heparitin-sulfate and Glioma

Heparan sulfate proteoglycans (HSPGs) are the main components of the extracellular matrix, where they interact with a large number of physiologically important macromolecules. The sulfation pattern of heparan sulfate (HS) chains determines the interaction potential of the proteoglycans. Enzymes of the biosynthetic and degradation pathways for HS chains are thus important regulators in processes ranging from embryonic development to tissue homeostasis, but also for tumor development. Formation of the nervous system is also critically dependent on intact HSPGs, and several studies have outlined the role of HS in neural induction from embryonic stem cells. High-grade glioma is the most common malignant primary brain tumor among adults, and the outcome is poor. Neural stem cells and glioma stem cells have several common traits, such as sustained proliferation and a highly efficient migratory capacity in the brain. There are also similarities between the neurogenic niche where adult neural stem cells reside, and the tumorigenic niche. These include interactions with the extracellular matrix, and many of the matrix components are deregulated in glioma, e.g. HSPGs and enzymes implementing the biosynthesis and modification of HS. In this article, we will present how HS-regulated pathways are involved in neural differentiation, and discuss their impact on brain development. We will also review and critically discuss the important role of structural modifications of HS in glioma growth and invasion. We propose that targeting invasive mechanisms of glioma cells through modulation of HS structure and HS-mediated pathways may be an attractive alternative to other therapeutic attempts, which so far have only marginally increased survival for glioma patients.

Topics: Animals; Brain Neoplasms; Carcinogenesis; Glioma; Heparitin Sulfate; Humans; Neovascularization, Pathologic; Neural Stem Cells; Neurogenesis; Prognosis; Signal Transduction

Fluid therapy influences glycocalyx shedding; however, the effect of this intervention on glycocalyx shedding in patients with glioma remains unclear. In this study, we have investigated glycocalyx shedding and cerebral metabolism during colloid loading in patients with and without glioma.. Forty patients undergoing general anesthesia were assigned to the glioma brain group (n = 20) or the normal brain group (n = 20); patients in the normal brain group were undergoing partial hepatectomy to treat liver cancer. All patients were subjected to 15 mL/kg hydroxyethyl starch (HES) loading after the induction of anesthesia. Glycocalyx shedding, reflected by syndecan-1 and heparan sulfate levels at the jugular venous bulb, was measured in both groups. We also evaluated cerebral metabolism parameters, including jugular venous oxygen saturation (SjvO. Our results showed that patients in the glioma brain group had lower preoperative basal syndecan-1 shedding in plasma than patients in the normal brain group. The hematocrit (Hct)-corrected syndecan-1 level was significantly increased after 15 mL/kg HES fluid administration (19.78 ± 3.83 ng/mL) compared with the Hct-correct baseline syndecan-1 level (15.67 ± 2.35 ng/mL) in patients in the glioma brain group. Similarly, for patients in the normal brain group, Hct-corrected syndecan-1 level was significantly increased after HES loading (34.71 ± 12.83 ng/mL) compared with the baseline syndecan-1 level (26.07 ± 12.52 ng/mL). However, there were no intergroup or intragroup differences in Hct-corrected heparan sulfate levels at any time point. Our study also showed that the SjvO. Preoperative 15 mL/kg HES loading had similar effects on systemic glycocalyx shedding in both the glioma brain and normal brain groups, although patients in the normal brain group had higher levels of plasma syndecan-1. Furthermore, the intraoperative anesthetic management may substantially influence cerebral metabolism in patients with glioma.

