Studies on the intracerebral injection of vincristine free and entrapped within liposomes in the rat

The cerebral tissue response and behaviour of rats injected with vincristine of increasing concentration, free and entrapped within liposomes was studied. In separate experiments, blood, urine and brain levels of vincristine were measured after intracerebral injection of free and liposome-entrapped vincristine. When entrapped within liposomes, vincristine clearance from the brain was significantly reduced and the amount of tissue damage was directly related to the amount of drug given, being slightly greater at the same dose when entrapped. These results indicate a potential application for drugs entrapped within liposomes acting as a depot preparation in the treatment of cerebral gliomas.     

A potential application for the intracerebral injection of drugs entrapped within liposomes in the treatment of human cerebral gliomas.

After intravenous injection of therapeutic doses of bleomycin only small amounts could be measured in glioma tissue obtained at operation in patients with malignant gliomas and the drug was rapidly cleared from the blood (T1/2 = 2 hrs). Negatively charged liposomes injected through Ommaya reservoirs into the glioma tumour bed were tolerated without observable side effect. The appearance of bleomycin in the blood and urinary clearance after intracerebral injection of bleomycin entrapped within negatively charged liposomes through an Ommaya reservoir in patients with malignant gliomas was decreased as compared with levels when free bleomycin was injected. These preliminary observations suggest a role of drugs entrapped within liposomes as a depot preparation in the treatment of human cerebral gliomas.     

Studies on the intracerebral injection of bleomycin free and entrapped within liposomes in the rat.

Reverse phase prepared liposomes of defined composition (dipalmitoyl phosphatidyl choline, cholesterol and dipalmitoyl phosphatidic acid; 7:2:1; DPC) when injected intracerebrally in the rat produced no tissue damage beyond that of the penetrating wound, or altered behaviour pattern over 1 week of observation. The cerebral tissue response and behaviour of rats injected with bleomycin of increasing concentration, free and entrapped within liposomes was studied in short and long term experiments. In separate experiments blood, urine and tissue levels of bleomycin were measured after intracerebral injection of free and liposome entrapped bleomycin in the rat. These studies demonstrated that bleomycin when entrapped within liposomes and injected intracerebrally was of low toxicity to normal cerebral tissue, and was cleared more slowly from the injection site than when the free drug was injected. The results obtained indicated a potential application for drugs entrapped within liposomes acting as a depot preparation in the treatment of cerebral gliomas.     

Anticonvulsant effect of liposome-entrapped superoxide dismutase in amygdaloid-kindled rats.

Amygdaloid-kindled rats received intravenous human copper-zinc superoxide dismutase (CuZn-SOD) either in free form or entrapped within liposomes (SOD-L), at 5, 10 or 20 mg/kg. The animals were stimulated at the generalized seizure-triggering threshold 5 min, 2 h and then every 24 h after the drug was given, until 5 consecutive stage 5 seizures were induced. Free CuZn-SOD had little or no effect. However, SOD-L, particularly at 10 mg/kg, had a prolonged anticonvulsant effect, although there was great individual variation in the onset and duration of seizure suppression. This effect of SOD-L may be due to the ability of liposomes to act as a depot for the sustained release of drugs.     

Delivery of antisense oligonucleotides to neuroblastoma cells

pH-Sensitive liposomes composed of dioleoylphosphatidylethanolamine and cholesterol hemisuccinate (3:2 mol/mol) were applied in delivery of antisense oligodeoxynucleotides (asODN) into NG 108-15 neuroblastoma and glioma cells. Fluorescently labelled asODN were entrapped in liposomes by a modified freeze-thawing method (20% encapsulation efficiency). The uptake of asODN (free or entrapped in liposomes) by NG 108-15 cells was monitored by fluorescence-activated cell sorting and confocal microscopy. Delivery of asODN was significantly improved when antisense were entrapped in liposomes as compared to free (nonliposomal) asODN. The uptake was dose-dependent and optimum was achieved after 2 h incubation.     

microRNA-128在胶质瘤中的表达及其临床意义

目的 研究人脑胶质瘤的microRNA-128(miR-128)表达水平及IDH1突变型、MGMT、Ki-67蛋白表达与胶质瘤病理分级、预后的关系.方法 收集脑胶质瘤手术标本21例,其中病理分级低级别者13例、高级别者8例;脑外伤清除组织6例.采用实时定量PCR法检测胶质瘤标本及胶质瘤细胞株U87、人小胶质细胞株HMC...     

