胶质瘤细胞血小板源生长因子B链的纯合二聚体自分泌环活性与肿瘤细胞增殖和凋亡的关系

目的探讨胶质瘤细胞血小板源生长因子Ｂ链的纯合二聚体（ＰＤＧＦＢＢ）自分泌环活性与其细胞增殖和凋亡的关系。方法用原位杂交、原位细胞凋亡检测和免疫组化ＡＢＣ法染色观察了７３例不同级别的胶质瘤组织。结果胶质瘤细胞ＰＤＧＦＢＢ自分泌环活性与其增殖活性呈显著性正相关，两者均随肿瘤恶性程度升高而增强。肿瘤细胞凋亡随肿瘤恶性程度升高而减少，并与肿瘤细胞ＰＤＧＦＢＢ自分泌环活性和增殖活性呈显著性负相关。结论以上指标对评价胶质瘤生物学行为均有参考价值。胶质瘤细胞ＰＤＧＦＢＢ自分泌环活性异常增加可能是刺激肿瘤细胞增殖和抑制其凋亡的重要因素，并在胶质瘤发生及恶性进展过程中起重要作用。     

长链非编码RNA CRNDE调控胶质瘤细胞凋亡

目的 探讨长链非编码RNA CRNDE在胶质瘤细胞凋亡中发挥的功能和可能的作用机制.方法 将CRNDE基因干扰siRNA转染人胶质瘤U87细胞系,利用PE Annexin-V/7-AAD双染,流式细胞仪检测细胞凋亡情况,并利用Western方法检测细胞凋亡关键蛋白的表达变化.结果 siRNA干扰CRNDE表达的胶质瘤细胞中,细胞凋亡程度增加,凋亡相关蛋白Caspase3、Caspase7、Caspase9、PARP表达量明显升高.结论 CRNDE可能通过降低凋亡相关蛋白活性及表达水平,抑制胶质瘤细胞凋亡能力.     

MiR-429通过CRKL靶向作用对U87胶质瘤细胞增殖和凋亡的影响

目的研究miR-429对人U87胶质瘤细胞增殖和凋亡的影响及可能机制。方法培养人U87胶质瘤细胞,应用LipofectamineLTX试剂将pre-miR-429质粒载体以及anti-miR-429质粒载体分别稳定转染人U87胶质瘤细胞;应用Real-time-PCR验证转染效率;应用CCK-8试剂盒检测miR-429对人U87胶质瘤细胞增殖能力的影响;应用Real-time PCR和Western blot检测人U87胶质瘤细胞中接头蛋白CRKL(v-crk avian sarcoma virus CT10oncogene homolog-like,CRKL)的mRNA和蛋白表达含量变化;将CRKL分别转染至U87胶质瘤细胞和miR-429过表达的U87胶质瘤细胞,应用CCK-8试剂盒检测人U87胶质瘤细胞增殖,应用流式细胞仪检测细胞凋亡的变化,应用Western blot法检测凋亡相关蛋白caspase-3和Bcl-2的蛋白表达变化。结果与对照组相比,miR-429过表达显著抑制了人U87胶质瘤细胞增殖,明显诱导了凋亡发生,显著降低了CRKLmRNA和蛋白在人U87胶质瘤细胞的表达水平,caspase-3的表达水平显著上调,Bcl-2的表达水平显著降低。CRKL过表达显著增强了人U87胶质瘤细胞增殖能力并且抑制了细胞凋亡,caspase-3的表达水平显著下调,Bcl-2的表达水平显著增强;CRKL过表达有效阻断了miR-429上调caspase-3、降低Bcl-2的作用,有效阻断了miR-429抑制U87胶质瘤细胞增殖和诱导凋亡的作用。结论 MiR-429抑制CRKL从而降低人U87胶质瘤细胞的增殖能力,诱导细胞凋亡。     

survivin基因与胶质瘤研究进展

细胞凋亡受多个基因的调控，其中抑制凋亡的基因主要包括bcl-2基因家族和凋亡抑制蛋白(IAP)基因家族，survivin基因是IAP家族新成员,在各种胶质瘤中高表达，并能强烈抑制胶质瘤细胞的凋亡。survivin在胶质瘤中的研究表明它是一种有效的判断胶质瘤患者预后的指标，并有望成为胶质瘤基因治疗的新靶点。     