Topics: Adult; Brain; Brain Neoplasms; Endothelium, Vascular; Female; Fluid Therapy; Glioma; Glycocalyx; Heparitin Sulfate; Humans; Hydroxyethyl Starch Derivatives; Intraoperative Care; Jugular Veins; Liver Neoplasms; Male; Middle Aged; Preoperative Care; Prospective Studies; Syndecan-1

Extracellular vesicles (EVs) play a crucial role in regulating cell behavior by delivering their cargo to target cells. However, the mechanisms underlying EV-cell interactions are not well understood. Previous studies have shown that heparan sulfate (HS) on target cell surfaces can act as receptors for exosomes uptake, but the ligand for HS on EVs has not been identified. In this study, we isolated EVs from glioma cell lines and glioma patients and identified Annexin A2 (AnxA2) on EVs as a key HS-binding ligand and mediator of EV-cell interactions. Our findings suggest that HS plays a dual role in EV-cell interactions, where HS on EVs captures AnxA2, and on target cells, it acts as a receptor for AnxA2. Removal of HS from the EV surface inhibits EV-target cell interaction by releasing AnxA2. Furthermore, we found that AnxA2-mediated binding of EVs to vascular endothelial cells promotes angiogenesis, and that antibody against AnxA2 inhibited the ability of glioma-derived EVs to stimulate angiogenesis by reducing the uptake of EVs. Our study also suggests that the AnxA2-HS interaction may accelerate the glioma-derived EVs-mediated angiogenesis and that combining AnxA2 on glioma cells with HS on endothelial cells may effectively improve the prognosis evaluation of glioma patients.

Topics: Annexin A2; Endothelial Cells; Extracellular Vesicles; Glioma; Heparitin Sulfate; Humans; Ligands

Heparan sulfate (HS) is an important component of the extracellular matrix and cell surface, which plays a key role in cell-cell and cell-matrix interactions. Functional activity of HS directly depends on its structure, which determined by a complex system of HS biosynthetic enzymes. During malignant transformation, the system can undergo significant changes, but for glioma, HS biosynthesis has not been studied in detail. In this study, we performed a comparative analysis of the HS biosynthetic system in human gliomas of different grades. RT-PCR analysis showed that the overall transcriptional activity of the main HS biosynthesis-involved genes (

Topics: Adult; Biosynthetic Pathways; Brain Neoplasms; Down-Regulation; Female; Glioblastoma; Glioma; Heparitin Sulfate; Humans; Male; Middle Aged; N-Acetylglucosaminyltransferases; Sulfotransferases; Tumor Microenvironment

Oncolytic herpes simplex virus (HSV) vectors have been used in early phase human clinical trials as a therapy for recurrent malignant glioblastoma. This treatment proved safe but limited improvements in patient survival were observed. The potency of these vectors might be enhanced by targeting vector infectivity to tumor cells. Glioma tumors often express a mutant form (vIII) of the epidermal growth factor receptor (EGFR) resulting in the presence of a novel epitope on the cell surface. This epitope is specifically recognized by a single-chain antibody designated MR1-1. HSV-1 infection involves initial binding to heparan sulfate (HS) on the cell surface mediated primarily by the viral envelope, glycoprotein C (gC). Here we joined the MR1-1 single-chain antibody (scFv) to the gC sequence deleted for the HS-binding domain as a means of targeting viral attachment to EGFRvIII on glial tumor cells. Virions bearing MR1-1-modified gC had fivefold increased infectivity for EGFRvIII-bearing human glioma U87 cells compared to mutant receptor-deficient cells. Further, MR1-1/EGFRvIII-mediated infection was more efficient for EGFRvIII-positive cells than was wild-type virus for either positive or negative cells. Sustained infection of EGFRvIII+ glioma cells by MR1-1-modified gC-bearing oncolytic virus, as compared to wild-type gC oncolytic virus, was also shown in subcutaneous tumors in vivo using firefly luciferase as a reporter of infection. These data show that HSV tropism can be manipulated so that virions recognize a cell-specific binding site with increased infectivity for the target cell. The retargeting of HSV infection to tumor cells should enhance vector specificity, tumor cell killing and vector safety.

