PTBP1在胶质瘤进展中的作用研究

目的:探讨多聚嘧啶区结合蛋白1（PTBP1）在胶质瘤进展中的作用。方法:利用多个数据库分析PTBP1在胶质瘤组织和正常脑组织中的表达水平及其与胶质瘤的组织学级别和患者预后的关系。构建稳定敲低PTBP1的LN229细胞系,通过Western印迹和RT-qPCR技术验证细胞中PTBP1的敲低效率。通过EdU实验检测细胞的增殖能力。利用Transwell实验检测细胞的迁移和侵袭能力。结果:PTBP1在胶质瘤组织中较正常脑组织表达更高（P＜0.000 1）,其表达水平随组织学级别的升高而升高（P＜0.000 1）;PTBP1高表达的胶质瘤患者总生存期（OS）明显缩短（P＜0.000 1）;稳定敲低PTBP1的LN229细胞系,细胞的增殖速度变慢（t=3.579,P=0.037 3）,迁移（t=13.16,P＜0.000 1）和侵袭能力（t=3.111,P=0.035 8）显著下降。结论:PTBP1在胶质瘤中高表达且与胶质瘤的组织学级别和患者不良预后呈正相关;PTBP1促进胶质瘤细胞的增殖、迁移、侵袭。     

Dynamic radiological change of gliomas located in the paralimbic system and its clinical significance

Background The paralimbic system, which is composed of three parts, is an important functional unit. Gliomas located in the region remain a challenge for clinical treatment. However, the dynamic change of gliomas in the area has not been well documented. The purpose of this study was to identify the growth tendency of gliomas located in the paralimbic system and to obtain some suggestions for clinical treatment.
Methods Eleven cases of gliomas located in the paralimbic system were recruited in the study. All of them were proven by pathology. Analysis of the serial radiological examinations in each patient was performed from the initial to the final examination, taking into consideration the following items： initial tumor location, final location and the growth tendency.
Results In the initial and final examinations the ratios of insula involvement were 64% and 100%, respectively. On the other hand, the ratios of gliomas located in two or more parts of paralimbic system increased from 64% to 100% during the dynamic examination.
Conclusions Even though the paralimbic system is composed of three independent anatomical parts, gliomas tend to involve all three parts, especially the insula. Therapeutic plans should aim at the whole region of the system, even during the early stages of gliomas.     

HDAC1过表达诱导胶质瘤细胞产生耐药性

目的:构建组蛋白去乙酰化酶(histone deacetylase 1,HDAC1)过表达胶质瘤U87细胞系,探讨HDAC1过表达对胶质瘤细胞化疗药耐药性的影响.方法:分别用HDAC1重组过表达慢病毒载体pCDH-CMV-MCS-HDAC1-EF1-Puro和阴性空载体病毒pCDH-CMV-MCS-EF1-Puro转染U87MG细胞,通过嘌呤梯度浓度筛选出HDAC1稳定过表达细胞系U87MG-HDAC1和空载体对照细胞系U87 MG-Control,经Western Blotting鉴定,用不同浓度替尼泊苷(VM-26)和顺铂(cisplatin,DDP)对两种细胞进行处理,MTT法检测存活率,Hoechst/PI双染法检测细胞凋亡,Western Blotting检测Bcl-2、Bax及Caspase-3蛋白表达.结果:成功构建U87MG-HDAC1稳定过表达细胞系.与U87 MG-Control组相比,U87MG-HDAC1组中U87MG-HDAC1蛋白的表达显著升高[(1.148 ±0.024) vs (0.580 ±0.003),P＜0.01];药物处理后,U87MG-HDAC1细胞存活率显著升高[0.1μg/ml VM-26:(95.57±0.45)％ vs (68.8±1.49)％,P＜0.01],[0.08 μg/ml DDP:(99.20±7.4)％vs(72.48±2.03)％,P＜0.01];凋亡细胞个数比例明显下降(均P ＜0.05),Caspase-3蛋白表达量显著降低(P＜0.01),Bcl-2/Bax蛋白表达量比值明显升高(P＜0.01).结论:胶质瘤U87MG细胞中HDAC1过表达明显增强细胞对化疗药耐药性与Caspase-3和Bcl-2/Bax表达有关.     

