人脑胶质瘤的表皮生长因子基因表达

采用Ｎｏｒｔｈｅｒｎ杂交和斑点杂交的方法检测了５０例胶质瘤、４个恶性胶质瘤体外细胞系和７例正常脑组织表皮生长因子（ＥＧＦ）ｍＲＮＡ表达水平。结果显示：上述组织或细胞都可表达５．０ｋｂ的ＥＧＦｍＲＮＡ片断，高恶度胶质瘤较低恶度胶质瘤和正常脑组织ＥＧＦｍＲＮＡ表达水平增高，低恶度胶质瘤与正常脑组织的表达无显著差异。在５０例胶质瘤中２９例（５８％）ＥＧＦｍＲＮＡ过表达，其中多见于恶性胶质瘤，ＥＧＦｍＲＮＡ表达与肿瘤的分级呈正相关。提示胶质瘤可以合成ＥＧＦ，在胶质瘤的发生发展过程中，ＥＧＦ参与或促进了其恶性进展。     

PDGF在骨髓问充质干细胞向胶质瘤趋化迁移过程中的作用

目的 观察血小板衍生生长因子(PDGF)和胶质瘤细胞条件培养基对人骨髓间充质干细胞(hMSCs)体外迁移能力的影响,探讨PDGF在hMSCs向胶质瘤趋化迁移过程中的作用. 方法 全骨髓贴壁细胞法分离培养hMSCs,应用RT-PCR检测hMSCs中PDGF受体α(PDGFR-α)和β(PDGFR-β)的表达;利用聚碳酸酯膜小室建立体外趋化迁移模型,观察5、50、125 ng/mL PDGF和胶质瘤细胞条件培养基对hMSCs的体外趋化作用以及加入PDGF抗体后对hMSCs趋化迁移的影响. 结果 RT-PCR检测到hMSCs表达PDGFR-α和PDGFR-β;PDGF可以浓度依赖性促进hMSCs的趋化迁移.胶质瘤细胞条件培养基也可趋化hMSCs的迁移.与空白对照组相比迁移细胞数差异均有统计学意义(JP<0.05);PDGF抗体可消除50 ng/mL PDGF、减弱胶质瘤细胞条件培养基对hMSCs趋化迁移的作用. 结论 PDGF促进hMSCs的趋化迁移.在hMSCs向胶质瘤选择性迁移过程中发挥"趋化因子"样作用.     

PDGF-B及其受体蛋白在缺血大鼠脑组织中的表达

目的 探讨血小板源性生长因子B链(PDGF—B)及其受体PDGFR—β在缺血性脑损伤后濒危神经元存活和损伤修复中的作用。方法 采用线栓法制备大鼠大脑中动脉局灶性缺血模型，分别于缺血2h再灌注6h、24h、3d、7d、14d和21d处死，用免疫组化分别检测PDGF—B和PDGFR—β蛋白在脑缺血区及其周围的表达。结果 缺血再灌注后24h，PDGF—B和PDGFR—β在缺血区及其周围的神经元的表达开始增强，并分别于3d和7d出现第一个高峰，其中PDGFR—β的表达还可见于反应性胶质细胞；两者的第二个表达高峰出现在再灌注后14d，主要表达于梗死区增生的胶质细胞、新生血管和胶质疤痕周围的神经元。结论局灶性脑缺血后，PDGF—B及其受体蛋白在时间和空间上的一致性表达，说明它们对濒危神经元的存活、胶质疤痕形成和血管发生均有重要的作用。     

PDGF-BB在人脑血管母细胞瘤中的表达及意义

目的研究血小板源生长因子B链的纯合二聚体(PDGF-BB)在人脑血管母细胞瘤和正常脑组织中的表达。方法应用链霉菌抗生物素蛋白-过氧化物酶法(S-P法),观察PDGF-BB在32例人脑血管母细胞瘤组织中的表达情况,并与10例正常脑组织作对照。结果 PDGF-BB在人脑血管母细胞瘤组织中的灰度值明显高于正常脑组织(P<0.01)。结论 PDGF-BB在脑血管母细胞瘤血管生成中起着重要作用,抗PDGF-BB治疗可能成为治疗脑血管母细胞瘤的新方法。     

Weak association of the platelet-derived growth factor beta (PDGFB) and PDGF receptor beta (PDGFRB) genes with schizophrenia and schizoaffective disorder

