High levels of gelatinase-B and active gelatinase-A in metastatic glioblastoma

Purpose: Extra-neural metastases from glioblastoma multiforme (GBM) are rare. Because gelatinases-A and -B have been implicated in tumor invasion/metastasis in non-neural tumors, we compared the expression of gelatinase-A and -B in 2 patients (both had a prior craniotomy performed) with extraneural metastases from GBM to expression levels in 24 other gliomas; 15 non-metastatic GBMs, 9 other lower grade gliomas, and 7 normal brain tissues. Methods: The intracerebral tumor from both patients, patient # 1's extraneural metastases, 24 other gliomas, 1 sample of reactive astrocytes and 7 normal brain tissues were studied using gelatin zymography. The active form of gelatinases was confirmed by co-migration after activation with APMA. Results: Expression of the latent form of gelatinase-A correlated with glioma grade (r = 0.486; p=0.0053). Active gelatinase-A was found only in the 2 GBMs with extraneural metastases and patient # 1's cervical metastases. In contrast, latent gelatinase-B levels correlated more strongly with histologic grade (r=0.577; p=0.0009) (higher levels with higher grades). Very high levels of gelatinase-B were seen in both GBMs with extraneural metastases, a cervical extraneural metastases, and 2 GBMs without metastases. Conclusions: We observed that gelatinases-A and -B are present in most gliomas but we found active gelatinase-A only in the GBMs with extraneural metastases suggesting that the active form of this enzyme may determine the metastatic potential of GBMs. We propose that high levels of gelatinolytic activities are associated with intracerebral invasion and rarely, metastases of GBMs.     

Increased gelatinase-A and gelatinase-B activities in malignant vs. benign breast tumors

Matrix metalloproteinases (MMP) types 2 and 9 (also known as gelatinase A and B) are thought to be causally involved in cancer invasion and metastasis. In normal as well as in malignant tissue, both these MMPs occur in multiple forms such as inactive precursors, active enzymes and enzyme-inhibitor complexes. Using newly developed quantitative activity assays, the levels of active MMP-2, total (active and activatable) MMP-2 and total MMP-9 were found to be significantly higher in breast carcinomas than in fibroadenomas. In addition, active MMP-2 and MMP-9 were detected more frequently in malignant than in benign breast carcinoma. These new quantitative activity assays are likely to be of use in studying the mechanism of action of both MMP-2 and -9, assessing their potential prognostic value in different cancers and in the design of MMP inhibitors for preventing cancer metastasis.     

Localization of endostatin in rat and human gliomas

BACKGROUND: Endostatin is a potent inhibitor of endothelial cell proliferation, angiogenesis, and tumor growth. Its occurrence and localization has not yet been examined in human brain tumors. The authors report the production of a monoclonal antibody and detection of endostatin in rat and human gliomas by immunohistochemistry. METHODS: The authors analyzed localization and tissue distribution of endostatin in 41 paraffin embedded glioma samples (18 glioblastoma multiforme, 7 WHO Grade III astrocytomas, 13 fibrillary, and 3 protoplasmic WHO Grade II astrocytomas) of human origin and 21 rat C6 gliomas by immunohistochemistry. Double labeling experiments confirmed the origin of endostatin-labeled cells. RESULTS: Endostatin immunoreactivity was detected in tumor cells, endothelial cells, macrophages, and lymphocytes of both rat and human gliomas. The percentage of cells labeled with the endostatin antibody was significantly lower (P = 0.0126) in the tumor parenchyma of human glioblastomas than in WHO Grade II astrocytomas. CONCLUSIONS: Endostatin was present in various cell types in rat and human gliomas in vivo. Lower levels in glioblastomas than in WHO Grade II astrocytomas might have reflected the shift of a probable regulatory balance between promoters and inhibitors of angiogenesis towards facilitation of neovascularization.     

Cell-cycle regulator cyclin D1 mRNA and protein overexpression occurs in primary malignant gliomas

We compared the in vitro effects of various cytokines on the expression of monocyte chemoattractant protein-1 (MCP-1) in glioma cell lines and found that MCP-1 expression was highly induced by tumor necrosis factor-alpha (TNF alpha) and interleukin-1 beta. The intra-tumoral injection of TNF alpha in rat glioma model increased the in vivo expression of MCP-1 at 1 to 12 h after the injection and induced macrophage infiltration into tumor tissue. The injection of TNF alpha into post-operative tumor cavity of human malignant glioma also increased the concentration of MCP-1 in the cavity fluid at 24 to 38 h after injection. These data, together with the previous finding that the growth of transplanted MCP-1-transfected cells was significantly inhibited by infiltrated macrophages, suggest that injection of TNF alpha inhibits turner growth via the induction of MCP-1 expression.     