survivin基因与胶质瘤研究进展

细胞凋亡受多个基因的调控 ,其中抑制凋亡的基因主要包括 bcl- 2基因家族和凋亡抑制蛋白 (IAP)基因家族 ,surv-ivin基因是 IAP家族新成员 ,在各种胶质瘤中高表达 ,并能强烈抑制胶质瘤细胞的凋亡。survivin在胶质瘤中的研究表明它是一种有效的判断胶质瘤患者预后的指标 ,并有望成为胶质瘤基因治疗的新靶点     

DNA拓扑异构酶-Ⅱα沉默对脑胶质瘤干细胞增殖和凋亡的影响

目的由U87MG细胞分离并鉴定脑胶质瘤干细胞,研究Topo-Ⅱα基因对脑胶质瘤干细胞增殖和凋亡的影响。方法培养脑胶质瘤U87MG细胞,分离和鉴定其中的胶质瘤干细胞。将Topo-Ⅱα基因特异性的siRNA转染胶质瘤干细胞。转染后,Western Blot检测转染后Topo-Ⅱα蛋白的表达,MTT法检测细胞增殖活力,双标流式法检测细胞凋亡率。结果成功分离出U87MG细胞球细胞,并鉴定其具有肿瘤干细胞特性。转染Topo-Ⅱα基因特异性的siRNA后,胶质瘤干细胞中的Topo-Ⅱα蛋白表达明显降低,同时,细胞增殖能力显著降低,凋亡率明显增加。结论由U87MG细胞系中分离出细胞球细胞具备肿瘤干细胞特性,Topo-Ⅱα基因沉默降低胶质瘤干细胞的增殖能力,促进细胞凋亡。     

热疗降低胶质瘤侵袭性作用过程中caspase 8改变的实验研究

目的:探讨caspase 8在热疗降低胶质瘤侵袭性过程中的作用。方法:利用Transwell构建胶质瘤侵袭模型,随机分为热疗对照组以及热疗30、60、120、180 min和240 min组。采用流式细胞术检测胶质瘤细胞凋亡水平,免疫印迹法检测胶质瘤细胞caspase 8的表达水平。结晶紫染色法测定胶质瘤侵袭性变化。结果:(1)热疗各组胶质瘤细胞凋亡率均明显高于热疗对照组(P0.05);(2)各热疗组胶质瘤细胞的caspase 8表达均高于热疗对照组,有统计学差异(P0.05);(3)各热疗组胶质瘤细胞的侵袭性均较对照组降低(P0.05)。结论:热疗后胶质瘤细胞侵袭性降低,这可能与caspase 8表达增加导致胶质瘤细胞凋亡有关。     

microRNA-93过表达促进A172脑胶质瘤细胞增殖并抑制其凋亡

目的探讨微小RNA-93(miR-93)对胶质瘤细胞A172增殖和凋亡的影响,观察miR-93对胶质瘤生物学行为的影响。方法通过荧光实时定量PCR(qRT-PCR)检测2例正常人脑组织、10例胶质瘤样本和5种胶质瘤细胞系中miR-93的表达;利用人工合成miR-93 mimic瞬时转染脑胶质瘤A172细胞,qRT-PCR检测细胞中miR-93的表达水平;采用MTT比色法检测A172细胞增殖情况;流式细胞术检测A172细胞周期与凋亡。结果胶质瘤样本及胶质瘤细胞系中miR-93的表达量较瘤旁与正常胶质细胞系高,miR-93 mimic上调了A172细胞中miR-93的表达水平,促进了A172细胞的增殖能力。miR-93转染细胞后,进入S期细胞显著增加,而G1期细胞则明显减少,同时A172细胞的凋亡数量减少。结论 miR-93在胶质瘤样本及胶质瘤细胞系中高表达,过表达miR-93有效促进了A172细胞的增殖,S期细胞增加G1期减少、细胞凋亡降低,提示miR-93可能成为胶质瘤诊断和治疗的新靶点。     