Abstract

Schizophrenia is a severe neuropsychiatric disorder with diverse characterization of symptoms. Extensive research has been performed to elucidate the etiology of schizophrenia. One of the most convincing hypotheses comes from the dopaminergic system although none of the core genes has been consistently positive in association studies. Objective. In this investigation, we explored the possibility that the genes for platelet-derived growth factor beta (PDGFB) and its receptor (PDGFRB) might play an important role in the development of schizophrenia based on previous reports pointing to their ability to interact with the dopamine D₂/D₄ and NMDA receptors as well as their role in neurite outgrowth. Methods. We investigated the association of variants around these genes with schizophrenia and schizoaffective disorder in 104 small nuclear families using the Sib-Transmission Disequilibrium Test (TDT-STDT). Furthermore, quantitative trait analysis using family-based association test was applied to determine possible association of age at onset (AAO). Results. Allele G in PDGFRB(rs758588) was associated with AAO (P=0.019). An over-transmission of allele T in PDGFB(rs130650) polymorphism (P=0.043) and an over-transmission of allele A in PDGFRB(rs6865659) polymorphism (P=0.046) were observed. Furthermore, the combined TDT-STDT yielded consistent results. Conclusion. Overall, PDGFB and PDGFRB genes might play a role in the etiology of schizophrenia.     

Fibroblast growth factor-2 (FGF-2) and platelet-derived growth factor AB (PDGF AB) promote adult SVZ-derived oligodendrogenesis in vivo

The capacity of multipotential progenitor cells of the adult mammalian forebrain to generate myelin-forming oligodendrocytes was tested by grafting fragments of different regions of the subventricular zone (SVZ) of the lateral ventricle and the striatum of 6-month-old wild-type mice into the brain of neonate shiverer and wild-type mice. Without growth factor treatment, only few cells of the rostral SVZ survived and formed myelin after engraftment. Treating donors prior to transplantation with a single intraperitoneal injection of epidermal growth factor, basic fibroblast growth factor 2 (FGF-2), and platelet-derived growth factor AB (PDGF(AB)) vigorously promoted the survival, migration, and differentiation of the grafted SVZ cells into myelin-forming oligodendrocytes. In situ, both growth factors expanded the constitutively proliferative PSA-NCAM+ population and favored their differentiation toward the neuronal and oligodendroglial cell fate. The adult central nervous system thus harbors a focal reservoir of FGF-2 and PDGF(AB)-responsive cells which are able to generate substantial amounts of myelin-forming oligodendrocytes in vivo, opening a new prospective area for therapy in demyelinating diseases.     

Activation of phosphoipase D by platelet-derived growth factor (PDGF) in rat C6 glioma cells: Possible role in mitogenic signal transduction

Abstract

The effects of platelet-derived growth factor (PDGF) on phosphoiipase D (PLD) activity and deoxyribonucleic acid (DNA) synthesis in rat C6 glioma cells have been investigated. Pretreatment of serum-starved C6 cells with PDGF results in enhanced choline production and the phosphatidylethanol (PEt) formation in the presence of ethanol’ indicating the activation of PLD acting on phosphatidylcholine (PG). The dose-response curve for choline generation and DNA synthesis were comparable. In addition, the effects of PDGF on both PEt formation and [ H]thymidine incorporation into acid-precipitable material was blocked by the potent protein kinase G (PKG) inhibitor 1-(5-isoquinolinesulphonyl)-2-methylpiperazine (H-7) but not by N-(2-guanidinoethyl)-5-isoquinolinesulphonamide (HA1004), a relatively weak inhibitor of PKC, suggesting that PDGF plays an important role as a positive regulator of glioma cell growth via a PLD-mediated mitogenic signal transduction cascades, which depends largely on the activation of PKG.     