Localization of acidic and basic fibroblast growth factor mRNA in human brain tumors

Acidic and basic fibroblast growth factors (aFGF and bFGF) are closely related peptide mitogens acting on both mesoderm- and neuroectoderm-derived cells, including fibroblasts, endothelial cells and glial cells. In order to identify the expression of mRNAs for these growth factors, in situ hybridization using human aFGF and bFGF RNA probes was performed in 24 human brain tumors. The mRNAs for aFGF and bFGF were expressed in the cells of various tumors (1/1 and 1/1 astrocytoma, 2/2 and 2/2 anaplastic astrocytomas, 6/6 and 6/6 glioblastomas, 4/4 and 4/4 meningiomas, 3/3 and 3/3 schwannomas, 1/2 and 1/2 pituitary adenomas, 4/4 and 4/4 metastatic carcinomas, 0/1 an 0/1 hemangioblastoma, 0/1 and 0/1 craniopharyngioma) and were also detected in endothelial cells and surrounding neuronal cells of brain tumors. These results suggest the possibilities that aFGF and bFGF contribute to the uncontrolled growth of tumor cells and the proliferation of endothelial cells in autocrine and paracrine manners, and that the expression of mRNAs for these growth factors in the surrounding neuronal cells results in enhancement of tumor growth.     

Heat-shock protein vaccines as active immunotherapy against human gliomas

Modern advances in cancer immunotherapy have led to the development of active immunotherapy that utilizes tumor-associated antigens to induce a specific immune response against the tumor. Current methods of immunotherapy implementation are based on the principle that tumor-associated antigens are capable of being processed by antigen-presenting cells and inducing an activated cytotoxic T-lymphocyte-specific immune response that targets the tumor cells. Antigen internalization and processing by antigen-presenting cells, such as dendritic cells, or macrophages results in their surface association with MHC class I molecules, which can be recognized by an antigen-specific cytotoxic T-lymphocyte adaptive immune response. With the aim of augmenting current immunotherapeutic modalities, much effort has been directed towards enhancing antigen-presenting cell activation and optimizing the processing of tumor-associated antigens and major histocompatibility molecules. The goal of these immunotherapy modifications is to ultimately improve the adaptive specific immune response in killing of tumor cells while sparing normal tissues. Immunotherapy has been actively studied and applied in glioblastomas. Preclinical animal models have shown the feasibility of an active immunotherapy approach through the utilization of tumor vaccines, and recently several clinical studies have also been initiated. Recently, endogenous heat-shock proteins have been implicated in the mediation of both the adaptive and innate immune responses. They are now being investigated as a potential modality and adjuvant to immunotherapy, and they represent a promising novel treatment for human glioblastomas.     

EMP1基因在人脑胶质瘤中的表达及其临床意义

目的:探讨上皮膜蛋白1基因(epithelial membrane protein 1,EMP1)在人脑胶质瘤中的表达及其与肿瘤恶性程度的相互关系。方法:肿瘤组织标本均取自上海长征医院神经外科2005至2006年部分手术病例,正常脑组织来源于捐献,分别采用逆转录酶聚合酶链反应(RT-PCR)和免疫组化染色方法检测33例星形细胞瘤、3例少枝胶质细胞瘤、2例室管膜瘤以及7例正常脑组织标本中EMP1 mRNA及蛋白的表达。结果:EMP1无论在基因还是在蛋白表达水平上,在胶质瘤和正常脑组织中均有不同程度表达,但在星形细胞瘤中表达的含量明显高于正常脑组织,且在星形细胞瘤中含量随着其病理分级的增高而增高,在低级别(WHOⅠ～Ⅱ级)与高级别(Ⅲ～Ⅳ级)之间存在显著差异(蛋白P<0.05;基因P<0.01)。结论:基因EMP1在人脑胶质瘤中显著高表达,并且与星形细胞瘤的恶性程度密切相关。     

p14ARF蛋白在人脑胶质瘤中的缺失及其临床意义

目的　研究人脑胶质瘤中p14ARF蛋白的缺失情况及其与临床病理的关系。方法　采用链霉菌素 生物素 (SP)免疫组织化学法对 5 5例脑胶质瘤标本进行分析。结果　在 5 5例人脑胶质瘤标本中p14ARF缺失率为 5 0 .9%。I级 II级病例p14ARF缺失率为 32 % ,III级 IV级病例p14ARF缺失率为 6 6 .7% (P <0 .0 5 )。结论　p14ARF蛋白缺失与脑胶质瘤的发生发展有一定的相关性 ,提示p14ARF基因的失活可能是脑胶质瘤恶性演变的重要因素。     

