myelin-basic-protein and Astrocytoma

The growth pattern of pilocytic astrocytoma (PAs) is unpredictable. Gene expression profiling has recently demonstrated an inverse relationship between myelin basic protein (MBP) expression and progression free survival (PFS) in PAs. We present here the pattern of expression of oligodendroglial differentiation markers (ODMs) in PAs by immunohistochemistry and their correlation with PI and PFS. Sixty-four cases of PA were reviewed and representative sections were stained for Ki-67 and ODMs, including MBP, platelet-derived growth factor receptor-alpha (PDGFR-alpha), Olig-1, and Olig-2. Sections were graded semi-quantitatively for intensity (I: 0-3+) and extent (E: 0-4+) of staining. PI was expressed as a percentage of Ki-67 positive cells. Immunoreactivity of MBP, PDGFR-alpha, Olig-1, and Olig-2 was observed in 84, 56, 97, and 75% of cases, respectively. There was a statistically significant inverse correlation between MBP expression and PI (r (2) = .696, p = .014). A positive correlation was observed between PDGFR-alpha and PI (r (2) = .727, p = .011). Further analysis showed a significant difference in PFS between low expressors [I + E score < or = 3] and high expressors (I + E score > or = 4) for PDGFR-alpha with p < .001. Notably, there was a significant difference in PFS between high expressors of MBP and high expressors of PDGFR-alpha with p < .001. These results suggest that expression of ODMs, especially MBP and PDGFR-alpha, may identify two clinical subsets of PA. In addition, we have shown the expression of 4 different ODMs in PAs, which may support the possibility that PAs arise from oligodendrocyte progenitor/precursor cells probably similar to the O2A progenitor cells in the mouse.

Topics: Adolescent; Adult; Antigens, Differentiation; Astrocytoma; Basic Helix-Loop-Helix Transcription Factors; Biomarkers, Tumor; Brain Neoplasms; Cell Differentiation; Child; Child, Preschool; Female; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Infant; Ki-67 Antigen; Male; Myelin Basic Protein; Nerve Tissue Proteins; Oligodendrocyte Transcription Factor 2; Oligodendroglia; Receptor, Platelet-Derived Growth Factor alpha; Retrospective Studies; Survival Analysis

The classification of human gliomas is currently based solely on neuropathological criteria. Prognostic and therapeutic parameters are dependent upon whether the tumors are deemed to be of astrocytic or oligodendroglial in origin. We sought to identify molecular reagents that might provide a more objective parameter to assist in the classification of these tumors. In order to identify mRNA transcripts for genes normally transcribed exclusively by oligodendrocytes. Northern blot analysis was carried out on RNA samples from 138 human gliomas. Transcripts encoding the myelin basic protein (MBP) were found in an equally high percentage of tumors that by neuropathological criteria were either astrocytic or oligodendroglial. In contrast, proteolipid protein (PLP) and cyclic nucleotide phosphodiesterase (CNP) mRNA molecules were found significantly more often in oligodendrogliomas than in astrocytomas. The strongest association with histological typing was found with the transcript for the myelin galactolipid biosynthetic enzyme UDP-galactose: ceramide galactosytransferase (CGT), which was about twice as frequently detected in tumors of oligodendroglial type. Results of glycolipid analyses were previously reported on a subset of the tumors studied herein. Statistical analyses of both molecular and biochemical data on this subset of astrocytomas, oligoastrocytomas, and oligodendrogliomas were performed to determine if a panel of markers could be used to separate astrocytic and oligodendroglial tumors. The presence of asialo GM1 (GA1) and the absence of paragloboside occurred most frequently in oligodendrogliomas. Ceramide monohexoside (CMH) levels correlated highly with the expression of mRNA for 4 myelin proteins: CGT, MBP, CNP, and PLP. The best combination of 2 markers of oligodendroglial tumors was CGT and GA1; the best combination of 3 markers was the presence of CGT, GA1, and the absence of paragloboside. We conclude that this combination of markers could be useful in distinguishing between astrocytic and oligodendroglial tumors.