Progenitor cells and glioma formation.

The gliomas are a collection of tumors that arise within the central nervous system and have characteristics similar to astrocytes, oligodendrocytes, or their precursors. Whether or not the glial characteristics of these tumors mean that they arise from the differentiated glia that they resemble or their precursors has been debated. Even under normal circumstances the cells within the central nervous system of an adult can trans-differentiate to other cell types. In addition, mutations found in gliomas further destabilize the differentiation status of these cells making a determination of what cell type gives rise to a given tumor histology difficult. Lineage tracing studies in animals can be used to correlate some specific cell characteristics with the histology of gliomas that arise from these cells. From these experiments it appears that undifferentiated cells are more sensitive to the oncogenic effects of certain signaling abnormalities than are differentiated cells, but that with the appropriate genetic abnormalities differentiated astrocytes can act as the cell-of-origin for gliomas. These data imply that small molecules that promote differentiation may be a rational component of glioma therapy in combination with other drugs aimed at specific molecular signaling targets.     

Characterization of three restricted specificity monoclonal antibodies raised against the human glioma cell line D-54 MG

Monoclonal antibodies ( MCAs ) have been derived from a fusion of P3-NS1/1-Ag 4-1 (NS1) myeloma cells and splenocytes immunized to human glioma cell line D-54 MG. MCAs 2F3 , 4C7 , and 5B7 were analyzed by cell surface radioimmunoassay (CS-RIA), quantitative absorption, indirect immunofluorescence, and peroxidase-anti-peroxidase (PAP) immunohistology of unfixed tissue samples. MCA 2F3 exhibits the most highly restricted pattern of reactivity we have observed, reacting only with 5/12 glioblastoma cell lines and 1/4 fetal skin lines by CS-RIA, and to 9/11 glioblastoma tissue samples by PAP and absorption analysis; this MCA is totally nonreactive with melanomas, neuroblastomas, meningiomas, and control non-central nervous system tumors, and to adult and fetal tissues including brain, thymus, spleen, liver, lung, heart, gut, skin, and muscle by PAP analysis. MCAs 4C7 and 5B7 demonstrate neuroectodermal tumor cross-reactivity profiles, reacting with either melanomas ( 5B7 ) or melanomas and neuroblastomas ( 4C7 ); both are reactive with fetal skin, brain, and thymus of less than or equal to 16 weeks of gestational age. Other than this latter fetal antigen reactivity, these MCAs share the same negative reactivity profile described above for MCA 2F3 . Data from experiments using control or 0.02% EDTA-treated confluent cell monolayers of D-54 MG as antibody absorbents showed that the antigens detected are present in the extracellular matrix material remaining following cell removal. The data presented here establish that these highly restrictive anti-human glioma cell line MCAs are expressed in primary human gliomas; that the markers defined are developmental in nature, in that they are expressed by human fetal tissue, but not by adult tissue; and that in conjunction with previously characterized specificities, these markers of antigenic heterogeneity will be valuable in model system studies of therapeutic response heterogeneity.     

Invasiveness of human glioma cell lines in vitro: Relation to tumorigenicity in athymic mice

Summary Five established cell lines derived from human anaplastic astrocytomas or glioblastoma multiforme were tested for invasiveness into precultured chick heart fragments in vitro. Four of the cell lines (U118 MG, D54 MG, U373 MG and A172) were strongly invasive into the heart tissue. A fifth cell line, U251 MG sp, which was only tumorigenic at doses of greater than 1×10⁸ cells in athymic mice, was non-invasive in vitro. One line, A172, was invasive but not tumorigenic in athymic mice, although a related invasive subline, D54 MG, at later passage levels was tumorigenic even at low cell doses. Invasion of the glioma cells was characterized by progressive and irreversible replacement of the precultured chick heart tissue. Both by light and transmission electron microscopy, a similar pattern of invasion was observed as earlier found with experimental rat glioma cells in the same system. Some human cell lines established from human gliomas retain invasive properties after a prolonged culture period in vitro.Supported by the Norwegian Cancer Society (LIdeR), and by grants CA 11898, CA32672, and NS 20023 (DDB)     

Differential effects of two hexahydropyrroloindole carbamate-based anticholinesterase drugs on the amyloid beta protein pathway involved in alzheimer disease