Perifosine通过抑制PI3K/Akt途径调节人胶质瘤U251细胞增殖、凋亡与自噬

 目的: 探讨Akt激酶抑制剂perifosine对人胶质瘤U251细胞凋亡、细胞周期和自噬的影响,确定perifosine诱导的细胞自噬与其促进胶质瘤细胞凋亡的相关性。方法: Perifosine处理U251细胞后,采用MTT法检测细胞活力;流式细胞术分析perifosine对U251细胞周期的影响;Annexin V-FITC/PI双标法检测perifosine对胶质瘤细胞凋亡的作用;免疫印迹法检测细胞内P21、P27和cyclin B1等细胞周期调控相关蛋白以及caspase-9、PARP等细胞凋亡相关蛋白的表达水平;通过观察细胞内自噬标志分子LC3-Ⅱ的分布与表达来确定perifosine对自噬的诱导作用。结果: Perifosine剂量依赖性地抑制U251细胞活力,能够通过抑制cyclin B1的表达而阻滞胶质瘤细胞周期于G₂期。Perifosine促进了U251细胞内caspase-9和PARP的剪切,抑制survivin表达,从而诱导胶质瘤细胞发生凋亡。同时,perifosine与自噬抑制剂氯喹联用后,U251细胞凋亡数量明显增加。结论: Perifosine能够抑制U251细胞的增殖,同时诱导细胞发生凋亡与自噬,抑制自噬促进了perifosine诱导的胶质瘤细胞凋亡。     

顺铂诱导大鼠C6胶质瘤细胞凋亡

为深入进行胶质瘤细胞凋亡的分了生物学研究及提高胶质瘤辅助化疗疗效打下基础。通过光镜,电镜,荧光显微镜分析,DNA断裂分析及流式细胞仪分析,进行顺铂诱导C6胶质瘤细胞调亡研究。本研究证实在3μg／mLCDDP作用72h,C6细胞出观细胞凋亡;光镜和电镜可见细胞形态学上出现细胞皱缩,染色质浓集贴达;流式细胞仅结果提示有凋亡峰出现,凋亡细胞占细胞总数17.3％±1.2％;荧光显微镜观察出现染色质浓集,染色质断裂：DNA电泳未表现出DNA呈梯状带型断裂。上述结果提示用顺铂成功地诱导大鼠C6胶质瘤细胞发生凋亡。     

胶质瘤细胞血小板源生长因子B链的纯合二聚体与其受体基因？…

目的 探讨胶质瘤细胞血小板源生长因子Ｂ链的纯合二聚合（ＰＤＧＦＢＢ）及其受体（ＤＧＦＲ）基因表达和ＰＤＧＦＲ活化汪洋在胶质瘤发生、发展听作用。方法 用原位杂交和免疫组化染色观察了７３例不同级别的人胶质瘤组织标本。结果 ６２例（８４．９％）的肿瘤细胞表达ＰＤＧＦＢｍＲＮＡ,基阳性率和阳性肿瘤细胞含量均随肿瘤恶性程度升高而递增。ＰＤＧＦＲα、ＰＤＧＦＲβ和这两种受体及其信号传递通路活化标记物酪氨酸磷酸     

胶质瘤细胞c—fos和c—myc基因表达与血小板源生长因子B链的？…

目的 探讨胶质瘤细胞ｃ－ｆｏｓ和ｃ－ｍｙｃ基因表达和血小板源生长因子Ｂ链的纯合二聚体自分泌环活性的改变及其相互关系。方法 用原位杂交和免疫组化方法观察了６７例人胶质瘤组织。结果 ６７例中,ｃ－ｆｏｓ ｍＲＮＡ,ｃ－ｆｏｓ蛋白,ｃ－ｍｙｃ ｍＲＮＡ及ｃ－ｍｙｃ蛋白阳性率分别为;１００％,１００％,８５．１％,８３．６％。     