A single intracerebral microinjection of platelet-derived growth factor (PDGF) accelerates the rate of remyelination in vivo

We had demonstrated that platelet-derived growth factor (PDGF) enhanced the reconstruction of myelin-like membranes after their disruption by lysophosphatidylcholine (LPC) in vitro. To investigate its role in vivo, a demyelinating lesion of the corpus callosum was induced in adult Wistar rats by a stereotaxic microinjection of 1 microl LPC, then 63 pairs of rats received either 1 microg PDGF, or its vehicle buffer which were injected above LPC. The effects of PDGF were significant after 2 weeks: the number of oligodendrocytes (OL) expressing 2',3'-cyclic nucleotide 3'-phosphodiesterase in the lesion increased by 49%, mature OL labelled by in situ hybridization for myelin basic protein-mRNA increased by 27% (P<10(-2)), and the total volume of demyelination decreased by 60% compared to controls. The proliferation of cells of the OL lineage was also enhanced up to 67% by PDGF compared to LPC controls (P<2.5 x 10(-2)). Ultrastructural studies confirmed this dramatic improvement, and the ratio of remyelinated to demyelinated axons, determined at the maximal demyelination site, in the centre of the lesion, increased by 10-fold (P<2.5 x 10(-3)) in animals treated with PDGF. Remyelination was complete after 3 months for both treatments. Neither exacerbation of gliosis nor glial tumoural transformation were observed. Mechanisms through which PDGF improves remyelination could involve proliferation of OL progenitors, and/or of already differentiated surviving OLs, and a chemotactic effect, which had been identified in vitro.     

Possible association of platelet-derived growth factor (PDGF) with the appearance of reactive astrocytes following brain injury in situ

The association of platelet-derived growth factor (PDGF) with the appearance of reactive astrocytes following injury was investigated by using a specific antagonist of PDGF, Trapidil. The cerebral cortex of 4-week-old male rats was unilaterally injured with a 22-gauge needle. Immunohistochemical staining with antiserum to glial fibrillary acidic protein revealed that reactive astrocytes had increased in number around the wound by 2 days following the injury and had spread to the ipsilateral areas distant from the wound by 3 days. The appearance of reactive astrocytes in areas distant from the wound was dramatically suppressed by the administration of Trapidil. This finding indicates that PDGF might play a role in gliosis following injury.     

结缔组织生长因子在脑胶质瘤组织中的表达和肿瘤级别的关系

目的通过检测人脑胶质瘤患者肿瘤组织中结缔组织生长因子的表达水平,探讨其和肿瘤级别的关系及作用机制。方法采用荧光实时定量聚合酶链式反应(RT-PCR)法检测结缔组织生长因子(CTGF)mRNA在47例脑胶质瘤组织和25例正常脑组织中的表达水平,统计分析表达水平和肿瘤级别之间的关系。结果CTGF在胶质瘤Ⅰ-Ⅱ级(高分化组)及胶质瘤Ⅲ~Ⅳ级(低分化组)中的表达均明显高于正常脑组织(P<0.01),而且在Ⅲ~Ⅳ级胶质瘤中的表达量显著高于胶质瘤Ⅰ~Ⅱ级(P<0.01),说明随着肿瘤级别的升高CTGF表达也增强。结论CTGF在胶质瘤组织中高表达,而且表达水平和恶性程度有密切联系。CTGF的检测可作为胶质瘤恶性程度判断的参考,为从基因水平上探讨胶质瘤的生物学行为、预后及治疗提供新的思路。     

E1B缺陷性腺病毒对人恶性脑胶质瘤的溶瘤作用

目的 研究E1B缺陷性腺病毒d11520对人恶性脑胶质瘤细胞株U251的体外溶瘤作用. 方法 按感染复数(MOI)为50、5、0.5、0.05、0.005、0 pfu将E1B缺陷性腺病毒dl1520感染常规培养的U251、Hep3B、T24细胞(Hep3B为阳性对照,T24为阴性对照),结晶紫染色观察细胞病变(CPE)出现的时间:MOI为5pfu时病毒空斑试验检测dl1520在3种细胞中的复制.将携带报告基因βgal的腺病毒载体Ad-βgal感染细胞,计算dl1520对3种细胞的感染率. 结果 结晶紫染色结果显示Hep3B细胞对dl1520最敏感、发生CPE效应最快,U251次之,而T24则不产生CPE效应;dl1520在U251细胞中复制数和感染率均低于Hep3B细胞,但明显高于T24细胞,差异均有统计学意义(P＜0.05). 结论 E1B缺陷性腺病毒dl1520对人恶性脑胶质瘤细胞具有显著的溶瘤作用.     