One of the main hallmarks of Alzheimer's disease (AD) is the brain deposition of senile plaques made up of toxic amyloid beta-peptide (Abeta), which is derived from a larger protein called the beta-amyloid precursor protein (APP). Both APP processing and cholinesterase activity are affected in the AD brain, but, yet, cholinesterase inhibitors (ChEI) remain the primary Food and Drug Administration approved drugs for AD within the United States. Herein, we evaluated the effects of two clinically relevant drugs on the APP pathway, which is presumably involved in AD pathogenesis. Specifically, we compared the actions of the classical ChEI physostigmine (PHY) and its analog phenserine (PHE) on neuronal cell viability, on IC50 and on levels of different amyloid proteins. Interestingly, these drugs share the same chemical backbone, inhibit acetylcholinesterase with similar potency, but differentially affect APP processing. PHE treatment decreased levels of APP in the human neuroblastoma cells (p=0.009) whereas PHY showed a similar but less-pronounced trend, which did not attain statistical significance. PHE treatment significantly decreased levels of Abeta in human neuroblastoma cells (p=0.02) whereas PHY showed no significant change under the same conditions. The divergent actions of these two structurally related drugs on the amyloid pathway indicate that the mechanisms underpinning the cholinergic and the amyloid-lowering properties for this class of drugs are independent of each other.     

Immunofluorescence study of lymphocytic infiltration in gliomas. Identification of T-lymphocytes.

Five human brain tumours (3 glioblastomas and 2 astrocytomas) and 5 rat brain tumours induced in Sprague--Dawley animals by systemic administration of N-methyl-N-nitrosourea (3 pleomorphic gliomas and 2 mixed gliomas) were studied. The human brain tumours were surgical specimens excised from patients with no cranial surgery prior to their disease. The experimental brain tumour had been adapted to tissue culture, propagated in vitro and then transplanted to immunocompetent and immunodeficient rats of the same stock. The above-described material was selected in consideration of the mononuclear cell infiltrates occurring in these tumours. Frozen sections of human and rat gliomas, the latter both primary and transplanted, were prepared and investigated as to the presence of T-lymphocytes within the mononuclear round cell infiltrates. This was done with the indirect immunofluorescence method using rabbit antisera against man and rat T-lymphocytes. With this technique a variable percentage of T-lymphocytes was demonstrated in the cell infiltrates of human and rat gliomas alike. The tumour transplanted in thymectomized rats showed only isolated, scattered, positive-reacting cells, i.e., cells recognizable as T-lymphocytes by the above method. The results can be interpreted as circumstantial evidence for the occurrence of tumour-specific and/or tumour-associated antigens in the parenchymal cells of spontaneous and chemically-induced gliomas.     

A SURVEY OF ETHYLNITROSOUREA-INDUCED RAT GLIOMAS FOR THE PRESENCE OF TUMOUR REJECTION ANTIGENS EXPRESSED IN VIVO

Spence A.M. & Priestley G. (1981) Neuropathology and Applied Neurobiology 7,63–75.
A survey of ethylnitrosourea-induced rat gliomas for the presence of tumour rejection antigens expressed in vivo
Transplanted lines of seven F-344 (Fischer) rat malignant gliomas induced transplacentally with ethylnitrosourea (ENU) were surveyed by in vivo im-munoprotection assays for the presence of tumour rejection antigens. These gliomas were representative of commonplace histological types of human primary brain tumours and were analyzed in early transplantation passages. The classical tumour ligation method of immunizing animals was attempted with five glioma lines, but was found unusable in four of these because of a high incidence of local tumour recurrences and distant metastases. In most experiments the animals were immunized by repeated inoculations of heavily-irradiated tumour cells. Two gliomas, a glioblastoma multiforme and a mixed astrocytoma-ependymoma, demonstrated weak but statistically significant tumour rejection responses. Immunization with three other tumours, a mixed oligodendroglioma-astrocytoma and two glioblastomas multiforme, led to enhanced outgrowth of the challenge cell inocula. Neither a rejection nor an enhancement response was observed in assays of the remaining two neoplasms, a glioblastoma multiforme and a mixed astrocytoma-oligodendroglioma. Immunization with a 3-methylcholanthrene-induced urinary bladder carcinoma line, used as a control in assays of six gliomas, had no effect on the outgrowth of transplanted glioma cells. These results suggest that ENU-induced malignant rat gliomas do not uniformly elicit strong tumour-rejection responses in vivo.     