胶质瘤bcd—2基因表达水平与其细胞增殖和凋亡关系的研究

目的 探讨胶质瘤细胞ｂｃｌ－２基因表达水平与肿瘤恶性程度、细胞增殖活性及凋亡程度的关系。方法 以６９例不同级别的人胶质瘤组织为研究对象,用原位杂交及免疫组化染色ＡＢＣ法分别检测ｂｃｌ－２ｍＲＮＡ、ｂｃｌ－２蛋白和增殖细胞核抗原（细胞增殖活性标记物）的表达,并用３’末标记法做原位细胞凋亡检测。结果 ６４例（９２．８％）表达ｂｃｌ－２ｍＲＮＡ,６０例（８７．０％）表达ｂｃｌ－２蛋白,两者的表达水平呈正     

IGF—IR反义硫代磷酸型寡核苷酸诱导胶质瘤细胞凋亡的病理学研究

目的：探讨IGF-IR基因的反义硫代磷酸型寡核苷酸对胶质瘤细胞的形态学影响。方法：根据IGF-IRcDNA序列设计正义,反义寡核苷酸片段,并对其部分碱基进行硫代磷酸修饰。体外培养的胶质瘤细胞分别经正义寡核苷酸和反义寡核苷酸处理,应用倒置显微镜活细胞观察,HE染色光镜观察,透射电镜及DNA琼脂糖凝胶电泳等方法研究IGF-IR反义硫代磷酸型寡核苷酸诱导胶质瘤细胞凋亡作用。结果：经反义寡核苷酸转染的胶质瘤细胞中,呈现典型的凋亡形态学改变,凋亡细胞最早期表现为细胞体积,容量减少,染色质凝聚,继之染色质集聚于核膜下成7新月状或块状;细胞核内染色质可完全固缩成团呈“黑洞”样或萎缩的核破裂形成一些较小的膜包绕的球体位于胞质内,最后出泡形成凋亡小体,DNA琼脂糖凝胶电泳分析经反义寡核苷酸处理的胶质瘤细胞DNA降解片段,可见有明显的小分子量DNA梯状条带,而野生型和正义寡核苷酸处理的胶质瘤细胞未见DNA梯状条带。结论：IGF-IR所介导失发泌环路IGF-I/IGF-IR。在胶质瘤细胞增殖和维持恶性表型中起重要作用。IGF-IR反义硫代磷酸型寡核苷酸能诱导胶质瘤细胞凋亡。     

PDGF autocrine stimulation dedifferentiates cultured astrocytes and induces oligodendrogliomas and oligoastrocytomas from neural progenitors and astrocytes in vivo

We present evidence that some low-grade oligodendrogliomas may be comprised of proliferating glial progenitor cells that are blocked in their ability to differentiate, whereas malignant gliomas have additionally acquired other mutations such as disruption of cell cycle arrest pathways by loss of Ink4a-Arf. We have modeled these effects in cell culture and in mice by generating autocrine stimulation of glia through the platelet-derived growth factor receptor (PDGFR). In cell culture, PDGF signaling induces proliferation of glial precursors and blocks their differentiation into oligodendrocytes and astrocytes. In addition, coexpression of PDGF and PDGF receptors has been demonstrated in human gliomas, implying that autocrine stimulation may be involved in glioma formation. In this study, using somatic cell type-specific gene transfer we investigated the functions of PDGF autocrine signaling in gliomagenesis by transferring the overexpression of PDGF-B into either nestin-expressing neural progenitors or glial fibrillary acidic protein (GFAP)-expressing astrocytes both in cell culture and in vivo. In cultured astrocytes, overexpression of PDGF-B caused significant increase in proliferation rate of both astrocytes and neural progenitors. Furthermore, PDGF gene transfer converted cultured astrocytes into cells with morphologic and gene expression characteristics of glial precursors. In vivo, gene transfer of PDGF to neural progenitors induced the formation of oligodendrogliomas in about 60% of mice by 12 wk of age; PDGF transfer to astrocytes induced the formation of either oligodendrogliomas or mixed oligoastrocytomas in about 40% of mice in the same time period. Loss of Ink4a-Arf, a mutation frequently found in high-grade human gliomas, resulted in shortened latency and enhanced malignancy of gliomas. The highest percentage of PDGF-induced malignant gliomas arose from of Ink4a-Arf null progenitor cells. These data suggest that chronic autocrine PDGF signaling can promote a proliferating population of glial precursors and is potentially sufficient to induce gliomagenesis. Loss of Ink4a-Arf is not required for PDGF-induced glioma formation but promotes tumor progression toward a more malignant phenotype.     