Autotaxin在人卵巢癌基因及蛋白水平表达的研究及意义

目的:探讨自分泌运动因子(Autotaxin,ATX)mRNA在人卵巢癌中的表达及其与卵巢癌临床病理特征之间的关系。方法:应用半定量逆转录聚合酶链反应(RT-PCR)、Western blot研究8例正常卵巢组织、18例良性卵巢上皮性肿瘤(以下简称良性卵巢肿瘤)、50例卵巢上皮性癌(以下简称卵巢癌)组织、23例大网膜转移灶中ATX mRNA及蛋白的表达。结果:8例正常卵巢组织、18例良性卵巢肿瘤、50例卵巢癌组织、23例大网膜转移灶中均有ATX mRNA表达;但ATX基因表达值在癌组织和大网膜转移灶中显著高于良性卵巢肿瘤和正常卵巢组织(P<0.001),分别为(89.31±10.15)%、(88.91±11.05)%、(40.18±16.71)%、(35.29±13.82)%。Western blot显示ATX蛋白在卵巢癌细胞中表达,在相对分子质量55×103、60×103大小的位置可见清楚的显色条带。ATX mRNA在卵巢癌细胞亦可见明显扩增条带。高表达ATX基因与卵巢癌手术分期和病理分化程度有关,而与年龄、病理类型等无关。结论:卵巢癌细胞中ATX分子在核酸与蛋白水平均有表达,两者结果一致;ATX基因过表达可能与卵巢癌的进展、转移有关。     

Epigenetics in human gliomas

Aberrant epigenetic landscapes and their involvement in genesis and progression of tumors, as well as in treatment responses and prognosis, indicate one of the most emerging fields in cancer research. In gliomas, the most common human primary brain tumors, and in particular in glioblastoma, the most malignant and devastating brain tumor entity in adults, the elucidation of distinct patterns of aberrant DNA methylation, histone modification, and miRNA expression and their interrelationship has fundamentally changed our point of view on these highly heterogeneous tumors. In the current review article, we address the basic principles of epigenetic control in gliomas, their current and putative future role in prognostic and predictive models and possible interactions within the epigenetic network. We discuss diagnostic and therapeutic opportunities appearing at horizon of epigenetic research. Moreover, we present current and propose future clinical workflow models for molecular characterization of malignant gliomas.     

Localization of BRCA1 protein in human breast cancer cells

There is still an ongoing debate concerning the cellular localization of BRCA1 protein in breast cancer. To address this question, we compared the localization of BRCA1 protein using several monoclonal (Ab-1) or polyclonal (C20, D20, I20) antibodies under different technical conditions on human breast cancer cell lines. We worked on the fixation and permeabilization conditions in order to preserve the morphological structures of the cells, as confirmed by transmission electron microscopy studies. As expected from the gene sequence analysis and the biochemical features, both nucleus and cytoplasmic BRCA1 protein staining were detected in cells fixed for 60 min in 4% paraformaldehyde and permeabilized with either 0.3% saponin or 0.02% Triton. In these conditions, the same results were obtained: (i) with the four antibodies tested, (ii) with several dilutions (up to tenfold) of the monoclonal antibody, and (iii) in all the tested breast cancer cell lines. In addition, we validated the functionality of these conditions by quantifying the effects of estrogens and their antagonists on the regulation of BRCA1 protein expression in the MCF7 cell line.     

Expression of gelatinase-A (MMP-2) in human colon cancer and normal colon mucosa.

Proteolytic enzymes, such as type IV collagenases (MMP-2 gelatinase A, 72-kD type IV collagenase and MMP-9 gelatinase B, 92-kD type IV collagenase) play an important role in tumor invasion and metastasis. In the present study the levels of MMP-2 antigenic concentration and immunohistochemical staining were compared in paired colorectal tumor (n = 64) and background colon tissue of the same patients with clinical and pathological staging. The antigenic concentrations were found to be statistically significantly higher in cancer tissue (mean 11.29 ng/mg protein) than in corresponding normal mucosa (10.23 ng/mg protein) (p = 0.008). There was also a positive correlation between MMP-2 antigenic concentration and clinicopathologic parameters such as grade (p < 0.001) and Dukes' stage (p = 0.001), but not with lymph node involvement. Immunohistological localization of MMP-2 was observed in tumor as well as in stromal cells. Staining intensity increased from adenoma to adenocarcinoma. The degree of staining was associated with grade (p < 0.001), Dukes' stage (p < 0.001) and lymph node involvement (p < 0.001).     