Altered expression of ganglioside phenotypes of human gliomas in vivo and in vitro

A library of epitope-defined antiganglioside monoclonal antibodies has been used to analyze the ganglioside phenotype of human glioma cell lines, rodent xenografts derived from them, and a separate panel of human glioma biopsies by multiple quantitative and qualitative assays. We have shown that the ganglioside phenotypes of cultured cell lines differ from the ganglioside phenotypes in the xenografts grown from the parent lines. The lacto series gangliosides 3′-isoLM1 and 3′, 6′-isoLD1 are expressed in the majority of primary human central nervous system neoplasms and xenografts derived from glioma cell lines, whereas glioma cell lines themselves express 3′-isoLM1 and 3′, 6′-isoLD1 in only 2/15 and 0/15 cases, respectively. Examination of the ganglioside profiles of serially passaged xenografts established from the glioma cell line D-54 MG, which does not express the lacto series, revealed the appearance of these gangliosides within one to two passages in vivo. The presence of these defined gangliosides in the majority of human gliomas and their absence in normal brain supports their application in compartmental therapy of primary central nervous sytem tumors.     

GM3 as a novel growth regulator for human gliomas

The simple ganglioside GM3 inhibits proliferation and induces apoptosis in proliferating immature rodent CNS cells. To determine whether GM3 influenced the expansion of human neural tumors the effects of GM3 treatment on primary human brain tumors were assayed. Here we demonstrate that GM3 treatment dramatically reduces cell numbers in primary cultures of high-grade human glioblastoma multiforme (GBM) tumors and the rat 9L cell gliosarcoma cell line. By contrast, GM3 treatment had little effect on cell number in cultures of normal human brain. A single injection of GM3 3 days after intracranial implantation of 9L tumor cells in a murine xenograft model system resulted in a significant increase in the symptom-free survival period of host animals. The effects of GM3 were not restricted to GBMs and 9L cells. Cultures of high-grade ependymomas, mixed gliomas, astrocytomas, oligodendrogliomas, and gangliogliomas were all susceptible to GM3 treatment. These results suggest that GM3 may have considerable value as a selectively toxic chemotherapeutic agent for human high-grade gliomas.     

New insights on culture and calcium signalling in neurons and astrocytes from epileptic patients

Primary brain cell cultures are a useful tool for understanding the physiopathology of epilepsy and for searching new potential antiepileptic drugs. These cell types are usually prepared from murine species and few human models have been described. The main goal of this study is the establishment of experimental conditions to isolate and culture neurons and astrocytes from human brain and to test its functionality. The tissues came from antiepileptic drug-resistant epileptic patients undergoing surgery. Human neurons and astrocytes were isolated following an enzymatic and mechanical dissociation protocol. Cultures were viable for 3-6 weeks. Cytological characterization was performed by immunocytochemistry using specific antibodies against both neuron (anti-NeuN) and astrocyte (anti-GFAP) protein markers. In order to test their viability and functionality, cells were loaded with the fluorescent calcium probe fura-2 and variations in cytosolic calcium concentrations ([Ca²⁺]_c) were measured by cell imaging. [Ca²⁺]_c increases were evoked upon cell stimulation with high K⁺ (KCl 75 mM), glutamate (500 μM) or bicuculline (100 μM). Interestingly, spontaneous [Ca²⁺]_c transients were also observed in some neuron-like cells. A novel unreported finding in this study has been the incorporation of human serum that was critical for cell functionality. The setting of these human cultures open the opportunity to new insights on culture and calcium signalling studies on the mechanism(s) of cell resistance to antiepileptic drugs, as well as to studies on plasticity, maturation and possible neurite emission for graft studies.     

Investigation of the expression of epidermal growth factor receptor and blood group A antigen in 110 human gliomas

The presence of epidermal growth factor receptor (EGF-R) and blood group A antigen was studied immunohistochemically in a series of 110 malignant gliomas using monoclonal antibodies. Fifty-seven percent of the tumours strongly expressed EGF-R on the malignant cells. Although blood group A antigen is present on EGF-R of A431 cells (a cell line derived from a human epidermoid carcinoma), in gliomas it was found only on vascular endothelial cells of tumours from blood group A patients. The results suggest that the EGF-R present in gliomas differs from that in A431 cells in the type or amount of the carbohydrate chains. This is in contrast to previous reports which have suggested that A antigen is present on EGF-R in gliomas. This has relevance in the choice of monoclonal antibodies used to study the EGF-R, as those directed against the A antigen component of the A431 cell EGF-R will not recognize EGF-R elsewhere and may cause normal blood group A antigen to be mistaken for EGF-R.     