Topics: Animals; Cell Membrane; Chlorocebus aethiops; ErbB Receptors; Female; Genetic Vectors; Glioma; Helper Viruses; Heparitin Sulfate; Herpesvirus 1, Human; Humans; Mice; Mice, Nude; Vero Cells; Viral Envelope Proteins; Virion

Malignant glioma tumor cells in situ exhibit on their surfaces the interleukin 13 (IL-13) receptor designated IL13Ralpha2. To target herpes simplex virus 1 to this receptor, we constructed a recombinant virus (R5111) in which the known heparan sulfate binding sites in glycoproteins B and C were deleted and IL-13 was inserted into both glycoproteins C and D. We also transduced a baby hamster kidney cell line lacking the known viral receptors (J1-1) and Vero cells with a plasmid encoding IL13Ralpha2. The J1-1 derivative (J-13R) cell line is susceptible to and replicates the R5111 recombinant virus but not the wild-type parent virus. We report the following. (i) Expression of IL13Ralpha2 was rapidly lost from the surface of transduced cells grown in culture. The loss appeared to be related to ligands present in fetal bovine serum in the medium. None of the malignant glioma cell lines cultivated in vitro and tested to date exhibited the IL13Ralpha2 receptor. (ii) Soluble IL-13 but not IL-4 or IL-2 blocked the replication of R5111 recombinant virus in J-13R cells. (iii) The endocytosis inhibitor PD98059 blocked the replication in J1-1 cells of a mutant lacking glycoprotein D (gD-/-) but not the replication of R5111 in the J-13R cells. We conclude that R5111 enters cells via its interaction with the IL13Ralpha2 receptor in a manner that cannot be differentiated from the interaction of wild-type virus with its receptors.

Topics: Animals; Cell Line; Cell Line, Tumor; Gene Deletion; Glioma; Heparitin Sulfate; Herpesvirus 1, Human; Humans; Interleukin-13; Interleukin-13 Receptor alpha1 Subunit; Receptors, Interleukin; Receptors, Interleukin-13; Receptors, Tumor Necrosis Factor; Receptors, Tumor Necrosis Factor, Member 14; Receptors, Virus; Recombination, Genetic; Viral Envelope Proteins; Virus Replication

The core protein of glypican-1, a glycosylphosphatidylinositol-linked heparan sulfate proteoglycan, can bind Cu(II) or Zn(II) ions and undergo S-nitrosylation in the presence of nitric oxide. Cu(II)-to-Cu(I)-reduction supports extensive and permanent nitrosothiol formation, whereas Zn(II) ions appear to support a more limited, possibly transient one. Ascorbate induces release of nitric oxide, which catalyzes deaminative degradation of the heparan sulfate chains on the same core protein. Although free Zn(II) ions support a more limited degradation, Cu(II) ions support a more extensive self-pruning process. Here, we have investigated processing of glypican-1 in rat C6 glioma cells and the possible participation of the copper-containing glycosylphosphatidylinositol-linked splice variant of ceruloplasmin in nitrosothiol formation. Confocal microscopy demonstrated colocalization of glypican-1 and ceruloplasmin in endosomal compartments. Ascorbate induced extensive, Zn(II)-supported heparan sulfate degradation, which could be demonstrated using a specific zinc probe. RNA interference silencing of ceruloplasmin expression reduced the extent of Zn(II)-supported degradation. In cell-free experiments, the presence of free Zn(II) ions prevented free Cu(II) ion from binding to glypican-1 and precluded extensive heparan sulfate autodegradation. However, in the presence of Cu(II)-loaded ceruloplasmin, heparan sulfate in Zn(II)-loaded glypican-1 underwent extensive, ascorbate-induced degradation. We propose that the Cu(II)-to-Cu(I)-reduction that is required for S-nitrosylation of glypican-1 can take place on ceruloplasmin and thereby ensure extensive glypican-1 processing in the presence of free Zn(II) ions.

Topics: Animals; Ascorbic Acid; Cell Line, Tumor; Cell-Free System; Ceruloplasmin; Chromatography; Copper; Glioma; Glycosylphosphatidylinositols; Heparan Sulfate Proteoglycans; Heparitin Sulfate; Ions; Microscopy, Confocal; Models, Biological; Nitric Oxide; Nitrogen; Rats; Zinc

