他各组.Western blot显示反义miRNA-221/222共转染组的p27kip1蛋白表达明显上调.结论 反义miRNA-221/222通过上调p27kip1蛋白表达来抑制胶质瘤细胞U251的生长.     

BMSCs作为HSV-tk载体联合CX43增强旁效应治疗胶质瘤的实验研究

目的 以骨髓间充质干细胞(BMSCs)为自杀基因HSV-tk载体,联合连接蛋白CX43介导的旁效应,对以BMSCs肿瘤追踪特性为基础的胶质瘤进行治疗研究.方法 以CX43质粒转染C6胶质瘤细胞,以腺病毒介导HSV-tk转染BMSCs;建立C6胶质瘤模型,实验动物分为4组:C6对照组、CX43-C6组、tk-BMSCs/C6/GCV治疗组和tk-BMSCs/CX43-C6/GCV治疗组.观察动物生存期,MRI监测肿瘤体积;脑切片行PCNA、原位凋亡检测肿瘤中央与边缘部位细胞增殖与凋亡情况.结果 CX43组、tk/GCV组生存期长于对照组,二者联合治疗组生存期最长,MRI示部分肿瘤消失;肿瘤内部与边缘细胞增殖活性下降,凋亡明显.结论 tk-BMSCs/GCV体系可有效杀伤侵袭瘤细胞在内的胶质瘤灶,连接蛋白CX43可增强此治疗效果.     

人隔蛋白7的真核表达载体的构建及表达

目的构建人隔蛋白7(SEPT7,hCDC10/SEPT7)的表达载体并对U251人脑恶性胶质瘤细胞系进行转染且检测其表达。方法RT-PCR方法扩增SEPT7cDNA片段,并将扩增的片段插入pCDNA3真核表达载体,构建成含SEPT7cDNA的重组载体pCDNA3/SEPT7,以脂质体介导该质粒转染人脑恶性胶质瘤细胞系U251,应用RT-PCR和免疫荧光染色鉴定转染细胞中hCDC10/SEPT7的表达。用流式细胞术对转染前后的U251细胞进行细胞周期分析。结果成功构建含SEPT7cDNA的重组载体pCDNA3/SEPT7,并使其稳定转染U251细胞,在转染的细胞中,证实有SEPT7mRNA表达上调。细胞周期检测结果G0/G1期细胞增多,SPF降低。结论成功构建SEPT7表达载体,并在人脑恶性胶质瘤细胞系获得表达,延迟细胞周期进展。     

靶向Ku70重组腺病毒shRNA在C6胶质瘤细胞的表达

目的 研究重组腺病毒Ad—Ku70shRNA对C6胶质瘤细胞系Ku70蛋白表达的影响，探讨放射治疗过程中基因增敏的新途径。方法以穿梭质粒为基础，构建重组腺病毒Ad—Ku70shRNA载体，扩增并鉴定其病毒滴度。然后转染至C6鼠脑胶质瘤细胞中，应用WestemBlot及免疫荧光观察其Ku70蛋白的表达情况，研究重组腺病毒Ad—Ku70shRNA对C6细胞Ku70表达的抑制效果。结果成功构建并扩增Ad—Ku70shRNA重组腺病毒，感染C6胶质瘤细胞后Ku70的表达明显降低。结论Ad—Ku70shRNA重组腺病毒载体可以明显降低C6胶质瘤细胞Ku70的表达。该结果为放射治疗基因增敏研究提供了有利的工具。     

RNAi下调PIK3 CB表达抑制U251胶质瘤细胞生长的体内外研究

目的 探讨应用RNAi技术靶向磷酸肌醇酯-3-激酶β催化亚单位(PIK3CB)抑制恶性胶质瘤细胞系U251的PIK3CB表达后在体内外对U251细胞生长抑制作用.方法 将短发夹RNA(shRNA)表达载体psiRNA-PIK3CB进行脂质体介导的U251人脑恶性胶质瘤细胞系表达,检测细胞转染前后的细胞增殖能力和凋亡的变化.应用裸鼠皮下荷瘤模型观察脂质体介导shRNA基因治疗对U251细胞生长抑制作用,对肿瘤组织应用免疫荧光双染色和免疫组化的方法分析结果.结果 靶向PIK3CB的shRNA转染后U251细胞生长受到抑制,细胞周期出现G2/M阻滞,细胞明显凋亡.裸鼠皮下荷瘤模型实验显示psiRNA-PIK3CB显著抑制皮下肿瘤生长(P＜0.01).结论 靶向PIK3CB的shRNA基因治疗可以成为胶质瘤治疗的新策略.     

反义miR-21抑制异种移植U251人脑胶质瘤生长的体内研究

目的 探讨敲低miR-21表达抑制裸鼠荷皮下U251人腩胶质瘤生长的疗效和机制. 方法 原位注射miR-21反义寡聚核苷酸(AS.miR-21)治疗裸鼠皮下荷U251人脑胶质瘤.定时测量肿瘤大小评估原位注射AS-miR-21治疗效果:使用Real time PCR和原位杂交方法鉴定治疗后miR-21表达水平下调;采用HE染色和免疫组织化学染色(PCNA、PTEN、MMPs、和Septins)评价治疗后肿瘤牛物学性状改变;TUNEL法检测肿瘤细胞凋亡. 结果 肿瘤生长曲线显示AS-miR-21治疗组肿瘤生长速度及体积小于空白对照与无义序列治疗组(F=52.458,P=0.000);Real-time PCR法:AS-miR-21治疗组miR-21表达下调为对照组的0.018±0.009:原位杂交显示AS-miR-21治疗组miR-21表达水平较对照与无义序列治疗组下调:组织病理学检测表明AS-miR-21治疗后肿瘤恶性度降低;TUNEL法检测可见AS-miR-21治疗组细胞凋亡数显著高于对照与无义序列治疗组(F=141.021,P=0.000).结论 以miR-21作为靶点抑制异种移植U251人脑胶质瘤生长,miR-21可能通过上调抑癌基因PTEN抑制胶质瘤的生长,可以作为人脑胶质瘤基因治疗的侯选靶点.     

神经上皮组织起源的脑肿瘤中连接蛋白的表达

目的　探讨连接蛋白 (Cx) 43、3 2在神经上皮组织起源的脑肿瘤中表达及其与肿瘤的病理类型、恶性程度的关系。方法　利用Cx43、Cx3 2和Ki 67单抗或多抗对 8例正常脑组织、5 0例神经上皮组织起源的脑肿瘤和 4个恶性脑瘤体外细胞系进行免疫组化检测。结果　神经上皮组织起源的脑肿瘤中Cx表达阳性率为 5 4% ,Cx3 2仅在低恶度少枝胶质细胞瘤中表达 ,Cx43表达随WHO分级升高而下降 ;与Ki 67标记指数 (LI)呈负相关。表达缺失多见于高Ki 67LI者。结论　神经上皮组织起源的脑肿瘤中CX 表达可下降或缺失 ,Cx43表达与肿瘤的病理类型及恶性程度密切相关