Topics: 3',5'-Cyclic-AMP Phosphodiesterases; Astrocytoma; Biomarkers, Tumor; Brain Neoplasms; Cerebrosides; G(M1) Ganglioside; Galactosyltransferases; Glycolipids; Humans; Myelin Basic Protein; Myelin Proteolipid Protein; N-Acylsphingosine Galactosyltransferase; Oligodendroglioma; RNA; Survival Rate

While 25% of human cancers harbor oncogenic Ras mutations, such mutations are not found in astrocytomas. We have previously demonstrated that the activation of receptor tyrosine kinases expressed by malignant human astrocytoma cells and specimens results in functional upregulation of the Ras signalling pathway and increased levels of activated Ras*GTP. Farnesyl transferase inhibitors (FTIs) are promising anti-cancer agents in early clinical trials, which may exert their effect through pharmacological inhibition of the Ras signalling pathway. In this study we establish the anti-tumorigenic properties of the FTI L-744,832 against a panel of malignant human astrocytoma cell lines. Furthermore, we demonstrate the multiple mechanisms by which L-744,832 exerts its effect. L-744,832 demonstrates both cytostatic and cytotoxic effects on astrocytoma cells, and cells expressing a truncated constitutively phosphorylated Epidermal Growth Factor Receptor common in high-grade astrocytomas (EGFRvIII/p140EGF-R) demonstrate increased sensitivity to the agent. L-744,832 is capable of inducing apoptosis in astrocytoma cells under anchorage-dependent conditions; this process occurs in a p53-independent manner and is associated with increased expression of Bax and Bak. L-744,832 also induces cell cycle arrest at both the G1/M and G2/S checkpoints; this process is also independent of p53 mutational status. Cell cycle arrest in drug-treated cells can be accompanied by induction of p21WAF1/CIP1, but this induction is not necessary for the cell cycle inhibitory effects, nor is it dependent on functional p53. Finally, angiogenesis in astrocytomas has been shown to be dependent on secretion of Vascular Endothelial Growth Factor (VEGF) by tumour cells, particularly under hypoxic conditions. L-744,832 potently inhibits the secretion of VEGF under hypoxic conditions. These combinations of mechanisms suggest that these tumours, despite the absence of oncogenic Ras mutations, will be amenable to growth inhibition by FTIs, through a combination of anti-proliferative, pro-apoptotic, and anti-angiogenic effects.

Topics: Alkyl and Aryl Transferases; Angiogenesis Inhibitors; Antineoplastic Agents; Apoptosis; Astrocytoma; bcl-2 Homologous Antagonist-Killer Protein; bcl-2-Associated X Protein; Bromodeoxyuridine; Cell Cycle; Cell Division; Central Nervous System Neoplasms; Dose-Response Relationship, Drug; Endothelial Growth Factors; Enzyme Inhibitors; ErbB Receptors; Farnesyltranstransferase; Genes, ras; Growth Inhibitors; Humans; Lymphokines; Membrane Proteins; Methionine; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinases; Myelin Basic Protein; Neovascularization, Pathologic; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-bcl-2; Tumor Cells, Cultured; Tumor Suppressor Protein p53; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors

Intracranial nervous-system tumours were diagnosed in three of 1092 bovine necropsy specimens submitted to the Department of Veterinary Pathology, Obihiro University between April 1983 and March 1996. A fourth case was a referral from the Department of Veterinary Pathology, Rakuno Gakuen University. Histopathological examination revealed four types of tumour: intracranial malignant peripheral nerve sheath tumour (MPNST), choroid plexus papilloma, differentiated fibrillary astrocytoma and anaplastic (malignant) astrocytoma. Immunohistochemically, the intracranial MPNST was strongly positive for S-100 protein and vimentin, and in places weakly positive for glial fibrillary acid protein (GFAP). The choroid plexus papilloma was strongly positive for epithelial membrane antigen (EMA), keratin, S-100 protein and vimentin, and positive for GFAP in places. The cytoplasm and fibrous component in the differentiated fibrillary astrocytoma were strongly positive for S-100 protein and GFAP. The anaplastic (malignant) astrocytoma was strongly positive for vimentin, S-100 protein and keratin in the cytoplasm and fibrous processes, and weakly positive for GFAP and EMA in places. Myelin basic protein (MBP) and synaptophysin showed a weak positive reaction in the marginal areas of the tumour.

Topics: Animals; Astrocytoma; Brain Neoplasms; Cattle; Cattle Diseases; Glial Fibrillary Acidic Protein; Glioblastoma; Glioma; Immunohistochemistry; Keratins; Mucin-1; Myelin Basic Protein; Nerve Sheath Neoplasms; S100 Proteins; Vimentin