Heparanase is a mammalian endoglycosidase that degrades heparan sulfate (HS) at specific intrachain sites, an activity that is strongly implicated in cell dissemination associated with metastasis and inflammation. In addition to its structural role in extracellular matrix assembly and integrity, HS sequesters a multitude of polypeptides that reside in the extracellular matrix as a reservoir. A variety of growth factors, cytokines, chemokines, and enzymes can be released by heparanase activity and profoundly affect cell and tissue function. Thus, heparanase bioavailability, accessibility, and activity should be kept tightly regulated. We provide evidence that HS is not only a substrate for, but also a regulator of, heparanase. Addition of heparin or xylosides to cell cultures resulted in a pronounced accumulation of, heparanase in the culture medium, whereas sodium chlorate had no such effect. Moreover, cellular uptake of heparanase was markedly reduced in HS-deficient CHO-745 mutant cells, heparan sulfate proteoglycan-deficient HT-29 colon cancer cells, and heparinase-treated cells. We also studied the heparanase biosynthetic route and found that the half-life of the active enzyme is approximately 30 h. This and previous localization studies suggest that heparanase resides in the endosomal/lysosomal compartment for a relatively long period of time and is likely to play a role in the normal turnover of HS. Co-localization studies and cell fractionation following heparanase addition have identified syndecan family members as candidate molecules responsible for heparanase uptake, providing an efficient mechanism that limits extracellular accumulation and function of heparanase.

Topics: Animals; Biological Transport; Breast Neoplasms; Cell Line, Tumor; CHO Cells; Cricetinae; Glioma; Glucuronidase; Heparan Sulfate Proteoglycans; Heparin; Heparitin Sulfate; Humans; Kinetics; Recombinant Proteins; Transfection

The C-terminal domain V of the basement membrane proteoglycan perlecan was previously shown to play a major role in extracellular matrix and cell interactions. A homologous sequence of 708 amino-acid residues from Drosophila has now been shown to be 33% identical to mouse perlecan domain V. It consists of three laminin G-type (LG) and epidermal growth factor-like (EG) modules but lacks the EG3 module and a link region found in mammalian perlecans. Recombinant production of Drosophila perlecan domain V in mammalian cells yielded a 100-kDa protein which was folded into a linear array of three globular LG domains. Unlike the mouse counterpart, domain V from Drosophila was not modified by glycosaminoglycans and endogenous proteolysis, due to the absence of the link region. It showed moderate affinities for heparin and sulfatides but did not bind to chick alpha-dystroglycan or to various mammalian basement membrane proteins. A single RGD sequence in LG3 of Drosophila domain V was also incapable of mediating cell adhesion. Production of a proteoglycan form of perlecan (approximately 450 kDa) in one Drosophila cell line could be demonstrated by immunoblotting with antibodies against Drosophila domain V. A strong expression was also found by in situ hybridization and immunohistology at various stages of embryonic development and expression was localized to several basement membrane zones. This indicates, as for mammalian species, a distinct role of perlecan during Drosophila development.

Topics: Amino Acid Sequence; Animals; Cell Adhesion; Cell Line; Chromatography, Affinity; Culture Media, Serum-Free; DNA, Complementary; Drosophila melanogaster; Gene Expression Regulation, Developmental; Genetic Vectors; Glioma; Heparan Sulfate Proteoglycans; Heparin; Heparitin Sulfate; Humans; Insect Proteins; Mice; Molecular Sequence Data; Organ Specificity; Protein Structure, Tertiary; Proteoglycans; Rats; Sequence Alignment; Sequence Homology, Amino Acid; Species Specificity; Transfection; Tumor Cells, Cultured