人脑胶质瘤细胞系miRNA表达谱初步研究

目的 确定部分人脑胶质瘤细胞系miRNA表达谱的初步特征.方法 提取人脑胶质母细胞瘤细胞系U251、TJ861、TJ905、TJ899和A172以及星形细胞瘤细胞系H4细胞的miRNA,miRNA微阵列芯片杂交,扫描后分析差异表达的miRNA.选择差异表达的miR-21设计反义寡核苷酸处理U251细胞后原位杂交和Western blot检查SEPT 7的表达.结果 在胶质瘤细胞系中hsa-miR-21等8种miRNA一致表达上调;hsa-miR-1等18种miRNA一致表达下调.miR-21锁核酸修饰反义寡核苷酸处理U251细胞72h后,原位杂交发现阳性信号集中在细胞核的miR-21表达显著下降,Western blot发现U251细胞中SEPT 7的表达明显上调.结论 miRNA的差异表达可能是胶质瘤的重要分子生物学标签,并在基因表达调控中具有潜在的研究价值.     

STI1 promotes glioma proliferation through MAPK and PI3K pathways

Gliomas are tumors derived from glia or their precursors within the central nervous system. Clinically, gliomas are divided into four grades and the glioblastoma multiforme (GBM), also referred as grade IV astrocytoma, is the most aggressive and the most common glioma in humans. The prognosis for patients with GBM remains dismal, with a median survival of 9-12 months. Despite their striking heterogeneity, common alterations in specific cellular signal transduction pathways occur within most GBMs. Previous work from our group identified the co-chaperone stress-inducible protein 1 (STI1) as a cell surface ligand for cellular prion (PrP(C)), which leads to the activation of several signal transduction pathways, some of which modulate cell survival. In the present work, we used thymidine incorporation assays to investigate the effect of STI1 upon proliferation of the human glioblastoma-derived cell line A172. Here we report that STI1 is secreted by and induces proliferation in tumor cells, an effect that is modulated by the Erk and PI3K pathways, and that, in contrast to glioma cells, STI1 does not induce proliferation of normal glia. In addition, our data suggest the involvement of PrP(C) in STI1-induced proliferation of A172 cells. These results provide initial evidence of a new functional role for STI1 on the physiology of human gliomas, and may lead to the identification of new therapeutic targets in these tumors.     

CDC2敲低治疗人脑胶质瘤的实验研究

目的 提供CDC2作为胶质瘤发生发展相关新分子的实验依据.方法 构建针对目的 基因的shRNA逆转录病毒表达载体;对体外培养的人脑胶质瘤细胞及其裸小鼠移植瘤进行转染,观察与目标基因相关的表型变化;荧光实时定量PCR检测mRNA表达,Western印迹检测蛋白表达;流式细胞仪检测细胞周期和凋亡的变化.结果 shRNA表达载体使人脑胶质瘤细胞株SHG44 CDC2的mRNA、蛋白表达显著下调,同时出现了明显的细胞G2/M期阻滞,细胞生长抑制,凋亡增加.裸小鼠皮下移植瘤明显缩小;肿瘤颅内移植裸小鼠生存期明显延长.结论 CDC2基因过表达是胶质瘤发生发展病因分子之一,敲低其表达可使肿瘤的恶性增殖得到控制.     

Altered expression of ganglioside phenotypes of human gliomas in vivo and in vitro

A library of epitope-defined antiganglioside monoclonal antibodies has been used to analyze the ganglioside phenotype of human glioma cell lines, rodent xenografts derived from them, and a separate panel of human glioma biopsies by multiple quantitative and qualitative assays. We have shown that the ganglioside phenotypes of cultured cell lines differ from the ganglioside phenotypes in the xenografts grown from the parent lines. The lacto series gangliosides 3′-isoLM1 and 3′, 6′-isoLD1 are expressed in the majority of primary human central nervous system neoplasms and xenografts derived from glioma cell lines, whereas glioma cell lines themselves express 3′-isoLM1 and 3′, 6′-isoLD1 in only 2/15 and 0/15 cases, respectively. Examination of the ganglioside profiles of serially passaged xenografts established from the glioma cell line D-54 MG, which does not express the lacto series, revealed the appearance of these gangliosides within one to two passages in vivo. The presence of these defined gangliosides in the majority of human gliomas and their absence in normal brain supports their application in compartmental therapy of primary central nervous sytem tumors.