Platelet–derived growth factor (PDGF) and receptor (PDGFR) expression in human meningiomas: correlations with clinicopathological features and cytogenetic analysis

PDGFs and their receptors expression were examined in a series of 46 meningiomas by using specific monoclonal antibodies. The immunostaining was quantified by an image analyser and the results correlated with clinical and morphological data (histological type and grade). In addition, since the PDGFB chain is encoded by the c–sis proto–oncogene localized on chromosome 22 and because monosomy 22 has been frequently reported in meningiomas, PDGFs and PDGFRs expression have been correlated with cytogenetic analysis performed in 29 cases. The results demonstrate PDGF A and PDGFB expression in most meningioma specimens and co–expression of these growth factors in numerous cells. PDGF A and B immunoreactivity was related to histo logical grade. PDGFR βexpression was strong in almost all meningiomas whereas PDGFR α was low. PDGFR α expression was related to tumour location and grade and PDGFR β to histological subtype only. The cytogenetic analysis was not related to PDGFB chain expression. Taken together these data further confirm PDGF and PDGFR expression in human meningioma; PDGF may exist as an heterodimer (AB) as well as its receptor. The lack of correlation between cytogenetic analysis and PDGF values, the low level of PDGFB in recurrent meningiomas suggests that it is unlikely that the c–sis proto–oncogene plays an important role in the genesis of meningiomas.     

人脑胶质瘤中表皮生长因子受体表达的研究

目的：探讨表皮生长因子受体（ＥＧＦＲ）基因表达与胶质瘤恶性程度的关系。方法：采用Ｎｏｒｔｈｅｒｎ印迹杂交及免疫组织化学技术从ｍＲＮＡ及蛋白水平检测了５０例人脑胶质瘤、４个体外恶性胶质瘤细胞系及８例正常脑组织的ＥＧＦＲ的基因表达。结果：免疫组化检测高恶度胶质瘤（ＷＨＯⅢ－Ⅳ级）ＥＧＦＲ表达６９％（２０／２９），而低恶度胶质瘤（ＷＨＯⅠ－Ⅱ级）表达率为３３％（７／２１），差异显著（Ｐ＜０．０１）；４例细胞系阳性表达１００％；８例正常脑组织无ＥＧＦＲ蛋白表达。ＷＨＯ分级与ＥＧＦＲ蛋白表达呈正相关（ｒ＝０．５５９７，Ｐ＜０．００１）。对５０例胶质瘤进行Ｎｏｒｔｈｅｒｎ印迹杂交，其结果与免疫组化检测结果一致，ＥＧＦＲｍＲＮＡ也随胶质瘤恶性程度的增加而表达增高。结论：ＥＧＦＲ可能在恶性胶质瘤的发生发展中起重要作用，ＥＧＦＲ过表达与胶质瘤分级相关性为从分子水平评估肿瘤的恶性程度及选择基因治疗的靶基因提供了参考。     

血管内皮生长因子与水孔蛋白4在胶质瘤及脑转移瘤中的表达及意义

目的 探讨血管内皮生长因子(VEGF)与水孔蛋白4(AQP4)在胶质瘤及脑转移瘤中的表达,并探讨两者与胶质瘤及脑转移瘤的组织病理学关系及在瘤周水肿形成过程中的作用.方法 选择福建医科大学附属第一医院神经外科自1999年至2001年手术切除并经病理检查证实的胶质瘤石蜡组织标本73例和脑转移瘤组织标本15例,并另取正常脑组织标本8例作为对照,应用免疫组织化学方法检测组织标本中VEGF与AOP4的表达.结果 正常脑组织中未见VEGF表达:高级别胶质瘤与低级别胶质瘤之间、低级别胶质瘤与正常脑组织之间、脑转移瘤与正常脑组织及低级别胶质瘤之间VEGF阳性表达比较差异有统计学意义(P<0.05),而脑转移瘤与高级别胶质瘤之间VEGF阳性表达比较差异无统计学意义(P>0.05).AQP4在所有组织标本中均有表达,正常脑组织与高级别胶质瘤、脑转移瘤之间,低级别胶质瘤与高级别胶质瘤、脑转移瘤之间AQP4阳性表达比较差异有统计学意义(P<0.05),而正常脑组织与低级别胶质瘤之间、脑转移瘤与高级别胶质瘤之间AQP4阳性表达比较差异无统计学意义(P>0.05).Spearman相关分析显示两者在胶质瘤及脑转移瘤组织中表达呈正相关关系(r=0.516,P<0.05).结论 VEGF与AQP4是参与形成肿瘤周围水肿的重要分子生物学因素,且两者可能存在某种协同作用.     