We examined the expression of glial- and neuronal-specific mRNAs within human gliomas using in situ hybridization. We found that low-grade astrocytomas contained a high number of proteolipid protein (PLP) mRNA-positive cells and that the number of PLP-stained cells decreased markedly with increasing tumor grade. Interestingly, the ratio of PLP mRNA-stained cells:myelin basic protein (MBP) mRNA-stained cells in normal white matter and low-grade astrocytoma was about 2:1 but approached 1:1 with increasing tumor grade. This parameter appeared to be a good indicator of tumor infiltration in astrocytomas, so we tested this in the analysis of other gliomas. Unlike astrocytomas, oligodendrogliomas were found consistently to contain few PLP mRNA- or MBP mRNA-expressing cells. In contrast, gemistocytic astrocytomas, typically highly invasive tumors, contained high numbers of PLP-positive cells and a ratio of PLP mRNA:MBP mRNA-stained cells of about 1.5:1, similar to low-grade astrocytomas. Nonradioactive in situ hybridization also enabled the morphological identification of specific cells. For example, gemistocytic astrocytes, which were found to be strongly vimentin mRNA positive, contained little glial fibrillary acidic protein mRNA and did not stain for PLP or MBP mRNAs. Neuronal mRNAs, such as neurofilament 68, were observed in small numbers of entrapped neurons within gliomas but were uninformative with respect to predicting tumor grade. Our results suggest that oligodendrocytes survive low-grade tumor infiltration and that glial tumor cells, unlike cell lines derived from them, do not express oligodendrocyte or neuronal mRNAs. In addition, the expression of mRNAs for the two major myelin protein genes, PLP and MBP, could be used to predict the grade and extent of tumor infiltration in astrocytomas.

Topics: Astrocytoma; Brain Neoplasms; Gene Expression Regulation, Neoplastic; Glial Fibrillary Acidic Protein; Glioma; Humans; In Situ Hybridization; Keratins; Myelin Basic Protein; Myelin Proteolipid Protein; Neurofilament Proteins; Neuroglia; Neurons; Oligodendroglia; Oligodendroglioma; RNA, Messenger; RNA, Neoplasm; Vimentin

An astrocytoma cell line (HTB-14), expressing high amounts of a CD44 variant compared to other astrocytoma lines was shown to bind myelin basic protein to a greater extent than low expressing lines in a concentration-dependent manner. The CD44 variant expressed by HTB-14 cells was determined to migrate in sodium dodecyl sulfate polyacrylamide gel electrophoresis with a molecular mass of 100 kDa compared to that from white matter which had a molecular mass of 80 kDa. The most cationic component of myelin basic protein (MBP), (component 1) bound more avidly than the least cationic isomer (component 8). Internalization of MBP was demonstrated by immunogold electron microscopy and was localized to the perinuclear area with some gold particles in the cytoplasm but not near the plasma membrane. Colocalization with glial fibrillary acid protein suggested an interaction between these two molecules. Binding and internalization of MBP was accompanied by an increase in CD44 as determined by quantitation of gold particles and the measurement of CD44 by sandwich enzyme-linked immunosorbent assay. The implication of these studies for the mechanism of demyelination is discussed.

Topics: Astrocytoma; Humans; Hyaluronan Receptors; Immunohistochemistry; Microscopy, Electron; Myelin Basic Protein; Protein Binding; Tumor Cells, Cultured

We measured the level of myelin basic protein (MBP) in the cerebrospinal fluid (CSF) of patients with various kinds of tumors, including malignant tumors, using radioimmunoassay. The CSF had been obtained by lumbar puncture through an Ommaya reservoir or a shunt device placed in the lateral ventricle. The level of MBP was high (> 4 ng/ml) in the patients with meningeal dissemination of malignant tumors, but in those who showed a good response to chemotherapy and/or radiation, it decreased or returned to the normal level, with improvement on the computed tomography and magnetic resonance imaging, cytological, general CSF, and neurological findings. Of seven malignant gliomas without CSF dissemination, six showed an elevated level of MBP before selective intra-arterial chemotherapy with a combination of etoposide and cisplatin administered via a microcatheter placed at A1, M1, P1-P2, and the basilar top. All CSF specimens obtained during the period of the intra-arterial chemotherapy showed an abnormally high (> 4 ng/ml) level of MBP that exceeded the prechemotherapy level. The MBP level decreased or returned to normal in the patients with a good response to chemotherapy after intra-arterial chemotherapy. In some patients with multiple metastatic brain tumors, the MBP level was elevated before treatment and returned to normal after treatment (surgical removal, chemotherapy, and/or irradiation) in all except one. Thus, there was a clear correlation between the timing of treatment and changes in imaging studies and MBP levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adult; Aged; Astrocytoma; Biomarkers, Tumor; Brain Damage, Chronic; Brain Neoplasms; Chemotherapy, Adjuvant; Cisplatin; Combined Modality Therapy; Cranial Irradiation; Etoposide; Female; Follow-Up Studies; Glioblastoma; Humans; Infusions, Intra-Arterial; Lymphoma, B-Cell; Lymphoma, Large B-Cell, Diffuse; Male; Meningeal Neoplasms; Meningioma; Middle Aged; Myelin Basic Protein; Treatment Outcome