The mitogenic action of insulin-like growth factors (IGFs) on target cells is determined by interaction with signaling IGF-I receptors and modulated by interactions with IGF-binding proteins (IGFBPs). IGFBP-3, an abundant IGFBP that binds IGF-I and IGF-II with high affinity, can form soluble inhibitory complexes with the IGFs that prevent them from binding to IGF-I receptors. Alternatively, IGFBP-3 can bind to the cell surface and possibly potentiate IGF action or act independently of the IGFs. Previous studies showed that heparin inhibited IGFBP-3 binding to the cell surface and increased its accumulation in the medium, suggesting that it might act as a competitive inhibitor of IGFBP-3 binding to structurally similar heparan sulfate proteoglycans on the cell surface. We evaluated this hypothesis by binding 125I-labeled recombinant glycosylated human IGFBP-3 to human fetal skin fibroblasts (GM-10) and to C6 rat glioma cells at 12 C. Heparin inhibited [125I]IGFBP-3 binding more effectively than chondroitin sulfate and dextran sulfate. Complete digestion of cell surface heparan sulfate and chondroitin sulfate glycosaminoglycans using heparitinase and chondroitinase ABC, however, did not significantly decrease IGFBP-3 binding. Quantitative removal was demonstrated by analysis of parallel cultures of cells whose glycosaminoglycans had been biosynthetically labeled using Na2 35SO4. These results suggested that IGFBP-3 did not bind to heparan sulfate glycosaminoglycans on the cell surface, and that the inhibition of IGFBP-3 binding by heparin most likely resulted from its direct interaction with the heparin-binding domains of IGFBP-3. When [125I]IGFBP-3 was incubated with GM-10 fibroblasts or C6 glioma cells at 37 C for 4 h, only 10% of the bound ligand remained associated with the cell surface; approximately 90% of the cell-associated radio-activity was internalized and could be recovered in lysates of acid-washed cells. Incubation with IGF-I or heparin decreased the total cell-associated radioactivity, but did not affect internalization. These results suggest that direct interaction of heparin or IGF-I with IGFBP-3 inhibits its ability to bind to the surface of GM-10 fibroblasts and C6 glioma cells.

Topics: Animals; Chondroitin Lyases; Fibroblasts; Glioma; Heparan Sulfate Proteoglycans; Heparin; Heparin Antagonists; Heparin Lyase; Heparitin Sulfate; Humans; Insulin-Like Growth Factor Binding Protein 3; Polysaccharide-Lyases; Proteoglycans; Rats; Skin; Tumor Cells, Cultured

Tumor cells of glial origin express high levels of basic fibroblast growth factor (bFGF) which stimulates their proliferation in an autocrine manner. In the present study we examined bFGF receptor (FGFR) expression and 125I-bFGF binding and processing in a human glioma cell line. RT-PCR demonstrated the co-expression of bFGF and FGFR mRNAs in five glioma cell lines examined. The high-affinity FGFR was visualized in U87-MG glioma cells by crosslinking with 125I-bFGF and by Western blotting with anti-receptor antisera. Both techniques identified a discrete 110-kDa moiety associated with the cell membrane, consistent with the reported size of one of the FGFR-1 isoforms. Western blotting also identified an intracellular receptor pool which was not accessible with exogenous 125I-bFGF. Suramin treatment induced a 2-fold increase in immunoreactive FGFR and a 1.5-fold increase in 125I-bFGF binding sites, indicating that FGFRs are chronically down-regulated by endogenous bFGF in U87-MG cells. Removal of extracellular bFGF with heparin resulted in a rapid, cycloheximide-sensitive increase in high-affinity bFGF binding sites. At 37 degrees C, receptor-bound 125I-bFGF was internalized and subjected to limited proteolytic cleavage over 12 h. U87-MG cells also contained abundant low-affinity bFGF binding sites which were removed by digestion with heparinase III but not by chondroitinase ABC. The presence of heparin (25 micrograms/ml) in the binding reaction eliminated the association of 125I-bFGF with the heparin-like sites but did not prevent binding to the high-affinity receptor. Scatchard binding analysis in the presence of heparin revealed a single class of high-affinity sites in U87-MG cells (Kd = 4.9 +/- 0.9 pM; 10-12 x 10(3) sites per cell). Neither heparin nor heparinase digestion prevented the binding of 125I-bFGF to the detergent-extractable high-affinity receptor, although both treatments significantly reduced the extent of 125I-bFGF association with the receptor. These findings indicate that in U87-MG cells, heparan sulfate proteoglycans may be involved in presentation of bFGF to the high-affinity receptor, but are not essential for high-affinity binding to occur.