Scatter factor/hepatocyte growth factor (SF/HGF) content and function in human gliomas

Scatter factor/hepatocyte growth factor (SF/HGF) is a pleiotrophic cytokine that stimulates motility and invasion of several cancer cell types and induces angiogenesis. Its receptor MET is a transmembrane tyrosine kinase encoded by the C-MET proto-oncogene. To assess the potential relevance of SF/HGF in gliomas we performed functional studies in vivo and in vitro, expression analyses and correlative studies. We showed that both SF/HGF and MET are expressed in gliomas in vivo and are upregulated during transition from low grade to malignant glioma. When SF/HGF cDNA was transfected into glioma cells that expressed the MET receptor the cells formed considerably larger and more vascularized intracranial tumors in vivo than SF/HGF negative control clones. In other glioma cells, which constitutively expressed both SF/HGF and MET, we abolished SF/HGF expression by antisense ribozyme-targeting, which led to a significant decrease in tumorigenicity and tumor growth. In vitro SF/HGF strongly stimulated glioma cell motility and to a lesser degree proliferation. SF/HGF also strongly increased endothelial cell motility in vitro and extracts of tumors derived from SF/HGF-transfected glioma cells were more mitogenic for endothelial cells and more angiogenic in the rat cornea angiogenesis assay than extracts from control tumors. In a three-dimensional in vitro angiogenesis assay basic fibroblast growth factor (bFGF) was found to synergize with either SF/HGF or vascular endothelial growth factor (VEGF) in inducing endothelial capillary-like tubes, whereas neither SF/HGF nor VEGF alone or in combination were effective. Interestingly, while both VEGF and SF/HGF levels appeared to be increased in malignant gliomas compared with low grade ones, this was not the case for bFGF of which biologically relevant levels were already present in low grade gliomas. It thus seems that bFGF alone is insufficient to induce angiogenesis in gliomas but may act synergistically with either VEGF and/or SF/HGF when these become upregulated during malignant progression. In conclusion, we showed that SF/HGF may contribute to glioma progression by stimulating tumor invasiveness, proliferation and neovascularization.     

Immunohistochemical study of chondroitin sulfate in human gliomas

Summary A polyclonal rabbit antiserum was utilized to localize chondroitin sulfate in human gliomas. Tissue sections were digested with chondroitinase ABC to create the antigenic determinant on the chondroitin sulfate proteoglycan molecule. Normal CNS tissue showed a positive immunohistochemical staining both in white and gray matter, sparing the cytoplasm of glial and neuronal cells. Diffenentiated astrocytomas presented the same pattern as the normal CNS. Anaplastic astrocytomas and glioblastomas showed progressive reduction of parenchymal positivity as anaplasia increased. These data suggest that chondroitin sulfate is a character expressed by differentiated CNS cells and that it is lost with dedifferentiation. Vascular structures presented positive material in the adventitia in all the oncotypes. A discontinuous positivity was observed in the basal membrane zone of the vessels.Supported by A.I.R. . (Italian Association for Cancer Research) and Grant no. 85.02364.44, Special Project Oncology, C.N.R., Rome     

EphA2在人脑胶质瘤中的表达及意义

目的：探讨EphA2在人脑胶质瘤组织中的表达水平及其意义。方法：采用反转录PCR和免疫组化法检测EphA2 mRNA和蛋白在126例人脑胶质瘤组织中的表达水平;采用ki67免疫组化染色检测肿瘤组织的增殖水平;采用TUNEL染色检测肿瘤组织的凋亡水平;利用统计学方法分析EphA2表达与肿瘤病理分级、增殖和凋亡之间的相互关系。结果：126例肿瘤标本中,51.6%表达EphA2 mRNA,46.8%表达EphA2蛋白。随着肿瘤分级的升高,EphA2 mRNA和蛋白的阳性表达率显著升高。此外,肿瘤细胞增殖水平与EphA2蛋白表达呈正相关,而其凋亡水平与EphA2蛋白表达呈负相关。结论：EphA2表达水平在人脑胶质瘤组织中显著升高,EphA2表达可能影响胶质瘤细胞的增殖和凋亡。