concanavalin-a and Oligodendroglioma

Oligodendrogliomas (n = 26) induced by ethylnitrosourea (ENU) in wistar rats were examined to assess the lectin specificity to oligodendroglial membranes. Two different types of oligodendrogliomas were found in our material: an isomorphous type (n = 12), and a polymorphous type (n = 14). The first one, with two variants according to its size, macro- (n = 9) and microtumors (n = 3), had predominantly a honey-comb pattern with 'clear halos' around the nuclei without anaplasia. The second type, composed mostly by macrotumours, was anaplastic, with high cellular density, necrosis and intratumoral hemorrhages. Peanut agglutinin (PNA) labelled plasma membranes of well-differentiated cellular components of the first group. The tumoral oligodendrocytes lost the property to bind PNA in the second group of tumours, while Concanavalin A (Con A) showed affinity to intracytoplasmic structures of these tumours. PNA is a reliable marker of oligodendroglial plasma membrane of well-differentiated ENU-induced oligodendrogliomas. This experimental model, using PNA and Con A, may have important clinical applications regarding the biological behaviour of this type of neoplasm.

Topics: Animals; Brain; Brain Neoplasms; Carcinogens; Concanavalin A; Ethylnitrosourea; Immunohistochemistry; Lectins; Oligodendroglioma; Peanut Agglutinin; Rats; Rats, Wistar

Ninety tumours classified as well-differentiated oligodendrogliomas (43 cases) and anaplastic oligodendrogliomas (47 cases) were studied with glial fibrillary acidic protein (GFAP) and bound with different lectins including: peanut agglutinin (PNA), concanavalin A (Con A), wheat germ agglutinin (WGA) and Ricinus communis agglutinin (RCA-1). PNA has shown high affinity to cellular membranes of well-differentiated oligodendrogliomas. The affinity decreases with the cellular differentiation to astrocytic lines and is lost in anaplastic oligodendrogliomas. Con A labelling is restricted to anaplastic oligodendroglioma cells and to reactive astrocytes showing a predominant somatic (cytoplasmatic) pattern of staining. Our findings showed that a combined search with GFAP and lectins may allow an accurate grading of oligodendrogliomas.

Topics: Adolescent; Adult; Aged; Child; Child, Preschool; Concanavalin A; Female; Humans; Lectins; Male; Middle Aged; Oligodendroglioma; Peanut Agglutinin; Plant Lectins; Wheat Germ Agglutinins

DNA synthesis was studied in primary glial cell cultures derived from adult human non-neoplastic and neoplastic brain tissues. Enhanced DNA synthesis occurred in 5/5 non-neoplastic astrocyte, one oligodendroglioma, and 2/5 astrocytoma cultures after exposure to medium containing 1.25-12.5% supernatant fluid (SF) from insoluble concanavalin A (Con A) stimulated unseparated or T lymphocyte-enriched human mononuclear leukocytes (MNL). Analyses of SF indicated that the presence of platelet-derived growth factor (PDGF) could not account for glial cell stimulation, and exposure to semi-purified interleukin-2 (IL-2) in amounts comparable to those in SF from Con A-stimulated MNL had no effect on glial cells. These data indicate that non-neoplastic astrocytes and other human glial cells are stimulated by products of human MNL.

Topics: Astrocytoma; Cells, Cultured; Concanavalin A; DNA; Glial Fibrillary Acidic Protein; Humans; Interleukin-2; Leukocytes; Neuroglia; Oligodendroglioma; Platelet-Derived Growth Factor

Using a lectin-peroxidase method, Concanavalin A binding was examined on formalin-fixed paraffin-embedded biopsy specimens (n = 143) of the most frequent central nervous system tumours. The brain tumours included oligodendrogliomas, astrocytomas, glioblastomas, ependymomas, neurinomas, meningiomas, medulloblastomas and plexus papillomas. In oligodendroglioma cells, only a weak granular intracytoplasmic staining was observed. The astrocytomas showed a strong reaction in fibrillary astrocytes and in tumour areas undergoing small cystic degeneration. Staining of protoplasmic astrocytes was weaker; pilocytic astrocytes demonstrated poor perinuclear staining. Intracytoplasmic Con A binding in gemistocytic astrocytes was distinct but inconstant and rather diffuse. In the glioblastomas the lymphocyte-like small astrocytes were negative. Giant multinucleated astrocytes stained strongly. In ependymomas no or at most a weak perinuclear reaction was observed, whereas the acceptor density was as high as in the normal ependymocytes in areas where the tumour was capable of producing organotypical structures. Plexus papillomas showed a strong intracytoplasmic staining comparable to the normal plexus epithelial cell. This feature was preserved in the malignant variants. In general, meningiomas and neurinomas were negative. Xanthomatous-degenerated meningioma cells, however, showed a distinct to strong intracytoplasmic staining. This feature was characteristic for the xanthomatous subtype of meningiomas. Granular cells with strong intracytoplasmic Con A staining often occurred at the border of fibrillary to reticular differentiated areas of neurinomas. Medulloblastomas were completely negative. Our results indicate that Con A binding to human brain tumours is specific and rather cytotypical than histotypical . The Con A acceptor density is probably related to the grade of differentiation. Lectin mapping of tumours leads to cytotypical binding patterns which may contribute to the differential diagnosis of neoplasias.

Topics: Astrocytoma; Brain; Brain Neoplasms; Cerebellar Neoplasms; Concanavalin A; Ependymoma; Glioma; Humans; Immunoenzyme Techniques; Medulloblastoma; Meningeal Neoplasms; Meningioma; Neurilemmoma; Oligodendroglioma; Papilloma; Receptors, Concanavalin A