Caveolin-1 promotes tumor cell proliferation and vasculogenic mimicry formation in human glioma

Vasculogenic mimicry (VM) plays an important role in human glioma progression and resistance to antiangiogenic therapy as a compensatory neovascularization mechanism in malignant tumors. Caveolin-1 (Cav-1) has been found to contribute to VM formation. However, it remains largely unknown whether Cav-1 expression correlates with VM in glioma. In this study, we examined CAV-1 expression levels and VM in human glioma cell lines and in 94 human gliomas with different grades of malignancy, and present Cox proportional hazards regression. The molecular role of Cav-1 in glioma cells was investigated using quantitative polymerase chain reaction (qRT-PCR) assays, western blotting, CCK-8 assays, and tubule formation assays. Cav-1 expression and VM formation were positively correlated with each other and both were closely associated with glioma development and progression as evidenced by the presence of cystic tumor, shortened survival time, and advanced-stage glioma in glioma patients with Cav-1 overexpression/increased VM formation. Cav-1 promoted U251 glioma cell proliferation and VM formation in a Matrigel-based 3D culture model. VM-associated factors including hypoxia-inducible factor 1α (HIF-1α) and p-Akt was significantly elevated by Cav-1 overexpression but suppressed by siCav-1 in U251 cells. Collectively, our study identified Cav-1 as an important regulator of glioma cell proliferation and VM formation, contributing to glioma development and progression.     

Autocrine Growth Regulation by Granulocyte Colony-Stimulating Factor and Granulocyte Macrophage Colony-Stimulating Factor in Human Gliomas with Tumor Progression

Granulocyte colony-stimulating factor (G-CSF) and granulocyte macrophage colony-stimulating factor (GM-CSF) and/or their receptors are increasingly detected in solid human tumors, although little is known about their function in tumor growth and invasion. We analyzed RNA and protein expression of both factors and their receptors in 22 human gliomas (WHO grade II, III, and IV) and derived cell cultures. G-CSF, GM-CSF, and/or their receptors were expressed in all tumors and derived cell cultures, but coexpression of both factors and receptors was almost exclusively found in grade IV glioblastomas and thus correlated with advanced tumor stage. The functional significance of G-CSF and GM-CSF as regulators for glioma cells was demonstrated by 1) stimulation of proliferation and migration in tumor cells expressing one or both receptors by the corresponding factor; 2) inhibition of growth and migration of glioma cells expressing G-CSF, GM-CSF, and their receptors by neutralizing antibodies to both factors. These results indicate a significant role for both factors in the autocrine regulation of growth and migration in late-stage malignant gliomas and suggest a shift from paracrine to autocrine regulation with tumor progression. The implication of G-CSF and GM-CSF in glioblastoma growth regulation could make these factors further prognostic indicators and raises questions concerning their use in cancer therapy.     

胚胎干细胞关键因子Nanog在胶质瘤中的表达及意义

目的 探讨胚胎干细胞关键因子Nanog在人胶质瘤中的表达及意义。方法 通过免疫荧光双标技术,分析40例胶质瘤组织内胚胎干细胞关键因子Nanog与肿瘤干细胞相关基因Nestin、CD133及胚胎干细胞全能性相关基因Oct4 的共表达情况,并通过RT-PCR、Western blotting技术分析胶质瘤组织内Nanog与脑胶质瘤恶性程度之间的关系。结果 Nanog在胶质瘤组织中的表达随着胶质瘤病理级别增高而升高,而且超过50%的Nanog阳性细胞同时表达Nestin和CD133。95%以上的Nanog阳性细胞都同时表达胚胎干细胞全能性相关基因Oct4。结论 胶质瘤组织中Nanog多表达在肿瘤干细胞中,与胶质瘤的恶性程度呈正相关,在胶质瘤的发生、发展过程中起着重要作用,为研究胶质瘤的起源及胶质瘤的诊断和预后判断提供帮助。