Ad.RGD-ING4-PTEN对神经胶质瘤U87细胞增殖、凋亡及侵袭的影响

目的:探讨经RGD修饰的生长抑制因子4(inhibitor of growth 4,ING4)基因与第10染色体缺失与张力蛋白同源的磷酸酶基因(phosphatase and tensin homologue deleted on chromosome ten,PTEN)双基因共表达的腺病毒载体(Ad.RGD-ING4-PTEN)体外对神经胶质瘤U87细胞的增殖、凋亡及侵袭的影响.方法:以Ad.RGD-ING4-PTEN为实验组,Ad.RGD-ING4/-PTEN为单基因对照组,PBS、Ad.RGD/Ad-GFP为空白对照组,分别体外感染U87神经胶质瘤细胞.Western blotting检测目的基因ING4和PTEN在U87细胞中的表达,MTT法检测实验组病毒感染对U87细胞增殖的影响,流式细胞术及Real-time PCR法检测神经胶质瘤细胞凋亡及凋亡相关基因(Bcl-2、Bax、caspase-3、HIF-1α)表达变化,划痕实验及Transwell实验检测实验组病毒感染对U87细胞迁移及侵袭能力的影响,Real-time PCR法检测侵袭相关基因(MMP-2、MMP-9)表达变化.结果:成功检测到ING4和PTEN仅在实验组及相应单基因对照组中表达.实验组第5天细胞抑制率可达(83.1±4.6)％、凋亡率可达(40.7±4.3)％,与单基因组及空白对照组相比差异均有统计学意义(P＜0.05);实验组能明显上调U87细胞中Bax、caspase-3和下调HIF-1α、Bcl-2等细胞凋亡相关蛋白的表达(均P＜0.05),而且肿瘤侵袭相关分子MMP-2、MMP-9的表达也明显下调(均P＜0.05);实验组细胞迁移距离[(70.1±6.2)μm]和穿膜细胞数[(26.6±3.5)个]均明显减少,与单基因组及空白对照组比较差异有统计学意义(均P＜0.05).结论:与单基因腺病毒相比,Ad.RGD-ING4-PTEN双基因具有更显著的抑制U87神经胶质瘤细胞增殖、诱导其凋亡,并抑制其迁移及侵袭能力.     

Strategies to improve delivery of anticancer drugs across the blood–brain barrier to treat glioblastoma

Glioblastoma (GBM) is a lethal and aggressive brain tumor that is resistant to conventional radiation and cytotoxic chemotherapies. Molecularly targeted agents hold great promise in treating these genetically heterogeneous tumors, yet have produced disappointing results. One reason for the clinical failure of these novel therapies can be the inability of the drugs to achieve effective concentrations in the invasive regions beyond the bulk tumor. In this review, we describe the influence of the blood–brain barrier on the distribution of anticancer drugs to both the tumor core and infiltrative regions of GBM. We further describe potential strategies to overcome these drug delivery limitations. Understanding the key factors that limit drug delivery into brain tumors will guide future development of approaches for enhanced delivery of effective drugs to GBM.     

上调 Notch－1基因对 U215细胞 AKT －mTOR 通路的影响

目的：观察上调 Notch －1基因对人胶质瘤 U251细胞生学物行为及 AKT －mTOR 信号通路的影响。方法：采用 pNL －NICD 慢病毒感染 U251细胞,以 RT －PCR 和 Western －Blot 检测 Notch －1基因 mRNA 和蛋白的表达,以 MTT 检测细胞增殖能力,流式细胞术检测细胞周期变化,Transwell 实验检测细胞侵袭能力,同时检测 Notch －1上调对 AKT、mTOR、P70S6K、4Ebp －1蛋白的影响。结果：与对照组比较,NICD 慢病毒转染72h后,Notch －1基因 mRNA 和蛋白表达明显增高（P ＜0．01）;Notch －1上调明显促进 U251细胞增殖、侵袭、促进细胞进入 S 期,增加周期蛋白 Cyclin D1、CDK －4的表达,促进 AKT、mTOR 蛋白磷酸化。结论：上调 Notch －1基因促进 U251细胞增殖、侵袭,其机制和活化 AKT －mTOR 通路有关。     

Genomic proifling oflower-grade gliomas uncovers cohesive disease groups:implications fordiagnosis andtreatment

Lower?grade gliomas (including low? and intermediate?grade gliomas, World Health Organization grades II and III) are diffusely inifltrative neoplasms that arise most often in the cerebral hemispheres of adults and have traditionally been classiifed based on their presumed histogenesis as astrocytomas, oligodendrogliomas, or oligoastrocytomas. Although the histopathologic classiifcation of lower?grade glioma has been the accepted standard for nearly a century, it suffers from high intra? and inter?observer variability and does not adequately predict clinical outcomes. Based on integrated analysis of multiplatform genomic data from The Cancer Genome Atlas, lower?grade gliomas have been found to segregate into three cohesive, clinically relevant molecular classes. Molecular classes were closely aligned with the status of isocitrate dehydrogenase (IDH) mutations, tumor protein 53 mutations and the co?deletion of chromosome arms 1p and 19q, but were not closely aligned with histologic classes. These ifndings emphasize the potential for improved deifnition of clinically relevant disease subsets using integrated molecular approaches and highlight the importance of biomarkers for brain tumor classiifcation.