A 30-year-old man suffered for a year of a typical syndrome of cerebellar tumor. At suboccipital craniectomy a soft tumor infiltrating both hemispheres and vermis, filling up part of the IV ventricle was found. After subtotal removal of the neoplasm the postoperative course was poor and the patient died 5 weeks later. Biopsy material consisted of three types of tissue: 1. large nests of carrot-shaped, hyperchromatic cells, 2. fields of "halo" cells presenting myelin basic protein (MBP) immunoreactivity and 3. fields and scattered strongly GFAP-positive cells. The histological and immunocytochemical pattern of the neoplasm indicates differentiation of the tumor into oligodendrogliomatous and astrocytomatous line being an uncommon example of dual glial differentiation capability in medulloblastoma.

Topics: Adult; Astrocytoma; Cell Differentiation; Cerebellar Neoplasms; Fatal Outcome; Glial Fibrillary Acidic Protein; Humans; Male; Medulloblastoma; Myelin Basic Protein; Neoplasm Invasiveness; Oligodendroglioma

Two cases of TS associated with brain tumors had severe psychomotor retardation and early onset of long-term intractable convulsions, compared with cases without tumors. In one case, the tumor was partially cystic and progressed rapidly. Immunohistochemical studies of neuron specific enolase, glial fibrillary acidic protein and myelin basic protein revealed differences in positivity between cell types and between cases. These results suggested that the origin of the tumor cells could be variably differentiated cells.

Topics: Adolescent; Adult; Astrocytoma; Brain Neoplasms; Female; Glial Fibrillary Acidic Protein; Humans; Immunohistochemistry; Myelin Basic Protein; Phosphopyruvate Hydratase; Staining and Labeling; Tomography, X-Ray Computed; Tuberous Sclerosis

Subependymal giant cell astrocytomas associated with tuberous sclerosis were studied with immunostains for glial fibrillary acidic protein (GFAP), myelin basic protein (MBP) and neuron-specific enolase (NSE). Tumor tissue was composed of three forms of cells; polygonal, ovoid and fusiform. A polygonal form was large in size and contained a vesicular nucleus, a distinct nucleolus and scarce Nissl granules resembling a nerve cell. An ovoid cell was similar to a gemistocytic astrocyte. Glial fibers stained with PTAH were observed to surround the tumor cell cluster. Immunocytochemically the polygonal cells were GFAP-and NSE-positive, the ovoid cells were GFAP-, MBP- and NSE-positive, and the fusiform cells were sometimes GFAP- and NSE-positive. The origin of tumor cells remains controversial, either glial or neuronal. This tumor occurs commonly in the subependymal region where germinal matrix cells appear at the early developmental stage. These results suggest that subependymal giant cell astrocytoma could have the totipotential to differentiate to astrocytic, oligodendrocytic as well as neuronal cells.

Topics: Astrocytoma; Brain Neoplasms; Cell Transformation, Neoplastic; Child; Female; Glial Fibrillary Acidic Protein; Humans; Immunoenzyme Techniques; Male; Myelin Basic Protein; Phosphopyruvate Hydratase; Tuberous Sclerosis

Four mixed oligodendrogliomas and astrocytomas were investigated by electron microscopy and immunohistochemistry (GFAP, NSE and MBP). GFAP-positive oligodendroglioma cells and their transitional cells to GFAP-negative oligodendroglioma cells were present, suggesting successive morphological changes of astrocytic tumor cells. NSE-positive cells, suggestive of residual neurons, also exhibited round nuclei and perinuclear halos. On electron microscopy, oligodendroglioma cells that showed glial filaments, vascular end-feet and zonulae adherentes were occasionally present. The tumor cells with or without astrocytic characteristics showed common features of cytoplasmic organelles. These findings suggest that most oligodendroglioma cells in mixed gliomas are of an astrocytic nature and that characteristic microscopic features of oligodendroglioma are of a common cellular form that can be taken by various types of cells under certain circumstances.

Topics: Astrocytoma; Glial Fibrillary Acidic Protein; Humans; Immunohistochemistry; Microscopy, Electron; Myelin Basic Protein; Oligodendroglioma; Phosphopyruvate Hydratase

Topics: Adolescent; Adult; Aged; Astrocytoma; Brain; Brain Chemistry; Brain Neoplasms; Child; Child, Preschool; Glial Fibrillary Acidic Protein; Humans; Immunoenzyme Techniques; Immunohistochemistry; Infant; Infant, Newborn; Middle Aged; Myelin Basic Protein; Phosphopyruvate Hydratase