Topics: Animals; Base Sequence; Binding Sites; Cattle; Cross-Linking Reagents; DNA Primers; Fibroblast Growth Factor 2; Gene Expression Regulation; Glioma; Heparin; Heparitin Sulfate; Humans; Molecular Sequence Data; Polymerase Chain Reaction; Protein Binding; Protein Processing, Post-Translational; Receptors, Fibroblast Growth Factor; RNA, Messenger; RNA, Neoplasm; Suramin; Tumor Cells, Cultured

A total of 14 surgical specimens, including 7 glioblastomas, 3 anaplastic astrocytomas, 2 brains adjacent to glioblastoma and 2 grossly normal brains, were investigated immunohistochemically for the expression of antithrombin III (AT-III), heparan sulfate proteoglycan (HSPG) and thrombomodulin (TM) in the endothelium of microvessels. The immunoreaction to AT-III was of moderate intensity in grossly normal brains, brains adjacent to glioblastoma, and anaplastic astrocytomas, but was only weak in glioblastomas, especially in the capillaries. The immunoreaction to HSPG was constantly intense in the microvessels in all the specimens. Although the immunoreaction to TM was negative or only faint in the microvessels in grossly normal brains, it was moderately to strongly intense in anaplastic astrocytomas and brains adjacent to glioblastoma. The intensity of immunoreaction to TM was variable, from faint to strong in the capillaries, and moderate to strong in larger microvessels in glioblastomas. The present study suggested that the alterations in the expression of those antithrombotic molecules could explain, at least in part, the tendencies for intratumoral hemorrhage as well as intravascular thrombosis in the different areas of malignant gliomas.

Topics: Antithrombin III; Brain; Brain Neoplasms; Endothelium, Vascular; Glioblastoma; Glioma; Heparan Sulfate Proteoglycans; Heparitin Sulfate; Humans; Immunohistochemistry; Microcirculation; Proteoglycans; Reference Values; Thrombomodulin

Conditioned medium from Sertoli cells, prepared from testes of 20-day-old rats, contains component(s) that inhibit the incorporation of [3H]-thymidine into DNA of peritubular myoid cells (PMC) and inhibit the proliferation of PMC. These components are trypsin-resistant, heat-stable compounds having a molecular weight less than 30,000. The active inhibitory components in Sertoli cell conditioned medium are inactivated by treatment with heparinase, but not by treatment with hyaluronidase or chondroitin sulfate lyases. Addition of heparin or heparan sulfate results in inhibition of DNA synthesis by PMC in a dose-dependent manner, whereas other glycosaminoglycans (GAGs) examined (hyaluronic acid, keratan sulfate, and chondroitin sulfate) have no detectable effects. Heparin and heparan sulfate are unique among GAGs tested in inhibiting the characteristic multilayer growth pattern of PMC following the attainment of confluence in serum-rich medium. On the basis of these and other data presented, it is concluded that heparin and other heparin-like GAGs synthesized by Sertoli cells are implicated in the modulation of growth of PMC in vitro during co-culture. It is postulated that heparin may play a similar role in maintaining the quiescent peritubular myoid cell phenotype in vivo.

Topics: Animals; Cell Division; Cell Line; DNA; Glioma; Glycosaminoglycans; Growth Inhibitors; Heparin; Heparinoids; Heparitin Sulfate; Male; Mice; Mitosis; Rats; Rats, Inbred Strains; Seminiferous Tubules; Sertoli Cells; Testis; Thymidine; Tritium