Glycosphingolipids of human gliomas

Histologically characterized human gliomas of various grades of malignancy obtained during surgery were extracted, and their glycolipids were isolated and partially identified. Among the gliomas analyzed, three types of glycolipid component distribution could be identified. The glycosphingolipid (GSL) type I pattern correlated closely with that of the most malignant gliomas (Grade IV). Its neutral GSLs consisted of glucosyl- and, as a major component, dihexosylceramide, in addition to globo- and neolactotetraosylceramide. Galactosylceramide and sulfatide were absent. The gangliosides of GSL type I were almost exclusively of the GLac family, aside from small amounts of neolacto-series-derived species. The neutral components of GSL type II were similar to those of GSL type I. The acidic compounds of GSL type II were gangliosides of the Gtri family and trace amounts of neolacto-series sialoglycolipids, in addition to GLac1 and GLac2. GSL type II contained no Gtet gangliosides and no sulfatide. The GSL type III pattern was that of the most benign gliomas, with all glycolipids present that are found in normal brain and, in addition, those of the GSL type II.     

Epigenetic regulation of glial fibrillary acidic protein by DNA methylation in human malignant gliomas

Glial fibrillary acidic protein (GFAP) is an intermediate filament expressed in glial cells that stabilizes and maintains the cytoskeleton of normal astrocytes. In glial tumors, GFAP expression is frequently lost with increasing grade of malignancy, suggesting that GFAP is important for maintaining glial cell morphology or regulating astrocytoma cell growth. Most permanent human glioma cell lines are GFAP negative by immunocytochemistry. Given that the GFAP gene is not mutated in human glioma specimens or glioma cell lines, we considered epigenetic mechanisms, such as promoter methylation, as a cause of silencing of GFAP in these tumors. In this study, we treated known GFAP-negative glioma cell lines with 5-aza-2'-deoxycytidine to examine GFAP promoter hypermethylation. Additionally, we performed bisulfite sequencing on primary glioma samples and glioma cell lines and showed an inverse relationship between GFAP promoter methylation status and GFAP expression. Using a gene reporter assay with the GFAP promoter cloned upstream of a luciferase gene, we showed that methylation of the GFAP promoter downregulates the expression of the luciferase gene. Our results suggest that epigenetic silencing of the GFAP gene through DNA methylation of its promoter region may be one mechanism by which GFAP is downregulated in human gliomas and glioma cell lines.     

Localization of common deletion regions on 1p and 19q in human gliomas and their association with histological subtype.

Allelic alterations of chromosomes 1 and 19 are frequent events in human diffuse gliomas and have recently proven to be strong predictors of chemotherapeutic response and prolonged survival in oligodendrogliomas (Cairncross et al., 1998; Smith et al., submitted). Using 115 human diffuse gliomas, we localized regions of common allelic loss on chromosomes 1 and 19 and assessed the association of these deletion intervals with glioma histological subtypes. Further, we evaluated the capacity of multiple modalities to detect these alterations, including loss of heterozygosity (LOH), fluorescence in situ hybridization (FISH), and comparative genomic hybridization (CGH). The correlation coefficients for detection of 1p and 19q alterations, respectively, between modalities were: 0.98 and 0.87 for LOH and FISH, 0.79 and 0.60 for LOH and CGH, and 0.79 and 0.53 for FISH and CGH. Minimal deletion regions were defined on 19q13.3 (D19S412-D19S596) and 1p (D1S468-D1S1612). Loss of the 1p36 region was found in 18% of astrocytomas (10/55) and in 73% (24/33) of oligodendrogliomas (P < 0.0001), and loss of the 19q13.3 region was found in 38% (21/55) of astrocytomas and 73% (24/33) of oligodendrogliomas (P = 0.0017). Loss of both regions was found in 11% (6/55) of astrocytomas and in 64% (21/33) of oligodendrogliomas (P < 0.0001). All gliomas with LOH on either 1p or 19q demonstrated loss of the corresponding FISH probe, 1p36 or 19q13.3, suggesting not only locations of putative tumor suppressor genes, but also a simple assay for assessment of 1p and 19q alterations as diagnostic and prognostic markers.