The expression of heparan sulfate proteoglycans (HSPGs) by human glioma cells was examined by biochemical and immunological methods in vitro and in vivo. Chondroitin sulfate was shown to represent the major [3H]glucosamine-labeled glycosaminoglycan synthesized by cultured normal brain cells. However, high-grade glioma-derived cells were shown to express significantly increased quantities of hyaluronic acid and heparan sulfate and approximately equal amounts of chondroitin sulfate compared with normal glial cells. To investigate further the differential expression of HSPGs, proteoglycans were isolated from glioma cells and were used as an immunogen to generate monoclonal antibodies (MAbs). One of these MAbs, 39H (an IgM), was shown to bind more to high-grade glioma-derived cells then to low-grade glioma or normal brain cells in vitro. MAb 39H was also observed to bind to isolated HSPGs but not to heparan sulfate glycosaminoglycan chains or trypsin-treated cells. Immunofluorescence staining of the cultured high-grade glioma cells revealed an intense diffuse cell surface staining pattern over the entire cell and also isolated footpads. In contrast, the low-grade tumor or normal glial cells showed a distinctive punctated staining. A similar differential staining of MAb 39H was most prominent between tissue sections of glioblastoma multiforme and anaplastic astrocytomas versus low-grade astrocytomas and normal brain. The low grade gliomas exhibited a weak punctated staining, whereas the high-grade gliomas showed significantly more intense staining, particularly along the apical regions of the cells. These results suggest that altered expression of HSPGs may be related to the malignant transformation or growth potential of glial-derived cells.

Topics: Antibodies, Monoclonal; Brain Neoplasms; Chondroitin Sulfate Proteoglycans; Glioma; Glycosaminoglycans; Heparan Sulfate Proteoglycans; Heparitin Sulfate; Humans; Proteoglycans; Tumor Cells, Cultured

The occurrence and the distribution of GAGs have been studied histochemically in 224 human cerebral tumors by means of Alcian blue techniques. In the normal peritumoral gray matter the alcianophilia is stronger than in the white matter and demonstrated the presence of HA and CS. In the glioma group the alcianophilia, due to HA and CS, is mainly related to the presence of infiltrated cortex. In the other tumors, GAGs are histochemically disclosed in relation to collagen, reticulin, mesodermic areas, etc. The vessels of every tumor show a positive staining for HA, CS and HS. The histochemical findings are consistent with the biochemical ones as reported in Part I, even though the significance of GAGs in cerebral tumors remains unknown.

Topics: Astrocytoma; Brain Neoplasms; Ependymoma; Glioma; Glycosaminoglycans; Heparitin Sulfate; Humans; Hyaluronic Acid; Lymphoma; Medulloblastoma; Meningeal Neoplasms; Meningioma; Neurilemmoma; Oligodendroglioma

Topics: Animals; Cell Line; Cells, Cultured; Chondroitin Sulfate Proteoglycans; Endothelium; Fibroblasts; Glioma; Glycosaminoglycans; Heparitin Sulfate; Humans; Neuroglia; Organ Specificity; Proteoglycans; Species Specificity; Sulfur Radioisotopes; Swine

The glycosaminoglycans (GAG) of human cultured normal glial and malignant glioma cell lines were studied using 35S-sulphate or 3H-glucosamine as markers. 35S-labelled GAG were assayed by precipitation with cetylpyridinium chloride; 3H-labelled sulphated GAG and 3H-labelled hyaluronic acid were quantitated after separation on a DEAE-cellulos column. The net production of GAG and the distribution, composition and turnover of GAG were similar in all of the normal cell lines tested, but showed a great variability in the malignant cell lines. Most of the glioma cell lines produced more hyaluronic acid and less sulphated GAG than the normal cell lines, but exceptions were noted. The GAG of the trypsin susceptible (pericellular pool of normal glial cells consisted mainly of heparan sulphate with only minor amounts of other GAG. The analogous material of most glioma cells showed hyaluronic acid as the major GAG. Material liberated by trypsin from EDTA-detached cells (membrane fraction) was enriched in heparan sulphate as compared to the entire pericellular pool. Substrate attached material (SAM) left with the plastic dish after EDTA treatment of normal cultures was rich in heparan sulphate, whereas SAM of glioma cells lacked heparan sulphate or showed greatly reduced amounts of this component. Release of newly synthesized GAG to the extracellular medium was a rapid process in the normal cells but was more or less delayed in the glioma cells. The extracellular medium of the malignant glioma cultures was consistently poor in dermatan sulphate, as compared to that of normal cultures.

Topics: Cell Adhesion; Cell Line; Dermatan Sulfate; Glioma; Glycosaminoglycans; Heparitin Sulfate; Humans; Hyaluronic Acid; Kinetics; Neoplasms, Experimental; Neuroglia; Subcellular Fractions